liu.seSearch for publications in DiVA
Change search
Refine search result
12345 1 - 50 of 244
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Abate, Ebba
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    The impact of helminth infection in patients with active tuberculosis2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The geographic distribution of helminth infection and tuberculosis (TB) overlap substantially. Experimental animal models and limited data from humans have shown that intestinal helminths could subvert the host immune response towards a T-helper 2 (Th2)-type immune response and an increased regulatory T-cell activity (Tregs). This in turn affects the host's ability to mount an effective Th1 immune-mediated protection against Mycobacterium tuberculosis. However, evidence for this hypothesis in the human setting from helminth infected TB patients is limited. This thesis primarily focuses on the immunological and clinical impact of helminth infection on pulmonary TB. The kinetics of the Quantiferon-Gold (QFN) assay, which measures IFN-³ response to TB-specific antigens in whole blood was assessed and showed a modest decline during TB treatment to the level observed for healthy blood donors. We further assessed another clinical monitoring tool, the-TB-score, composed of clinical signs and symptoms of TB, and found an early decline two weeks after initiation of TB- treatment where a failure of decline correlated with increased mortality. Overall, the helminth co-infection rate was significantly higher in TB patients compared to healthy controls. Helminth co-infection was associated to a significantly higher rate of eosinophilia and IgE-levels in healthy controls and patients with tuberculosis. During the first weeks of anti-TB treatment, a marked decrease in the rate of helminth infection was observed in HIV co-infected compared to HIV-negative TB patients. However, helminth co-infection was more common in HIV negative than HIV positive TB patients. There was no detectable impact of helminth infection on the clinical presentation of pulmonary tuberculosis. At baseline, helminth co-infected TB patients showed an increased frequency of Tregs compared to helminth negative TB patients and healthy controls. This was accompanied by an increased rate of PPD stimulated IL-5 and spontaneous production of IL-10 by peripheral blood mononuclear cells among helminth co-infected TB patients. A placebo controlled randomized trial was conducted in order to test the hypothesis that albendazole treatment of helminth positive TB patients may improve the clinical response of TB by reducing the immunmodulatory effect of helminthes on TB immunity. A total of 140 helminth co-infected TB patients were randomized to albendazole (400 mg per os for three consecutive days) or placebo. No significant difference was observed between the albendazole and placebo group in terms of the primary outcome (TB score change between baseline and week 8). Among the secondary outcomes, a significant decline of peripheral eosinophil cells was observed in the albendazole treated group, but no effect on other outcome variables (changes in chest x-ray findings, IgE level and sputum smear conversion). Regarding the immunological assessment no significant difference was observed for changes in Tregs, and PPD-induced production of IFN- ³ or IL-5 although a non-significant trend of a decrease in IL-10 expressing PBMCs were observed in the albendazole group. Taken together, the burden of helminth infection was higher in TB patients than in a healthy control group. Helminth co-infection during pulmonary TB in the human setting induces an immune response characterized by increased IgE production, eosinophilia as well as increased levels of Tregs and spontaneous IL-10 production. Thus, the immunological impact of helminth infection on the outcome and risk for developing TB merits further investigation.

    List of papers
    1. Kinetics of the QuantiFERON((R))-TB Gold In-Tube test during treatment of patients with sputum smear-positive tuberculosis in relation to initial TST result and severity of disease
    Open this publication in new window or tab >>Kinetics of the QuantiFERON((R))-TB Gold In-Tube test during treatment of patients with sputum smear-positive tuberculosis in relation to initial TST result and severity of disease
    Show others...
    2010 (English)In: Scandinavian journal of infectious diseases, ISSN 1651-1980, Vol. 42, no 9, p. 650-657Article in journal (Refereed) Published
    Abstract [en]

    Abstract The QuantiFERON((R))-TB Gold In-Tube test (QFN) measures interferon-gamma production in response to Mycobacterium tuberculosis antigens. Our aim was to assess the kinetics of the QFN and initial tuberculin skin test (TST) result in relation to severity of disease in a tuberculosis (TB) endemic area. Smear-positive TB patients (n = 71) were recruited at Gondar University Hospital, Ethiopia. The TST, QFN, CD4+ cell count and clinical symptoms (TB score) were assessed and followed up during treatment. From baseline to 7 months after treatment, there was a significant decrease in QFN reactivity (93.8% to 62.5% in HIV-negative/TB; 70.3% to 33.3% in HIV-positive/TB patients) down to a level comparable to a control group of blood donors (51.2%). The agreement between TST and QFN was poor in TB patients compared to healthy controls. A negative TST correlated to more advanced TB in contrast to a negative QFN test. We conclude that the QFN reactivity is significantly reduced at the end of treatment against active TB to the background level of healthy blood donors, and that the agreement between TST and QFN is poor including correlation to the severity of disease.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-58804 (URN)10.3109/00365548.2010.482942 (DOI)000282716000002 ()20465490 (PubMedID)
    Available from: 2010-08-27 Created: 2010-08-27 Last updated: 2013-05-02
    2. Early treatment response evaluated by a clinical scoring system correlates with the prognosis of pulmonary tuberculosis patients in Ethiopia: A prospective follow-up study.
    Open this publication in new window or tab >>Early treatment response evaluated by a clinical scoring system correlates with the prognosis of pulmonary tuberculosis patients in Ethiopia: A prospective follow-up study.
    Show others...
    2012 (English)In: Scandinavian journal of infectious diseases, ISSN 1651-1980, Vol. 44, no 11, p. 828-834Article in journal (Refereed) Published
    Abstract [en]

    Background: In resource-limited settings the monitoring of tuberculosis (TB) patients is challenging, and early identification of TB patients with a high mortality risk is important. The aim of this study was to investigate prospectively whether early changes in a clinical scoring system (TB score) can predict treatment outcome in Ethiopian patients with pulmonary tuberculosis. Method: TB patients (n = 250) and blood donors (n = 82) were recruited prospectively at Gondar University Hospital, Ethiopia. Clinical scoring was performed using an interview-based questionnaire and clinical examination. Results: Among TB patients (53.6% of whom were HIV co-infected) the median TB score declined from week 0 to week 2 (8 (interquartile range (IQR) 6-9) vs 4 (IQR 2-6)) and dropped to a low level at week 8, which was still significantly higher than that found in blood donors (2 (IQR 1-4) vs 0 (IQR 0-1), p < 0.0001). Patients who died had a significantly higher TB score at week 0, week 2, and week 8 than survivors. Mortality was associated with a failure to achieve a decrease greater than 25% in the TB score at 2 weeks. Baseline CD4 + cell counts (< 200 cells/mm(3)) were associated with mortality but not with initial TB score results. Conclusions: The TB score was increased during the first 2 months of treatment among patients who died. Failure to achieve a greater than 25% decrease in TB score after 2 weeks of treatment was associated with increased mortality. Repeated clinical scoring during the intensive phase of TB treatment could be useful to identify high-risk patients.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-85315 (URN)10.3109/00365548.2012.694468 (DOI)000310008900004 ()22812387 (PubMedID)
    Note

    funding agencies|Swedish Heart and Lung Foundation||EU/EDCTP project|JP 2009.10800.006|Swedish heart and lung Foundation (King Oscar II Jubilee Foundation)||EU/EDCP|JP.10800.006|

    Available from: 2012-11-15 Created: 2012-11-15 Last updated: 2013-05-02
    3. The Impact of Asymptomatic Helminth Co-Infection in Patients with Newly Diagnosed Tuberculosis in North-West Ethiopia
    Open this publication in new window or tab >>The Impact of Asymptomatic Helminth Co-Infection in Patients with Newly Diagnosed Tuberculosis in North-West Ethiopia
    Show others...
    2012 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 8Article in journal (Refereed) Published
    Abstract [en]

    Background: Areas endemic of helminth infection, tuberculosis (TB) and HIV are to a large extent overlapping. The aim of this study was to assess the impact of asymptomatic helminth infection on the immunological response among TB patients with and without HIV, their house hold contacts and community controls. less thanbrgreater than less thanbrgreater thanMethodology: Consecutive smear positive TB patients (n = 112), their household contacts (n = 71) and community controls (n = 112) were recruited in Gondar town, Ethiopia. Stool microscopy, HIV serology, serum IgE level, eosinophil and CD4 counts were performed and tuberculosis patients were followed up for 3 months after initiation of anti-TB treatment. less thanbrgreater than less thanbrgreater thanResults: Helminth co-infection rate was 29% in TB patients and 21% in both community control and household contacts (p = 0.3) where Ascaris lumbricoides was the most prevalent parasite. In TB patients the seroprevalence of HIV was 47% (53/112). Eosinophilia and elevated IgE level were significantly associated with asymptomatic helminth infection. During TB treatment, the worm infection rate of HIV+/TB patients declined from 31% (10/32) at week 0 to 9% (3/32) at week 2 of TB treatment, whereas HIV2/TB patients showed no change from baseline to week 2, 29% (13/45) vs. 22.2% (10/45). This trend was stable at week 8 and 12 as well. less thanbrgreater than less thanbrgreater thanConclusion: One third of smear positive TB patients were infected with helminths. Eosinophilia and elevated IgE level correlated with asymptomatic worm infection, indicating an effect on host immunity. The rate of worm infection declined during TB treatment in HIV+/TB co-infected patients whereas no decline was seen in HIV2/TB group.

    Place, publisher, year, edition, pages
    Public Library of Science, 2012
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-84349 (URN)10.1371/journal.pone.0042901 (DOI)000308206000014 ()
    Note

    Funding Agencies|Swedish Agency for Research Cooperation with Developing Countries||Swedish International Development Cooperation Agency (SAREC/SIDA)||European-Developing Countries Clinical Trials Partnership (EU/EDCTP)|JP 10800.006|Swedish Research Council||Swedish Heart and Lung Foundation (Oscar II Jubilee Foundation)||

    Available from: 2012-10-05 Created: 2012-10-05 Last updated: 2017-12-07
    4. Impact of helminth infection on the clinical presentation 1 of pulmonary tuberculosis
    Open this publication in new window or tab >>Impact of helminth infection on the clinical presentation 1 of pulmonary tuberculosis
    Show others...
    2013 (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Background: The effects of helminth infection on chronic infectious diseases such as HIV and tuberculosis (TB) merit further characterization. Thus, we assessed the baseline clinical characteristics of helminth infection in patients with active TB in a high endemic area.

    Methodology: Consecutive, newly diagnosed TB patients were recruited from three health institutions in the north Gondar administrative zone, Ethiopia. Structured questionnaires were used to collect socio-demographic and clinical characteristics. Additionally, the TB score, mid upper arm circumference, body mass index (BMI), BCG vaccination status, stool and sputum microscopy as well as HIV serology and CD4+T cells counts were evaluated.

    Results: A total of 377 pulmonary TB patients were included in the study. The helminth co infection rate was 33% (123/377) and the most prevalent parasite was Ascaris lumbricoides (53%, 65/123). The HIV co-infection rate was 29% (110/377). Seventy percent (77/110) of the HIV co-infected patients were on anti- retroviral therapy at the time of TB diagnosis. Helminth infection was more prevalent in HIV-negative TB patients compared to HIV-positive TB patients (p=0.025). Smoking and walking bare foot were independently associated to helminth infection in TB patients after adjusting for the influence of HIV. Other than increased eosinophilia, no other significant differences were observed between helminth positive and helminth negative TB patients in the clinical presentation including the TB score, CD4+T-cells, BMI or bacterial load.

    Conclusion: The clinical presentation of active pulmonary tuberculosis was not affected by helminth infection. Helminth infection was less frequent among HIV-positive TB patients and this finding merits further investigation.

    Keywords
    Tuberculosis, HIV, helminth, TB score, CD4, Ethiopia
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-91825 (URN)
    Available from: 2013-05-02 Created: 2013-05-02 Last updated: 2013-05-02Bibliographically approved
    5. Effects of albendazole treatment on the clinical outcome and immunological responses in patients with helminth infection and pulmonary tuberculosis: a randomized clinical trial
    Open this publication in new window or tab >>Effects of albendazole treatment on the clinical outcome and immunological responses in patients with helminth infection and pulmonary tuberculosis: a randomized clinical trial
    Show others...
    2013 (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Background: The impact of helminth infection on the host immune response to tuberculosis (TB) has been characterized in experimental models but less so in the clinical setting. The objective of this study was to investigate the impact of deworming on the clinical outcome and cell mediated immune response in active TB.

    Methods: Newly diagnosed pulmonary TB patients in Gondar, Ethiopia were examined for helminth infection. Helminth-positive TB patients (W+/TB) were randomized to albendazole (400mg X III per os) or placebo. The primary outcome was change in TB-score after 2 months, and secondary outcomes were sputum smear conversion at the 2nd month, and changes in chest x-ray pattern, CD4+ T-cell count, eosinophil count, IgE-levels and immunological responses after 3 months. In a subset of W+/TB, W-/TB patients and healthy controls, flow cytometry and ELISPOT assays were used to characterize the regulatory T-cell population (Tregs) and the frequency of PPD- stimulated IFN-γ, IL-5 and IL-10 producing peripheral blood mononuclear cells (PBMCs).

    Results: A total of 140 helminth co-infected TB patients were included with an HIV coinfection rate of 22.8 %. Following albendazole treatment of the W+/TB patients, there was a significant decrease in helminth infection compared to placebo (8% (4/49) vs. 48 % (22/46), p<0.001). No significant effect was observed for albendazole compared to placebo on the primary outcome as evaluated by the TB-score (5.6 ±2.87 vs. 5.87 ±2.54, p=0.59). Eosinophil counts decreased significantly in the albendazole group. In a subgroup analysis of helminthnegative patients following albendazole treatment versus placebo, the albendazole group showed a trend for lower levels of IL-10 producing cells at month three (p=0.08). At baseline, W+/TB patients had a significantly higher mean level of Tregs (% Tregs/CD4+) compared to W-/TB patients and helminth-positive community controls. Additionally, the frequency of IFN-γ, IL-5 and spontaneous IL-10 levels was increased in helminth-positive compared to helminth-negative TB patients.

    Conclusions: No significant effects on the clinical outcome as measured with the TB-score was detected after albendazole treatment of helminth-positive TB patients compared to placebo. However, significant changes were observed in specific immunological responses such as reduced eosinophil counts and a trend towards lower levels of IL-10 producing cells. At baseline, helminth co-infected TB patients exhibited an increased Treg response as well as an increased IL-5 and spontaneous IL-10 production.

