liu.seSök publikationer i DiVA
Ändra sökning
Avgränsa sökresultatet
12 1 - 50 av 70
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Abate, E.
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. University of Gondar, Ethiopia.
    Elias, D.
    University of Southern Denmark, Denmark.
    Getachew, A.
    University of Gondar, Ethiopia.
    Alemu, S.
    University of Gondar, Ethiopia.
    Diro, E.
    University of Gondar, Ethiopia.
    Britton, S.
    Karolinska Hospital, Sweden.
    Aseffa, A.
    Armauer Hansen Research Institute, Ethiopia.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Schön, Thomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Kalmar County Hospital, Sweden.
    Effects of albendazole on the clinical outcome and immunological responses in helminth co-infected tuberculosis patients: a double blind randomised clinical trial2015Ingår i: International Journal of Parasitology, ISSN 0020-7519, E-ISSN 1879-0135, Vol. 45, nr 2-3, s. 133-140Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Despite several review papers and experimental studies concerning the impact of chronic helminth infection on tuberculosis in recent years, there is a scarcity of data from clinical field studies in highly endemic areas for these diseases. We believe this is the first randomised clinical trial investigating the impact of albendazole treatment on the clinical and immunological outcomes of helminth co-infected tuberculosis patients. A randomised, double-blind, placebo-controlled trial of albendazole (400 mg per day for 3 days) in helminth-positive tuberculosis patients was conducted in Gondar, Ethiopia. The primary outcome was clinical improvement (Delta TB score) after 2 months. Among secondary outcomes were changes in the levels of eosinophils, CD4+ T cells, regulatory T cells, IFN-gamma, IL-5 and IL-10 after 3 months. A total of 140 helminth co-infected tuberculosis patients were included with an HIV co-infection rate of 22.8%. There was no significant effect on the primary outcome (Delta TB score: 5.6 +/- 2.9 for albendazole versus 5.9 +/- 2.5 for placebo, P = 0.59). The albendazole-treated group showed a decline in eosinophil cells (P = 0.001) and IL-10 (P = 0.017) after 3 months. In an exploratory analysis after 12 weeks, the albendazole treated group showed a trend towards weight gain compared with the placebo group (11.2 +/- 8.5 kg versus 8.2 +/- 8.7 kg, P = 0.08)). The reductions in eosinophil counts and IL-10 show that asymptomatic helminth infection significantly affects host immunity during tuberculosis and can be effectively reversed by albendazole treatment. The clinical effects of helminth infection on chronic infectious diseases such as tuberculosis merit further characterisation. (C) 2014 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  • 2.
    Abate, Ebba
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Belayneh, Meseret
    University of Addis Ababa, Ethiopia .
    Gelaw, Aschalew
    University of Gondar, Ethiopia .
    Idh, Jonna
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    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
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Schön, Thomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    The Impact of Asymptomatic Helminth Co-Infection in Patients with Newly Diagnosed Tuberculosis in North-West Ethiopia2012Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, nr 8Artikel i tidskrift (Refereegranskat)
    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.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. University of Gondar, Ethiopia.
    Belayneh, Meseret
    University of Addis Ababa, Ethiopia.
    Idh, Jonna
    Vastervik Hospital, Sweden.
    Diro, Ermias
    University of Gondar, Ethiopia.
    Elias, Daniel
    University of Southern Denmark, Denmark.
    Britton, Sven
    Karolinska Hospital, Sweden.
    Aseffa, Abraham
    Armauer Hansen Research Institute, Ethiopia.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Schön, Thomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. Kalmar County Hospital, Sweden.
    Asymptomatic Helminth Infection in Active Tuberculosis Is Associated with Increased Regulatory and Th-2 Responses and a Lower Sputum Smear Positivity2015Ingår i: PLoS Neglected Tropical Diseases, ISSN 1935-2727, E-ISSN 1935-2735, Vol. 9, nr 8, artikel-id e0003994Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background The impact of intestinal helminth infection on the clinical presentation and immune response during active tuberculosis (TB) infection is not well characterized. Our aim was to investigate whether asymptomatic intestinal helminth infection alters the clinical signs and symptoms as well as the cell mediated immune responses in patients with active TB.

    Methodology Consecutive, newly diagnosed TB patients and healthy community controls (CCs) were recruited in North-west Ethiopia. TB-score, body mass index and stool samples were analyzed. Cells from HIV-negative TB patients (HIV-/TB) and from CCs were analyzed for regulatory T-cells (Tregs) and cytokine responses using flow cytometry and ELISPOT, respectively.

    Results A significantly higher ratio of helminth co-infection was observed in TB patients without HIV (Helm+/HIV-/TB) compared to HIV negative CCs, (40% (121/306) versus 28% (85/306), p = 0.003). Helm+/HIV-/TB patients showed significantly increased IL-5 secreting cells compared to Helm-/HIV-/TB (37 SFU (IQR:13-103) versus 2 SFU (1-50); p = 0.02, n = 30). Likewise, levels of absolute Tregs (9.4 (3.2-16.7) cells/mu l versus 2.4 (1.1-4.0) cells/mu l; p = 0.041) and IL-10 secreting cells (65 SFU (7-196) versus 1 SFU (0-31); p = 0.014) were significantly higher in Helm+/HIV-/TB patients compared to Helm-/HIV-/TB patients. In a multivariate analysis, a lower rate of sputum smear positivity for acid fast bacilli, lower body temperature, and eosinophilia were independently associated with helminth infection in TB patients.

    Conclusions Asymptomatic helminth infection is associated with increased regulatory T-cell and Th2-type responses and a lower rate of sputum smear positivity. Further studies are warranted to investigate the clinical and immunological impact of helminth infection in TB patients.

  • 4.
    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
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Schön, Thomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Effects of albendazole treatment on the clinical outcome and immunological responses in patients with helminth infection and pulmonary tuberculosis: a randomized clinical trial2013Manuskript (preprint) (Övrigt vetenskapligt)
    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.

  • 5.
    Abate, Ebba
    et al.
    Gondar College of Medical and Health Sciences, Gondar University, Gondar, Ethiopia; Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
    Idh, Jonna
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    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
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Schön, Thomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Impact of helminth infection on the clinical presentation 1 of pulmonary tuberculosis2013Manuskript (preprint) (Övrigt vetenskapligt)
    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.

  • 6.
    Abdalla, Hana
    et al.
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Diab, Asim
    Department of Neurology, University of Texas Southwestern Medical Center, Dallas, USA.
    Forslund, Tony
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Bakhiet, Moiz
    Department of Medicine, Divisions of lnfectious Diseases, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden.
    Stendahl, Olle
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Sundqvist, Tommy
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Expression of inducible nitric oxide synthases and nitrotyrosine during the course of Haemophilus influenzae type b meningitis in ratManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Bacterial meningitis continues to be a major health problem and despite great advances in antimicrobial therapy the fatality rate remains high. There is increasing evidence that leukocyte-endothelial interactions are involved in CNS damage during bacterial meningitis. Once leukocytes have entered the CSF they cause injury by releasing toxic molecules such as nitric oxide (NO) and reactive oxygen species (ROS). The induction of iNOS was examined by assessing intracerebral mRNA expression and protein production during the course of Haemophilus influenzae type b (Hib) meningitis in the rat. Induction of iNOS mRNA was detected 12h postinoculation (pi), followed by a gradual reduction. The increased number of intracerebral iN OS expressing cells was detected at 12h pi. followed by further elevation to peak expression at 72h pi. The iNOS positive tissue also bound antibodies specific for nitrotyrosine. The expression of iNOS and NO production, as shown by nitrotyrosine expression, correlated with disease severity, suggesting that activation of iNOS may play an important role in Haemophilus irifluenzae type b meningitis.

  • 7.
    Abdalla, Hana
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Forslund, Tony
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Schön, Thomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Sundqvist, Tommy
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Effects of CNI-1493 on human granulocyte functions2006Ingår i: Immunobiology, ISSN 0171-2985, E-ISSN 1878-3279, Vol. 211, nr 3, s. 191-197Artikel i tidskrift (Refereegranskat)
    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.

  • 8.
    Andersson, Henrik
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Eklund, Daniel
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Ngoh, Eyler
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Persson, Alexander
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Andersson, Blanka
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Svensson, Kristoffer
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Blomgran, Robert
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Apoptotic neutrophils augment the inflammatory response to Mycobacterium tuberculosis infection in human macrophages2014Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, nr 7, s. e101514-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Macrophages in the lung are the primary cells being infected by Mycobacterium tuberculosis (Mtb) during tuberculosis. Innate immune cells such as macrophages and neutrophils are first recruited to the site of infection, and mount the early immune protection against this intracellular pathogen. Neutrophils are short-lived cells and removal of apoptotic cells by resident macrophages is a key event in the resolution of inflammation and tissue repair. Such anti-inflammatory activity is not compatible with effective immunity to intracellular pathogens. We therefore investigated how uptake of apoptotic neutrophils by Mtb-activated human monocyte-derived macrophages modulates their function. We show that Mtb infection exerts a potent pro-inflammatory activation of human macrophages with enhanced gene activation and release of several cytokines (TNF, IL-1ß, IL-6, IL-18 and IL-10). This response was augmented by apoptotic neutrophils. Macrophages containing both Mtb and apoptotic cells showed a stronger cytokine expression than non-infected cells. The enhanced macrophage response is linked to apoptotic neutrophil-driven activation of the NLRP3 inflammasome and subsequent IL-1β signalling. We also demonstrate that apoptotic neutrophils not only modulate the inflammatory response, but also enhance the capacity of infected macrophages to control intracellular growth of virulent Mtb. Taken together, these results suggest a novel role for apoptotic neutrophils in the modulation of the macrophage-dependent inflammatory response, which can contribute to the early control of Mtb infection.