    Keywords
    Regulatory T-cells, helminth, tuberculosis, albendazole, deworming, Ethiopia, HIV
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-91827 (URN)
    Available from: 2013-05-02 Created: 2013-05-02 Last updated: 2013-05-02Bibliographically approved
  • 2.
    Abate, Ebba
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Belayneh, Meseret
    University of Addis Ababa, Ethiopia .
    Gelaw, Aschalew
    University of Gondar, Ethiopia .
    Idh, Jonna
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Getachew, Assefa
    University of Gondar, Ethiopia .
    Alemu, Shitaye
    University of Gondar, Ethiopia .
    Diro, Ermias
    University of Gondar, Ethiopia .
    Fikre, Nigussu
    University of Addis Ababa, Ethiopia .
    Britton, Sven
    Karolinska Hospital, Sweden .
    Elias, Daniel
    University of So Denmark, Denmark .
    Aseffa, Abraham
    Armauer Hansen Research Institute, Ethiopia .
    Stendahl, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Schön, Thomas
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    The Impact of Asymptomatic Helminth Co-Infection in Patients with Newly Diagnosed Tuberculosis in North-West Ethiopia2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 8Article in journal (Refereed)
    Abstract [en]

    Background: Areas endemic of helminth infection, tuberculosis (TB) and HIV are to a large extent overlapping. The aim of this study was to assess the impact of asymptomatic helminth infection on the immunological response among TB patients with and without HIV, their house hold contacts and community controls. less thanbrgreater than less thanbrgreater thanMethodology: Consecutive smear positive TB patients (n = 112), their household contacts (n = 71) and community controls (n = 112) were recruited in Gondar town, Ethiopia. Stool microscopy, HIV serology, serum IgE level, eosinophil and CD4 counts were performed and tuberculosis patients were followed up for 3 months after initiation of anti-TB treatment. less thanbrgreater than less thanbrgreater thanResults: Helminth co-infection rate was 29% in TB patients and 21% in both community control and household contacts (p = 0.3) where Ascaris lumbricoides was the most prevalent parasite. In TB patients the seroprevalence of HIV was 47% (53/112). Eosinophilia and elevated IgE level were significantly associated with asymptomatic helminth infection. During TB treatment, the worm infection rate of HIV+/TB patients declined from 31% (10/32) at week 0 to 9% (3/32) at week 2 of TB treatment, whereas HIV2/TB patients showed no change from baseline to week 2, 29% (13/45) vs. 22.2% (10/45). This trend was stable at week 8 and 12 as well. less thanbrgreater than less thanbrgreater thanConclusion: One third of smear positive TB patients were infected with helminths. Eosinophilia and elevated IgE level correlated with asymptomatic worm infection, indicating an effect on host immunity. The rate of worm infection declined during TB treatment in HIV+/TB co-infected patients whereas no decline was seen in HIV2/TB group.

  • 3.
    Abate, Ebba
    et al.
    Gondar College of Medical and Health Sciences, Gondar University, Gondar, Ethiopia; Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
    Elias, Daniel
    University of Southern Denmark, Institute of Molecular Medicine, Department of cancer and inflammation, Odense, Denmark.
    Getachew, Assefa
    Gondar College of Medical and Health Sciences, Gondar University, Gondar, Ethiopia.
    Alemu, Shitaye
    Gondar College of Medical and Health Sciences, Gondar University, Gondar, Ethiopia.
    Diro, Ermias
    Department of Radiology, University of Gondar, Gondar, Ethiopia.
    Britton, Sven
    Department of Infectious Diseases, Karolinska Hospital, Stockholm, Sweden.
    Aseffa, Abraham
    Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
    Stendahl, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Schön, Thomas
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Effects of albendazole treatment on the clinical outcome and immunological responses in patients with helminth infection and pulmonary tuberculosis: a randomized clinical trial2013Manuscript (preprint) (Other academic)
    Abstract [en]

    Background: The impact of helminth infection on the host immune response to tuberculosis (TB) has been characterized in experimental models but less so in the clinical setting. The objective of this study was to investigate the impact of deworming on the clinical outcome and cell mediated immune response in active TB.

    Methods: Newly diagnosed pulmonary TB patients in Gondar, Ethiopia were examined for helminth infection. Helminth-positive TB patients (W+/TB) were randomized to albendazole (400mg X III per os) or placebo. The primary outcome was change in TB-score after 2 months, and secondary outcomes were sputum smear conversion at the 2nd month, and changes in chest x-ray pattern, CD4+ T-cell count, eosinophil count, IgE-levels and immunological responses after 3 months. In a subset of W+/TB, W-/TB patients and healthy controls, flow cytometry and ELISPOT assays were used to characterize the regulatory T-cell population (Tregs) and the frequency of PPD- stimulated IFN-γ, IL-5 and IL-10 producing peripheral blood mononuclear cells (PBMCs).

    Results: A total of 140 helminth co-infected TB patients were included with an HIV coinfection rate of 22.8 %. Following albendazole treatment of the W+/TB patients, there was a significant decrease in helminth infection compared to placebo (8% (4/49) vs. 48 % (22/46), p<0.001). No significant effect was observed for albendazole compared to placebo on the primary outcome as evaluated by the TB-score (5.6 ±2.87 vs. 5.87 ±2.54, p=0.59). Eosinophil counts decreased significantly in the albendazole group. In a subgroup analysis of helminthnegative patients following albendazole treatment versus placebo, the albendazole group showed a trend for lower levels of IL-10 producing cells at month three (p=0.08). At baseline, W+/TB patients had a significantly higher mean level of Tregs (% Tregs/CD4+) compared to W-/TB patients and helminth-positive community controls. Additionally, the frequency of IFN-γ, IL-5 and spontaneous IL-10 levels was increased in helminth-positive compared to helminth-negative TB patients.

    Conclusions: No significant effects on the clinical outcome as measured with the TB-score was detected after albendazole treatment of helminth-positive TB patients compared to placebo. However, significant changes were observed in specific immunological responses such as reduced eosinophil counts and a trend towards lower levels of IL-10 producing cells. At baseline, helminth co-infected TB patients exhibited an increased Treg response as well as an increased IL-5 and spontaneous IL-10 production.

  • 4.
    Abate, Ebba
    et al.
    Gondar College of Medical and Health Sciences, Gondar University, Gondar, Ethiopia; Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
    Idh, Jonna
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Belayneh, Meseret
    School of Medical Laboratory Sciences, Medical Faculty, Addis Ababa University, Addis Ababa.
    Getachew, Assefa
    Gondar College of Medical and Health Sciences, Gondar University, Gondar, Ethiopia.
    Alemu, Shitaye
    Gondar College of Medical and Health Sciences, Gondar University, Gondar, Ethiopia.
    Diro, Ermias
    Department of Radiology, University of Gondar, Gondar, Ethiopia.
    Britton, Sven
    Department of Infectious Diseases, Karolinska Hospital, Stockholm, Sweden.
    Elias, Daniel
    University of Southern Denmark, Institute of Molecular Medicine, Department of cancer and inflammation, Odense, Denmark.
    Aseffa, Abraham
    Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
    Stendahl, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Schön, Thomas
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Impact of helminth infection on the clinical presentation 1 of pulmonary tuberculosis2013Manuscript (preprint) (Other academic)
    Abstract [en]

    Background: The effects of helminth infection on chronic infectious diseases such as HIV and tuberculosis (TB) merit further characterization. Thus, we assessed the baseline clinical characteristics of helminth infection in patients with active TB in a high endemic area.

    Methodology: Consecutive, newly diagnosed TB patients were recruited from three health institutions in the north Gondar administrative zone, Ethiopia. Structured questionnaires were used to collect socio-demographic and clinical characteristics. Additionally, the TB score, mid upper arm circumference, body mass index (BMI), BCG vaccination status, stool and sputum microscopy as well as HIV serology and CD4+T cells counts were evaluated.

    Results: A total of 377 pulmonary TB patients were included in the study. The helminth co infection rate was 33% (123/377) and the most prevalent parasite was Ascaris lumbricoides (53%, 65/123). The HIV co-infection rate was 29% (110/377). Seventy percent (77/110) of the HIV co-infected patients were on anti- retroviral therapy at the time of TB diagnosis. Helminth infection was more prevalent in HIV-negative TB patients compared to HIV-positive TB patients (p=0.025). Smoking and walking bare foot were independently associated to helminth infection in TB patients after adjusting for the influence of HIV. Other than increased eosinophilia, no other significant differences were observed between helminth positive and helminth negative TB patients in the clinical presentation including the TB score, CD4+T-cells, BMI or bacterial load.

    Conclusion: The clinical presentation of active pulmonary tuberculosis was not affected by helminth infection. Helminth infection was less frequent among HIV-positive TB patients and this finding merits further investigation.

  • 5.
    Abdalla, Hana
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Forslund, Tony
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Schön, Thomas
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Stendahl, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Effects of CNI-1493 on human granulocyte functions2006In: Immunobiology, ISSN 0171-2985, E-ISSN 1878-3279, Vol. 211, no 3, p. 191-197Article in journal (Refereed)
    Abstract [en]

    During acute bacterial infections such as sepsis and meningitis, activation of inflammatory mediators such as nitric oxide (NO) plays a crucial role in both pathogenesis and host defense. We have previously reported that CNI-1493, a macrophage deactivator, reduced mortality in infant rats infected with Haemophilus influenzae type b (Hib) with associated decrease in the number of granulocytes in the infected tissue. The aim of the present study was to investigate how CNI-1493 affects granulocytes and macrophages in vitro. Murine macrophages (RAW 264.7) pre-incubated with CNI-1493 prior to activation with lipopolysaccharide (LPS)/interferon gamma (IFNγ) had decreased NO production measured as NO2/NO3 levels and reduction in inducible NO-synthase (iNOS) expression. Reactive oxygen species (ROS) production was increased in formylmethionyl-leucyl-phenylalanine (FMLP)-stimulated granulocytes following CNI-1493 treatment, whereas F-actin content, motility and chemotaxis were decreased under the same conditions. The effects of CNI-1493 on both NO production in LPS/IFNγ-activated macrophages and ROS production, F-actin content, motility and chemotaxis in granulocytes, may contribute to the reduced inflammatory response and increased survival in Hib-infected animals treated with CNI-1493.

  • 6.
    Ahlen, K.
    et al.
    Åhlén, K., Dept. Med. Biochem. and Microbiol., University of Uppsala, Biomedical Center, SE-751 23 Uppsala, Sweden.
    Ring, P.
    Dept. Med. Biochem. and Microbiol., University of Uppsala, Biomedical Center, SE-751 23 Uppsala, Sweden.
    Tomasini-Johansson, B.
    Dept. Med. Biochem. and Microbiol., University of Uppsala, Biomedical Center, SE-751 23 Uppsala, Sweden, Department of Medicine, University of Wisconsin-Madison, 4285 MSC, 1300 University Ave, Madison, WI 53706, United States.
    Holmqvist, K.
    Dept. Med. Biochem. and Microbiol., University of Uppsala, Biomedical Center, SE-751 23 Uppsala, Sweden, Department of Medical Cell Biology, University of Uppsala, Biomedical Center, SE-751 23 Uppsala, Sweden.
    Magnusson, Karl-Eric
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology .
    Rubin, K.
    Dept. Med. Biochem. and Microbiol., University of Uppsala, Biomedical Center, SE-751 23 Uppsala, Sweden.
    Platelet-derived growth factor-BB modulates membrane mobility of ß1 integrins2004In: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 314, no 1, p. 89-96Article in journal (Refereed)
    Abstract [en]

    Platelet-derived growth factor (PDGF)-BB elicits a migratory response including reorganization of the actin cytoskeleton in different cell types. Here we have investigated the effects of PDGF-BB stimulation on ß 1 integrin containing focal adhesions in human diploid fibroblasts adhered to collagen type I. Stimulation with PDGF-BB dissociated focal adhesions and relocated ß1 integrins from focal adhesions to the periphery of the cells. These changes were rapid and transient in character. Relocation of ß1 integrins was prevented by inhibitors of phosphoinositide-3-kinase and protein kinase C. PDGF-BB stimulated fibroblasts exhibited an increased diffusion coefficient of cell surface ß1 integrins as determined by fluorescence recovery of photobleaching. The cell surface expression of ß1 integrins was not changed after stimulation with PDGF-BB. Our data suggest that PDGF-BB increases the dynamic properties of cell-surface ß1 integrins, which most likely are important for the migratory response elicited by PDGF-BB. © 2003 Elsevier Inc. All rights reserved.

  • 7.
    Aksenova, Vasilisa
    et al.
    Russian Academy of Sciences, St. Petersburg, Russia.
    Turoverova, Lidia
    Russian Academy of Sciences, St. Petersburg, Russia.
    Khotin, Mikhail
    Russian Academy of Sciences, St. Petersburg, Russia.
    Magnusson, Karl-Eric
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Tulchinsky, Eugene
    University of Leicester, UK.
    Melino, Gerry
    Saint-Petersburg Technological Institute, Russia.
    Pinaev, George P.
    Russian Academy of Sciences, St. Petersburg, Russia.
    Barlev, Nicolai
    Russian Academy of Sciences, St. Petersburg, Russia.
    Tentler, Dmitri
    Russian Academy of Sciences, St. Petersburg, Russia.
    Actin-binding protein alpha-actinin 4 (ACTN4) is a transcriptional co-activator of RelA/p65 sub-unit of NF-kB2013In: OncoTarget, ISSN 1949-2553, E-ISSN 1949-2553, Vol. 4, no 2, p. 362-372Article in journal (Refereed)
    Abstract [en]

    ACTN4 is an actin-binding protein that participates in cytoskeleton organisation. It resides both in the cytoplasm and nucleus and physically associates with various transcription factors. Here, we describe an effect of ACTN4 expression on transcriptional activity of the RelA/p65 subunit of NF-kB. We demonstrate that ACTN4 enhances RelA/p65-dependant expression of c-fos, MMP-3 and MMP-1 genes, but it does not affect TNC, ICAM1 and FN1 expression. Importantly, actin-binding domains of ACTN4 are not critical for the nuclear translocation and co-activation of RelA/p65-dependent transcription. Collectively, our data suggest that in the nucleus, ACTN4 functions as a selective transcriptional co-activator of RelA/p65.

  • 8.
    Aldonyte, R
    et al.
    Vilnius University, Zygimantu 9, Vilnius LT-01102, Lithuania.
    Tunaitis, V
    Vilnius University, Zygimantu 9, Vilnius LT-01102, Lithuania.
    Surovas, A
    Vilnius University, Zygimantu 9, Vilnius LT-01102, Lithuania.
    Suriakaite, K
    Vilnius University, Zygimantu 9, Vilnius LT-01102, Lithuania.
    Jarmalaviciute, A
    Vilnius University, Zygimantu 9, Vilnius LT-01102, Lithuania.
    Magnusson, Karl-Erik
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Pivoriunas, A
    Vilnius University, Zygimantu 9, Vilnius LT-01102, Lithuania.
    Effects of major human antiprotease alpha-1-antitrypsin on the motility and proliferation of stromal cells from human exfoliated deciduous teeth2010In: e-biomed: Journal of Regenerating Medicine, ISSN 1524-8909, Vol. 5, no 4, p. 633-643Article in journal (Refereed)
    Abstract [en]

    AIM: Intrinsic tissue regeneration mechanisms are still not fully understood. The destruction/reconstruction processes are usually in fine balance; however, this can be easily destroyed, for example in the environment of chronic inflammation. One of the major proteins present at the inflammatory sites is the multifunctional protein alpha-1-antitrypsin (AAT). In this study, potential therapeutic effects of this major human antiprotease on progenitor cells are assessed.

    MATERIALS & METHODS: Stromal cells from human exfoliated deciduous teeth (SHEDs) were used, which are similar to the mesenchymal stromal cells isolated from other tissues. SHEDs were cultivated in the presence of subphysiological, physiological and inflammatory concentrations of AAT, and their proliferation and motility traits were assayed. Some intracellular signaling pathways, AAT internalization by SHEDs and their matrix metalloprotease profile were studied in parallel.

    RESULTS: Physiologic and inflammatory concentrations of AAT significantly increased the cell proliferation rate, induced phosphorylation of several key protein kinases and increased the amount of secreted active gelatinases. Moreover, cells exposed to physiologic and inflammatory levels of AAT were able to invade and migrate more efficiently. Subphysiologic AAT levels did not change cell behavior significantly.

    CONCLUSION: AAT at physiologic and inflammatory concentrations positively modulates the proliferation and motility of SHEDs in vitro. These results suggest the importance of AAT in the maintenance and regulation of tissue progenitor cells in vivo.

  • 9.
    Almstrand, R
    et al.
    University of Gothenburg, Sweden .
    Lydmark, P
    University of Gothenburg, Sweden .
    Lindgren, Per-Eric
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Sorensson, F
    University of Gothenburg, Sweden .
    Hermansson, M
    University of Gothenburg, Sweden .
    Dynamics of specific ammonia-oxidizing bacterial populations and nitrification in response to controlled shifts of ammonium concentrations in wastewater2013In: Applied Microbiology and Biotechnology, ISSN 0175-7598, E-ISSN 1432-0614, Vol. 97, no 5, p. 2183-2191Article in journal (Refereed)
    Abstract [en]

    Ammonia-oxidizing bacteria (AOB) are essential for the nitrification process in wastewater treatment. To retain these slow-growing bacteria in wastewater treatment plants (WWTPs), they are often grown as biofilms, e.g., on nitrifying trickling filters (NTFs) or on carriers in moving bed biofilm reactors (MBBRs). On NTFs, a decreasing ammonium gradient is formed because of the AOB activity, resulting in low ammonium concentrations at the bottom and reduced biomass with depth. To optimize the NTF process, different ammonium feed strategies may be designed. This, however, requires knowledge about AOB population dynamics. Using fluorescence in situ hybridization (FISH) and confocal laser scanning microscopy, we followed biomass changes during 6 months, of three AOB populations on biofilm carriers. These were immersed in aerated MBBR tanks in a pilot plant receiving full-scale wastewater. Tanks were arranged in series, forming a wastewater ammonium gradient mimicking an NTF ammonium gradient. The biomass of one of the dominating Nitrosomonas oligotropha-like populations increased after an ammonium upshift, reaching levels comparable to the high ammonium control in 28 days, whereas a Nitrosomonas europaea-like population increased relatively slowly. The MBBR results, together with competition studies in NTF systems fed with wastewater under controlled ammonium regimes, suggest a differentiation between the two N. oligotropha populations, which may be important for WWTP nitrification.

  • 10.
    Amin, M.
    et al.
    CIHR Group in Matrix Dynamics and Dental Research Institute, University of Toronto, Toronto, ON, Canada.
    Magnusson, Karl-Eric
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology .
    Kapus, A.
    Department of Surgery, St. Michael's Hospital Research Institute, Toronto, ON, Canada.
    Glogauer, M.
    CIHR Group in Matrix Dynamics and Dental Research Institute, University of Toronto, Toronto, ON, Canada.
    Ellen, R.P.
    CIHR Group in Matrix Dynamics and Dental Research Institute, University of Toronto, Toronto, ON, Canada, CIHR Group in Matrix Dynamics, University of Toronto, Faculty of Dentistry, 124 Edward Street, Toronto, ON M5G 1G6, Canada.
    Treponema denticola Msp-deduced peptide conjugate, P34BSA, promotes RhoA-dependent actin stress fiber formation independent of its internalization by fibroblasts2008In: Cell Motility and the Cytoskeleton, ISSN 0886-1544, E-ISSN 1097-0169, Vol. 65, no 5, p. 406-421Article in journal (Refereed)
    Abstract [en]

    P34BSA, a BSA conjugate of a synthetic 10-mer peptide deduced from Treponema denticola major outer sheath protein (Msp), stabilizes actin filaments in fibroblasts and retards cell motility. We reported previously that it is internalized by cells, binds and bundles actin filaments in vitro, and activates RhoA, yet, its site and mechanism of action were not defined. We have assessed P34BSA's modes of interaction with and signaling to fibroblasts. At 4°C, P34BSA was not internalized, but it bound to the plasma membrane and promoted actin stress fiber formation at ~80% capacity compared with 37°C controls, casting doubt that cellular uptake is a critical step for its cytoskeleton-stabilizing property. In Rho G-LISA™ and co-immunoprecipitation assays, P34BSA was found to activate RhoA, even at 4°C, to promote its interaction with guanosine nucleotide exchange factor p114RhoGEF. It also caused phosphorylation of cofilin. Upon RhoA inhibition, either by C3 transferase RhoA inhibitor or by transfection with a dominant negative RhoA construct, P34BSA did not achieve the stress fiber formation seen with P34BSA alone. By inhibiting phosphatidylinositol-3 kinase (PI 3-K) with LY294002, the P34BSA effects were completely blocked. Depletion of cholesterol with methyl-ß-cyclodextrin (MßCD) partially inhibited P34BSA signaling via the plasma membrane to the cytoskeleton. This suggests that multivalent P34BSA activation of lipid raft components requires active PI 3-K, and initiates the pathway through a RhoGEF and RhoA, which mediates stress fiber formation in fibroblasts. Hence, P34BSA may represent a novel tool to investigate RhoA-dependent processes, such as remodeling filamentous actin in eukaryotic cells. © 2008 Wiley-Liss, Inc.

  • 11.
    Andersson, A.
    et al.
    Marine Ecology, Department of Ecology and Environmental Science, Umeå University, SE-901 87 Umeå, Sweden, Umeå Marine Sciences Centre, SE-910 20 Hörnefors, Sweden.
    Samuelsson, Kristina
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology .
    Haecky, P.
    Umeå Marine Sciences Centre, SE-910 20 Hörnefors, Sweden, Botanical Institute, University of Copenhagen, Oster Farimagsgade 2D, DK-1353 Copenhagen K, Denmark.
    Albertsson, J.
    Umeå Marine Sciences Centre, SE-910 20 Hörnefors, Sweden.
    Changes in the pelagic microbial food web due to artificial eutrophication2006In: Aquatic Ecology, ISSN 1386-2588, E-ISSN 1573-5125, Vol. 40, no 3, p. 299-313Article in journal (Refereed)
    Abstract [en]

    The effect of nutrient enrichment on the structure and carbon flow in the pelagic microbial food web was studied in mesocosm experiments using seawater from the northern Baltic Sea. The experiments included food webs of at least four trophic levels, (1) phytoplankton-bacteria, (2) flagellates, (3) ciliates and (4) mesozooplankton. In the enriched treatments high autotrophic growth rates were observed, followed by increased heterotrophic production. The largest growth increase was due to heterotrophic bacteria, indicating that the heterotrophic microbial food web was promoted. This was further supported by increased growth of heterotrophic flagellates and ciliates in the high nutrient treatments. The phytoplankton peak in the middle of the experiments was mainly due to an autotrophic nanoflagellate, Pyramimonas sp. At the end of the experiment, the proportion of heterotrophic organisms was higher in the nutrient enriched than in the nutrient-poor treatment, indicating increased predation control of primary producers. The proportion of potentially mixotrophic plankton, prymnesiophyceans, chrysophyceans and dinophyceans, were significantly higher in the nutrient-poor treatment. Furthermore, the results indicated that the food web efficiency, defined as mesozooplankton production per basal production (primary production + bacterial production - sedimentation), decreased with increasing nutrient status, possibly due to increasing loss processes in the food web. This could be explained by promotion of the heterotrophic microbial food web, causing more trophic levels and respiration steps in the food web. © Springer Science+Business Media B.V. 2006.

  • 12.
    Andersson, Cecilia
    et al.
    Swedish Institute Communicable Disease Control.
    Henriksson, Sara
    Uppsala University.
    Magnusson, Karl-Eric
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Nilsson, Mats
    Uppsala University.
    Mirazimi, Ali
    Swedish Institute Communicable Disease Control.
    In situ rolling circle amplification detection of Crimean Congo hemorrhagic fever virus (CCHFV) complementary and viral RNA2012In: Virology, ISSN 0042-6822, E-ISSN 1096-0341, Vol. 426, no 2, p. 87-92Article in journal (Refereed)
    Abstract [en]

    Crimean Congo hemorrhagic fever virus (CCHFV) is a human pathogen that causes a severe disease with high fatality rate for which there is currently no specific treatment. Knowledge regarding its replication cycle is also highly limited. In this study we developed an in situ technique for studying the different stages during the replication of CCHFV. By integrating reverse transcription, padlock probes, and rolling circle amplification, we were able to detect and differentiate between viral RNA (vRNA) and complementary RNA (cRNA) molecules, and to detect viral protein within the same cell. These data demonstrate that CCHFV nucleocapsid protein (NP) is detectable already at 6 hours post infection in vRNA- and cRNA-positive cells. Confocal microscopy showed that cRNA is enriched and co-localized to a large extent with NP in the perinuclear area, while vRNA has a more random distribution in the cytoplasm with only some co-localize with NP. However, vRNA and cRNA did not appear to co-localize directly.

  • 13.
    Andersson, I.
    et al.
    Ctr. Microbiological Preparedness, Swed. Inst. for Infect. Dis. Control, SE-171 82 Solna, Sweden.
    Bladh, L.
    Ctr. Microbiological Preparedness, Swed. Inst. for Infect. Dis. Control, SE-171 82 Solna, Sweden.
    Mousavi-Jazi, M.
    Ctr. Microbiological Preparedness, Swed. Inst. for Infect. Dis. Control, SE-171 82 Solna, Sweden.
    Magnusson, Karl-Eric
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology .
    Lundkvist, A.
    Lundkvist, Å., Ctr. Microbiological Preparedness, Swed. Inst. for Infect. Dis. Control, SE-171 82 Solna, Sweden, MTC/Karolinska Institutet, SE-171 77 Stockholm, Sweden.
    Haller, O.
    Department of Virology, University of Freiburg, D-79008 Freiburg, Germany.
    Mirazimi, A.
    Ctr. Microbiological Preparedness, Swed. Inst. for Infect. Dis. Control, SE-171 82 Solna, Sweden.
    Human MxA Protein Inhibits the Replication of Crimean-Congo Hemorrhagic Fever Virus2004In: Journal of Virology, ISSN 0022-538X, E-ISSN 1098-5514, Vol. 78, no 8, p. 4323-4329Article in journal (Refereed)
    Abstract [en]

    Crimean-Congo hemorrhagic fever virus (CCHFV) belongs to the genus Nairovirus within the family Bunyaviridae and is the causative agent of severe hemorrhagic fever. Despite increasing knowledge about hemorrhagic fever viruses, the factors determining their pathogenicity are still poorly understood. The interferon-induced MxA protein has been shown to have an inhibitory effect on several members of the Bunyaviridae family, but the effect of MxA against CCHFV has not previously been studied. Here, we report that human MxA has antiviral activity against CCHFV. The yield of progeny virus in cells constitutively expressing MxA was reduced up to 1,000-fold compared with control cells, and accumulation of viral genomes was blocked. Confocal microscopy revealed that MxA colocalizes with the nucleocapsid protein (NP) of CCHFV in the perinuclear regions of infected cells. Furthermore, we found that MxA interacted with NP by using a coimmunoprecipitation assay. We also found that an amino acid substitution (E645R) within the C-terminal domain of MxA resulted in a loss of MxA antiviral activity and, concomitantly, in the capacity to interact with CCHFV NP. These results suggest that MxA, by interacting with a component of the nucleocapsid, prevents replication of CCHFV viral RNA and thereby inhibits the production of new infectious virus particles.

  • 14.
    Ansell, Ricky
    et al.
    National Laboratory of Forensic Science (SKL), Linköping, Sweden.
    Rasmusson, Birgitta
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    A Swedish PerspectiveThe Forensic Use of Bioinformation: Ethical Issues: Nuffield Council on Bioethics2008In: BioSocieties, ISSN 1745-8552, E-ISSN 1745-8560, Vol. 3, no 1, p. 88-92Article in journal (Other academic)
    Abstract [en]

    The Nuffield Report is well-written, clear, extensive and up to date, and it covers most of the major ethical issues in the field of forensic DNA analysis and database searching. The ethical analysis is thorough and based on solid theoretical ground.

  • 15.
    Babakov, V.N.
    et al.
    Department of Cell Cultures, Institute of Cytology, Tikhoretsky Ave. 4, St. Petersburg, 194064, Russian Federation.
    Petukhova, O.A.
    Department of Cell Cultures, Institute of Cytology, Tikhoretsky Ave. 4, St. Petersburg, 194064, Russian Federation.
    Turoverova, L.V.
    Department of Cell Cultures, Institute of Cytology, Tikhoretsky Ave. 4, St. Petersburg, 194064, Russian Federation.
    Kropacheva, I.V.
    Department of Cell Cultures, Institute of Cytology, Tikhoretsky Ave. 4, St. Petersburg, 194064, Russian Federation.
    Tentler, D.G.
    Department of Cell Cultures, Institute of Cytology, Tikhoretsky Ave. 4, St. Petersburg, 194064, Russian Federation.
    Bolshakova, A.V.
    Department of Cell Cultures, Institute of Cytology, Tikhoretsky Ave. 4, St. Petersburg, 194064, Russian Federation.
    Podolskaya, E.P.
    Laboratory of Environmental and Biomedical Mass Spectrometry, Institute for Analytical Instrumentation, St. Petersburg, 198103, Russian Federation.
    Magnusson, Karl-Eric
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology .
    Pinaev, G.P.
    Department of Cell Cultures, Institute of Cytology, Tikhoretsky Ave. 4, St. Petersburg, 194064, Russian Federation.
    RelA/NF-?B transcription factor associates with a-actinin-42008In: Experimental Cell Research, ISSN 0014-4827, E-ISSN 1090-2422, Vol. 314, no 5, p. 1030-1038Article in journal (Refereed)
    Abstract [en]

    The NF-?B/RelA family of transcription factors regulates inducible transcription of a large number of genes in response to diverse stimuli. Little is known, however, about the location of NF-?B in the cytoplasm and the transport mechanism to the nucleus. We found that NF-?B is associated with the actin-binding protein a-actinin-4. NF-?B and a-actinin-4 co-localized along actin stress fibers and in membrane lamellae in A431 cells. After a 30-min stimulation with EGF or TNF-a, a-actinin-4 and p65 were found in the nucleus. Disruption of cytoskeleton by cytochalasin D prior to treatment with TNF-a led to increase of p65 nuclear translocation. Antibodies to p65 subunit of NF-?B co-immunoprecipitated a-actinin-4 from A431 cell lysates and nuclear extracts, but a-actinin-1 and ß-actin were not found in the precipitates. Affinity chromatography experiments displayed that p65 and p50 subunits of NF-?B can bind to matrix-bound chicken gizzard a-actinin. We suggest that the a-actinin-4 is important for the NF-?B nuclear translocation and its functions inside the nucleus. © 2007 Elsevier Inc. All rights reserved.