  • 9.
    Andersson, Kerstin
    et al.
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Magnusson, Karl-Eric
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Majeed, Meytham
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Fällman, Maria
    Department of Cell and Molecular Biology, University of Umeå, Umeå, Sweden.
    Yersinia pseudotuberculosis-induced calcium signaling in neutrophils is blocked by the virulence effector YopH1999Ingår i: Infection and Immunity, ISSN 0019-9567, E-ISSN 1098-5522, Vol. 67, nr 5, s. 2567-2574Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Pathogenic species of the genus Yersinia evade the bactericidal functions of phagocytes. This evasion is mediated through their virulence effectors, Yops, which act within target cells. In this study we investigated the effect of Yersinia pseudotuberculosis on Ca 2+ signaling in polymorphonuclear neutrophils. The intracellular free calcium concentration in single adherent human neutrophils was monitored during bacterial infection and, in parallel, the encounter between the bacteria and cells was observed. When a plasmid-cured strain was used for infection, adherence of a single bacterium to the cellular surface induced a β 1 integrin-dependent transient increase in the intracellular concentration of free calcium. This was, however, not seen with Yop-expressing wild-type bacteria, which adhered to the cell surface without generating any Ca 2+ signal. Importantly, the overall Ca 2+ homeostasis was not affected by the wild-type strain; the Ca 2+ signal mediated by the G-protein-coupled formyl-methionyl-leucyl- phenylalanine receptor was still functioning. Hence, the blocking effect was restricted to certain receptors and their signaling pathways. The use of different Yop mutant strains revealed that the protein tyrosine phosphatase YopH was responsible for the inhibition. This virulence determinant has previously been implicated in very rapid Yersinia-mediated effects on target cells as the key effector in the blockage of phagocytic uptake. The present finding, that Y. pseudotuberculosis, via YopH, specifically inhibits a self- induced immediate-early Ca 2+ signal in neutrophils, offers more-detailed information concerning the effectiveness of this virulence effector and implies an effect on Ca 2+-dependent, downstream signals.

  • 10.
    Augustinsson (Nilsdotter-Augustinsson), Åsa
    et al.
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Infektionsmedicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Medicincentrum, Infektionskliniken i Östergötland.
    Frydén, Anders
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Lindgren, Per-Eric
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Öhman, Lena
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Infektionsmedicin. Linköpings universitet, Hälsouniversitetet.
    Interaction of staphylococcus epidermidis from infected hip prostheses with neutrophil granulocytes2001Ingår i: Scandinavian Journal of Infectious Diseases, ISSN 0036-5548, E-ISSN 1651-1980, Vol. 33, nr 6, s. 408-412Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study focuses on the interaction of Staphylococcus epidermis isolated from granulation tissue covering infected hip prostheses and neutrophil granulocytes. Bacterial strains isolated from normal flora were used as controls. The bacteria were well characterized with routine methods and further characterized with random amplified polymorphic DNA analyses and slime tests. Phagocytosis and chemiluminescence (CL) assays were used in the neutrophil interaction studies. The prostheses strains were ingested to a lesser extent than strains from normal flora (p ≤ 0.001). There was no significant difference between the prostheses strains and the normal flora strains in terms of total CL response. However, the extracellular CL response from the neutrophils was lower in comparison with the normal flora when interacting with the prostheses strains. The results of this study support the notion that S. epidermidis strains isolated from infected hip prostheses have an enhanced capacity to resist phagocytosis and that most of these strains elicit a reduced inflammatory response, measured as the production of extracellular oxidative metabolites from the neutrophils, compared to normal flora.

  • 11. Bengtsson, T.
    et al.
    Jaconi, ME
    Gustafsson, Mikael
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Kardiologiska kliniken US.
    Magnusson, Karl-Eric
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Theler, JM
    Lew, DP
    Stendahl, Olle
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Actin dynamics in human neutrophils during adhesion and phagocytosis is controlled by changes in intracellular free calcium1993Ingår i: European Journal of Cell Biology, ISSN 0171-9335, E-ISSN 1618-1298, Vol. 62, nr 1, s. 19-58Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The role of changes in cytosolic free calcium concentration ([Ca2+]i) in the assembly and disassembly of actin during adhesion and phagocytosis was evaluated. Rhodamine-phalloidin staining combined with quantitative fluorescence and confocal laser scanning microscopy was used to measure local F-actin changes in single adherent human neutrophils phagocytosing yeast particles on different surfaces and under different calcium conditions. Cells were suspended in a) calcium-containing medium (CCM) or b) calcium-free medium (CFM) or c) were first depleted of calcium (i.e., MAPT/AM-loaded in CFM) and then suspended in CFM (MAPT). In parallel, local [Ca2+]i changes were monitored using a fura-2 ratio imaging system. In CCM or CFM, attachment to the substrate and formation of pseudopods around a yeast particle generated, within a few seconds, rises in [Ca2+]i, both around the phagosome and in the cell body. During continued phagocytosis, [Ca2+]i was more elevated around the phagosome compared to the rest of the cell. No [Ca2+]i fluctuations were observed in MAPT cells. Adhesion and phagocytosis led to a several-fold increase in F-actin. The increase was transient in cells in CCM and CFM, but remained high in Ca-depleted neutrophils. A distinct ring of F-actin was formed around a phagosome with a yeast particle. Twenty min after ingestion the amount of this actin decreased more than 50% in CCM and CFM cells but increased by 40 to 100% in MAPT cells. The accumulation of F-actin in MAPT cells was reduced to resting levels by adding Ca2+ and ionomycin after ingestion. This treatment reestablished the periphagosomal [Ca2+]i rises, as observed in CCM cells. In conclusion, the present study shows that the actin polymerization, occurring in human neutrophils during adhesion and phagocytosis, is not influenced by changes in [Ca2+]i, whereas the subsequent depolymerization is. The accumulation of actin filaments around the phagosome in calcium-depleted cells could be involved in the inhibition of phagolysosome fusion seen in the absence of [Ca2+]i changes (Jaconi et al., J. Cell Biol. 110, 1555-1564 (1990)). This suggests that the actin network, controlled by [Ca2+]i, regulates the movement of granules during phagocytosis.

  • 12.
    Blomgran, Robert
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Brodin Patcha, Veronika
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Verma, Deepti
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Cellbiologi. Linköpings universitet, Hälsouniversitetet.
    Bergström, Ida
    Linköpings universitet, Institutionen för medicin och hälsa, Kardiologi. Linköpings universitet, Hälsouniversitetet.
    Söderkvist, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Cellbiologi. Linköpings universitet, Hälsouniversitetet.
    Sjöwall, Christoffer
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Reumatologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Reumatologiska kliniken i Östergötland.
    Eriksson, Per
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Reumatologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Njurmedicinska kliniken US.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Sarndahl, Eva
    University of Örebro.
    Common Genetic Variations in the NALP3 Inflammasome Are Associated with Delayed Apoptosis of Human Neutrophils2012Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, nr 3Artikel i tidskrift (Refereegranskat)
    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.

  • 13.
    Blomgran, Robert
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Zheng, Limin
    State Key Laboratory of Biocontrol, College of Life Sciences, Sun Yatsen (Zhongshan) University, Guangzhou, China.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Cathepsin-cleaved Bid promotes apoptosis in human neutrophils via oxidative stress-induced lysosomal membrane permeabilization2007Ingår i: Journal of Leukocyte Biology, ISSN 0741-5400, E-ISSN 1938-3673, Vol. 81, s. 1213-1223Artikel i tidskrift (Refereegranskat)
    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.

  • 14.
    Blomgran, Robert
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Zheng, Limin
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Uropathogenic Escherichia coli triggers oxygen-dependent apoptosis in human neutrophils through the cooperative effect of type 1 fimbriae and lipopolysaccharide2004Ingår i: Infection and Immunity, ISSN 0019-9567, Vol. 72, nr 8, s. 4570-4578Artikel i tidskrift (Refereegranskat)
    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.

  • 15.
    Braian, Clara
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Hogea, Valentin
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Mycobacterium tuberculosis-Induced Neutrophil Extracellular Traps Activate Human Macrophages2013Ingår i: Journal of Innate Immunity, ISSN 1662-811X, E-ISSN 1662-8128, Vol. 5, nr 6, s. 591-602Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Neutrophils activated by Mycobacterium tuberculosis (Mtb) form neutrophil extracellular traps (NETs), containing DNA and several biologically active cytosolic and granular proteins. These NETs may assist in the innate immune defense against different pathogens. We investigated whether the NET-forming neutrophils mediate an activating signal to macrophages during the early multicellular inflammatory reaction and granuloma formation. Mtb-induced NETs were found to be reactive oxygen species dependent and phagocytosis dependent. A neutrophil elastase inhibitor also delayed NET formation. However, NET formation occurred independently of Mtb-induced apoptosis. We observed close interactions between macrophages and Mtb-activated neutrophils, where macrophages bound and phagocytosed NETs. Significant secretion of the cytokines interleukin (IL)-6, tumor necrosis factor-alpha, IL-1 beta and IL-10 were detected from macrophages cocultured with NETs from Mtb-activated but not phorbol myristate acetate-activated neutrophils. NETs binding heat shock protein 72 (Hsp72) or recombinant Hsp72 were able to trigger cytokine release from macrophages. Only Mtb-induced NETs contained Hsp72, suggesting that these NETs can transfer this danger signal to adjacent macrophages. We propose that Hsp72 sequestered in NETs plays an important role in the interaction between neutrophils and macrophages during the early innate immune phase of an Mtb infection. The immunomodulatory role of NETs and proteins derived from them may influence not only chronic inflammation during tuberculosis but also immune regulation and autoimmunity.