  • 16.
    Björnsson, Bergthor
    et al.
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Winbladh, Anders
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Bojmar, Linda
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Trulsson, Lena
    Linköping University, Department of Clinical and Experimental Medicine, Surgery. Linköping University, Faculty of Health Sciences.
    Olsson, Hans
    Linköping University, Department of Clinical and Experimental Medicine, Molecular and Immunological Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Gullstrand, Per
    Östergötlands Läns Landsting, Centre for Surgery, Orthopaedics and Cancer Treatment, Department of Surgery UHL.
    Sandström, Per
    Linköping University, Department of Clinical and Experimental Medicine, Surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Surgery, Orthopaedics and Cancer Treatment, Department of Surgery in Östergötland.
    Remote or Conventional Ischemic Preconditioning -Local Liver Metabolism in Rats Studied with Microdialysis2012In: Journal of Surgical Research, ISSN 0022-4804, E-ISSN 1095-8673, Vol. 176, no 1, p. 55-62Article in journal (Refereed)
    Abstract [en]

    Background. Ischemic preconditioning (IPC) of the liver decreases liver injury secondary to ischemia and reperfusion. An attractive alternative to IPC is remote ischemic preconditioning (R-IPC), but these two methods have not previously been compared. Material and Methods. Eighty-seven rats were randomized into four groups: sham operated (n = 15), 1 h segmental ischemia (IRI, n = 24), preceeded by IPC (n = 24), or R-IPC (n = 24) (to the left hindleg). IPC and R-IPC were performed with 10 min ischemia and 10 min of reperfusion. Analyses of liver microdialysate (MD), serum transaminase levels, and liver histology were made. Results. Rats treated with IPC and R-IPC had significantly lower AST, 71.5 (19.6) IU/L respective 96.6 (12.4) at 4 h reperfusion than those subjected to IRI alone, 155 (20.9), P = 0.0004 and P = 0.04 respectively. IPC also had lower ALT levels, 41.6 (11.3) IU/L than had IRI 107.4 (15.5), P = 0.003. The MD glycerol was significantly higher during ischemia in the R-IPC = 759 (84) mu M] and the IRI = 732 (67)] groups than in the IPC 514 (70) group, P = 0.022 and P = 0.046 respectively. The MD glucose after ischemia was lower in the IPC group 7.1 (1.2) than in the IRI group 12.7 (1.6), P = 0.005. Preconditioning to the liver caused an direct increase in lactate, glucose and glycerol in the ischemic segment compared with the control segment an effect not seen in the R-IPC and IRI groups. Conclusions. IPC affects glucose metabolism in the rat liver, observed with MD. IPC reduces liver cell injury during ischemic and reperfusion in rats. R-IPC performed over the same length of time as IPC does not have the same effect as the latter on ALT levels and MD glycerol; this may suggest that R-IPC does not offer the same protection as IPC in this setting of rat liver IRI.

  • 17.
    Björnström, Karin
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Anaesthesiology. Östergötlands Läns Landsting, Anaesthesiology and Surgical Centre, Department of Intensive Care UHL.
    Turina, Dean
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Anesthesiology .
    Loverock, A.
    Department of Anaesthesiology Linköping University.
    Lundgren, S.
    Department of Anaesthesiology Linköping University.
    Wijkman, Magnus
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Internal Medicine .
    Lindroth, Margaretha
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology .
    Eintrei, Christina
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Anesthesiology . Östergötlands Läns Landsting, Anaesthesiology and Surgical Centre, Department of Intensive Care UHL.
    Characterisation of the signal transduction cascade caused by propofol in rat neurons: From the GABAA receptor to the cytoskeleton2008In: Journal of Physiology and Pharmacology, ISSN 0867-5910, E-ISSN 1899-1505, Vol. 59, no 3, p. 617-632Article in journal (Refereed)
    Abstract [en]

    The anaesthetic propofol interacts with the GABAA receptor, but its cellular signalling pathways are not fully understood. Propofol causes reorganisation of the actin cytoskeleton into ring structures in neurons. Is this reorganisation a specific effect of propofol as apposed to GABA, and which cellular pathways are involved? We used fluorescence-marked actin in cultured rat neurons to evaluate the percentage of actin rings caused by propofol or GABA in combination with rho, rho kinase (ROK), PI3-kinase or tyrosine kinase inhibitors, with or without the presence of extracellular calcium. Confocal microscopy was performed on propofol-stimulated cells and changes in actin between cellular compartments were studied with Western blot. Propofol (3 μg·ml-1), but not GABA (5 μM), caused transcellular actin ring formation, that was dependent on influx of extracellular calcium and blocked by rho, ROK, PI3-kinase or tyrosine kinase inhibitors. Propofol uses rho/ROK to translocate actin from the cytoskeleton to the membrane and its actin ring formation is dependent on an interaction site close to the GABA site on the GABAA receptor. GABA does not cause actin rings, implying that this is a specific effect of propofol.

  • 18.
    Blomgran, Robert
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Microbe-induced apoptosis in phagocytic cells and its role in innate immunity2006Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Apoptosis, or programmed cell death, is a controlled process by which aged or damages cells are eliminated in multicellular organisms. Neutrophils, short-lived phagocytes of the innate immune system, are highly equipped effectors that can sense, locate, ingest and kill bacterial pathogens. Inflammatory mediators and the presence of bacterial products at the foci of infection regulate the function and life span of these cells. Modulation of neutrophil apoptosis and the subsequent clearance by scavenger cells, such as macrophages, is part of a balanced inflammatory process leading to resolution of inflammation. Many pathogens are capable of modulating host cell apoptosis, and thereby influence the progression of disease. Hence, this thesis was aiming at elucidating mechanisms involved in pathogen- and host-modulated apoptosis and its contribution to the inflammatory process.

    We found that different routes of bacterial entry, i.e. through invasion or by receptor-mediated phagocytosis, triggered different signaling pathways within phagocytes. Invasion of virulent Salmonella caused apoptosis, a process requiring activation of the Rho GTPases Rac1 and Cdc42. On the other hand, phagocytosis of the non-invasive Salmonella inhibited apoptosis despite similar intracellular survival as the invasive bacteria. Protection against phagocytosis-induced apoptosis was regulated by tyrosine- and PI3-kinase-dependent activation of AKT (also called PKB for protein kinase B). Furthermore, inhibiting the intraphagosomal production of reactive oxygen species (ROS) in neutrophils during phagocytosis of E. coli decreased apoptosis below spontaneous apoptosis, further indicating that both pro- and anti-apoptotic pathways are triggered by receptor-mediated phagocytosis.

    Type 1 fimbria-expressing E. coli adhering to neutrophils resisted ingestion, and induced a ROS-dependent apoptosis by a cooperative effect of the FimH adhesin and LPS. To explore how compartmentalization of ROS during neutrophil activation was involved in modulating apoptosis, we evaluated the stability of lysosomes. In contrast to phagocytosis of E. coli, the adhesive strain induced intracellular non-phagosomal ROS production which triggered early permeabilization and release of lysosomal enzymes to the cytosol. Cathepsin B and/or L were responsible for targeting of the pro-apoptotic Bcl-2 protein Bid, thereby inducing mitochondrial damage, and apoptosis. These data propose a novel pathway for ROS-induced apoptosis in human neutrophils, where the location of the ROS rather than production per se is important.

    Moreover, we found that pathogen-induced apoptotic neutrophils, in contrast to uninfected apoptotic neutrophils, activated blood-monocyte derived macrophages to increase their FcγRI surface expression and to produce large quantities of the pro-inflammatory cytokine TNF-α. This demonstrates that during the early phase of infection, pathogen-induced neutrophil apoptosis will help local macrophages to gain control over the microbes. Furthermore, we suggest that heat shock protein 60 and 70 represent a stress signal that enables macrophages to distinguish between, and react differently to, uninfected and inflammatory apoptotic neutrophils.

    List of papers
    1. Differential effects of invasion by and phagocytosis of Salmonella typhimurium on apoptosis in human macrophages: potential role of Rho–GTPases and Akt
    Open this publication in new window or tab >>Differential effects of invasion by and phagocytosis of Salmonella typhimurium on apoptosis in human macrophages: potential role of Rho–GTPases and Akt
    Show others...
    2003 (English)In: Journal of Leukocyte Biology, ISSN 0741-5400, E-ISSN 1938-3673, Vol. 74, no 4, p. 620-629Article in journal (Refereed) Published
    Abstract [en]

    In addition to direct activation of caspase-1 and induction of apoptosis by SipB, invasive Salmonella stimulates multiple signaling pathways that are key regulators of host cell survival. Nevertheless, little is known about the relative contributions of these pathways to Salmonella-mediated death of macrophages. We studied human monocytic U937 cells and found that apoptosis was induced by invading wild-type Salmonella typhimurium but not by phagocytosed, serum-opsonized, noninvasive Salmonella mutants. Pretreating U937 cells with inhibitors of tyrosine kinases or phosphatidylinositol-3 kinase (PI-3K) completely blocked phagocytosis of opsonized Salmonella mutants but did not affect invasion by wild-type Salmonella or the apoptosis caused by invasion. However, pretreatment with GGTI-298, a geranylgeranyltransferase-1 inhibitor that prevents prenylation of Cdc42 and Rac1, suppressed Salmonella-induced apoptosis by ∼70%. Transduction of Tat fusion constructs containing dominant-negative Cdc42 or Rac1 significantly inhibited Salmonella-induced cell death, indicating that the cytotoxicity of Salmonella requires activation of Cdc42 and Rac. In contrast to phagocytosis of opsonized bacteria, invasion by S. typhimurium stimulated Cdc42 and Rac1, regardless of the activities of tyrosine- or PI-3K. Moreover, Salmonella infection activated Akt protein in a tyrosine-kinase or PI-3K-dependent manner, and a reduced expression of Akt by antisense transfection rendered the cells more sensitive to apoptosis induced by opsonized Salmonella. These results indicate that direct activation of Cdc42 and Rac1 by invasive Salmonella is a prerequisite of Salmonella-mediated death of U937 cells, whereas the simultaneous activation of Akt by tyrosine kinase and PI-3K during receptor-mediated phagocytosis protects cells from apoptosis.

    Keywords
    macrophages, bacterial apoptosis, signal transduction
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-14003 (URN)10.1189/jlb.1202586 (DOI)
    Available from: 2006-09-27 Created: 2006-09-27 Last updated: 2017-12-13Bibliographically approved
    2. Uropathogenic Escherichia coli triggers oxygen-dependent apoptosis in human neutrophils through the cooperative effect of type 1 fimbriae and lipopolysaccharide
    Open this publication in new window or tab >>Uropathogenic Escherichia coli triggers oxygen-dependent apoptosis in human neutrophils through the cooperative effect of type 1 fimbriae and lipopolysaccharide
    2004 (English)In: Infection and Immunity, ISSN 0019-9567, Vol. 72, no 8, p. 4570-4578Article in journal (Refereed) Published
    Abstract [en]

    Type 1 fimbriae are the most commonly expressed virulence factor on uropathogenic Escherichia coli. In addition to promoting avid bacterial adherence to the uroepithelium and enabling colonization, type 1 fimbriae recruit neutrophils to the urinary tract as an early inflammatory response. Using clinical isolates of type 1 fimbriated E. coli and an isogenic type 1 fimbria-negative mutant (CN1016) lacking the FimH adhesin, we investigated if these strains could modulate apoptosis in human neutrophils. We found that E. coli expressing type 1 fimbriae interacted with neutrophils in a mannose- and lipopolysaccharide (LPS)-dependent manner, leading to apoptosis which was triggered by the intracellular generation of reactive oxygen species. This induced neutrophil apoptosis was abolished by blocking FimH-mediated attachment, by inhibiting NADPH oxidase activation, or by neutralizing LPS. In contrast, CN1016, which did not adhere to or activate the respiratory burst of neutrophils, delayed the spontaneous apoptosis in an LPS-dependent manner. This delayed apoptosis could be mimicked by adding purified LPS and was also observed by using fimbriated bacteria in the presence of D-mannose. These results suggest that LPS is required for E. coli to exert both pro- and antiapoptotic effects on neutrophils and that the difference in LPS presentation (i.e., with or without fimbriae) determines the outcome. The present study showed that there is a fine-tuned balance between type 1 fimbria-induced and LPS-mediated delay of apoptosis in human neutrophils, in which altered fimbrial expression on uropathogenic E. coli determines the neutrophil survival and the subsequent inflammation during urinary tract infections.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-14004 (URN)10.1128/IAI.72.8.4570-4578.2004 (DOI)
    Available from: 2006-09-27 Created: 2006-09-27 Last updated: 2009-04-28
    3. Cathepsin-cleaved Bid promotes apoptosis in human neutrophils via oxidative stress-induced lysosomal membrane permeabilization
    Open this publication in new window or tab >>Cathepsin-cleaved Bid promotes apoptosis in human neutrophils via oxidative stress-induced lysosomal membrane permeabilization
    2007 (English)In: Journal of Leukocyte Biology, ISSN 0741-5400, E-ISSN 1938-3673, Vol. 81, p. 1213-1223Article in journal (Refereed) Published
    Abstract [en]

    Lysosomal membrane permeabilization (LMP) is emerging as an important regulator of cell apoptosis. Human neutrophils are highly granulated phagocytes, which respond to pathogens by exhibiting increased production of reactive oxygen species (ROS) and lysosomal degranulation. In a previous study, we observed that intracellular, nonphagosomal generation of ROS triggered by adherent bacteria induced ROS-dependent neutrophil apoptosis, whereas intraphagosomal production of ROS during phagocytosis had no effect. In the present study, we measured lysosomal membrane stability and leakage in human neutrophils and found that adherent, noningested, Type 1-fimbriated Escherichia coli bacteria induced LMP rapidly in neutrophils. Pretreatment with the NADPH oxidase inhibitor diphenylene iodonium markedly blocked the early LMP and apoptosis in neutrophils stimulated with Type 1-fimbriated bacteria but had no effect on the late LMP seen in spontaneously apoptotic neutrophils. The induced lysosomal destabilization triggered cleavage of the proapoptotic Bcl-2 protein Bid, followed by a decrease in the antiapoptotic protein Mcl-1. Involvement of LMP in initiation of apoptosis is supported by the following observations: Bid cleavage and the concomitant drop in mitochondrial membrane potential required activation of cysteine-cathepsins but not caspases, and the differential effects of inhibitors of cysteine-cathepsins and cathepsin D on apoptosis coincided with their ability to inhibit Bid cleavage in activated neutrophils. Together, these results indicate that in microbe-induced apoptosis in neutrophils, ROS-dependent LMP represents an early event in initiation of the intrinsic apoptotic pathway, which is followed by Bid cleavage, mitochondrial damage, and caspase activation.