  • 16.
    Eklund, Daniel
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Persson, Hans Lennart
    Linköpings universitet, Institutionen för medicin och hälsa, Lungmedicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Lungmedicinska kliniken US.
    Larsson, Marie C.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Welin, Amanda
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Idh, Jonna
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Paues, Jakob
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Infektionsmedicin. Linköpings universitet, Hälsouniversitetet.
    Fransson, Sven-Göran
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Schön, Thomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Vitamin D enhances IL-1β secretion and restricts growth of Mycobacterium tuberculosis in macrophages from TB patients2013Ingår i: International Journal of Mycobacteriology, ISSN 2212-5531, Vol. 2, nr 1, s. 18-25Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The emergence of multidrug-resistant strains of Mycobacterium tuberculosis (MTB), the bacterium responsible for tuberculosis (TB), has rekindled the interest in the role of nutritional supplementation of micronutrients, such as vitamin D, as adjuvant treatment. Here, the growth of virulent MTB in macrophages obtained from the peripheral blood of patients with and without TB was studied. The H37Rv strain genetically modified to express Vibrio harveyi luciferase was used to determine the growth of MTB by luminometry in the human monocyte-derived macrophages (hMDMs) from study subjects. Determination of cytokine levels in culture supernatants was performed using a flow cytometry-based bead array technique. No differences in intracellular growth of MTB were observed between the different study groups. However, stimulation with 100 nM 1,25-dihydroxyvitamin D significantly enhanced the capacity of hMDMs isolated from TB patients to control the infection. This effect was not observed in hMDMs from the other groups. The interleukin (IL)-1β and IL-10 release by hMDMs was clearly increased upon stimulation with 1,25-dihydroxyvitamin D. Furthermore, the 1,25-dihydroxyvitamin D stimulation also led to elevated levels of TNF-α (tumor necrosis factor-alpha) and IL-12p40. It was concluded that vitamin D triggers an inflammatory response in human macrophages with enhanced secretion of cytokines, as well as enhancing the capacity of hMDMs from patients with active TB to restrict mycobacterial growth.

  • 17.
    Eklund, Daniel
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Welin, Amanda
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Andersson, Henrik
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Verma, Deepti
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för inflammationsmedicin. Linköpings universitet, Hälsouniversitetet.
    Söderkvist, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för cellbiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk patologi och klinisk genetik.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Särndahl, Eva
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för cellbiologi. Linköpings universitet, Hälsouniversitetet.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Human gene variants linked to enhanced NLRP3 activity limit intramacrophage growth of Mycobacterium tuberculosis2014Ingår i: The Journal of infectious diseases, ISSN 1537-6613, Vol. 209, nr 5, s. 749-753Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Activation of the NLRP3 inflammasome and subsequent generation of IL-1β is initiated in macrophages upon recognition of several stimuli. In the present work, we show that gain-of-function gene variants of inflammasome components known to predispose individuals to inflammatory disorders have a host-protective role during infection with Mycobacterium tuberculosis. By isolation of macrophages from patients and healthy blood donors with genetic variants in NLRP3 and CARD8 and subsequently infecting the cells by virulent M. tuberculosis, we show that these gene variants, combined, are associated with increased control of bacterial growth in human macrophages.

  • 18.
    Eklund, Daniel
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Welin, Amanda
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Schon, Thomas
    Kalmar County Hospital.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Huygen, Kris
    Science Institute for Public Health, Belgium .
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Validation of a Medium-Throughput Method for Evaluation of Intracellular Growth of Mycobacterium tuberculosis2010Ingår i: Clinical and Vaccine Immunology, ISSN 1556-6811, E-ISSN 1556-679X, Vol. 17, nr 4, s. 513-517Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Intracellular pathogens such as Mycobacterium tuberculosis have adapted to a life inside host cells, in which they utilize host nutrients to replicate and spread. Ineffective methods for the evaluation of growth of intracellular pathogens in their true environment pose an obstacle for basic research and drug screening. Here we present the validation of a luminometry-based method for the analysis of intramacrophage growth of M. tuberculosis. The method, which is performed in a medium-throughput format, can easily be adapted for studies of other intracellular pathogens and cell types. The use of host cells in drug-screening assays dedicated to find antimicrobials effective against intracellular pathogens permits the discovery of not only novel antibiotics but also compounds with immunomodulatory and virulence-impairing activities, which may be future alternatives or complements to antibiotics.

  • 19.
    Favre, Cécile J.
    et al.
    Division of Infectious Diseases, University Hospital, Geneva, Switzerland.
    Jerström, Petra
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Foti, Michelangelo
    Division of Infectious Diseases, University Hospital, Geneva, Switzerland.
    Stendahl, Olle
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Huggler, Elzbieta
    Division of Infectious Diseases, University Hospital, Geneva, Switzerland.
    Lew, Daniel P.
    Division of Infectious Diseases, University Hospital, Geneva, Switzerland.
    Krause, Karl-Heinz
    Division of Infectious Diseases, University Hospital, Geneva, Switzerland.
    Organization of Ca2+ stores in myeloid cells: association of SERCA2b and the type-1 inositol-1,4,5-trisphosphate receptor1996Ingår i: Biochemical Journal, ISSN 0264-6021, E-ISSN 1470-8728, Vol. 316, nr 1, s. 137-142Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, we have analysed the relationship between Ca2+ pumps and Ins(1,4,5)P3-sensitive Ca2+ channels in myeloid cells. To study whether sarcoplasmic/endoplasmic reticulum Ca2+-ATPase (SERCA)-type Ca2+-ATPases are responsible for Ca2+ uptake into Ins(1,4,5)P3-sensitive Ca2+ stores, we used the three structurally unrelated inhibitors thapsigargin, 2,5-di-t-butylhydroquinone and cyclopiazonic acid. In HL-60 cells, all three compounds precluded formation of the phosphorylated intermediate of SERCA-type Ca2+-ATPases. They also decreased, in parallel, ATP-dependent Ca2+ accumulation and the amount of Ins(1,4,5)P3-releasable Ca2+. Immunoblotting with subtype-directed antibodies demonstrated that HL-60 cells contain the Ca2+ pump SERCA2 (subtype b), and the Ca2+-release-channel type-1 Ins(1,4,5)P3 receptor. In subcellular fractionation studies, SERCA2 and type-1 Ins(1,4,5)P3 receptor co-purified. Immunofluorescence studies demonstrated that both type-1 Ins(1,4,5)P3 receptor and SERCA2 were evenly distributed throughout the cell in moving neutrophils. During phagocytosis both proteins translocated to the periphagosomal space. Taken together, our results suggest that in myeloid cells (i) SERCA-type Ca2+-ATPases function as Ca2+ pumps of Ins(1,4,5)P3-sensitive Ca2+ stores, and (ii) SERCA2 and type-1 Ins(1,4,5)P3 receptor reside either in the same or two tightly associated subcellular compartments.

  • 20.
    Forsberg, Maria
    et al.
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Blomgran, Robert
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Lem, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Särndahl, Eva
    Linköpings universitet, Institutionen för biomedicin och kirurgi, Cellbiologi. Linköpings universitet, Hälsouniversitetet.
    Sebti, Said M.
    Drug Discovery Program, H. Lee Moffitt Cancer Center & Research Institute, Department of Oncology, University of South Florida, Tampa.
    Hamilton, Andrew
    Department of Chemistry, Yale University, New Haven, Connecticut .
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Zheng, Limin
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Differential effects of invasion by and phagocytosis of Salmonella typhimurium on apoptosis in human macrophages: potential role of Rho–GTPases and Akt2003Ingår i: Journal of Leukocyte Biology, ISSN 0741-5400, E-ISSN 1938-3673, Vol. 74, nr 4, s. 620-629Artikel i tidskrift (Refereegranskat)
    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.

  • 21.
    Forsberg, Maria
    et al.
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Druid, Pia
    Linköpings universitet, Institutionen för biomedicin och kirurgi, Cellbiologi. Linköpings universitet, Hälsouniversitetet.
    Zheng, Limin
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Särndahl, Eva
    Linköpings universitet, Institutionen för biomedicin och kirurgi, Cellbiologi. Linköpings universitet, Hälsouniversitetet.
    Activation of Rac2 and Cdc42 on Fc and complement receptor ligation in human neutrophils2003Ingår i: Journal of Leukocyte Biology, ISSN 0741-5400, E-ISSN 1938-3673, Vol. 74, nr 4, s. 611-619Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Phagocytosis is a complex process engaging a concerted action of signal-transduction cascades that leads to ingestion, subsequent phagolysosome fusion, and oxidative activation. We have previously shown that in human neutrophils, C3bi-mediated phagocytosis elicits a significant oxidative response, suggesting that activation of the small GTPase Rac is involved in this process. This is contradictory to macrophages, where only Fc receptor for immunoglobulin G (FcγR)-mediated activation is Rac-dependent. The present study shows that engagement of the complement receptor 3 (CR3) and FcγR and CR3- and FcγR-mediated phagocytosis activates Rac, as well as Cdc42. Furthermore, following receptor-engagement of the CR3 or FcγRs, a downstream target of these small GTPases, p21-activated kinase, becomes phosphorylated, and Rac2 is translocated to the membrane fraction. Using the methyltransferase inhibitors N-acetyl-S-farnesyl-L-cysteine and N-acetyl-S-geranylgeranyl-L-cysteine, we found that the phagocytic uptake of bacteria was not Rac2- or Cdc42-dependent, whereas the oxidative activation was decreased. In conclusion, our results indicate that in neutrophils, Rac2 and Cdc42 are involved in FcR- and CR3-induced activation and for properly functioning signal transduction involved in the generation of oxygen radicals.

  • 22.
    Forsberg, Maria
    et al.
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Löfgren, Ragnhild
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Zheng, Limin
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Tumour necrosis factor-α potentiates CR3-induced respiratory burst by activating p38 MAP kinase in human neutrophils2001Ingår i: Immunology, ISSN 0019-2805, E-ISSN 1365-2567, Vol. 103, nr 4, s. 465-472Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    CR3 and FcγRs are the main receptors involved in the phagocytic process leading to engulfment and killing of microbes by production of reactive oxygen intermediates (ROI) and degranulation. Various inflammatory mediators, such as tumour necrosis factor-α (TNF-α) and lipopolysaccharide (LPS), are known to prime neutrophils leading to increased bactericidal responses, but the underlying mechanism of priming has only been partially elucidated. The purpose of this study was to investigate how TNF-α primes neutrophils for subsequent stimuli via either CR3 or FcγR. The receptors were specifically activated with pansorbins (protein-A-positive Staphylococcus aureus) coated with anti-CR3, anti-FcγRIIa, or anti-FcγRIIIb monoclonal antibody. Activation of neutrophils with these particles resulted in ROI production as measured by chemiluminescence. Anti-CR3 pansorbins induced the most prominent ROI production in neutrophils. TNF-α potentiated the CR3-mediated respiratory burst but had little effect on that mediated by FcγRs. The priming effect of TNF-α on CR3-mediated ROI production is associated with an increased activation of p38 MAPK as well as tyrosine phosphorylation of p72syk. Pretreatment of neutrophils with the inhibitors for p38 MAPK and p72syk markedly suppressed the respiratory burst induced by CR3. Furthermore, TNF-α induced about a three-fold increase in the expression of CR3 in neutrophils, an effect which is blocked by the p38 MAPK inhibitor. Taken together, these results showed that TNF-α potentiates the CR3-mediated respiratory burst in neutrophils not only by triggering a p38 MAPK-dependent up-regulation of CD11b/CD18 but also by modulating the signalling pathways.

  • 23.
    Hedlund, Sebastian
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Persson, Alexander
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Vujic, Ana
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Fru Che, Karlhans
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Molekylär virologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Larsson, Marie
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Molekylär virologi. Linköpings universitet, Hälsouniversitetet.
    Dendritic cell activation by sensing Mycobacterium tuberculosis-induced apoptotic neutrophils via DC-SIGN2010Ingår i: HUMAN IMMUNOLOGY, ISSN 0198-8859, Vol. 71, nr 6, s. 535-540Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mycobacterium tuberculosis (Mtb) manipulates cells of the innate immune system to provide the bacteria with a sustainable intracellular niche. Mtb spread through aerosol carrying them deep into the lungs, where they are internalized by phagocytic cells, such as neutrophils (PMNs), dendritic cells (DCs), and macrophages. PMNs undergo accelerated apoptosis after interaction with the bacterium, and apoptotic cells are sequestered by neighboring phagocytes. Removal of aged apoptotic cells because of natural tissue turnover is described as an immunologically silent process facilitating resolution of inflammation and inhibition of DC maturation. Silencing of immune cells could be favorable for intracellular bacteria. The aim of this study was to clarify the interaction between Mtb-induced apoptotic PMNs and DCs, and evaluate whether this interaction follows the proposed anti-inflammatory pathway. In contrast to aged apoptotic cells, Mtb-induced apoptotic PMNs induced functional DC maturation. We found that the cell fraction from Mtb-induced apoptotic PMNs contained almost all stimulatory capacity, suggesting that cell-cell interaction is crucial for DC activation. Inhibitory studies showed that this cell contact-dependent activation required binding of the PMN Mac-1 (CD11b/CD18) to the DC via DC-SIGN and endocytic activity involving the alpha(v)beta(5) but did not involve the scavenger receptor CD36. Taken together, this study demonstrates that the DCs can distinguish between normal and infected apoptotic PMNs via cellular crosstalk, where the DCs can sense the presence of danger on the Mtb-infected PMNs and modulate their response accordingly.

  • 24.
    Hedlund, Sebastian R.
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Persson, Alexander
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Vujic, Ana
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Larsson, Marie
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Molekylär virologi. Linköpings universitet, Hälsouniversitetet.
    Dendritic cell activation by sensing Mycobacterium tuberculosis-induced apoptotic neutrophils via DC-SIGNManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    In Mycobacterium tuberculosis (Mtb)-infected individuals cells of the innate immune system accumulate in the spleen and in granulomas, but how this relates to the protection against Mtb or in the pathogenesis is unknown. Mtb is internalized in the lung by phagocytic cells, such as neutrophils (PMNs), dendritic cells (DCs) and macrophages. PMNs undergo accelerated apoptosis after internalization of the bacterium and are subsequently sequestered by neighbouring phagocytes. Removal of aged apoptotic cells is an immunologically silent process and the aim of this study was to clarify the interaction between Mtb-induced apoptotic PMNs and DCs, and evaluate if this interaction induced functional maturation of the DCs. In fact, Mtb-induced apoptotic PMNs induced DC maturation, whereas exposure to spontaneous apoptotic PMNs had no effect on DCs maturation status. We found that the cell fraction contained almost all stimulatory capacity, suggesting that the cell-cell interaction is crucial for DC activation. Inhibitory studies showed that this cell contact-dependent activation required binding of the PMN Mac-1 (CD11b/CD18) to the DC via DC-SIGN and endocytic activity. Taken together, this study proves that the DCs can distinguish between normal and infected apoptotic PMNs via cellular cross talk, where the DCs can sense the presence of danger on the Mtb-infected PMNs and modulate their response accordingly.

  • 25.
    Idh, Jonna
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Abate, Ebba
    Gondar College of Medical and Health Sciences, Gondar University, Gondar, Ethiopia; Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
    Westman, Anna
    Department of Infectious Diseases, Karolinska Hospital, Stockholm, Sweden.
    Elias, Daniel
    Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
    Janols, Helena
    Department of Infectious Diseases, Malmö University Hospital, Malmö, Sweden.
    Gelaw, Aschalew
    Gondar College of Medical and Health Sciences, Gondar University, Gondar, Ethiopia.
    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.
    Aseffa, Abraham
    Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
    Britton, Sven
    Department of Infectious Diseases, Karolinska Hospital, Stockholm, Sweden.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Schön, Thomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    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 disease2010Ingår i: Scandinavian journal of infectious diseases, ISSN 1651-1980, Vol. 42, nr 9, s. 650-657Artikel i tidskrift (Refereegranskat)
    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.

  • 26.
    Idh, Jonna
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Raffetseder, Johanna
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Eklund, Daniel
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Larsson, Marie
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Pienaar, Elsje
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Forslund, Tony
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Werngren, Jim
    Department of Preparedness, Unit of Highly Pathogenic Microorganisms, Swedish Institute for Communicable Disease Control, Sweden.
    Juréen, Pontus
    Department of Preparedness, Swedish Institute for Communicable Disease Control, Sweden.
    Ängeby, Kristian
    Department of Clinical Microbiology, Karolinska Institute, Karolinska University Hospital, Sweden.
    Sundqvist, Tommy
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Schön, Thomas
    Department of Infectious Diseases and Clinical Microbiology, Kalmar County Hospital, Sweden.
    Susceptibility of Clinical Strains of Mycobacterium tuberculosis to Reactive Nitrogen Species in Activated MacrophagesManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Background: Nitric oxide (NO) is produced in macrophages by the inducible NO synthase (iNOS) upon activation by pro-inflammatory cytokines. NO has been shown to be essential for the control of Mycobacterium tuberculosis infection in murine models whereas its importance in man is not as clear. There is a lack of studies regarding the susceptibility to reactive nitrogen species (RNS) in clinical strains of M. tuberculosis and the relation to first-line drug resistance, such as to isoniazid (INH). The aim of this study was to explore susceptibility to RNS and intracellular survival of clinical strains of M. tuberculosis, with or without INH resistance.

    Method: Seven clinical strains of M. tuberculosis were transformed with the pSMT1-plasmid encoding Vibrio harveyi luciferase. Survival was analysed by luminometry following exposure to the NO donor DETA/NO or peroxynitrite (SIN-1). Intracellular killing was studied in murine macrophages (RAW 264.7) activated with interferon gamma (IFN-γ) and lipopolysaccharide (LPS).

    Results: There was a significant effect on growth control of M. tuberculosis strains upon macrophage activation, which showed variability among clinical isolates. In the cell-free system, all strains showed a dose-dependent susceptibility to DETA/NO and SIN-1, and clinical strains were in general more resistant than H37Rv to DETA/NO. INH-resistant strains with an inhA mutation were significantly more tolerant to DETA/NO than inhA wild type.

    Conclusion: Reactive nitrogen species inhibited growth of clinical M. tuberculosis isolates both in an intra- and extracellular model with significant difference between strains. Increased tolerance to NO was associated with isoniazid resistance mediated by inhA.

  • 27.
    Idh, Jonna
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Mekonnen, M.
    Department of Microbiology, Immunology and Parasitology, Addis Ababa University, Ethiopia.
    Abate, E.
    Armauer Hansen Research Institute, Ethiopia.
    Wedajo, W.
    Armauer Hansen Research Institute, Ethiopia.
    Werngren, J.
    Department of Preparedness, Unit of Highly Pathogenic Microorganisms, Swedish Institute for Communicable Disease Control, Sweden.
    Ängeby, K.
    Clinical Microbiology, MTC, Karolinska Institute, Karolinska University Hospital, Sweden.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Elias, D.
    University of Southern Denmark, Institute of Molecular Medicine, Department of Cancer and Inflammation, Denmark.
    Sundqvist, Tommy
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Aseffa, A.
    Armauer Hansen Research Institute, Ethiopia.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Schön, T.
    Department of Infectious Diseases and Department of Clinical Microbiology, Kalmar County Hospital, Sweden.
    Resistance to First-Line Anti-TB Drugs is Associated with Reduced Nitric Oxide Susceptibility in Mycobacterium tuberculosis2012Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, nr 1, s. e39891-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background and objective: The relative contribution of nitric oxide (NO) to the killing of Mycobacterium tuberculosis in human tuberculosis (TB) is controversial, although this has been firmly established in rodents. Studies have demonstrated that clinical strains of M. tuberculosis differ in susceptibility to NO, but how this correlates to drug resistance and clinical outcome is not known.