    Keywords
    bacteria, Bcl-2 family proteins, Escherichia coli, lysosomes, Mcl-1, reactive oxygen species
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-14005 (URN)doi:10.1189/jlb.0506359 (DOI)
    Available from: 2006-09-27 Created: 2006-09-27 Last updated: 2017-12-13
    4. Pathogen-Induced Apoptotic Neutrophils Express Heat Shock Proteins and Elicit Activation of Human Macrophages
    Open this publication in new window or tab >>Pathogen-Induced Apoptotic Neutrophils Express Heat Shock Proteins and Elicit Activation of Human Macrophages
    Show others...
    2004 (English)In: Journal of immunology, ISSN 0022-1767, Vol. 173, no 10, p. 6319-6326Article in journal (Refereed) Published
    Abstract [en]

    Ingestion of aged or irradiated apoptotic neutrophils actively suppresses stimulation of macrophages (MΦ). Many bacterial pathogens can also provoke apoptosis in neutrophils, but little is known about how such apoptotic cells influence MΦ activation. We found that neutrophils undergoing apoptosis induced by UV irradiation, Escherichia coli, or Staphylococcus aureus could either stimulate or inhibit MΦ activation. In contrast to MΦ that had ingested irradiated apoptotic neutrophils, MΦ that had phagocytosed bacteria-induced apoptotic neutrophils exhibited markedly increased production of the proinflammatory cytokine TNF-α, but not the anti-inflammatory cytokine TGF-β. Moreover, ingestion of bacteria, but not UV-induced apoptotic neutrophils, caused increased expression of FcγRI on MΦ, and this effect was not provoked directly by bacteria associated with the apoptotic neutrophils. Instead, we found that a link between pathogen-induced apoptotic neutrophils and up-regulation of the heat shock proteins HSP60 and HSP70, and we also observed that recombinant HSP60 and HSP70 potentiated LPS-stimulated production of TNF-α in MΦ. The opposing macrophage responses to neutrophils undergoing apoptosis induced in different ways may represent a novel mechanism that regulates the extent of the immune response to invading microbes in two steps: first by aiding the functions of MΦ at an early stage of infection, and subsequently by deactivating those cells through removal of uninfected apoptotic neutrophils. HSP induction in neutrophils may provide the danger signals required to generate a more effective macrophage response.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-14006 (URN)
    Available from: 2006-09-27 Created: 2006-09-27 Last updated: 2009-06-09
  • 19.
    Blomgran, Robert
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Brodin Patcha, Veronika
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Verma, Deepti
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Bergström, Ida
    Linköping University, Department of Medical and Health Sciences, Cardiology. Linköping University, Faculty of Health Sciences.
    Söderkvist, Peter
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Sjöwall, Christoffer
    Linköping University, Department of Clinical and Experimental Medicine, Rheumatology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Centre, Department of Rheumatology in Östergötland.
    Eriksson, Per
    Linköping University, Department of Clinical and Experimental Medicine, Rheumatology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Centre, Department of Nephrology UHL.
    Lerm, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Stendahl, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Sarndahl, Eva
    University of Örebro.
    Common Genetic Variations in the NALP3 Inflammasome Are Associated with Delayed Apoptosis of Human Neutrophils2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 3Article in journal (Refereed)
    Abstract [en]

    Background: Neutrophils are key-players in the innate host defense and their programmed cell death and removal are essential for efficient resolution of inflammation. These cells recognize a variety of pathogens, and the NOD-like receptors (NLRs) have been suggested as intracellular sensors of microbial components and cell injury/stress. Some NLR will upon activation form multi-protein complexes termed inflammasomes that result in IL-1 beta production. NLR mutations are associated with auto-inflammatory syndromes, and our previous data propose NLRP3 (Q705K)/CARD-8 (C10X) polymorphisms to contribute to increased risk and severity of inflammatory disease by acting as genetic susceptibility factors. These gene products are components of the NALP3 inflammasome, and approximately 6.5% of the Swedish population are heterozygote carriers of these combined gene variants. Since patients carrying the Q705K/C10X polymorphisms display leukocytosis, the aim of the present study was to find out whether the inflammatory phenotype was related to dysfunctional apoptosis and impaired clearance of neutrophils by macrophages. less thanbrgreater than less thanbrgreater thanMethods and Findings: Patients carrying the Q705K/C10X polymorphisms displayed significantly delayed spontaneous as well as microbe-induced apoptosis compared to matched controls. Western blotting revealed increased levels and phosphorylation of Akt and Mcl-1 in the patients neutrophils. In contrast to macrophages from healthy controls, macrophages from the patients produced lower amounts of TNF; suggesting impaired macrophage clearance response. less thanbrgreater than less thanbrgreater thanConclusions: The Q705K/C10X polymorphisms are associated with delayed apoptosis of neutrophils. These findings are explained by altered involvement of different regulators of apoptosis, resulting in an anti-apoptotic profile. Moreover, the macrophage response to ingestion of microbe-induced apoptotic neutrophils is altered in the patients. Taken together, the patients display impaired turnover and clearance of apoptotic neutrophils, pointing towards a dysregulated innate immune response that influences the resolution of inflammation. The future challenge is to understand how microbes affect the activation of inflammasomes, and why this interaction will develop into severe inflammatory disease in certain individuals.

  • 20.
    Blomgran, Robert
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology .
    Stendalh, O
    Linkoping Univ, IHM, SE-58185 Linkoping, Sweden.
    Zheng, Limin
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology .
    Activation of Protein Kinase B in human monocytic U937 cells by Salmonella typhimurium2001In: Molecular Biology of the Cell, ISSN 1059-1524, E-ISSN 1939-4586, Vol. 12, p. 1794-Conference paper (Other academic)
  • 21.
    Blomgran, Robert
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Zheng, Limin
    State Key Laboratory of Biocontrol, College of Life Sciences, Sun Yatsen (Zhongshan) University, Guangzhou, China.
    Stendahl, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Cathepsin-cleaved Bid promotes apoptosis in human neutrophils via oxidative stress-induced lysosomal membrane permeabilization2007In: Journal of Leukocyte Biology, ISSN 0741-5400, E-ISSN 1938-3673, Vol. 81, p. 1213-1223Article in journal (Refereed)
    Abstract [en]

    Lysosomal membrane permeabilization (LMP) is emerging as an important regulator of cell apoptosis. Human neutrophils are highly granulated phagocytes, which respond to pathogens by exhibiting increased production of reactive oxygen species (ROS) and lysosomal degranulation. In a previous study, we observed that intracellular, nonphagosomal generation of ROS triggered by adherent bacteria induced ROS-dependent neutrophil apoptosis, whereas intraphagosomal production of ROS during phagocytosis had no effect. In the present study, we measured lysosomal membrane stability and leakage in human neutrophils and found that adherent, noningested, Type 1-fimbriated Escherichia coli bacteria induced LMP rapidly in neutrophils. Pretreatment with the NADPH oxidase inhibitor diphenylene iodonium markedly blocked the early LMP and apoptosis in neutrophils stimulated with Type 1-fimbriated bacteria but had no effect on the late LMP seen in spontaneously apoptotic neutrophils. The induced lysosomal destabilization triggered cleavage of the proapoptotic Bcl-2 protein Bid, followed by a decrease in the antiapoptotic protein Mcl-1. Involvement of LMP in initiation of apoptosis is supported by the following observations: Bid cleavage and the concomitant drop in mitochondrial membrane potential required activation of cysteine-cathepsins but not caspases, and the differential effects of inhibitors of cysteine-cathepsins and cathepsin D on apoptosis coincided with their ability to inhibit Bid cleavage in activated neutrophils. Together, these results indicate that in microbe-induced apoptosis in neutrophils, ROS-dependent LMP represents an early event in initiation of the intrinsic apoptotic pathway, which is followed by Bid cleavage, mitochondrial damage, and caspase activation.

  • 22.
    Blomgran, Robert
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Zheng, Limin
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Stendahl, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Uropathogenic Escherichia coli triggers oxygen-dependent apoptosis in human neutrophils through the cooperative effect of type 1 fimbriae and lipopolysaccharide2004In: Infection and Immunity, ISSN 0019-9567, Vol. 72, no 8, p. 4570-4578Article in journal (Refereed)
    Abstract [en]

    Type 1 fimbriae are the most commonly expressed virulence factor on uropathogenic Escherichia coli. In addition to promoting avid bacterial adherence to the uroepithelium and enabling colonization, type 1 fimbriae recruit neutrophils to the urinary tract as an early inflammatory response. Using clinical isolates of type 1 fimbriated E. coli and an isogenic type 1 fimbria-negative mutant (CN1016) lacking the FimH adhesin, we investigated if these strains could modulate apoptosis in human neutrophils. We found that E. coli expressing type 1 fimbriae interacted with neutrophils in a mannose- and lipopolysaccharide (LPS)-dependent manner, leading to apoptosis which was triggered by the intracellular generation of reactive oxygen species. This induced neutrophil apoptosis was abolished by blocking FimH-mediated attachment, by inhibiting NADPH oxidase activation, or by neutralizing LPS. In contrast, CN1016, which did not adhere to or activate the respiratory burst of neutrophils, delayed the spontaneous apoptosis in an LPS-dependent manner. This delayed apoptosis could be mimicked by adding purified LPS and was also observed by using fimbriated bacteria in the presence of D-mannose. These results suggest that LPS is required for E. coli to exert both pro- and antiapoptotic effects on neutrophils and that the difference in LPS presentation (i.e., with or without fimbriae) determines the outcome. The present study showed that there is a fine-tuned balance between type 1 fimbria-induced and LPS-mediated delay of apoptosis in human neutrophils, in which altered fimbrial expression on uropathogenic E. coli determines the neutrophil survival and the subsequent inflammation during urinary tract infections.

  • 23.
    Bolshakova, A.
    et al.
    Department of Cell Cultures, Institute of Cytology, Tikhoretsky Avenue 4, St. Petersburg, 194064, Russian Federation.
    Petukhova, O.
    Department of Cell Cultures, Institute of Cytology, Tikhoretsky Avenue 4, St. Petersburg, 194064, Russian Federation.
    Turoverova, L.
    Department of Cell Cultures, Institute of Cytology, Tikhoretsky Avenue 4, St. Petersburg, 194064, Russian Federation.
    Tentler, D.
    Department of Cell Cultures, Institute of Cytology, Tikhoretsky Avenue 4, St. Petersburg, 194064, Russian Federation.
    Babakov, V.
    Department of Cell Cultures, Institute of Cytology, Tikhoretsky Avenue 4, St. Petersburg, 194064, Russian Federation.
    Magnusson, Karl-Eric
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology .
    Pinaev, G.
    Department of Cell Cultures, Institute of Cytology, Tikhoretsky Avenue 4, St. Petersburg, 194064, Russian Federation.
    Extra-cellular matrix proteins induce re-distribution of a-actinin-1 and a-actinin-4 in A431 cells2007In: Cell Biology International, ISSN 1065-6995, E-ISSN 1095-8355, Vol. 31, no 4 SPEC. ISS., p. 360-365Article in journal (Refereed)
    Abstract [en]

    Alpha-actinins are actin-binding proteins of non-muscle cells, which can participate in the regulation of transcription factor activity. We describe the distribution of a-actinin-1 and -4 depending on different actin cytoskeleton formed as a result of cell adhesion to extracellular matrix proteins, such as fibronectin and laminin 2/4. Immunofluorescent studies show a difference in the distribution of a-actinin and -4. Both isoforms localise along stress-fibres, but a-actinin-1 localises in the perinuclear region more abundantly than a-actinin-4. Western blot analysis demonstrated existence of truncated forms of both isoforms. Truncated a-actinin-1 appears in cells spread on fibronectin or laminin. Cell spreading also correlated with more tight association of a-actinin-4 with chromatin. Basing on our previous finding of an interaction of a-actinin-4 with p65 subunit of the NF-?B, we checked the possible influence of immobilised ligands on its redistribution in nuclear complexes containing p65. a-Actinin-4 seems to be present in some but not all nuclear complexes containing p65. Immobilised ligands may affect the interaction of a-actinin-4/p65 complexes with chromatin. The data suggest that adhesion to extra-cellular matrix may interfere in cellular reactions mediated by a-actinin-1 and -4. © 2007 International Federation for Cell Biology.

  • 24.
    Bolshakova, Anastasia
    et al.
    Russian Academic Science, Russia .
    Magnusson, Karl-Eric
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Pinaev, George
    Russian Academic Science, Russia .
    Petukhova, Olga
    Russian Academic Science, Russia .
    Functional compartmentalisation of NF-B-associated proteins in A431 cells2013In: Cell Biology International, ISSN 1065-6995, E-ISSN 1095-8355, Vol. 37, no 4, p. 387-396Article in journal (Refereed)
    Abstract [en]

    NF-B proteins belong to a family of ubiquitous transcription factors involved in a number of cellular responses. While the pathways of NF-B activation and input into the regulation of gene activity have been comprehensively investigated, its cytoplasmic functions are poorly understood. In this study we addressed effects of the compartmentalisation of NF-B proteins RelA/p65 and p50 in relation to the inhibitor IB-, using fibronectin (FN) and epidermal growth factor (EGF) for environmental stimulation of epidermoid carcinoma A431 cells. We thus assessed the presence of NF-B family proteins in the cytosol, membrane, nuclear and cytoskeletal fractions with a special attention to the cytoskeletal fraction to define whether NF-B was active or not. Sub-cellular fractionation demonstrated that the proportion of RelA/p65 differed in diverse sub-cellular fractions, and that the cytoskeleton harboured about 7% thereof. Neither the nuclear nor the cytoskeleton fraction did contain IB-. The cytoskeleton binding of RelA/p65 and p50 was further confirmed by co-localisation and electron microscopy data. During 30-min EGF stimulation similar dynamics were found for RelA/p65 and IB- in the cytosol, RelA/p65 and p50 in the nucleus and p50 and IB- in the membrane. Furthermore, EGF stimulation for 30min resulted in a threefold accumulation of RelA/p65 in cytoskeletal fraction. Our results suggest that nuclear-, membrane- and cytoskeleton-associated NF-B are dynamic and comprise active pools, whereas the cytoplasmic is more constant and likely non-active due to the presence of IB-. Moreover, we discovered the existence of a dynamic, IB--free pool of RelA/p65 associated with cytoskeletal fraction, what argues for a special regulatory role of the cytoskeleton in NF-B stimulation.