    Methods: In this study, 50 sputum smear- and culture-positive patients with pulmonary TB in Gondar, Ethiopia were included. Clinical parameters were recorded and drug susceptibility profile and spoligotyping patterns were investigated. NO susceptibility was studied by exposing the strains to the NO donor DETA/NO.

    Results: Clinical isolates of M. tuberculosis showed a dose- and time-dependent response when exposed to NO. The most frequent spoligotypes found were CAS1-Delhi and T3_ETH in a total of nine known spoligotypes and four orphan patterns. There was a significant association between reduced susceptibility to NO (>10% survival after exposure to 1mM DETA/NO) and resistance against first-line anti-TB drugs, in particular isoniazid (INH). Patients infected with strains of M. tuberculosis with reduced susceptibility to NO showed no difference in cure rate or other clinical parameters, but a tendency towards lower rate of weight gain after two months of treatment.

    Conclusion: There is a correlation between resistance to first-line anti-TB drugs and reduced NO susceptibility in clinical strains of M. tuberculosis. Further studies including the mechanisms of reduced NO susceptibility are warranted and could identify targets for new therapeutic interventions.

  • 28.
    Idh, Jonna
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Westman, Anna
    Karolinska Hospital.
    Elias, Daniel
    Armauer Hansen Research Institute.
    Moges, Feleke
    Gondar University.
    Getachew, Assefa
    Gondar University.
    Gelaw, Aschalew
    Gondar University.
    Sundqvist, Tommy
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Forslund, Tony
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Alemu, Addis
    Gondar University.
    Ayele, Belete
    Gondar University.
    Diro, Ermias
    Gondar University.
    Melese, Endalkachew
    Gondar University.
    Wondmikun, Yared
    Gondar University.
    Britton, Sven
    Karolinska Hospital.
    Stendahl, Olle
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi.
    Schön, Thomas
    Kalmar City Hospital.
    Nitric oxide production in the exhaled air of patients with pulmonary tuberculosis in relation to HIV co-infection2008Ingår i: BMC Infectious Diseases, ISSN 1471-2334, E-ISSN 1471-2334, Vol. 8, nr 146Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Nitric oxide (NO) is essential for host defense in rodents, but the role of NO during tuberculosis (TB) in man remains controversial. However, earlier observations that arginine supplementation facilitates anti-TB treatment, supports the hypothesis that NO is important in the host defense against TB. Local production of NO measured in fractional exhaled air (FeNO) in TB patients with and without HIV co-infection has not been reported previously. Thus, our aim was to investigate levels of FeNO in relation to clinical symptoms and urinary NO metabolites (uNO).

    Methods: In a cross sectional study, FeNO and uNO were measured and clinical symptoms, chest x-ray, together with serum levels of arginine, tumor necrosis factor alpha (TNF-alpha) and interleukin 12 (IL-12) were evaluated in sputum smear positive TB patients (HIV+/TB, n = 36, HIV-/TB, n = 59), their household contacts (n = 17) and blood donors (n = 46) from Gondar University Hospital, Ethiopia.

    Results: The proportion of HIV-/TB patients with an increased FeNO level (> 25 ppb) was significantly higher as compared to HIV+/TB patients, but HIV+/TB patients had significantly higher uNO than HIV-/TB patients. HIV+ and HIV-/TB patients both had lower levels of FeNO compared to blood donors and household contacts. The highest levels of both uNO and FeNO were found in household contacts. Less advanced findings on chest x-ray, as well as higher sedimentation rate were observed in HIV+/TB patients as compared to HIV-/TB patients. However, no significant correlation was found between FeNO and uNO, chest x-ray grading, clinical symptoms, TNF-alpha, IL-12, arginine levels or sedimentation rate.

    Conclusion: In both HIV negative and HIV co infected TB patients, low levels of exhaled NO compared to blood donors and household were observed. Future studies are needed to confirm whether low levels of exhaled NO could be a risk factor in acquiring TB and the relative importance of NO in human TB.

  • 29.
    Janols, Helena
    et al.
    Department of Clinical Sciences, Section for Infectious Diseases, Skåne University Hospital, Lund University, Malmö, Sweden.
    Abate, Ebba
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi.
    Idh, Jonna
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi.
    Senbeto, Meseret
    Department of Medical Laboratory Sciences, University of Gondar, Ethiopia.
    Britton, Sven
    Department of Infectious Diseases, Karolinska Hospital, Stockholm, Sweden.
    Alemu, Shitaye
    Department of Internal Medicine, University of Gondar, Gondar, Ethiopia.
    Aseffa, Abraham
    Armauer Hansen Research Institute (AHRI), Addis Ababa, Ethiopia.
    Stendahl, Olle
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi.
    Schön, Thomas
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi.
    Early treatment response evaluated by a clinical scoring system correlates with the prognosis of pulmonary tuberculosis patients in Ethiopia: A prospective follow-up study.2012Ingår i: Scandinavian journal of infectious diseases, ISSN 1651-1980, Vol. 44, nr 11, s. 828-834Artikel i tidskrift (Refereegranskat)
    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.

  • 30.
    Jerström Skarman, Petra
    et al.
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Majeed, Meytham
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Ernst, Joel D.
    Department of Medicine, Division of Infectious Diseases, and The Rosalind Russell Arthritis Research Laboratory, University of California, San Francisco, USA.
    Carpentier, Jean-Louis
    Department of Morphology, University of Geneva, Switzerland.
    Stendahl, Olle
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Subcellular distribution of annexins, gelsolin and filamentous actin in adherent human neutrophils during phagocytosisManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Subcellular elevations of cytosolic free calcium concentration ([ea2+];), are critical for certain functional responses within the neutrophil, such asfilamentous actin (F-actin) reorganization and phagolysosome fusion (PLF). During this event, an accumulation of phospholipid- and calciumbinding proteins, annexins, can be seen in the periphagosomal area. A prerequisite for phagolysosome fusion is the elimination of F-actin around the phagosomes to facilitate the membrane contact between lysosomes and phagosomes. Gelsolin is a protein that severs F:actin by binding to the barbed ends, and thereby affect further polymerization. In this study, we used immunofluorescence staining and immunogold technique to analyse the distribution of annexin I, annexin III and gelsolin, in relation to the rearrangement ofF-actin during phagocytosos of complement-opsonized yeast particles by adherent human neutrophils. Iu unchallenged cells, both the aunexins and gelsolin were evenly distributed throughout the cells, whereas F-actin was found mostly in the protruding pseudopodia. Upon phagocytosis an accumulation of both. annexin I and annexin III, and gelsolin could be seen w1thm the vicimty of the phagocytic cups and phagosomes where they colocalized with Factin around the ingested particle.

    In calcium-depleted cells, the subcellular distributions of annexins and gelsolin were unaffected. On the other hand, there was a total increase inF-actin polymerization.

    Our data may indicate that gelsolin is important for the rearrangement of F-actin and that annexin I and annexin III, which are present in high concentrations in neutrophils, may participate in the following calciumdependent PLF in human neutrophils.

  • 31.
    Larsson, Jenny
    et al.
    Linköpings universitet, Institutionen för nervsystem och rörelseorgan, Patologi. Linköpings universitet, Hälsouniversitetet.
    Serrander, Lena
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Lundqvist-Gustafsson, Helen
    Linköpings universitet, Institutionen för nervsystem och rörelseorgan, Patologi. Linköpings universitet, Hälsouniversitetet.
    Involvement of the ß2-integrin CD18 in apoptosis signal transduction in human neutrophils2000Ingår i: Inflammation Research, ISSN 1023-3830, E-ISSN 1420-908X, Vol. 49, nr 9, s. 452-459Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objective and design: To examine the hypothesis that an accelerated rate of neutrophil apoptosis occurs following β2-integrin activation, and further investigate the signal transduction pathways involved.

    Material: Human polymorphonuclear neutrophils.

    Treatment: Neutrophils were challenged with pansorbins coated with antibodies towards the β2-integrin subunit CD18 in a proportion of 1:100 with or without the inhibitors diphenylene iodonium (10 M), cytochalasin B (5 μg/ml), genistein (10 nM), herbimycin A (10 M) and Z-VAD-FMK (10 μM).

    Methods: Measurement of phosphatidylserine exposure and DNA fragmentation in flow cytometry and assessment of H2O2-production through spectrofluorometry. The results were analysed using Mann Whitney U test and Kruskal Wallis.

    Results: Pansorbins coated with antibodies to CD18 induce apoptosis in neutrophils (p < 0.01), and activate the production of reactive oxygen species (p < 0.01). Pre-treatment with the inhibitors have no effect on anti-CD18 induced apoptosis.

    Conclusion: Anti-CD18 pansorbins induce apoptosis in neutrophils through an alternative pathway not involving reactive oxygen species and independent of tyrosine phosphorylation, cytoskeletal reorganisation and caspases.

  • 32.
    Lerm, Maria
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Brodin Patcha, Veronika
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Ruishalme, Iida
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Särndahl, Eva
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Cellbiologi. Linköpings universitet, Hälsouniversitetet.
    Inactivation of Cdc42 is nessecary for depolymerization of phagosomal F-actin and subsequent phagosomal maturation2007Ingår i: Journal of Immunology, ISSN 0022-1767, Vol. 178, nr 11, s. 7357-7365Artikel i tidskrift (Refereegranskat)
    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.