  • 25.
    Bolshakova, A.V.
    et al.
    Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia.
    Petukhova, O.A.
    Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia.
    Pinaev, G.P.
    Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia.
    Magnusson, Karl-Erik
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Comparative analysis of subcellular fractionation methods for revealing a-actinin 1 and a-actinin 4 in A431 cells2009In: Cell and Tissue Biology, ISSN 1990-519X, Vol. 3, no 2, p. 188-197Article in journal (Refereed)
    Abstract [en]

    a-Actinin 1 and a-actinin 4 are actin-binding proteins with shared structural functions that are responsible for the regulation of several processes in the cell. Based on previous data on the different distribution of these proteins in the nucleus and cytoplasm, we have studied in detail the presence of a-actinin 1 and a-actinin 4 in subcellular fractions in the A431 cells spread on fibronectin. The detection of a-actinins in some particular fractions has been shown to depend on the method of lysis, as well as whether the preliminary low-temperature freezing of cells was used. The application of various fractionation methods has allowed us to conclude that a-actinin 4 is present in all cytoplasmic and nuclear subfractions, whereas, in addition to in the cytoplasm, a-actinin 1 can also be revealed in the nuclear envelope fraction.

  • 26.
    Bolshakova, A.V.
    et al.
    Institute of Cytology RAS, St. Petersburg, Russian Federation.
    Petukhova, O.A.
    Institute of Cytology RAS, St. Petersburg, Russian Federation.
    Pinaev, G.P.
    Institute of Cytology RAS, St. Petersburg, Russian Federation.
    Magnusson, Karl-Erik
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    The comparative analysis of subcellular fractionation methods for revealing of a-actinin 1 and a-actinin 4 in A431 cells2009In: Tsitologiya, ISSN 0041-3771, Vol. 51, no 2, p. 122-129Article in journal (Refereed)
    Abstract [en]

    a-Actinin 1 and a-actinin 4 belong to a family of actin-binding proteins with shared structural function and regulation of several processes in a cell. Based on previous data on different distribution of these proteins in the nucleus and cytoplasm, we have explored in detail the distribution of a-actinin 1 and a-actinin 4 in subcellular fractions in A431 cells spread on fibronectin. Several methods of subcellular fractionation were used. Complex approach allowed resuming that revealing of a-actinin isoforms in fractions depended on the composition of lysis buffer and preliminary low-temperature freezing of the cells. We have drawn a conclusion that a-actinin 4 can be found in all cytoplasmic and nuclear subfractions, while a-actinin 1 is characterized by cytoplasmic and membrane localization with specificity of its distribution tightly to the nuclear membrane.

  • 27.
    Borjesson, Stefan
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Matussek, A
    Unilabs, Gothenburg.
    Melin, Sara
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Lofgren, S
    County Hospital Ryhov.
    Lindgren, Per-Eric
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Methicillin-resistant Staphylococcus aureus (MRSA) in municipal wastewater: an uncharted threat?2010In: JOURNAL OF APPLIED MICROBIOLOGY, ISSN 1364-5072, Vol. 108, no 4, p. 1244-1251Article in journal (Refereed)
    Abstract [en]

    Aims: (i) To cultivate methicillin-resistant Staphylococcus aureus (MRSA) from a full-scale wastewater treatment plant (WWTP), (ii) To characterize the indigenous MRSA-flora, (iii) To investigate how the treatment process affects clonal distribution and (iv) To examine the genetic relation between MRSA from wastewater and clinical MRSA. Methods: Wastewater samples were collected during 2 months at four key sites in the WWTP. MRSA isolates were characterized using spa typing, antibiograms, SSCmec typing and detection of Panton-Valentine leukocidin (PVL). Conclusions: MRSA could be isolated on all sampling occasions, but only from inlet and activated sludge. The number of isolates and diversity of MRSA were reduced by the treatment process, but there are indications that the process was selected for strains with more extensive antibiotic resistance and PVL+ strains. The wastewater MRSA-flora had a close genetic relationship to clinical isolates, most likely reflecting carriage in the community. Significance and Impact of the Study: This study shows that MRSA survives in wastewater and that the WWTP may be a potential reservoir for MRSA.

  • 28.
    Borutinskaite, Veronica
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology . Linköping University, Faculty of Health Sciences.
    Magnusson, Karl-Eric
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Navakauskiene, Ruta
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Effects of retinoic acid and histone deacetylase inhibitor Bml-210 on protein expression in NB4 cells2005In: Biologija, ISSN 1392-0146, Vol. 4, p. 88-93Article in journal (Refereed)
  • 29.
    Borutinskaite, Veronica
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology . Linköping University, Faculty of Health Sciences.
    Navakauskiene, Ruta
    Department of Developmental Biology, Institute of Biochemistry, Vilnius, Lithuania .
    Magnusson, Karl-Eric
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Retinoic acid and histone deacelytase inhibitor BML-210 inhibit proliferation of human cervical cancer HeLa cells2006In: Annals of the New York Academy of Sciences, ISSN 0077-8923, Vol. 1091, p. 346-355Article in journal (Refereed)
    Abstract [en]

    Human papillomavirus (HPV) infection is believed to be the central cause of cervical cancer. The viral proteins E6 and E7 from high-risk HPV types prevent cells from differentiating apoptosis and inducing hyperproliferative lesions. Human cervical carcinoma HeLa cells contain integrated human papillomavirus type 18 (HPV-18). Retinoic acid (RA) is a key regulator of epithelial cell differentiation and a growth inhibitor in vitro of HeLa cervical carcinoma cells. Cellular responses to RA are mediated by nuclear retinoic acid receptors (RARs) and retinoid X receptors. On the other hand, histone deacetylase inhibitors have been shown to be chemopreventive agents for the treatment of cancer cells. In this article, we have examined the antiproliferative effect of RA and histone deacetylase inhibitor BML-210 on HeLa cells, and particularly the effects on protein expression that may be involved in the cell cycle control and apoptosis. Our data suggest that a combination of RA and BML-210 leads to cell growth inhibition with subsequent apoptosis in a treatment time-dependent manner. We confirm that BML-210 alone or in combination with RA causes a marked increase in the level of p21. The changes in the p53 level are under the influence of p38 phosphorylation. We also discovered that the histone deacetylase inhibitor BML-210 causes increased levels of anti-apoptotic protein Bcl-2 and phosphorylated p38 MAP Kinase; the latter link in cell cycle arrest with response to extracellular stimuli. Our results suggest that RA and BML-210 are involved in different signaling pathways that regulate cell cycle arrest and lead to apoptosis of HeLa cells.

  • 30.
    Borutinskaite, Veronika V
    et al.
    Vilnius State University, Lithuania .
    Magnusson, Karl-Eric
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Navakauskiene, Ruta
    Vilnius State University, Lithuania .
    Histone deacetylase inhibitor BML-210 induces growth inhibition and apoptosis and regulates HDAC and DAPC complex expression levels in cervical cancer cells2012In: Molecular Biology Reports, ISSN 0301-4851, E-ISSN 1573-4978, Vol. 39, no 12, p. 10179-10186Article in journal (Refereed)
    Abstract [en]

    Histone deacetylase inhibitors (HDACIs) represent a new class of targeted anti-cancer agents and different other diseases, like muscular disorders. A number of studies have shown that extracellular signal-activated kinases can target chromatin-modifying complexes directly and regulate their function. The molecular connection between the dystrophin-associated protein complex (DAPC) and chromatin has been described, by showing that NO signaling regulates histone deacetylase (HDAC) activity and influences gene expression in different cell types. In present study, we investigated HDACs changes in HeLa cells undergoing growth inhibition and apoptosis, caused by HDACI BML-210 and retinoic acid (ATRA). Cell cycle analysis indicated that HeLa cell treatment with 20 and 30 mu M concentration of BML-210 increased the proportion of cells in G0/G1 phase, and caused accumulation in subG1, indicating that the cells are undergoing apoptosis. We determined down-regulation of HDAC 1-5 and 7 after treatment with BML-210. Also, we demonstrated expression of different isoforms of alpha-dystrobrevin (alpha-DB) and other components of DAPC such as syntrophin, dystrophin, beta-dystrobrevin (beta-DB) and NOS in HeLa cells after treatments. We determined changes in protein expression level of dystrophin, NOS1, alpha- and beta-DB and in subcellular localization of alpha-DB after treatments with BML-210 and ATRA. In conclusion, these results suggest that HDACI BML-210 can inhibit cell growth and induce apoptosis in cervical cancer cells, what correlates with down-regulation of HDAC class I and II and changes in the DAPC expression levels. This can be important for identifying target proteins in DAPC signaling to HDACs, as a target of pharmacological intervention for treatment of muscular dystrophies and other diseases.

  • 31.
    Borutinskaité, Veronika
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Magnusson, Karl-Eric
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Navakauskiene, R
    Institute for Biochemistry, Vilnius.
    alpha-Dystrobrevin distribution and association with other proteins in human promyelocytic NB4 cells treated for granulocytic differentiation2011In: MOLECULAR BIOLOGY REPORTS, ISSN 0301-4851, Vol. 38, no 5, p. 3001-3011Article in journal (Refereed)
    Abstract [en]

    Dystrobrevins (DBs) bind directly to dystrophin and are prominent components of the dystrophin-associated protein complex (DAPC) that links the cytoskeleton to the extracellular matrix. They are involved in brain development, synapse formation and plasticity, as well as water and ion homeostasis. However, the role of DB in non-muscular cells is not clear. In this study, we show that different alpha-dystrobrevin isoforms are present in promyelocytic leukemia (NB4) cells. Only the biggest alpha-dystrobrevin isoform (DB-alpha), which can be important for its function, was expressed in the membrane fraction of NB4 cells; the other alpha-DB isoforms were found in the hydrophilic cell fractions. Employing the immunoprecipitation and mass spectrometry, we identified novel alpha-DB-interacting proteins involved in cytoskeleton reorganization (actin, tropomyosin, gelsolin, tubulin) and signal transduction process (stathmin, prohibitin, RIBA) during proliferation and differentiation of NB4 cells. Our results suggest that alpha-DB isoforms play a central role in cytoskeleton reorganization via their multiple interactions with actin and actin-associating proteins and may participate in signal transduction process during NB4 cell granulocytic differentiation via directly and non directly associated proteins.

  • 32.
    Brighenti, Susanna
    et al.
    Center for Infectious Medicine, Huddinge Hospital Karolinska Institute.
    Lerm, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    How Mycobacterium tuberculosis Manipulates Innate and Adaptive Immunity: New Views of an Old Topic2012In: Understanding Tuberculosis: Analyzing the Origin of Mycobacterium Tuberculosis Pathogenicity / [ed] Pere-Joan Cardona, InTech Open , 2012, p. 207-234Chapter in book (Other academic)
    Abstract [en]

    Mycobacterium tuberculosis in an attempt to understand the extent to which the bacilli has adapted itself to the host and to its final target. On the other hand, there is a section in which other specialists discuss how to manipulate this immune response to obtain innovative prophylactic and therapeutic approaches to truncate the intimal co-evolution between Mycobacterium tuberculosis and the Homo sapiens.

  • 33.
    Brodin Patcha, Veronika
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Pro- and anti-inflammatory regulation of β2 integrin signalling in human neutrophils2007Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The body is under constant attack from pathogens trying to slip by our immune defence. If the barrier is breached, invading pathogens enter the tissues and cause inflammation. During this process neutrophils, constituting the first line of defence, leave the bloodstream and seek out and kill the invading pathogens. The mechanisms leading to activation of receptors on neutrophils must be closely orchestrated. Pro- and anti-inflammatory substances can influence the outcome of the inflammation process by affecting the involved players. If not well balanced, inflammatory diseases, such as atherosclerosis and rheumatoid arthritis, can be the outcome.

    The aim of this thesis was to elucidate the effect of pro- (fMLP, Leukotriene B4, and Interleukin-8) and anti- (lipoxins, aspirin and statins) inflammatory substances on the β2 integrins, mediating adhesion of neutrophils both under “normal” conditions and during coronary artery disease. More specifically, the effect of these substances on the β2 integrins were studied in regard to: i) the activity (i.e. affinity and avidity) of β2 integrins, ii) the signalling capacity of β2 integrins (i.e. detected as release of arachidonic acid, and the production of reactive oxygen species, and iii) the signal transduction mediated by the β2 integrins (i.e. phosphorylation of Pyk2).

    The pro-inflammatory substances belong to the family of chemoattractants that induces transmigration and chemotaxis. A hierarchy exists between the different family members; the end-target chemoattractants (e.g. fMLP) being more potent than intermediary chemoattractants (e.g. IL-8 and LTB4). It was found that intermediary chemoattractants regulate β2 integrins by mainly affecting the avidity of β2 integrins. End-target chemoattractants on the other hand, affected the β2 integrins by increasing the avidity and the affinity, as well as their signalling capacity.

    The anti-inflammatory substances used in this study were the exogenous aspirin and statins, and the endogenous lipoxins. In the presence of aspirin, stable analogues of lipoxin (i.e. epi-lipoxins) are formed in a trans-cellular process. Lipoxin inhibited the signalling capacity of β2 integrins mediated by intermediary chemoattractants, as well as the signal transduction induced by end-target chemoattractants. Moreover, the signalling capacity of β2 integrins in neutrophils from patients suffering from coronary artery disease (CAD) was impaired. Arachidonic acid, the precursor for both pro- and anti-inflammatory eicosanoid, induced an increase in the β2 integrin activity (both affinity and avidity), but had no effect on the signal transduction.

    In conclusion, different “roles” were observed for end-target and intermediary chemoattractants in the regulation of β2 integrins. The inhibitory effects of the anti-inflammatory lipoxins support earlier studies suggesting that these agents function as “stop signals” in inflammation. This is also confirmed by our findings in CAD patients, who have elevated levels of epi-lipoxins due to aspirin treatment. Moreover, Pyk2 was identified as a possible target for the inhibitory effect of anti-inflammatory drugs.

    List of papers
    1. Differential inside-out activation of β2 integrins by leukotriene B4 and fMLP in human neutrophils
    Open this publication in new window or tab >>Differential inside-out activation of β2 integrins by leukotriene B4 and fMLP in human neutrophils
    Show others...
    2004 (English)In: Experimental Cell Research, ISSN 0014-4827, E-ISSN 1090-2422, Vol. 300, no 2, p. 308-319Article in journal (Refereed) Published
    Abstract [en]

    We have investigated how LTB4, an endogenous chemoattractant encountered early in the inflammatory process, and fMLP, a bacteria-derived chemotactic peptide emanating from the site of infection, mediate inside-out regulation of the β2-integrin. The role of the two chemoattractants on β2-integrin avidity was investigated by measuring their effect on β2-integrin clustering and surface mobility, whereas their effect on β2-integrin affinity was measured by the expression of a high affinity epitope, a ligand-binding domain on β2-integrins, and by integrin binding to s-ICAM. We find that the two chemoattractants modulate the β2-integrin differently. LTB4 induces an increase in integrin clustering and surface mobility, but only a modest increase in integrin affinity. fMLP evokes a large increase in β2-integrin affinity as well as in clustering and mobility. Lipoxin, which acts as a stop signal for the functions mediated by pro-inflammatory agents, was used as a tool for further examining the inside-out mechanisms. While LTB4-induced integrin clustering and mobility were inhibited by lipoxin, only a minor inhibition of fMLP-induced β2-integrin avidity and no inhibition of integrin affinity were detected. The different modes of the inside-out regulation of β2-integrins suggest that distinct mechanisms are involved in the β2-integrin modulation induced by various chemoattractants.

    Keywords
    β2-Integrins, Cell adhesion, Chemotactic factors, Eicosanoids, Inflammation, Leukotriene B4, Lipoxins, Human Neutrophils, Signal transduction
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-14629 (URN)10.1016/j.yexcr.2004.07.015 (DOI)
    Available from: 2007-09-13 Created: 2007-09-13 Last updated: 2017-12-13Bibliographically approved
    2. LIpoxin A4 inhibits the fMet-Leu-Phe-induced, but not the β2 integrin-induced activation of the non-receptor tyrosine kinase Pyk2 in Human Leukemia 60 cells
    Open this publication in new window or tab >>LIpoxin A4 inhibits the fMet-Leu-Phe-induced, but not the β2 integrin-induced activation of the non-receptor tyrosine kinase Pyk2 in Human Leukemia 60 cells
    Manuscript (Other academic)
    Identifiers
    urn:nbn:se:liu:diva-14630 (URN)
    Available from: 2007-09-13 Created: 2007-09-13 Last updated: 2010-01-13
    3. Inside-out regulated β2-integrin-induced release of arachidonic acid in Human Leukemia 60 cells
    Open this publication in new window or tab >>Inside-out regulated β2-integrin-induced release of arachidonic acid in Human Leukemia 60 cells
    Manuscript (Other academic)
    Identifiers
    urn:nbn:se:liu:diva-14631 (URN)
    Available from: 2007-09-13 Created: 2007-09-13 Last updated: 2010-01-13
    4. Inactivation of Cdc42 is nessecary for depolymerization of phagosomal F-actin and subsequent phagosomal maturation
    Open this publication in new window or tab >>Inactivation of Cdc42 is nessecary for depolymerization of phagosomal F-actin and subsequent phagosomal maturation
    Show others...
    2007 (English)In: Journal of Immunology, ISSN 0022-1767, Vol. 178, no 11, p. 7357-7365Article in journal (Refereed) Published
    Abstract [en]

    Phagocytosis is a complex process involving the activation of various signaling pathways, such as the Rho GTPases, and the subsequent reorganization of the actin cytoskeleton. In neutrophils, Rac and Cdc42 are activated during phagocytosis but less is known about the involvement of these GTPases during the different stages of the phagocytic process. The aim of this study was to elucidate the role of Cdc42 in phagocytosis and the subsequent phagosomal maturation. Using a TAT-based protein transduction technique, we introduced dominant negative and constitutively active forms of Cdc42 into neutrophil-like HL60 (human leukemia) cells that were allowed to phagocytose IgG-opsonized yeast particles. Staining of cellular F-actin in cells transduced with constitutively active Cdc42 revealed that the activation of Cdc42 induced sustained accumulation of periphagosomal actin. Moreover, the fusion of azurophilic granules with the phagosomal membrane was prevented by the accumulated F-actin. In contrast, introducing dominant negative Cdc42 impaired the translocation per se of azurophilic granules to the periphagosomal area. These results show that efficient phagosomal maturation and the subsequent eradication of ingested microbes in human neutrophils is dependent on a strictly regulated Cdc42. To induce granule translocation, Cdc42 must be in its active state but has to be inactivated to allow depolymerization of the F-actin cage around the phagosome, a process essential for phagolysosome formation.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-14632 (URN)
    Available from: 2007-09-13 Created: 2007-09-13
    5. Neutrophil activation status in stable coronary artery disease.
    Open this publication in new window or tab >>Neutrophil activation status in stable coronary artery disease.
    Show others...
    2007 (English)In: PLoS ONE, ISSN 1932-6203, Vol. 2, no 10, p. e1056-Article in journal (Refereed) Published
    Abstract [en]

    Background: During the last years, neutrophils have emerged as important players in atherogenesis. They are highly activated in peripheral blood of patients with unstable angina. Moreover, a primed state of circulating neutrophils has been proposed in patients with stable angina. Our aim was to investigate the neutrophil activation status in patients with stable coronary artery disease (CAD) at conventional drug treatment.

    Methodology and principal findings: Thirty patients with stable CAD and 30 healthy controls were included using a paired design. The neutrophil expression of CD18 and high-affinity state of CD11b was analysed by flow cytometry before and after stimulation with chemoattractants. Also, the production of reactive oxygen species (ROS) was determined by chemiluminescence. During basal conditions, the neutrophil expression of CD18 or high-affinity state of CD11b did not differ between patients and controls. Chemoattractants (Interleukin-8 and Leukotriene B(4)) did not increase either the expression or the amount of high-affinity CD11b/CD18-integrins in CAD patients compared to controls, and had no effect on the production of ROS. On the other hand, the ROS production in response to C3bi-opsonised yeast particles and the neutrophils' inherent capacity to produce ROS were both significantly decreased in patients.

    Conclusion/Significance: We could not find any evidence that neutrophils in patients with stable CAD were primed, i.e. more prone to activation, compared to cells from healthy controls. According to our data, the circulating neutrophils in CAD patients rather showed an impaired activation status. It remains to be elucidated whether the neutrophil dysfunction in CAD is mainly a marker of chronic disease, an atherogenic factor or a consequence of the drug treatment.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-17246 (URN)10.1371/journal.pone.0001056 (DOI)17957240 (PubMedID)
    Available from: 2009-03-12 Created: 2009-03-12 Last updated: 2010-01-14
  • 34.
    Bucardo, Filemon
    et al.
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences. Department of Microbiology, University of León, UNAN-León, Nicaragua.
    Carlsson, Beatrice
    Linköping University, Department of Clinical and Experimental Medicine, Molecular Virology. Linköping University, Faculty of Health Sciences.
    Nordgren, Johan
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Larson, Göran
    University of Gothenburg, Göteborg, Sweden.
    Blandon, Patricia
    Department of Microbiology University of León, Nicaragua (UNAN-León).
    Vilchez, Samuel
    Department of Microbiology University of León, Nicaragua (UNAN-León).
    Svensson, Lennart
    Linköping University, Department of Clinical and Experimental Medicine, Molecular Virology. Linköping University, Faculty of Health Sciences.
    Susceptibility of Children to Sapovirus Infections, Nicaragua, 2005–20062012In: Emerging Infectious Diseases, ISSN 1080-6040, E-ISSN 1080-6059, Vol. 18, no 11, p. 1875-1878Article in journal (Refereed)
    Abstract [en]

    We describe the genetic diversity of sapovirus (SaV) in children in Nicaragua and investigate the role of host genetic factors and susceptibility to SaV infections. Our results indicate that neither ABO blood group, Lewis phenotype, nor secretor status affects susceptibility to SaV infection in Nicaragua.

  • 35.
    Bucardo, Filemon
    et al.
    University of Leon.
    Lindgren, Per-Eric
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Svensson, Lennart
    Linköping University, Department of Clinical and Experimental Medicine, Molecular Virology. Linköping University, Faculty of Health Sciences.
    Nordgren, Johan
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Low Prevalence of Rotavirus and High Prevalence of Norovirus in Hospital and Community Wastewater after Introduction of Rotavirus Vaccine in Nicaragua2011In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 6, no 10Article in journal (Refereed)
    Abstract [en]

    Rotavirus (RV) and norovirus (NoV) are major causes of pediatric diarrhea and are altogether associated with approximately 800,000 deaths in young children every year. In Nicaragua, national RV vaccination program using the pentavalent RV5 vaccine from Merck was implemented in October 2006. To determine whether RV vaccination decreased the overall number of RV infections, we investigated the occurrence of RV and NoV in wastewater in the city of Leon from July 2007 to July 2008 and compared these data with pre-vaccination data. The major finding was the low prevalence of RV compared to NoV in all sampling points (11% vs 44%, pandlt;0.05), and that RV concentration was lower as compared to NoV. RV was observed mainly during the rainy season (July-September), and the majority of all RV detected (6/9) belonged to subgroup (SG) I. The partial VP7-gene obtained from one RV positive sample was similar (99% nt identity) to a G6 VP7-gene of bovine origin and similar to the corresponding gene of the vaccine strain (98%). Furthermore RV G-types 2 and 4 were found in the incoming wastewater. NoV strains were detected throughout the year, of which a majority (20/21) were of genotype GII.4. We conclude that the introduction of RV vaccination reduced the transmission of RV in the community in Nicaragua. However, the burden of diarrhea in the country remains high, and the high prevalence of NoVs in hospital and municipal wastewater is noteworthy. This study highlights the need for further assessment of NoV following RV vaccine introduction.

  • 36.
    Bucardo, Filemon
    et al.
    Department of Microbiology, University of León, UNAN-León, Nicaragua.
    Nordgren, Johan
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Carlsson, Beatrice
    Linköping University, Department of Clinical and Experimental Medicine, Molecular Virology . Linköping University, Faculty of Health Sciences.
    Paniagua, Margarita
    Microbiology, Tumor and Cell Biology Centre, Karolinska Institutet, S-171 77 Stockholm, Sweden.
    Lindgren, Per-Eric
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Espinoza, Felix
    Department of Microbiology, University of León, UNAN-León, Nicaragua.
    Svensson, Lennart
    Linköping University, Department of Clinical and Experimental Medicine, Molecular Virology . Linköping University, Faculty of Health Sciences.
    Pediatric norovirus diarrhea in Nicaragua2008In: Journal of Clinical Microbiology, ISSN 0095-1137, E-ISSN 1098-660X, Vol. 46, no 8, p. 2573-2580Article in journal (Refereed)
    Abstract [en]

    Information about norovirus (NoV) infections in Central America is limited. Through a passive community and hospital pediatric diarrhea surveillance program, a total of 542 stool samples were collected between March 2005 and February 2006 in León, Nicaragua. NoV was detected in 12% (65/542) of the children; of these, 11% (45/409) were in the community and 15% (20/133) were in the hospital, with most strains (88%) belonging to genogroup II. NoV infections were age and gender associated, with children of <2 years of age (P < 0.05) and girls (P < 0.05) being most affected. Breast-feeding did not reduce the number of NoV infections. An important proportion (57%) of NoV-infected children were coinfected with diarrheagenic Escherichia coli. A significant proportion (18/31) of NoV-positive children with dehydration required intravenous rehydration. Nucleotide sequence analysis (38/65) of the N-terminal and shell region in the capsid gene revealed that at least six genotypes (GI.4, GII.2, GII.4, GII.7, GII.17, and a potentially novel cluster termed "GII.18-Nica") circulated during the study period, with GII.4 virus being predominant (26/38). The majority (20/26) of those GII.4 strains shared high nucleotide homology (99%) with the globally emerging Hunter strain. The mean viral load was approximately 15-fold higher in children infected with GII.4 virus than in those infected with other G.II viruses, with the highest viral load observed for the group of children infected with GII.4 and requiring intravenous rehydration. This study, the first of its type from a Central American country, suggests that NoV is an important etiological agent of acute diarrhea among children of <2 years of age in Nicaragua.

  • 37.
    Bucardo, Filemon
    et al.
    University of Leon.
    Nordgren, Johan
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Paniagua, Margarita
    University of Leon.
    Mollby, Roland
    Karolinska Institute.
    Svensson, Lennart
    Linköping University, Department of Clinical and Experimental Medicine, Molecular Virology . Linköping University, Faculty of Health Sciences.
    Asymptomatic Norovirus Infections in Nicaraguan Children and its Association With Viral Properties and Histo-blood Group Antigens2010In: PEDIATRIC INFECTIOUS DISEASE JOURNAL, ISSN 0891-3668, Vol. 29, no 10, p. 934-939Article in journal (Refereed)
    Abstract [en]

    Background: It has been previously reported that histo-blood group antigens (HBGAs) and particularly secretor status provides protection against symptomatic norovirus infection, but it remains unclear to what extent this includes asymptomatic infections in children. Methods: To explore whether HBGAs or certain viral genotypes are associated with asymptomatic norovirus infections in a pediatric population in Nicaragua, we investigated 163 children andlt;= 5 years of age, without a recent history of diarrhea (andlt;= 10 days). Results: Asymptomatic norovirus infections were observed in 11.7% (19/163), with children andlt;= 6 months of age being most frequently infected (16%). Of the 19 norovirus-positive children, 4 (21%) and 10 (53%) were infected with genogroups GI and GII, respectively, and 4 children (21%) were infected with viruses of both genogroups. Most children had andgt;= 10(6) viral genomes per gram of feces. Nucleotide sequence analysis (15/19) revealed uncommon genotypes, such as, GII. 7 (n = 5) and GII. 2 (n = 3). An interesting observation was the low frequency of norovirus GII. 4 strains among the asymptomatic children. AB blood type, Lewis a (Lea(a+b-)) phenotype and nonsecretor genotype (se(428)se(428)) were not found among the asymptomatic children, but they occurred in population controls. Conclusions: Frequency of asymptomatic norovirus infections was similar to that observed in symptomatic children from Nicaragua. Norovirus GII. 2 and GII. 7 were frequently detected but the globally dominating GII. 4 was infrequent. Host genetic factors previously observed to be associated with protection against symptomatic norovirus infection were not found in this study.

  • 38.
    Byström, IngMarie
    et al.
    Linköping University, Department of Medical and Health Sciences, Nursing Science. Linköping University, Faculty of Health Sciences.
    Hollén, Elisabet
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Fälth-Magnusson, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Pediatrics. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre of Paediatrics and Gynecology and Obstetrics, Department of Paediatrics in Linköping.
    Johansson, AnnaKarin
    Linköping University, Department of Medical and Health Sciences, Nursing Science. Linköping University, Faculty of Health Sciences.
    Health-Related Quality of Life in Children and Adolescents with Celiac Disease: From the Perspectives of Children and Parents2012In: Gastroenterology Research and Practice, ISSN 1687-6121, E-ISSN 1687-630X, Vol. 2012Article in journal (Refereed)
    Abstract [en]

    Aim. To examine how celiac children and adolescents on gluten-free diet valued their health-related quality of life, and if age and severity of the disease at onset affected the childrens self-valuation later in life. We also assessed the parents valuation of their childs quality of life. Methods. The DISABKIDS Chronic generic measure, short versions for both children and parents, was used on 160 families with celiac disease. A paediatric gastroenterologist classified manifestations of the disease at onset retrospectively. Results. Age or sex did not influence the outcome. Children diagnosed before the age of five scored higher than children diagnosed later. Children diagnosed more than eight years ago scored higher than more recently diagnosed children, and children who had the classical symptoms of the disease at onset scored higher than those who had atypical symptoms or were asymptomatic. The parents valuated their childrens quality of life as lower than the children did. Conclusion. Health-related quality of life in treated celiac children and adolescents was influenced by age at diagnosis, disease severity at onset, and years on gluten-free diet. The disagreement between child-parent valuations highlights the importance of letting the children themselves be heard about their perceived quality of life.

  • 39.
    Börgeson, Emma
    et al.
    Linköping University, Department of Medical and Health Sciences, Pharmacology. Linköping University, Faculty of Health Sciences.
    Lönn, Johanna
    Linköping University, Department of Medical and Health Sciences, Pharmacology. Linköping University, Faculty of Health Sciences.
    Bergström, Ida
    Linköping University, Department of Medical and Health Sciences, Cardiology. Linköping University, Faculty of Health Sciences.
    Brodin Patcha, Veronika
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Ramström, Sofia
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Chemistry. Linköping University, Faculty of Health Sciences.
    Nayeri, Fariba
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Medicine, Department of Infectious Diseases in Östergötland.
    Sarndahl, Eva
    University Orebro.
    Bengtsson, Torbjörn
    Linköping University, Department of Medical and Health Sciences, Pharmacology. Linköping University, Faculty of Health Sciences.
    Lipoxin A(4) Inhibits Porphyromonas gingivalis-Induced Aggregation and Reactive Oxygen Species Production by Modulating Neutrophil-Platelet Interaction and CD11b Expression2011In: INFECTION AND IMMUNITY, ISSN 0019-9567, Vol. 79, no 4, p. 1489-1497Article in journal (Refereed)
    Abstract [en]

    Porphyromonas gingivalis is an etiological agent that is strongly associated with periodontal disease, and it correlates with numerous inflammatory disorders, such as cardiovascular disease. Circulating bacteria may contribute to atherogenesis by promoting CD11b/CD18-mediated interactions between neutrophils and platelets, causing reactive oxygen species (ROS) production and aggregation. Lipoxin A(4) (LXA(4)) is an endogenous anti-inflammatory and proresolving mediator that is protective of inflammatory disorders. The aim of this study was to investigate the effect of LXA(4) on the P. gingivalis-induced activation of neutrophils and platelets and the possible involvement of Rho GTPases and CD11b/CD18 integrins. Platelet/leukocyte aggregation and ROS production was examined by lumiaggregometry and fluorescence microscopy. Integrin activity was studied by flow cytometry, detecting the surface expression of CD11b/CD18 as well as the exposure of the high-affinity integrin epitope, whereas the activation of Rac2/Cdc42 was examined using a glutathione S-transferase pulldown assay. The study shows that P. gingivalis activates Rac2 and Cdc42 and upregulates CD11b/CD18 and its high-affinity epitope on neutrophils, and that these effects are diminished by LXA(4). Furthermore, we found that LXA(4) significantly inhibits P. gingivalis-induced aggregation and ROS generation in whole blood. However, in platelet-depleted blood and in isolated neutrophils and platelets, LXA(4) was unable to inhibit either aggregation or ROS production, respectively. In conclusion, this study suggests that LXA(4) antagonizes P. gingivalis-induced cell activation in a manner that is dependent on leukocyte-platelet interaction, likely via the inhibition of Rho GTPase signaling and the downregulation of CD11b/CD18. These findings may contribute to new strategies in the prevention and treatment of periodontitis-induced inflammatory disorders, such as atherosclerosis.

  • 40.
    Börjesson, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Antibiotic Resistance in Wastewater: Methicillin-resistant Staphylococcus aureus (MRSA)and antibiotic resistance genes2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    A large part of the antibiotics consumed ends up in wastewater, and in the wastewater the antibiotics may exert selective pressure for or maintain resistance among microorganisms. Antibiotic resistant bacteria and genes encoding antibiotic resistance are commonly detected in wastewater, often at higher rates and concentrations compared to surface water. Wastewater can also provide favourable conditions for the growth of a diverse bacterial community, which constitutes a basis for the selection and spread of antibiotic resistance. Therefore, wastewater treatment plants have been suggested to play a role in the dissemination and development of antibiotic resistant bacteria. Methicillin-resistant Staphylococcus aureus (MRSA) is a large problem worldwide as a nosocomial pathogen, but knowledge is limited about occurrence in non-clinical environments, such as wastewater, and what role wastewater plays in dissemination and development of MRSA.

     

    In this thesis we investigated the occurrence of MRSA in a full-scale wastewater treatment plant (WWTP). We also investigated the concentration of genes encoding resistance to aminoglycosides (aac(6’)-Ie+aph(2’’)), β-lactam antibiotics (mecA) and tetracyclines (tetA and tetB) in three wastewater-associated environments: (1) soil from an overland flow area treating landfill leachates, (2) biofilm from a municipal wastewater treatment plant, and (3) sludge from a hospital wastewater pipeline. In addition, concentrations of mecA, tetA and tetB were investigated over the treatment process in the WWTP. These investigations were performed to determine how the prevalence and concentration of MRSA and the antibiotic resistence genes are affected in wastewater and wastewater treatment processes over time. The occurrence of MRSA was investigated by cultivation and a commercially available real-time PCR assay. In order to determine concentrations of the genes aac(6’)-Ie+aph(2’’), mecA, tetA and tetB in wastewater we developed a LUXTM real-time PCR assay for each gene.

     

    Using cultivation and real-time PCR we could for the first time describe the occurrence of MRSA in wastewater and show that it had a stable occurrence over time in a WWTP. MRSA could mainly be detected in the early treatment steps in the WWTP, and the wastewater treatment process reduced the number and diversity of cultivated MRSA. However, our results also indicate that the treatment process selects for strains with more extensive resistance and possibly higher virulence. The isolated wastewater MRSA strains were shown to have a close genetic relationship to clinical isolates, and no specific wastewater lineages could be detected, indicating that they are a reflection of carriage in the community. Taken together, these data indicate that wastewater may be a potential reservoir for MRSA and that MRSA are more prevalent in wastewater than was previously thought.

     

    The real-time PCR assays, for aac(6’)-Ie+aph(2’’), mecA, tetA, and tetB that we developed, were shown to be sensitive, fast, and reproducible methods for detection and quantification of these genes in wastewater environments. The highest concentrations of all genes were observed in the hospital pipeline, and the lowest in the overland flow system, with tetA and aac(6´)-Ie+aph(2´´) detected in all three environments. In the full-scale WWTP, we continuously detected mecA, tetA and tetB over the treatment process and over time. In addition, it was shown that the treatment process reduces concentrations of all three genes. The data presented in this thesis also indicate that the reduction for all three genes may be connected to the removal of biomass, and in the reduction of tetA and tetB, sedimentation and precipitation appear to play an important role.

    List of papers
    1. Quantification of genes encoding resistance to aminoglycosides, β-lactams and tetracyclines in wastewater environments by real-time PCR
    Open this publication in new window or tab >>Quantification of genes encoding resistance to aminoglycosides, β-lactams and tetracyclines in wastewater environments by real-time PCR
    Show others...
    2009 (English)In: International Journal of Environmental Health Research, ISSN 0960-3123, E-ISSN 1369-1619, p. 1-12Article in journal (Refereed) Published
    Abstract [en]

    In this study real-time PCR assays, based on the LUX-technique, were developed for quantification of genes mediating resistance to aminoglycosides [aac(6 ')-Ie + aph(2 ' ')], beta-lactams (mecA), and tetracyclines (tetA and tetB), for use in wastewater environments. The developed assays were applied on DNA extracted from three wastewater-associated environments: soil from an overland flow area treating landfill leachates, biofilm from a municipal wastewater treatment plant, and sludge from a hospital wastewater pipeline. The highest concentration of all genes was observed in the hospital pipeline and the lowest in the overland flow system. TetA and aac(6 ')-Ie + aph(2 ' ') could be detected in all environments. The tetB gene was detected in the overland flow area and the hospital wastewater pipeline and mecA was detected in the wastewater treatment plant and the hospital pipeline. The developed LUX real-time PCR assays were shown to be fast and reproducible tools for detection and quantification of the four genes encoding antibiotic resistance in wastewater.

    Place, publisher, year, edition, pages
    Taylor & Francis, 2009
    Keywords
    Water pollutants; sewage pollution; water quality; aac(6')-Ie + aph(2''); mecA; tetA; tetB; LUX™ real-time PCR
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-18293 (URN)10.1080/09603120802449593 (DOI)19370439 (PubMedID)
    Available from: 2009-05-15 Created: 2009-05-15 Last updated: 2017-12-13Bibliographically approved
    2. A seasonal study of the mecA gene and Staphylococcus aureus including methicillin-resistant S. aureus in a municipal wastewater treatment plant
    Open this publication in new window or tab >>A seasonal study of the mecA gene and Staphylococcus aureus including methicillin-resistant S. aureus in a municipal wastewater treatment plant
    2009 (English)In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 43, no 4, p. 925-932Article in journal (Refereed) Published
    Abstract [en]

    The spread of methicillin-resistant Staphylococcus aureus (MRSA), in which the mecA gene mediates resistance, threatens the treatment of staphylococcal diseases. The aims were to determine the effect of wastewater treatment processes on mecA gene concentrations, and the prevalence of S. aureus and MRSA over time. To achieve this a municipal wastewater treatment plant was investigated for the mecA gene, S. aureus and MRSA, using real-time PCR assays. Water samples were collected monthly for one year, at eight sites in the plant, reflecting different aspects of the treatment process. The mecA gene and S. aureus could be detected throughout the year at all sampling sites. MRSA could also be detected, but mainly in the early treatment steps. The presence of MRSA was verified through cultivation from inlet water. The concentration of the mecA gene varied between months and sampling sites, but no obvious seasonal variation could be determined. The wastewater treatment process reduced the mecA gene concentration in most months. Taken together our results show that the mecA gene, S. aureus and MRSA occur over the year at all sites investigated.

    Keywords
    Methicillin-resistant, Staphylococcus aureus, mecA, LUX (TM) real-time PCR, spa Typing, Wastewater treatment plant, Seasonal study
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-17599 (URN)10.1016/j.watres.2008.11.036 (DOI)19084256 (PubMedID)
    Note
    Original Publication: Stefan Börjesson, Sara Melin, Andreas Matussek and Per-Eric Lindgren, A seasonal study of the mecA gene and Staphylococcus aureus including methicillin-resistant S. aureus in a municipal wastewater treatment plant, 2009, Water Research, (43), 4, 925-932. http://dx.doi.org/10.1016/j.watres.2008.11.036 Copyright: Elsevier Science B.V., Amsterdam. http://www.elsevier.com/ Available from: 2009-07-09 Created: 2009-04-06 Last updated: 2017-12-13Bibliographically approved
    3. Methicillin-resistant Staphylococcus aureus (MRSA) in municipal wastewater: An uncharted threat?
    Open this publication in new window or tab >>Methicillin-resistant Staphylococcus aureus (MRSA) in municipal wastewater: An uncharted threat?
    Show others...
    (English)Manuscript (Other academic)
    Abstract [en]

    Methicillin-resistant S. aureus (MRSA) was recently detected in municipal wastewater, why there is a need for further studies to elucidate if MRSA in wastewater constitutes a health risk, and to determine how wastewater treatment processes affects MRSA. We cultivated MRSA from a full-scale wastewater treatment plant to characterise the indigenous MRSA-flora and to investigate how the wastewater treatment process affects the clonal distribution. MRSA isolates were characterised using spa typing, antibiograms, SSCmec typing and detection of Panton Valentine leukocidin (PVL) genes. We found that the wastewater MRSA-flora has a close genetic relationship to clinical isolates, but we also isolated novel spa types, primarily from the activated sludge treatment step. The number of isolates and the diversity of MRSA are reduced by the treatment process, but the process also selects for more extensive antibiotic resistant strains as well as for PVL positive strains.

    Keywords
    Staphylococcus aureus, MRSA, methicillin, β-lactam, SCCmec, spa typing, Panton Valentine leukocidin, PVL, antibiotic resistance, antibiogram
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-18295 (URN)
    Available from: 2009-05-15 Created: 2009-05-15 Last updated: 2010-01-14Bibliographically approved
    4. Genes encoding tetracycline resistance in a full-scale municipal wastewater treatment plant investigated during one year
    Open this publication in new window or tab >>Genes encoding tetracycline resistance in a full-scale municipal wastewater treatment plant investigated during one year
    (English)Manuscript (Other academic)
    Abstract [en]

    Tetracycline-resistant bacteria and genes encoding tetracycline resistance are common in anthropogenic environments. We studied how wastewater treatment affects the prevalence and concentration of two genes that encode resistance to tetracycline: tetA and tetB. Using real-time PCR we analysed wastewater samples collected monthly for one year at eight key-sites in a full-scale municipal wastewater treatment plant (WWTP). We detected tetA and tetB at each sampling site and the concentration of both genes, expressed per wastewater volume or per total-DNA, decreased over the treatment process. The reduction of tetA and tetB was partly the result of the sedimentation process. The ratio of tetA and tetB, respectively, to total DNA was lower in or after the biological processes. Taken together our data show that tetracycline resistance genes occur throughout the WWTP and that the concentrations are reduced under conventional operational strategies. However, it is not possible to conclude the eventual risk for humans with respect to resistance spreading.

    Keywords
    tetA, tetB, tetracycline, LUXTM real-time PCR, wastewater treatment plant
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-18296 (URN)
    Available from: 2009-05-15 Created: 2009-05-15 Last updated: 2010-01-14Bibliographically approved
  • 41.
    Börjesson, Stefan
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Dienues, Olaf
    Department of Clinical Microbiology, County Hospital Ryhov, Jönköping, Sweden.
    Jarnheimer, Per-Åke
    Department of Infectious Diseases, Kalmar County Hospital, Kalmar, Sweden.
    Olsen, Björn
    Department of Natural Science, University of Kalmar, Kalmar, Sweden/Department of Clinical Sciences, Uppsala University Hospital, Uppsala, Sweden.
    Matussek, Andreas
    Department of Clinical Microbiology, County Hospital Ryhov, Jönköping, Sweden/Unilabs, Capio, St Goumlran's Hospital, Stockholm, Sweden.
    Lindgren, Per-Eric
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Quantification of genes encoding resistance to aminoglycosides, β-lactams and tetracyclines in wastewater environments by real-time PCR2009In: International Journal of Environmental Health Research, ISSN 0960-3123, E-ISSN 1369-1619, p. 1-12Article in journal (Refereed)
    Abstract [en]