  • 33.
    Lindmark, Maria
    et al.
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Andersson, Christina
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Lundqvist-Gustafsson, Helen
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Rasmusson, Birgitta
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Lipophosphoglycan (LPG) from Leishmania donovani inhibits phagosomal maturation and oxygen redical production in human neutrophilsManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Lipophosphoglycan (LPG) is the major surface glycoconjugate on Leishmania donovani promastigotes. LPG inhibits phagosome maturation and is crucial for parasite survival in macrophages. Fusion of vesicles with the phagosome is essential for the formation of a mature phagolysosorne and depolymerization of periphagosomal F-actin is likely a prerequisite for vesicle fusion. In macrophages LPG induces an accumulation of periphagosomal F-actin which is correlated to inhibition of vesicle fusion to the phagosome. In this work we investigated the effects of LPG on phagosome maturation in human neutrophils. We found that ingestion of serum-opsonised, LPG-coated yeast particles induced increased levels of periphagosomal Factin in neutrophils. Phagosome maturation was studied using antibodies to CD63 (azurophil granules), synaptotagmin II (specific granules) and LAMP-1 (specific granules, secretory vesicles, multivesicular bodies/multilaminar compartments). Results showed impaired translocation of all these three markers to phagosomes containing LPG-coated prey. The translocation of the early endosome marker Rab5A to the phagosome was not affected by LPG. The late endosomal marker Rab7 was not found in human neutrophils. Chemiluminescence studies revealed that serum-opsonised, LPG-coated yeast induced less production of reactive oxygen metabolites (ROM) compared to controls and that the production was mainly intracellular.

  • 34.
    Lindmark, Maria
    et al.
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Johansson, Carin
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Schiavo, Giampietro
    Molecular NeuroPathoBiology Laboratory, The Imperial Cancer Research Fund, London, UK.
    Rasmusson, Birgitta
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Complement- and IgG-mediated phagocytosis in human macrophages in calcium dependent and involves synoptotagmin IVManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Calcium regulates membrane fusion events during phagolysosome formation in neutrophil granulocytes and vesicle fusion at the neural synapse. Calcium is also required for uptake of IgG-opsonised particles by human neutrophils. The role of calcium during macrophage phagocytosis is less clear. Here we show that phagocytosis of IgG- or serum-opsonised prey is strictly calcium dependent in human monocyte-derived macrophages. We also show the presence and involvement of synaptotagmin II and IV in human macrophages and in the murine macrophage cell line J774. Synaptotagmin IV displayed a granular distribution in resting human macrophages with some translocation to the plasma membrane. Synaptotagrnin IV did not eo localise with the nucleus, the endoplasmic reticulum or the Golgi apparatus. During phagocytosis of IgG- or serum-opsonised prey we observed a distinct, transient translocation of synaptotagmin IV to the phagosome. The kinnetics of synaptotagmin IV translocation was similar to Rab5. LAMP-1, a marker of late endosomes and mature phagolysosomes fused with the phagosome at a later time point. Our results show that complement- and IgG-mediated phagocytosis are dependent on calcium in human macrophages and indicate a role for synaptotagmin IV in the calcium dependent fusion of the phagosome with components of the early endocytic pathway.

  • 35.
    Lindmark, Maria
    et al.
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Karlsson, Anna
    The Phagocyte Laboratory, Department of Medical Microbiology, Göteborg University, Göteborg, Sweden.
    Serrander, Lena
    Division of Infectious Diseases, University Hospital Geneva, Geneva, Switzerland.
    Francois, Patrice
    Division of Infectious Diseases, University Hospital Geneva, Geneva, Switzerland.
    Lew, Daniel
    Division of Infectious Diseases, University Hospital Geneva, Geneva, Switzerland.
    Rasmusson, Birgitta
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Nüße, Oliver
    Immunology Group, Faculty of Science, Univ. Nancy, Vandoeuvre, France.
    Synaptotagmin II could confer Ca2+ sensitivity to phagocytosis in human neutrophils2002Ingår i: Biochimica et Biophysica Acta. Molecular Cell Research, ISSN 0167-4889, E-ISSN 1879-2596, Vol. 1590, nr 1-3, s. 159-166Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Phagolysosome fusion and granule exocytosis in neutrophils are calcium-dependent processes. The calcium requirements vary between granule types, suggesting the presence of different calcium sensors. The synaptotagmins, a family of calcium-binding proteins, previously shown to participate in vesicle fusion and vesicle recycling in excitable cells, are putative calcium-sensors of exocytosis in excitable cells. In this study, we show that synaptotagmin II is present in human neutrophils and may participate in phagocytic and in exocytotic processes. In protein extracts from human neutrophils, we identified synaptotagmin II by Western blot as an 80 kDa protein. Subcellular fractionation revealed that synaptotagmin II was associated with the specific granules. In fMLP-stimulated cells, synaptotagmin II translocated to the plasma membrane. This correlated with the upregulation of complement receptor 3 (CR 3), reflecting the translocation of specific granules to the cell surface. Synaptotagmin II also translocated to the phagosome after complement-mediated phagocytosis in the presence of calcium. LAMP-1 translocated in parallel but probably was located to another subcellular compartment than synaptotagmin II. Under calcium-reduced conditions, neither synaptotagmin II nor LAMP-1 translocated to the phagosome. We therefore suggest a role for synaptotagmin II as calcium-sensor during phagocytosis and secretion in neutrophils.

  • 36.
    Löfgren, Ragnhild
    et al.
    Linköpings universitet, Institutionen för biomedicin och kirurgi, Cellbiologi. Linköpings universitet, Hälsouniversitetet.
    Serrander, Lena
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Forsberg, Maria
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Wilsson, Åsa
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Wasteson, Åke
    Linköpings universitet, Institutionen för biomedicin och kirurgi, Cellbiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    CR3, FcγRIIA and FcγRIIIB induce activation of the respiratory burst in human neutrophils: the role of intracellular Ca2+, phospholipase D and tyrosine phosphorylation1999Ingår i: Biochimica et Biophysica Acta. Molecular Cell Research, ISSN 0167-4889, E-ISSN 1879-2596, Vol. 1452, nr 1, s. 46-59Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Human neutrophils express two different types of phagocytic receptors, complement receptors (CR) and Fc receptors. In order to characterize the different signaling properties of each receptor we have used non-adherent human neutrophils and investigated CR3, FcγRIIA and FcγRIIIB for their signaling capacity. Selective activation of each receptor was achieved by coupling specific antibodies to heat-killed Staphylococcus aureus particles, Pansorbins, through their Fc moiety. Despite the fact that these particles are not phagocytosed, we show that addition of Pansorbins with anti-CD18 antibodies recognizing CR3 induced prominent signals leading to a respiratory burst. Stimulation with anti-FcγRIIIB Pansorbins induced about half of the response induced by anti-CR3 Pansorbins, whereas anti-FcγRIIA Pansorbins induced an even weaker signal. However, FcγRIIA induced strong phosphorylation of p72syk whereas FcγRIIIB induced only a very weak p72syk phosphorylation. During CR3 stimulation no tyrosine phosphorylation of p72syk was seen. Both phospholipase D and NADPH oxidase activities were dependent on intracellular calcium. This is in contrast to tyrosine phosphorylation of p72syk that occurred even in calcium-depleted cells, indicating that oxygen metabolism does not affect p72syk phosphorylation. Inhibitors of tyrosine phosphorylation blocked the respiratory burst induced by both FcγRIIA and FcγRIIIB as well as CR3. This shows that tyrosine phosphorylation of p72syk is an early signal in the cascade induced by FcγRIIA but not by CR3.

  • 37.
    Majeed, Meytham
    et al.
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Klinisk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Gustafsson, Mikael
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Kihlström, Erik
    Department of clinical microbiology, Örebro medical center hospital, Örebro, Sweden.
    Stendahl, Olle
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Roles of Ca2+ and F-actin in intracellular aggregation of Chlamydia trachomatis in eucaryotic cells1993Ingår i: Infection and Immunity, ISSN 0019-9567, E-ISSN 1098-5522, Vol. 61, nr 4, s. 1406-1414Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The effect of intracellular free Ca2+ ([Ca2+]i) on the intracellular aggregation of Chlamydia trachomatis serovars L2 and E in McCoy and HeLa cells is investigated. Loading the cells with the Ca2+ chelator MAPT/AM (1,2-bis-5-methyl-amino-phenoxylethane-N,N-n'-tetra-acetoxymethyl acetate), thereby decreasing the [Ca2+]i from 67 to 19 nM, decreased the number of cells with a local aggregation of chlamydiae in a dose-dependent manner. Neither the attachment nor the uptake of elementary bodies (EBs) was, however, affected after depletion of Ca2+ from the cells. There was no significant difference in the level of measured [Ca2+]i between infected and uninfected cells. Reducing the [Ca2+]i also significantly inhibited chlamydial inclusion formation. Differences in the organization of the actin filament network were observed in response to [Ca2+]i depletion. In Ca(2+)-depleted cells, where few EB aggregates were formed, few local accumulations of F-actin were observed in the cytosol. These results suggest that the aggregation of EBs in eucaryotic cells requires a normal homeostasis of intracellular Ca2+. By affecting F-actin reorganization and putatively certain Ca(2+)-binding proteins, [Ca2+]i plays a vital role in the infectious process of chlamydiae.

  • 38.
    Majeed, Meytham
    et al.
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi.
    Krause, K-H
    Clark, RA
    Kihlström, Erik
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för hälsa och miljö. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk mikrobiologi.
    Stendahl, Olle
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi.
    Localization of intracellular Ca2+ stores in HeLa cells during infection with Chlamydia trachomatis. 1999Ingår i: Journal of Cell Science, ISSN 0021-9533, E-ISSN 1477-9137, Vol. 112, s. 35-44Artikel i tidskrift (Refereegranskat)
  • 39.
    Majeed, Meytham
    et al.
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Perskvist, Nasrin
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Ernst, Joel D.
    Division of Infectious Diseases and Rosalind Russell Research Laboratory, University of California, San Francisco and San Francisco General Hospital, San Francisco, CA, U.S.A..
    Orselius, Kristina
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Roles of calcium and annexins in phagocytosis and elimination of an attenuated strain of Mycobacterium tuberculosisin human neutrophils1998Ingår i: Microbial Pathogenesis, ISSN 0882-4010, E-ISSN 1096-1208, Vol. 24, nr 5, s. 309-320Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The phagocytic function of neutrophils is a crucial element in the host defence against invading microorganisms. We investigated phagocytosis and intracellular killing of an attenuated strain of Mycobacterium tuberculosis(H37Ra) by human neutrophils focusing on the role of the cytosolic free calcium concentration [Ca2+]iand certain cytosolic calcium-dependent membrane-binding proteins annexins. Phagocytic uptake did not trigger a calcium rise and occurred independently of different calcium conditions, and in a serum-dependent manner. Changes in the viability of H37Ra were determined by agar plate colony count and a radiometric assay. Neutrophils showed a capacity to kill ingested mycobacteria and this occurred without a rise in [Ca2+]i. The ability to kill H37Ra decreased in the absence of extracellular calcium and when intra-extracellular calcium was reduced. Immunofluorescence staining revealed that during phagocytosis of H37Ra, annexins III, IV and VI translocated from cytoplasm to the proximity of the H37Ra-containing phagosomes, whereas the localization of annexin I and V remained unchanged. The translocation of annexin IV occurred even when Ca2+-depleted neutrophils ingested H37Ra in the absence of extracellular calcium. We concluded that neutrophil-mediated killing of mycobacteria is a Ca2+-dependent process. The fact that the association of certain annexins to the membrane vesicle containing H37Ra differ from other phagosomes suggests a selective regulatory mechanism during phagocytosis of mycobacteria by neutrophils.

  • 40.
    Nilsdotter-Augustinsson, Åsa
    et al.
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Infektionsmedicin. Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Medicincentrum, Infektionskliniken i Östergötland.
    Wilsson, Åsa
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Larsson, Jenny
    Linköpings universitet, Institutionen för nervsystem och rörelseorgan, Patologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Öhman, Lena
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Infektionsmedicin. Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Lundqvist Gustafsson, Helen
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Institutionen för nervsystem och rörelseorgan, Patologi. Linköpings universitet, Hälsouniversitetet.
    Staphylococcus aureus, but not Staphylococcus epidermidis, modulates the oxidative response and induces apoptosis in human neutrophils2004Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 112, nr 2, s. 109-118Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    S. epidermidis is the most common isolate in foreign body infections. The aim of this study was to understand why S. epidermidis causes silent biomaterial infections. In view of the divergent inflammatory responses S. epidermidis and S. aureus cause in patients, we analyzed how they differ when interacting with human neutrophils. Neutrophils interacting with S. epidermidis strains isolated either from granulation tissue covering infected hip prostheses or from normal skin flora were tested by measuring the oxidative response as chemiluminescence and apoptosis as annexin V binding. Different S. aureus strains were tested in parallel. All S. epidermidis tested were unable to modulate the oxidative reaction in response to formyl-methionyl-leucyl-phenylalanine (fMLP) and did not provoke, but rather inhibited, apoptosis. In contrast, some S. aureus strains enhanced the oxidative reaction, and this priming capacity was linked to p38-mitogen-activated-protein-kinase (p38-MAPK) activation and induction of apoptosis. Our results may explain why S. epidermidis is a weak inducer of inflammation compared to S. aureus, and therefore responsible for the indolent and chronic course of S. epidermidis biomaterial infections.

  • 41. Nimeri, Ghada
    et al.
    Augustinsson (Nilsdotter-Augustinsson), Åsa
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Infektionsmedicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Medicincentrum, Infektionskliniken i Östergötland.
    Lassen, Bo
    Stendahl, Olle
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi.
    Öhman, Lena
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för molekylär och klinisk medicin, Infektionsmedicin. Östergötlands Läns Landsting, Medicincentrum, Infektionskliniken i Östergötland.
    Elwing, Hans
    The chemiluminescence response of neutrophils on polymer surfaces made by glow discharge plasma polymerization.1994Ingår i: Journal of Biomaterials Science. Polymer Edition, ISSN 0920-5063, E-ISSN 1568-5624, Vol. 6, nr 8, s. 741-749Artikel i tidskrift (Refereegranskat)
  • 42.
    Perskvist, Nasrin
    et al.
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Long, Min
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Zheng, Limin
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Mycobacterium tuberculosis Promotes Apoptosis in Human Neutrophils by Activating Caspase-3 and Altering Expression of Bax/Bcl-xL Via an Oxygen-Dependent Pathway2002Ingår i: Journal of Immunology, ISSN 0022-1767, E-ISSN 1550-6606, Vol. 168, nr 12, s. 6358-6365Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In addition to direct bactericidal activities, such as phagocytosis and generation of reactive oxygen species (ROS), neutrophils can regulate the inflammatory response by undergoing apoptosis. We found that infection of human neutrophils with Mycobacterium tuberculosis (Mtb) induced rapid cell death displaying the characteristic features of apoptosis such as morphologic changes, phosphatidylserine exposure, and DNA fragmentation. Both a virulent (H37Rv) and an attenuated (H37Ra) strain of Mtb were equally effective in inducing apoptosis. Pretreatment of neutrophils with antioxidants or an inhibitor of NADPH oxidase markedly blocked Mtb-induced apoptosis but did not affect spontaneous apoptosis. Activation of caspase-3 was evident in neutrophils undergoing spontaneous apoptosis, but it was markedly augmented and accelerated during Mtb-induced apoptosis. The Mtb-induced apoptosis was associated with a speedy and transient increase in expression of Bax protein, a proapoptotic member of the Bcl-2 family, and a more prominent reduction in expression of the antiapoptotic protein Bcl-xL. Pretreatment with an inhibitor of NADPH oxidase distinctly suppressed the Mtb-stimulated activation of caspase-3 and alteration of Bax/Bcl-xL expression in neutrophils. These results indicate that infection with Mtb causes ROS-dependent alteration of Bax/Bcl-xL expression and activation of caspase-3, and thereby induces apoptosis in human neutrophils. Moreover, we found that phagocytosis of Mtb-induced apoptotic neutrophils markedly increased the production of proinflammatory cytokine TNF-α by human macrophages. Therefore, the ROS-dependent apoptosis in Mtb-stimulated neutrophils may represent an important host defense mechanism aimed at selective removal of infected cells at the inflamed site, which in turn aids the functional activities of local macrophages.

  • 43.
    Perskvist, Nasrin
    et al.
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Roberg, Karin
    Linköpings universitet, Institutionen för nervsystem och rörelseorgan, Patologi. Linköpings universitet, Hälsouniversitetet.
    Kulyte, Agné
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Rab5a GTPase regulates fusion between pathogen-containing phagosomes and cytoplasmic organelles in human neutrophils2002Ingår i: Journal of Cell Science, ISSN 0021-9533, E-ISSN 1477-9137, Vol. 115, nr 6, s. 1321-1330Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Biogenesis of phagolysosomes proceeds through a sequential series of interactions with endocytic organelles, a process known to be regulated by Rab and SNARE proteins. The molecular mechanisms underlying phagosome maturation in neutrophils are, however, not clearly understood. We investigated fusion between phagosomes containing the intracellular pathogen Mycobacterium tuberculosis versus the extracellular pathogen Staphylococcus aureus (designated MCP for mycobacteria-containing phagosome and SCP for S. aureus-containing phagosome) and cytoplasmic compartments in human neutrophils. Western blot analysis of phagosomes isolated after internalisation revealed that lactoferrin (a constituent of secondary granules) and LAMP-1 were incorporated into both SCP and MCP, whereas hck (marker of azurophil granules) interacted solely with SCP. The subcellular distribution of the proteins Rab5a and syntaxin-4 suggested a role in docking of granules and/or endosomes to the target membrane in the neutrophil. We observed that during phagocytosis, Rab5a in GTP-bound form interacted with syntaxin-4 on the membrane of MCP and were retained for up to 90 minutes, whereas the complex was recruited to the SCP within 5 minutes but was selectively depleted from these vacuoles after 30 minutes of phagocytosis. Downregulation of Rab5a by antisense oligonucleotides efficiently reduced the synthesis of Rab5a, the binding of syntaxin-4 to MCP and SCP and the capacity for fusion exhibited by the pathogen-containing phagosomes, but it had no effect on bacteria internalisation. These data indicate that the difference in granule fusion is correlated with a difference in the association of Rab5a and syntaxin-4 with the phagosomes. Intracellular pathogen-containing phagosomes retain Rab5a and syntaxin-4, whereas extracellular pathogen-containing phagosomes bind briefly to this complex. These results also identified Rab5a as a key regulator of phagolysosome maturation in human neutrophils.

  • 44.
    Perskvist, Nasrin
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Zheng, Limin
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Mycobacterium tuberculosis induce rapid apoptosis in human neutrophils through oxygen-dependent pathway2000Konferensbidrag (Övrigt vetenskapligt)
  • 45.
    Perskvist, Nasrin
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Zheng, Limin
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Activation of Human Neutrophils by Mycobacterium tuberculosis H37Ra Involves Phospholipase Cγ2, Shc Adapter Protein, and p38 Mitogen-Activated Protein Kinase2000Ingår i: Journal of Immunology, ISSN 0022-1767, E-ISSN 1550-6606, Vol. 164, nr 2, s. 959-965Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recent studies have shown that human neutrophils play a significant protective role in mycobacteria infection. When encountered with mycobacteria, neutrophils exhibit the typical early bactericidal responses including phagocytosis and generation of reactive oxygen intermediates (ROI), but the underlying mechanisms are largely unknown. The present study shows that stimulation of neutrophils with an attenuated strain of Mycobacterium tuberculosis H37Ra (Mtb) led to a tyrosine kinase-dependent ROI production in these cells. Stimulation with Mtb induces a rapid and transient tyrosine phosphorylation of several proteins, one of which was identified as phospholipase Cγ2 (PLCγ2). Several tyrosine-phosphorylated proteins were associated with the PLCγ2 precipitates from Mtb-stimulated neutrophils, of which pp46 was characterized as the Shc adapter protein. A role for PLCγ2-Shc association in the generation of ROI is supported by the observations that stimulation with Mtb causes the activation of p38 mitogen-activated protein kinase (MAPK), a downstream target of the Shc/Ras signaling cascade, and that the effect of genistein on ROI production coincided with its ability to inhibit both PLCγ2-Shc association and p38 MAPK activation. Moreover, pretreatment of neutrophils with a PLC inhibitor markedly suppresses the Mtb-stimulated ROI production as well as p38 MAPK activation in these cells. Taken together, these results indicate that stimulation of neutrophils with Mtb triggers the tyrosine phosphorylation of PLCγ2 and its association with Shc, and that such association is critical for the Mtb-stimulated ROI production through activating p38 MAPK.

  • 46.
    Persson, Alexander
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Blomgran, Robert
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Eklund, Daniel
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Lundstrom, Charlotte
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Induction of apoptosis in human neutrophils by Mycobacterium tuberculosis is dependent on mature bacterial lipoproteins2009Ingår i: Microbial Pathogenesis, ISSN 0882-4010, E-ISSN 1096-1208, Vol. 47, nr 3, s. 143-150Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Modulation of immune cell apoptosis is a key evasion strategy utilized by Mycobacterium tuberculosis (Mtb). To be able to multiply within macrophages, the bacterium delays apoptosis and down-regulates pro-inflammatory activation in these cells, whereas apoptosis is rapidly induced in the potently bactericidal neutrophils. Initial host-pathogen interactions between neutrophils and Mtb, subsequently leading to apoptosis, need to be investigated to understand the early features during Mtb infections. Opsonized Mtb were readily phagocytosed, and the immuno-mediated phagocytosis triggered early activation of anti-apoptotic Akt in the neutrophils but the bacteria still induced apoptosis to the same extent as non-phagocytosed Mtb. Mtb-induced apoptosis was strictly dependent on NADPH oxidase-generated reactive oxygen species, compounds shown to damage lysosomal granules. Despite this, we found no involvement of damaged azurophilic granules in Mtb-induced apoptosis in human neutrophils. Instead, the Mtb-induced apoptosis was p38 MAPK dependent and induced through the mitochondrial pathway. Moreover, Mtb deficient of mature lipoproteins lacked the determinants required for induction of neutrophil apoptosis. These results show that Mtb exert a strong intrinsic capacity to induce apoptosis in neutrophils that is capable of overcoming the anti-apoptotic signaling in the cell.

  • 47.
    Persson, Alexander
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Blomgran-Julinder, Robert
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Rahman, Sayma
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Zheng, Limin
    Sun Yansen (Zhongshan) University.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Mycobacterium tuberculosis-induced apoptotic neutrophils trigger a pro-inflammatory response in macrophages through release of heat shock protein 72, acting in synergy with the bacteria2008Ingår i: Microbes and infection, ISSN 1286-4579, E-ISSN 1769-714X, Vol. 10, nr 3, s. 233-240Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mycobacterium tuberculosis (Mtb) survive inside macrophages by manipulating microbicidal functions such as phago-lysosome fusion, production of reactive oxygen species and nitric oxide, and by rendering macrophages non-responsive to IFN-γ. Mtb-infected lung tissue does however not only contain macrophages, but also significant numbers of infiltrating polymorphonuclear neutrophils (PMN). These are able to phagocytose and kill ingested Mtb, but are short-lived cells that constantly need to be removed from tissues to avoid tissue damage. Phagocytosis of aged or UV-induced apoptotic PMN by macrophages induce an anti-inflammatory response in macrophages. However, in the present study, we show that engulfment of Mtb-induced apoptotic PMN by macrophages initiates secretion of TNF-α from the macrophages, reflecting a pro-inflammatory response. Moreover, Mtb-induced apoptotic PMN up-regulate heat shock proteins 60 and 72 (Hsp60, Hsp72) intracellularly and also release Hsp72 extracellularly.

    We found that both recombinant Hsp72 and released Hsp72 enhanced the pro-inflammatory response to both Mtb-induced apoptotic PMN and Mtb. This stimulatory effect of the supernatant was abrogated by depleting the Hsp72 with immunoprecipitation. These findings indicate that released Hsp72 from Mtb-infected PMN can trigger macrophage activation during the early stage of Mtb infections, thereby creating a link between innate and adaptive immunity.

  • 48.
    Persson, Hans Lennart
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Lungmedicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Lungmedicinska kliniken US.
    Eklund, Daniel
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Welin, Amanda
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Paues, Jakob
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Infektionsmedicin. Linköpings universitet, Hälsouniversitetet.
    Idh, Jonna
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Fransson, Sven-Göran
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Schön, Thomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Alveolar macrophages from patients with tuberculosis exhibit reduced capacity of restricting growth of Mycobacterium tuberculosis: a pilot study of vitamin D stimulation in vitro2013Ingår i: HOAJ Biology, ISSN 2050-0874Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: The role of vitamin D supplementation as adjuvant treatment of tuberculosis (TB) has lately attracted increasing interest. Our aim was to investigate the capacity of alveolar macrophages (AMs) from patients with or without exposure to TB to control intracellular growth of virulent Mycobacterium tuberculosis (Mtb).

    Methods: AMs were freshly harvested from the bronchoalveolar lavage fluid of 7 patients with a history of TB (4 patients with previous TB and 3 patients with current TB) and 4 non-TB subjects. The H37Rv strain, genetically modified to express Vibrio harveyi luciferase, was used to determine the growth of Mtb by luminometry in the AMs from study subjects. Cytokine levels in culture supernatants were determined using a flow cytometry-based bead array technique.

    Results: AMs from patients with a TB history were less efficient in restricting Mtb growth. Stimulation with 100 nM1, 25-dihydroxyvitamin D (1,25D3) did not significantly influence the capacity of AMs from any study subjects to control the infection. Out of the cytokines evaluated (TNF-α, IL-1β, IL-10 and IL-12p40) only TNF-α demonstrated detectable levels in culture supernatants, but did not respond to stimulation with 1,25D3.

    Conclusions: We conclude that AMs of TB-patients show reduced ability to control mycobacterial growth in vitro, and, that AMs in this pilot study do no respond to 1, 25D3-stimulation. The former observation supports the concept that innate immunity is crucial for the control of TB infection.

  • 49.
    Persson, Hans Lennart
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa. Linköpings universitet, Hälsouniversitetet.
    Jacobson, Petra
    Linköpings universitet, Institutionen för medicin och hälsa. Linköpings universitet, Hälsouniversitetet.
    Eklund, Daniel
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Larsson, Marie C.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Welin, Amanda
    Göteborgs universitet.
    Paues, Jakob
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Cellbiologi. Linköpings universitet, Hälsouniversitetet.
    Idh, Jonna
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Fransson, Sven-Göran
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Schon, Thomas
    Kalmar länssjukhus.
    Alveolar macrophages from patients with tuberculosis display a reduced capacity to inhibit growth of Mycomacterium tuberculosis2012Konferensbidrag (Övrigt vetenskapligt)
  • 50.
    Schon, T
    et al.
    Kalmar County Hospital, Sweden .
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Shortening the short-course therapy-insights into host immunity may contribute to new treatment strategies for tuberculosis2013Ingår i: Journal of Internal Medicine, ISSN 0954-6820, E-ISSN 1365-2796, Vol. 273, nr 4, s. 368-382Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Schon T, Lerm M, Stendahl O (Kalmar County Hospital, Kalmar; and Linkoping University, Linkoping; Sweden). Shortening the short-course therapy: insights into host immunity may contribute to newtreatment strategies for tuberculosis (Review). J Intern Med 2013; 273: 368-382. Achieving global control of tuberculosis (TB) is a great challenge considering the current increase in multidrug resistance and mortality rate. Considerable efforts are therefore being made to develop new effective vaccines, more effective and rapid diagnostic tools as well as new drugs. Shortening the duration of TB treatment with revised regimens and modes of delivery of existing drugs, as well as development of new antimicrobial agents and optimization of the host response with adjuvant immunotherapy could have a profound impact on TB cure rates. Recent data show that chronic worm infection and deficiencies in micronutrients such as vitamin D and arginine are potential areas of intervention to optimize host immunity. Nutritional supplementation to enhance nitric oxide production and vitamin D-mediated effector functions as well as the treatment of worm infection to reduce immunosuppressive effects of regulatory T (Treg) lymphocytes may be more suitable and accessible strategies for highly endemic areas than adjuvant cytokine therapy. In this review, we focus mainly on immune control of human TB, and discuss how current treatment strategies, including immunotherapy and nutritional supplementation, could be optimized to enhance the host response leading to more effective treatment.

12 1 - 50 av 70
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf