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  • 1.
    Tukenmez, Hasan
    et al.
    Umea Univ, Sweden.
    Edstrom, Isabel
    Umea Univ, Sweden.
    Kalsum, Sadaf
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Braian, Clara
    Not Found:Linkoping Univ, Dept Clin and Expt Med, SE-58183 Linkoping, Sweden.
    Ummanni, Ramesh
    CSIR IICT, India.
    Fick, Stina Berglund
    Umea Univ, Sweden.
    Sundin, Charlotta
    Umea Univ, Sweden.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Elofsson, Mikael
    Umea Univ, Sweden.
    Larsson, Christer
    Umea Univ Hosp, Sweden.
    Corticosteroids protect infected cells against mycobacterial killing in vitro2019Ingår i: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 511, nr 1, s. 117-121Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The effect of corticosteroids on human physiology is complex and their use in tuberculosis patients remains controversial. In a high-throughput screening approach designed to discover virulence inhibitors, several corticosteroids were found to prevent cytolysis of fibroblasts infected with mycobacteria. Further experiments with Mycobacterium tuberculosis showed anti-cytolytic activity in the 10 nM range, but no effect on bacterial growth or survival in the absence of host cells at 20 mu M. The results from a panel of corticosteroids with various affinities to the glucocorticoid- and mineralocorticoid receptors indicate that the inhibition of cytolysis most likely is mediated through the glucocorticoid receptor. Using live-imaging of M. tuberculosis-infected human monocyte-derived macrophages, we also show that corticosteroids to some extent control intracellular bacteria. In vitro systems with reduced complexity are to further study and understand the interactions between bacterial infection, immune defense and cell signaling. (C) 2019 The Authors. Published by Elsevier Inc.

  • 2.
    Tenland, Erik
    et al.
    Lund Univ, Sweden.
    Pochert, Alexander
    Ulm Univ, Germany.
    Krishnan, Nitya
    Imperial Coll London, England.
    Rao, Komal Umashankar
    Lund Univ, Sweden.
    Kalsum, Sadaf
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Braun, Katharina
    Lund Univ, Sweden.
    Glegola-Madejska, Izabela
    Imperial Coll London, England.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Robertson, Brian D.
    Imperial Coll London, England.
    Linden, Mika
    Ulm Univ, Germany.
    Godaly, Gabriela
    Lund Univ, Sweden.
    Effective delivery of the anti-mycobacterial peptide NZX in mesoporous silica nanoparticles2019Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 14, nr 2, artikel-id e0212858Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background Intracellular delivery of antimicrobial agents by nanoparticles, such as mesoporous silica particles (MSPs), offers an interesting strategy to treat intracellular infections. In tuberculosis (TB), Mycobacterium tuberculosis avoids components of the immune system by residing primarily inside alveolar macrophages, which are the desired target for TB therapy. Methods and findings We have previously identified a peptide, called NZX, capable of inhibiting both clinical and multi-drug resistant strains of M. tuberculosis at therapeutic concentrations. In this study we analysed the potential of MSPs containing NZX for the treatment of tuberculosis. The MSPs released functional NZX gradually into simulated lung fluid and the peptide filled MSPs were easily taken up by primary macrophages. In an intracellular infection model, the peptide containing particles showed increased mycobacterial killing compared to free peptide. The therapeutic potential of peptide containing MSPs was investigated in a murine infection model, showing that MSPs preserved the effect to eliminate M. tuberculosis in vivo. Conclusions In this study we found that loading the antimicrobial peptide NZX into MSPs increased the inhibition of intracellular mycobacteria in primary macrophages and preserved the ability to eliminate M. tuberculosis in vivo in a murine model. Our studies provide evidence for the feasibility of using MSPs for treatment of tuberculosis.

  • 3.
    Das, Jyotirmoy
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi, infektion och inflammation. Linköpings universitet, Medicinska fakulteten.
    Verma, Deepti
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för cellbiologi. Linköpings universitet, Medicinska fakulteten.
    Gustafsson, Mika
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Bioinformatik. Linköpings universitet, Tekniska fakulteten.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi, infektion och inflammation. Linköpings universitet, Medicinska fakulteten.
    Identification of DNA methylation patterns predisposing for an efficient response to BCG vaccination in healthy BCG-naive subjects2019Ingår i: Epigenetics, ISSN 1559-2294, E-ISSN 1559-2308, Vol. 14, nr 6, s. 589-601Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The protection against tuberculosis induced by the Bacille Calmette Guerin (BCG) vaccine is unpredictable. In our previous study, altered DNA methylation pattern in peripheral blood mononuclear cells (PBMCs) in response to BCG was observed in a subgroup of individuals, whose macrophages killed mycobacteria effectively (responders). These macrophages also showed production of Interleukin-1 beta (IL-1 beta) in response to mycobacterial stimuli before vaccination. Here, we hypothesized that the propensity to respond to the BCG vaccine is reflected in the DNA methylome. We mapped the differentially methylated genes (DMGs) in PBMCs isolated from responders/non-responders at the time point before vaccination aiming to identify possible predictors of BCG responsiveness. We identified 43 DMGs and subsequent bioinformatic analyses showed that these were enriched for actin-modulating pathways, predicting differences in phagocytosis. This could be validated by experiments showing that phagocytosis of mycobacteria, which is an event preceding mycobacteria-induced IL-1 beta production, was strongly correlated with the DMG pattern.

  • 4.
    Elkington, Paul
    et al.
    Univ Southampton, England.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi, infektion och inflammation. Linköpings universitet, Medicinska fakulteten.
    Kapoor, Nidhi
    Florida Hosp Adventist Hlth Syst, FL USA.
    Mahon, Robert
    NIAID, MD 20892 USA.
    Pienaar, Elsje
    Purdue Univ, IN 47907 USA.
    Huh, Dongeun
    Univ Penn, PA 19104 USA.
    Kaushal, Deepak
    Texas Biomed Res Inst, TX USA.
    Schlesinger, Larry S.
    Texas Biomed Res Inst, TX USA.
    In Vitro Granuloma Models of Tuberculosis: Potential and Challenges2019Ingår i: Journal of Infectious Diseases, ISSN 0022-1899, E-ISSN 1537-6613, Vol. 219, nr 12, s. 1858-1866Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Despite intensive research efforts, several fundamental disease processes for tuberculosis (TB) remain poorly understood. A central enigma is that host immunity is necessary to control disease yet promotes transmission by causing lung immunopathology. Our inability to distinguish these processes makes it challenging to design rational novel interventions. Elucidating basic immune mechanisms likely requires both in vivo and in vitro analyses, since Mycobacterium tuberculosis is a highly specialized human pathogen. The classic immune response is the TB granuloma organized in three dimensions within extracellular matrix. Several groups are developing cell culture granuloma models. In January 2018, NIAID convened a workshop, entitled "3-D Human in vitro TB Granuloma Model" to advance the field. Here, we summarize the arguments for developing advanced TB cell culture models and critically review those currently available. We discuss how integrating complementary approaches, specifically organoids and mathematical modeling, can maximize progress, and conclude by discussing future challenges and opportunities.

  • 5.
    Abate Waktola, Ebba Abate
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. EPHI, Ethiopia.
    Blomgran, Robert
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Verma, Deepti
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Fredrikson, Mats
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten.
    Belayneh, Meseret
    Univ Addis Abeba, Ethiopia.
    Söderkvist, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för cellbiologi. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk genetik.
    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, Kalmar, Sweden.
    Polymorphisms in CARD8 and NLRP3 are associated with extrapulmonary TB and poor clinical outcome in active TB in Ethiopia2019Ingår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, artikel-id 3126Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Innate immunity is a first line defense against Mycobacterium tuberculosis infection where inflammasome activation and secretion of the pro-inflammatory cytokine IL-1beta, plays a major role. Thus, genetic polymorphisms in innate immunity-related genes such as CARD8 and NLRP3 may contribute to the understanding of why most exposed individuals do not develop infection. Our aim was to investigate the association between polymorphisms in CARD8 and NLRP3 and active tuberculosis (TB) as well as their relationship to treatment outcome in a high-endemic setting for TB. Polymorphisms in CARD8 (C10X) and NLRP3 (Q705K) were analysed in 1190 TB patients and 1990 healthy donors (HD). There was a significant association between homozygotes in the CARD8 polymorphism and extrapulmonary TB (EPTB), which was not the case for pulmonary TB or HDs. Among TB-patients, there was an association between poor treatment outcome and the NLRP3 (Q705K) polymorphism. Our study shows that inflammasome polymorphisms are associated with EPTB and poor clinical outcome in active TB in Ethiopia. The practical implications and determining causal relationships on a mechanistic level needs further study.

  • 6.
    Ederth, Thomas
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Orihuela, Beatriz
    Duke Univ, NC 28516 USA.
    Rittschof, Daniel
    Duke Univ, NC 28516 USA.
    Resistance of Zwitterionic Peptide Monolayers to Biofouling2019Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 35, nr 5, s. 1818-1827Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Self-assembled monolayers (SAMs) are widely used in science and engineering, and recent progress has demonstrated the utility of zwitterionic peptides with alternating lysine (K) and glutamic acid (E) residues for antifouling purposes. Aiming at developing a peptide-based fouling-resistant SAM suitable for presentation of surface-attached pheromones for barnacle larvae, we have investigated five different peptide SAMs, where four are based on the EK motif, and the fifth was designed based on general principles for fouling resistance. The SAMs were formed by self-assembly onto gold substrates via cysteine residues on the peptides, and formation of SAMs was verified via ellipsometry, wettability, infrared reflection-absorption spectroscopy and cyclic voltammetry. Settlement of cypris larvae of the barnacle Balanus (=Amphibalanus) amphitrite, the target of pheromone studies, was tested. SAMs were also subjected to fouling assays using protein solutions, blood serum, and the bacterium Mycobacterium marinum. The results confirm the favorable antifouling properties of EK-containing peptides in most of the assays, although this did not apply to the barnacle larvae settlement test, where settlement was low on only one of the peptide SAMs. The one peptide that had antifouling properties for barnacles did not contain a pheromone motif, and would not be susceptible to degredation by common serine proteases. We conclude that the otherwise broadly effective antifouling properties of EK-containing peptide SAMs is not directly applicable to barnacles, and that great care must be exercised in the design of peptide-based SAMs for presentation of barnacle-specific ligands.

  • 7.
    Raffetseder, Johanna
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten.
    Iakobachvili, Nino
    Division of Nanoscopy, The Maastricht Multimodal Molecular Imaging Institute, Maastricht University, Maastricht, The Netherlands.
    Loitto, Vesa
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi, infektion och inflammation. Linköpings universitet, Medicinska fakulteten.
    Peters, Peter J.
    Division of Nanoscopy, The Maastricht Multimodal Molecular Imaging Institute, Maastricht University, Maastricht, The Netherlands.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi, infektion och inflammation. Linköpings universitet, Medicinska fakulteten.
    Retention of EsxA in the Capsule-Like Layer of Mycobacterium tuberculosis Is Associated with Cytotoxicity and Is Counteracted by Lung Surfactant2019Ingår i: Infection and Immunity, ISSN 0019-9567, E-ISSN 1098-5522, Vol. 87, nr 3, artikel-id e00803-18Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mycobacterium tuberculosis, the pathogen that causes tuberculosis, primarily infects macrophages but withstands the host cells bactericidal effects. EsxA, also called virulence factor 6-kDa early secretory antigenic target (ESAT-6), is involved in phagosomal rupture and cell death. We provide confocal and electron microscopy data showing that M. tuberculosis bacteria grown without detergent retain EsxA on their surface. Lung surfactant has detergent-like properties and effectively strips off this surface-associated EsxA, which advocates a novel mechanism of lung surfactant-mediated defense against pathogens. Upon challenge of human macrophages with these M. tuberculosis bacilli, the amount of surface-associated EsxA rapidly declines in a phagocytosis-independent manner. Furthermore, M. tuberculosis bacteria cultivated under exclusion of detergent exert potent cytotoxic activity associated with bacterial growth. Together, this study suggests that the surface retention of EsxA contributes to the cytotoxicity of M. tuberculosis and highlights how cultivation conditions affect the experimental outcome.

  • 8.
    Tenland, Erik
    et al.
    Lund Univ, Sweden.
    Krishnan, Nitya
    Imperial Coll London, England.
    Ronnholin, Anna
    Lund Univ, Sweden.
    Kalsum, Sadaf
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Puthia, Manoj
    Lund Univ, Sweden.
    Morgelin, Matthias
    Cobsyx AB, Sweden.
    Davoudi, Mina
    Lund Univ, Sweden.
    Otrocka, Magdalena
    Karolinska Inst, Sweden.
    Alaridah, Nader
    Lund Univ, Sweden.
    Glegola-Madejska, Izabela
    Imperial Coll London, England.
    Sturegard, Erik
    Lund Univ, Sweden.
    Schmidtchen, Artur
    Lund Univ, Sweden.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Robertson, Brian D.
    Imperial Coll London, England.
    Godaly, Gabriela
    Lund Univ, Sweden.
    A novel derivative of the fungal antimicrobial peptide plectasin is active against Mycobacterium tuberculosis2018Ingår i: Tuberculosis, ISSN 1472-9792, E-ISSN 1873-281X, Vol. 113, s. 231-238Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Tuberculosis has been reaffirmed as the infectious disease causing most deaths in the world. Co-infection with HIV and the increase in multi-drug resistant Mycobacterium tuberculosis strains complicate treatment and increases mortality rates, making the development of new drugs an urgent priority. In this study we have identified a promising candidate by screening antimicrobial peptides for their capacity to inhibit mycobacterial growth. This non-toxic peptide, NZX, is capable of inhibiting both clinical strains of M. tuberculosis and an MDR strain at therapeutic concentrations. The therapeutic potential of NZX is further supported in vivo where NZX significantly lowered the bacterial load with only five days of treatment, comparable to rifampicin treatment over the same period. NZX possesses intracellular inhibitory capacity and co-localizes with intracellular bacteria in infected murine lungs. In conclusion, the data presented strongly supports the therapeutic potential of NZX in future anti-TB treatment.

  • 9.
    Lerm, Maria
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Dockrell, H. M.
    London Sch Hyg and Trop Med, England.
    Addressing diversity in tuberculosis using multidimensional approaches2018Ingår i: Journal of Internal Medicine, ISSN 0954-6820, E-ISSN 1365-2796, Vol. 284, nr 2, s. 116-124Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Tuberculosis is a complex disease, which can affect many organs other than the lungs. Initial infection may be cleared without inducing immunological memory, or progress directly to primary disease. Alternatively, the infection may be controlled as latent TB infection, that may progress to active tuberculosis at a later stage. There is now a greater understanding that these infection states are part of a continuum, and studies using PET/CT imaging have shown that individual lung granulomas may respond to infection independently, in an un-synchronized manner. In addition, the Mycobacterium tuberculosis organisms themselves can exist in different states: as nonculturable forms, as persisters, as rapidly growing bacteria and a biofilm-forming cording phenotype. The omics approaches of transcriptomics, metabolomics and proteomics can help reveal the mechanisms underlying these different infection states in the host, and identify biosignatures with diagnostic potential, that can predict the development of disease, in progressors as early as 12-18 months before it can be detected clinically, or that can monitor the success of anti-TB therapy. Further insights can be obtained from studies of BCG vaccination and new TB vaccines. For example, epigenetic changes associated with trained immunity and a stronger immune responses following BCG vaccination can be identified. These omics approaches may be particularly valuable when linked to studies of mycobacterial growth inhibition, as a direct read-out of the ability to control mycobacterial growth. The second generation of omics studies is identifying much smaller signatures based on as few as 3 or 4 genes. Thus, narrowing down omics-derived biosignatures to a manageable set of markers now opens the way to field-friendly point of care assays.

  • 10.
    Venkata Ramanarao, Parasa
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Rose, Jeronimo
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Castillo-Diaz, Luis Alberto
    Ctr Invest and Asistencia Tecnol and Diseno Estado Ja, Mexico.
    de Jesus Aceves-Sanchez, Michel
    Ctr Invest and Asistencia Tecnol and Diseno Estado Ja, Mexico.
    Jazmin Vega-Dominguez, Perla
    Ctr Invest and Asistencia Tecnol and Diseno Estado Ja, Mexico.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Alberto Flores-Valdez, Mario
    Ctr Invest and Asistencia Tecnol and Diseno Estado Ja, Mexico.
    Evaluation of the immunogenic capability of the BCG strains BCG Delta BCG1419c and BCG Delta BCG1416c in a three-dimensional human lung tissue model2018Ingår i: Vaccine, ISSN 0264-410X, E-ISSN 1873-2518, Vol. 36, nr 14, s. 1811-1815Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Tuberculosis (TB) still remains as an unmet global threat. The current vaccine is not fully effective and novel alternatives are needed. Here, two vaccine candidate strains derived from BCG carrying deletions in the BCG1416c or BCG1419c genes were analysed for their capacity to modulate the cytoldne/chemokine profile and granuloma formation in a human lung tissue model (LTM). We show that the clustering of monocytes, reminiscent of early granuloma formation, in LTMs infected with BCG strains was similar for all of them. However, BCG Delta BCG1419c, like M. tuberculosis, was capable of inducing the production of IL-6 in contrast to the other BCG strains. This work suggests that LTM could be a useful ex vivo assay to evaluate the potential immunogenicity of novel TB vaccine candidates.

  • 11.
    Scheer, Vendela
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Sinnescentrum, Anestesi- och intensivvårdskliniken US (ANOPIVA).
    Bergman, Malin
    Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk mikrobiologi. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Serrander, Lena
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk mikrobiologi.
    Kalén, Anders
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för Kirurgi, Ortopedi och Onkologi. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Centrum för kirurgi, ortopedi och cancervård, Ortopedkliniken i Linköping.
    Topical benzoyl peroxide application on the shoulder reduces Propionibacterium acnes: a randomized study2018Ingår i: Journal of shoulder and elbow surgery, ISSN 1058-2746, E-ISSN 1532-6500, Vol. 27, nr 6, s. 957-961Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Propionibacterium acnes is a common cause of infection following shoulder surgery. Studies have shown that standard surgical preparation does not eradicate P acnes. The purpose of this study was to examine whether topical application of benzoyl peroxide (BPO) gel could decrease the presence of P acnes compared with todays standard treatment with chlorhexidine soap (CHS). We also investigated and compared the recolonization of the skin after surgical preparation and draping between the BPO- and CHS-treated groups. Methods: In this single-blinded nonsurgical study, 40 volunteers-24 men and 16 women-were randomized to preoperative topical treatment at home with either 5% BPO or 4% CHS on the left shoulder at the area of a deltopectoral approach. Four skin swabs from the area were taken in a standardized manner at different times: before and after topical treatment, after surgical skin preparation and sterile draping, and 120 minutes after draping. Results: Topical treatment with BPO significantly reduced the presence of P acnes measured as the number of colony-forming units on the skin after surgical preparation. P acnes was found in 1 of 20 subjects in the BPO group and 7 of 20 in the CHS group (P = .044). The results remained after 2 hours (P = .048). Conclusion: Topical preparation with BPO before shoulder surgery may be effective in reducing P acnes on the skin and preventing recolonization. Conclusion: Topical preparation with BPO before shoulder surgery may be effective in reducing P acnes on the skin and preventing recolonization. (C) 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.

  • 12.
    Brighenti, S.
    et al.
    Karolinska Inst, Sweden.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Toward the understanding of human tuberculosis2018Ingår i: Journal of Internal Medicine, ISSN 0954-6820, E-ISSN 1365-2796, Vol. 284, nr 2, s. 113-115Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    n/a

  • 13.
    Verma, Deepti
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för cellbiologi. Linköpings universitet, Medicinska fakulteten.
    Ramanarao Parasa, Venkata
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Raffetseder, Johanna
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten.
    Martis, Mihaela-Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för cellbiologi. Linköpings universitet, Medicinska fakulteten.
    Bhai Mehta, Ratnesh
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten.
    Netea, Mihai
    Radboud University of Nijmegen, Netherlands.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Anti-mycobacterial activity correlates with altered DNA methylation pattern in immune cells from BCG-vaccinated subjects2017Ingår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, artikel-id 12305Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The reason for the largely variable protective effect against TB of the vaccine Bacille Calmette-Guerin (BCG) is not understood. In this study, we investigated whether epigenetic mechanisms are involved in the response of immune cells to the BCG vaccine. We isolated peripheral blood mononuclear cells (PBMCs) from BCG-vaccinated subjects and performed global DNA methylation analysis in combination with functional assays representative of innate immunity against Mycobacterium tuberculosis infection. Enhanced containment of replication was observed in monocyte-derived macrophages from a subgroup of BCG-vaccinated individuals (identified as responders). A stable and robust differential DNA methylation pattern in response to BCG could be observed in PBMCs isolated from the responders but not from the non-responders. Gene ontology analysis revealed that promoters with altered DNA methylation pattern were strongly enriched among genes belonging to immune pathways in responders, however no enrichments could be observed in the non-responders. Our findings suggest that BCG-induced epigenetic reprogramming of immune cell function can enhance anti-mycobacterial immunity in macrophages. Understanding why BCG induces this response in responders but not in nonresponders could provide clues to improvement of TB vaccine efficacy.

  • 14.
    Venkata Ramanarao, Parasa
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Muvva, Jagadeeswara R.
    Karolinska Institute, Sweden.
    Rose, Jeronimo F.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Braian, Clara
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Brighenti, Susanna
    Karolinska Institute, Sweden.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Inhibition of Tissue Matrix Metalloproteinases Interferes with Mycobacterium tuberculosis-Induced Granuloma Formation and Reduces Bacterial Load in a Human Lung Tissue Model2017Ingår i: Frontiers in Microbiology, ISSN 1664-302X, E-ISSN 1664-302X, Vol. 8, artikel-id 2370Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Granulomas are hallmarks of pulmonary tuberculosis (TB) and traditionally viewed as host-protective structures. However, recent evidence suggest that Mycobacterium tuberculosis (Mtb) uses its virulence factors to stimulate the formation of granuloma. In the present study, we investigated the contribution of matrix metalloproteinases (MMPs), host enzymes that cause degradation of the extracellular matrix, to granuloma formation and bacterial load in Mtb-infected tissue. To this end, we used our lung tissue model for TB, which is based on human lung-derived cells and primary human monocyte-derived macrophages. Global inhibition of MMPs in the Mtb-infected tissue model reduced both granuloma formation and bacterial load. The infection caused upregulation of a set of MMPs (MMP1, 3, 9, and 12), and this finding could be validated in lung biopsies from patients with non-cavitary TB. Data from this study indicate that MMP activation contributes to early TB granuloma formation, suggesting that host-directed, MMP-targeted intervention could be considered as adjunct therapy to TB treatment.

  • 15.
    Idh, Jonna
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Andersson, Blanka
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. Karolinska Institute, Sweden.
    Raffetseder, Johanna
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten.
    Eklund, Daniel
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten.
    Woksepp, Hanna
    Linneaus University, Sweden; Kalmar County Hospital, Sweden.
    Werngren, Jim
    Public Health Agency Sweden, Sweden.
    Mansjo, Mikael
    Public Health Agency Sweden, Sweden.
    Sundqvist, Tommy
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för kliniska vetenskaper. Linköpings universitet, Medicinska fakulteten.
    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. Linneaus University, Sweden; Kalmar County Hospital, Sweden.
    Reduced susceptibility of clinical strains of Mycobacterium tuberculosis to reactive nitrogen species promotes survival in activated macrophages2017Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 12, nr 7, artikel-id e0181221Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background Drugs such as isoniazid (INH) and pretomanid (PRT), used against Mycobacterium tuberculosis are active partly through generation of reactive nitrogen species (RNS). The aim of this study was to explore variability in intracellular susceptibility to nitric oxide (NO) in clinical strains of M. tuberculosis. Method Luciferase-expressing clinical M. tuberculosis strains with or without INH resistance were exposed to RNS donors (DETA/NO and SIN-1) in broth cultures and bacterial survival was analysed by luminometry. NO-dependent intracellular killing in a selection of strains was assessed in interferon gamma/lipopolysaccharide-activated murine macrophages using the NO inhibitor L-NMMA. Results When M. tuberculosis H37Rv was compared to six clinical isolates and CDC1551, three isolates with inhA mediated INH resistance showed significantly reduced NO-susceptibility in broth culture. All strains showed a variable but dose-dependent susceptibility to RNS donors. Two clinical isolates with increased susceptibility to NO exposure in broth compared to H37Rv were significantly inhibited by activated macrophages whereas there was no effect on growth inhibition when activated macrophages were infected by clinical strains with higher survival to NO exposure in broth. Furthermore, the most NO-tolerant clinical isolate showed increased resistance to PRT both in broth culture and the macrophage model compared to H37Rv in the absence of mutational resistance in genes associated to reduced susceptibility against PRT or NO. Conclusion In a limited number of clinical M. tuberculosis isolates we found a significant difference in susceptibility to NO between clinical isolates, both in broth cultures and in macrophages. Our results indicate that mycobacterial susceptibility to cellular host defence mechanisms such as NO need to be taken into consideration when designing new therapeutic strategies.

  • 16.
    Kalsum, Sadaf
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Braian, Clara
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Koeken, Valerie A. C. M.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. Radboud University of Nijmegen, Netherlands.
    Raffetseder, Johanna
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten.
    Lindroth, Margaretha
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    van Crevel, Reinout
    Radboud University of Nijmegen, Netherlands.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    The Cording Phenotype of Mycobacterium tuberculosis Induces the Formation of Extracellular Traps in Human Macrophages2017Ingår i: Frontiers in Cellular and Infection Microbiology, E-ISSN 2235-2988, Vol. 7, artikel-id 278Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The causative agent of tuberculosis, Mycobacterium tuberculosis, shares several characteristics with organisms that produce biofilms during infections. One of these is the ability to form tight bundles also known as cords. However, little is known of the physiological relevance of the cording phenotype. In this study, we investigated whether cord-forming M. tuberculosis induce the formation of macrophage extracellular traps (METs) in human monocyte-derived macrophages. Macrophages have previously been shown to produce extracellular traps in response to various stimuli. We optimized bacterial culturing conditions that favored the formation of the cord-forming phenotype as verified by scanning electron microscopy. Microscopy analysis of METs formation during experimental infection of macrophages with M. tuberculosis revealed that cord-forming M. tuberculosis induced significantly more METs compared to the non-cording phenotype. Deletion of early secreted antigenic target-6 which is an important virulence factor of M. tuberculosis, abrogated the ability of the bacteria to induce METs. The release of extracellular DNA from host cells during infection may represent a defense mechanism against pathogens that are difficult to internalize, including cord-forming M. tuberculosis.

  • 17.
    Lerm, Maria
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Netea, M. G.
    Radboud University of Nijmegen, Netherlands.
    Trained immunity: a new avenue for tuberculosis vaccine development2016Ingår i: Journal of Internal Medicine, ISSN 0954-6820, E-ISSN 1365-2796, Vol. 279, nr 4, s. 337-346Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Adaptive immunity towards tuberculosis (TB) has been extensively studied for many years. In addition, in recent years the profound contribution of innate immunity to host defence against this disease has become evident. The discovery of pattern recognition receptors, which allow innate immunity to tailor its response to different infectious agents, has challenged the view that this arm of immunity is nonspecific. Evidence is now accumulating that innate immunity can remember a previous exposure to a microorganism and respond differently during a second exposure. Although the specificity and memory of innate immunity cannot compete with the highly sophisticated adaptive immune response, its contribution to host defence against infection and to vaccine-induced immunity should not be underestimated and needs to be explored. Here, we present the concept of trained immunity and discuss how this may contribute to new avenues for control of TB.

  • 18.
    Braian, Clara
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Svensson, Mattias
    Karolinska Institute, Sweden.
    Brighenti, Susanna
    Karolinska Institute, Sweden.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Parasa, Venkata R.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. Karolinska Institute, Sweden.
    A 3D Human Lung Tissue Model for Functional Studies on Mycobacterium tuberculosis Infection2015Ingår i: Journal of Visualized Experiments, ISSN 1940-087X, E-ISSN 1940-087X, nr 104, s. 1-9, artikel-id e53084Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Tuberculosis (TB) still holds a major threat to the health of people worldwide, and there is a need for cost-efficient but reliable models to help us understand the disease mechanisms and advance the discoveries of new treatment options. In vitro cell cultures of monolayers or co-cultures lack the three-dimensional (3D) environment and tissue responses. Herein, we describe an innovative in vitro model of a human lung tissue, which holds promise to be an effective tool for studying the complex events that occur during infection with Mycobacterium tuberculosis (M. tuberculosis). The 3D tissue model consists of tissue-specific epithelial cells and fibroblasts, which are cultured in a matrix of collagen on top of a porous membrane. Upon air exposure, the epithelial cells stratify and secrete mucus at the apical side. By introducing human primary macrophages infected with M. tuberculosis to the tissue model, we have shown that immune cells migrate into the infected-tissue and form early stages of TB granuloma. These structures recapitulate the distinct feature of human TB, the granuloma, which is fundamentally different or not commonly observed in widely used experimental animal models. This organotypic culture method enables the 3D visualization and robust quantitative analysis that provides pivotal information on spatial and temporal features of host cell-pathogen interactions. Taken together, the lung tissue model provides a physiologically relevant tissue micro-environment for studies on TB. Thus, the lung tissue model has potential implications for both basic mechanistic and applied studies. Importantly, the model allows addition or manipulation of individual cell types, which thereby widens its use for modelling a variety of infectious diseases that affect the lungs.

  • 19.
    Kumar, Manish
    et al.
    Department of Chemistry, Bose Institute, Kolkata 700009, India.
    Sahu, Sanjaya Kumar
    Department of Chemistry, Bose Institute, Kolkata 700009, India.
    Kumar, Ranjeet
    Department of Chemistry, Bose Institute, Kolkata 700009, India.
    Subuddhi, Arijita
    Department of Chemistry, Bose Institute, Kolkata 700009, India.
    Maji, Ranjan Kumar
    Bioinformatics Centre, Bose Institute, Kolkata 700054, India.
    Jana, Kuladip
    Division of Molecular Medicine, Bose Institute, Kolkata 700054, India.
    Gupta, Pushpa
    National Jalma Institute for Leprosy and Other Mycobacterial Diseases, Tajganj, Agra 282006, India.
    Raffetseder, Johanna
    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.
    Ghosh, Zhumur
    Bioinformatics Centre, Bose Institute, Kolkata 700054, India.
    van Loo, Geert
    VIB Inflammation Research Center, Ghent University, 9052 Ghent / Department of Biomedical Molecular Biology, Ghent University, 9052 Ghent, Belgium.
    Beyaert, Rudi
    VIB Inflammation Research Center, Ghent University, 9052 Ghent / Department of Biomedical Molecular Biology, Ghent University, 9052 Ghent, Belgium.
    Gupta, Umesh D
    National Jalma Institute for Leprosy and Other Mycobacterial Diseases, Tajganj, Agra 282006, India.
    Kundu, Manikuntala
    Bioinformatics Centre, Bose Institute, Kolkata 700054, India.
    Basu, Joyoti
    Bioinformatics Centre, Bose Institute, Kolkata 700054, India.
    MicroRNA let-7 Modulates the Immune Response to Mycobacterium tuberculosis Infection via Control of A20, an Inhibitor of the NF-κB Pathway.2015Ingår i: Cell host & microbe, ISSN 1934-6069, Vol. 17, nr 3, s. 345-56Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The outcome of the interaction between Mycobacterium tuberculosis (Mtb) and a macrophage depends on the interplay between host defense and bacterial immune subversion mechanisms. MicroRNAs critically regulate several host defense mechanisms, but their role in the Mtb-macrophage interplay remains unclear. MicroRNA profiling of Mtb-infected macrophages revealed the downregulation of miR-let-7f in a manner dependent on the Mtb secreted effector ESAT-6. We establish that let-7f targets A20, a feedback inhibitor of the NF-κB pathway. Expression of let-7f decreases and A20 increases with progression of Mtb infection in mice. Mtb survival is attenuated in A20-deficient macrophages, and the production of TNF, IL-1β, and nitrite, which are mediators of immunity to Mtb, is correspondingly increased. Further, let-7f overexpression diminishes Mtb survival and augments the production of cytokines including TNF and IL-1β. These results uncover a role for let-7f and its target A20 in regulating immune responses to Mtb and controlling bacterial burden.

  • 20.
    Larsson, Marie C
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk mikrobiologi.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Ängeby, Kristian
    Karolinska University Hospital, Hospital, Stockholm, Sweden; University of the West Indies, Kingston, Jamaica.
    Nordvall, Michaela
    Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk mikrobiologi.
    Jureen, Pontus
    Public Health Agency of Sweden, Stockholm, Sweden.
    Schön, Thomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet. Kalmar County Hospital, Sweden; Linnaeus University, Kalmar, Sweden.
    A luciferase-based assay for rapid assessment of drug activity against Mycobacterium tuberculosis including monitoring of macrophage viability2014Ingår i: Journal of Microbiological Methods, ISSN 0167-7012, E-ISSN 1872-8359, Vol. 106, s. 146-150Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The intracellular (IC) effect of drugs against Mycobacterium tuberculosis (Mtb) is not well established but increasingly important to consider when combining current and future multidrug regimens into the best possible treatment strategies. For this purpose, we developed an IC model based on a genetically modified Mtb H37Rv strain, expressing the Vibrio harvei luciferase (H37Rv-lux) infecting the human macrophage like cell line THP-1. Cells were infected at a low multiplicity of infection (1:1) and subsequently exposed to isoniazid (INH), ethambutol (EMB), amikacin (AMI) or levofloxacin (LEV) for 5 days in a 96-well format. Cell viability was evaluated by Calcein AM and was maintained throughout the experiment. The number of viable H37Rv-lux was determined by luminescence and verified by a colony forming unit analysis. The results were compared to the effects of the same drugs in broth cultures. AMI, EMB and LEV were significantly less effective intracellularly (MIC90: greater than4 mg/L, 8 mg/L and 2 mg/L, respectively) compared to extracellularly (MIC90: 0.5 mg/L for AMI and EMB; 0.25 mg/L for LEV). The reverse was the case for INH (IC: 0.064 mg/L vs EC: 0.25 mg/L). In conclusion, this luciferase based method, in which monitoring of cell viability is included, has the potential to become a useful tool while evaluating the intracellular effects of anti-mycobacterial drugs.

  • 21.
    Pienaar, Elsje
    et al.
    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.
    A mathematical model of the initial interaction between Mycobacterium tuberculosis and macrophages2014Ingår i: Journal of Theoretical Biology, ISSN 0022-5193, E-ISSN 1095-8541, Vol. 342, s. 23-32Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    There is a large body of literature describing molecular level interactions between Mycobacterium tuberculosis (Mtb) and macrophages. Macrophages initiate a range of anti-bacterial mechanisms in response to infection, and Mtb is capable of surviving and circumventing many of these responses. We apply a computational approach to ask: what are the effects on the cellular level of these opposing interactions? The model considers the interplay between bacterial killing and the pathogen's interference with macrophage function. The results reveal an oscillating balance between host and pathogen, but the balance is transient and varies in length, indicating that stochasticity in the bacterial population or host response could contribute to the diverse incubation periods observed in exposed individuals. The model captures host and strain variation and gives new insight into host-pathogen compatibility and co-evolution.

  • 22.
    Abuzeid, Nadir
    et al.
    Medical and Aromat Plants Research Institute, Sudan; Omdurman Islamic University, Sudan.
    Kalsum, Sadaf
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Koshy, Richin John
    Larsson, Marie C
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Glader, Mikaela
    Andersson, Henrik
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Raffetseder, Johanna
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Pienaar, Elsje
    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 inflammationsmedicin. Linköpings universitet, Hälsouniversitetet.
    Alhassan, Muddathir S.
    Medical and Aromat Plants Research Institute, Sudan.
    AlGadir, Haidar A.
    Medical and Aromat Plants Research Institute, Sudan.
    Koko, Waleed S.
    Medical and Aromat Plants Research Institute, Sudan.
    Schon, Thomas
    Kalmar County Hospital, Sweden.
    Ahmed Mesaik, M.
    University of Kebangsaan Malaysia, Malaysia; University of Karachi, Pakistan.
    Abdalla, Omer M.
    University of Karachi, Pakistan.
    Khalid, Asaad
    Medical and Aromat Plants Research Institute, Sudan.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Antimycobacterial activity of selected medicinal plants traditionally used in Sudan to treat infectious diseases2014Ingår i: Journal of Ethnopharmacology, ISSN 0378-8741, E-ISSN 1872-7573, Vol. 157, s. 134-139Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ethnopharmacological relevance: The emergence of multidrug-resistant strains of Mycobacterium tuberculosis underscores the need for continuous development of new and efficient methods to determine the susceptibility of isolates of Mycobacterium tuberculosis in the search for novel antimycobacterial agents. Natural products constitute an important source of new drugs, and design and implementation of antimycobacterial susceptibility testing methods are necessary to evaluate the different extracts and compounds. In this study we have explored the antimycobacterial properties of 50 ethanolic extracts from different parts of 46 selected medicinal plants traditionally used in Sudan to treat infectious diseases. Materials and methods: Plants were harvested and ethanolic extracts were prepared. For selected extracts, fractionation with hydrophilic and hydrophobic solvents was undertaken. A luminometry-based assay was used for determination of mycobacterial growth in broth cultures and inside primary human macrophages in the presence or absence of plant extracts and fractions of extracts. Cytotoxicity was also assessed for active fractions of plant extracts. Results: Of the tested extracts, three exhibited a significant inhibitory effect on an avirulent strain of Mycobacterium tubercluosis (H37Ra) at the initial screening doses (125 and 6.25 mu g/ml). These were bark and leaf extracts of Khaya senegalensis and the leaf extract of Rosmarinus officinalis L. Further fractions of these plant extracts were prepared with n-hexane, chloroform, ethyl acetate, n-butanol, ethanol and water, and the activity of these extracts was retained in hydrophobic fractions. Cytotoxicity assays revealed that the chloroform fraction of Khaya senegalensis bark was non-toxic to human monocyte-derived macrophages and other cell types at the concentrations used and hence, further analysis, including assessment of IC50 and intracellular activity was done with this fraction. Conclusion: These results encourage further investigations to identify the active compound(s) within the chloroform fraction of Khaya senegalensis bark. (C) 2014 Elsevier Ireland Ltd. All rights reserved.

  • 23.
    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.

  • 24.
    Pienaar, Elsje
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Correction: A mathematical model of the initial interaction between Mycobacterium tuberculosis and macrophages (vol 342, pg 23, 2014) in JOURNAL OF THEORETICAL BIOLOGY vol 349 pg 1722014Ingår i: Journal of Theoretical Biology, ISSN 0022-5193, E-ISSN 1095-8541, Vol. 349, s. 1s. 172-172Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    n/a

  • 25.
    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.

  • 26.
    Ramanarao Parasa, Venkata
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Karolinska Institute, Sweden.
    Jubayer Rahman, Muhammad
    Karolinska Institute, Sweden .
    Ngyuen Hoang, Anh Thu
    Karolinska Institute, Sweden .
    Svensson, Mattias
    Karolinska Institute, Sweden .
    Brighenti, Susanna
    Karolinska Institute, Sweden .
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Modeling Mycobacterium tuberculosis early granuloma formation in experimental human lung tissue2014Ingår i: Disease Models and Mechanisms, ISSN 1754-8403, E-ISSN 1754-8411, Vol. 7, nr 2, s. 281-288Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The widely used animal models for tuberculosis ( TB) display fundamental differences from human TB. Therefore, a validated model that recapitulates human lung TB is attractive for TB research. Here, we describe a unique method for establishment of TB infection in an experimental human lung tissue model. The model is based on cell lines derived from human lungs and primary macrophages from peripheral blood, and displays characteristics of human lung tissue, including evenly integrated macrophages throughout the epithelium, production of extracellular matrix, stratified epithelia and mucus secretion. Establishment of experimental infection in the model tissue with Mycobacterium tuberculosis, the bacterium that causes TB, resulted in clustering of macrophages at the site of infection, reminiscent of early TB granuloma formation. We quantitated the extent of granuloma formation induced by different strains of mycobacteria and validated our model against findings in other TB models. We found that early granuloma formation is dependent on ESAT-6, which is secreted via the type VII secretion machinery of virulent mycobacteria. Our model, which can facilitate the discovery of the interactions between mycobacteria and host cells in a physiological environment, is the first lung tissue model described for TB.

  • 27.
    Raffetseder, Johanna
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Pienaar, Elsje
    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.
    Eklund, Daniel
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för inflammationsmedicin. Linköpings universitet, Hälsouniversitetet.
    Brodin Patcha, Veronika
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för kliniska vetenskaper. Linköpings universitet, Hälsouniversitetet.
    Andersson, Henrik
    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.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Replication Rates of Mycobacterium tuberculosis in Human Macrophages Do Not Correlate with Mycobacterial Antibiotic Susceptibility2014Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, nr 11, s. e112426-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The standard treatment of tuberculosis (TB) takes six to nine months to complete and this lengthy therapy contributes to the emergence of drug-resistant TB. TB is caused by Mycobacterium tuberculosis (Mtb) and the ability of this bacterium to switch to a dormant phenotype has been suggested to be responsible for the slow clearance during treatment. A recent study showed that the replication rate of a non-virulent mycobacterium, Mycobacterium smegmatis, did not correlate with antibiotic susceptibility. However, the question whether this observation also holds true for Mtb remains unanswered. Here, in order to mimic physiological conditions of TB infection, we established a protocol based on long-term infection of primary human macrophages, featuring Mtb replicating at different rates inside the cells. During conditions that restricted Mtb replication, the bacterial phenotype was associated with reduced acid-fastness. However, these phenotypically altered bacteria were as sensitive to isoniazid, pyrazinamide and ethambutol as intracellularly replicating Mtb. In support of the recent findings with M. smegmatis, we conclude that replication rates of Mtb do not correlate with antibiotic tolerance.

  • 28.
    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.

  • 29.
    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.

  • 30.
    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.

  • 31.
    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)
  • 32.
    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.

  • 33.
    Brighenti, Susanna
    et al.
    Center for Infectious Medicine, Huddinge Hospital Karolinska Institute.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    How Mycobacterium tuberculosis Manipulates Innate and Adaptive Immunity: New Views of an Old Topic2012Ingår i: Understanding Tuberculosis: Analyzing the Origin of Mycobacterium Tuberculosis Pathogenicity / [ed] Pere-Joan Cardona, InTech Open , 2012, s. 207-234Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

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

  • 34.
    Welin, Amanda
    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.
    Inside or outside the phagosome? The controversy of the intracellular localization of Mycobacterium tuberculosis2012Ingår i: Tuberculosis, ISSN 1472-9792, E-ISSN 1873-281X, Vol. 92, nr 2, s. 113-120Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    The localization of Mycobacterium tuberculosis (Mtb) inside the macrophage has been a matter of debate in recent years. Upon inhalation, the bacterium is taken up into macrophage phagosomes, which are manipulated by the bacterium. Subsequent translocation of the bacilli into the cytosol has been observed by several groups, while others fail to observe this phenomenon. Here, we review the available literature in favour of and against this idea, and scrutinize the existing data on how human macrophages control Mtb infection, relating this to the robustness of the host cell. We conclude that both phagosomal maturation inhibition and escape from the phagosome are part of the greater infection strategy of Mtb. The balance between the host cell and the infecting bacterium is an important factor in determining the outcome of infection as well as whether phagosomal escape occurs and can be captured.

  • 35.
    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.

  • 36.
    Verma, Deepti
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Eriksson, Per
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Reumatologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Medicincentrum, Länskliniken för Reumatologi i Östergötland.
    Fredriksson, Mats
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Yrkes- och miljömedicin. Linköpings universitet, Hälsouniversitetet.
    Andersson, Henrik
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Cellbiologi. Linköpings universitet, Hälsouniversitetet.
    Jönsson, Jan-Ingvar
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Experimentell hematologi. Linköpings universitet, Hälsouniversitetet.
    Särndahl, Eva
    Department of Clinical Medicine, School of Health & Medical Sciences, Örebro University, SE-701 82 Örebro, Sweden.
    Söderkvist, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Cellbiologi. Linköpings universitet, Hälsouniversitetet.
    The Q705K polymorphism in NLRP3 is a gain-of-function alteration leading to excessive interleukin-1β and IL-18 production2012Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, nr 4Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: The Q705K polymorphism in NLRP3 has been implicated in several chronic inflammatory diseases. In this study, we determine the functional role of this commonly occurring polymorphism using an in-vitro system.

    Methods / Principle findings: NLRP3-WT and NLRP3-Q705K were retrovirally transduced into the human monocytic cell line THP-1, followed by the assessment of IL-1β and IL-18 levels in the cell culture supernatant. THP-1 cells expressing the above NLRP3 variants were sorted based upon Green Fluorescent Protein (GFP) expression. Cytokine response to alum (one of the most widely used adjuvants in vaccines) in the cells stably expressing NLRP3-WT and NLRP3-Q705K were determined. IL-1β and IL-18 levels were found to be elevated in THP-1 cells transduced with NLRP3-Q705K compared to the NLRP3-WT. Upon exposure to alum, THP-1 cells stably expressing NLRP3-Q705K displayed an increased production of IL-1β, IL-18 and TNF-α, in a caspase-1 and IL-1 receptor-dependent manner.

    Conclusions: Collectively, these findings show that the Q705K polymorphism in NLRP3 is a gain-of-function alteration leading to an overactive NLRP3 inflammasome. The option of IL-1β blockade may be considered in patients with chronic inflammatory disorders that are unresponsive to conventional treatments.

  • 37.
    Zurek, Birte
    et al.
    University of Cologne, Germany .
    Schoultz, Ida
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Kirurgi. Linköpings universitet, Hälsouniversitetet.
    Neerincx, Andreas
    University of Cologne, Germany .
    Napolitano, Luisa M
    Telethon Institute Genet and Med, Italy Cluster Biomed CBM, Italy .
    Birkner, Katharina
    University of Cologne, Germany .
    Bennek, Eveline
    University Hospital Aachen, Germany .
    Sellge, Gernot
    University Hospital Aachen, Germany .
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Meroni, Germana
    Cluster Biomed CBM, Italy .
    Söderholm, Johan D
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Kirurgi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Kirurgiska kliniken i Östergötland.
    Kufer, Thomas A
    University of Cologne, Germany .
    TRIM27 Negatively Regulates NOD2 by Ubiquitination and Proteasomal Degradation2012Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, nr 7Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    NOD2, the nucleotide-binding domain and leucine-rich repeat containing gene family (NLR) member 2 is involved in mediating antimicrobial responses. Dysfunctional NOD2 activity can lead to severe inflammatory disorders, but the regulation of NOD2 is still poorly understood. Recently, proteins of the tripartite motif (TRIM) protein family have emerged as regulators of innate immune responses by acting as E3 ubiquitin ligases. We identified TRIM27 as a new specific binding partner for NOD2. We show that NOD2 physically interacts with TRIM27 via the nucleotide-binding domain, and that NOD2 activation enhances this interaction. Dependent on functional TRIM27, ectopically expressed NOD2 is ubiquitinated with K48-linked ubiquitin chains followed by proteasomal degradation. Accordingly, TRIM27 affects NOD2-mediated pro-inflammatory responses. NOD2 mutations are linked to susceptibility to Crohns disease. We found that TRIM27 expression is increased in Crohns disease patients, underscoring a physiological role of TRIM27 in regulating NOD2 signaling. In HeLa cells, TRIM27 is partially localized in the nucleus. We revealed that ectopically expressed NOD2 can shuttle to the nucleus in a Walker A dependent manner, suggesting that NOD2 and TRIM27 might functionally cooperate in the nucleus. We conclude that TRIM27 negatively regulates NOD2-mediated signaling by degradation of NOD2 and suggest that TRIM27 could be a new target for therapeutic intervention in NOD2-associated diseases.

  • 38.
    Welin, Amanda
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Eklund, Daniel
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi.
    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.
    Human Macrophages Infected with a High Burden of ESAT-6-Expressing M. tuberculosis Undergo Caspase-1-and Cathepsin B-Independent Necrosis2011Ingår i: PLOS ONE, ISSN 1932-6203, Vol. 6, nr 5Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mycobacterium tuberculosis (Mtb) infects lung macrophages, which instead of killing the pathogen can be manipulated by the bacilli, creating an environment suitable for intracellular replication and spread to adjacent cells. The role of host cell death during Mtb infection is debated because the bacilli have been shown to be both anti-apoptotic, keeping the host cell alive to avoid the antimicrobial effects of apoptosis, and pro-necrotic, killing the host macrophage to allow infection of neighboring cells. Since mycobacteria activate the NLRP3 inflammasome in macrophages, we investigated whether Mtb could induce one of the recently described inflammasome-linked cell death modes pyroptosis and pyronecrosis. These are mediated through caspase-1 and cathepsin-B, respectively. Human monocyte-derived macrophages were infected with virulent (H37Rv) Mtb at a multiplicity of infection (MOI) of 1 or 10. The higher MOI resulted in strongly enhanced release of IL-1 beta, while a low MOI gave no IL-1 beta response. The infected macrophages were collected and cell viability in terms of the integrity of DNA, mitochondria and the plasma membrane was determined. We found that infection with H37Rv at MOI 10, but not MOI 1, over two days led to extensive DNA fragmentation, loss of mitochondrial membrane potential, loss of plasma membrane integrity, and HMGB1 release. Although we observed plasma membrane permeabilization and IL-1 beta release from infected cells, the cell death induced by Mtb was not dependent on caspase-1 or cathepsin B. It was, however, dependent on mycobacterial expression of ESAT-6. We conclude that as virulent Mtb reaches a threshold number of bacilli inside the human macrophage, ESAT-6-dependent necrosis occurs, activating caspase-1 in the process.

  • 39.
    Welin, Amanda
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Raffetseder, Johanna
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Eklund, Daniel
    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.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Importance of phagosomal functionality for growth restriction of Mycobacterium tuberculosis in primary human macrophages2011Ingår i: Journal of Innate Immunity, ISSN 1662-811X, E-ISSN 1662-8128, Vol. 3, nr 5, s. 508-518Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The best characterized survival mechanism of Mycobacterium tuberculosis inside the macrophage is the inhibition of phagosomal maturation. Phagosomal maturation involves several steps including fusion with lysosomes and acidification. However, it has not been elucidated which components of phagosomal maturation correlate with growth restriction of virulent mycobacteria in human macrophages, and we aimed to study this. We infected human monocyte-derived macrophages with M. tuberculosis and assessed bacterial replication, translocation of CD63 to the phagosome, and phagosomal acidification. We found that unstimulated macrophages were able to control infection with M. tuberculosis upon inoculation at a low, but not high, multiplicity of infection (MOI). H37Rv and H37Ra infection, at both high and low MOI, led to equally ineffective translocation of CD63 to the phagosome. This was true despite the impaired growth ability of H37Rv at the low MOI and of H37Ra even at the high MOI, indicating that inhibition of CD63 translocation was not sufficient for growth to occur. On the other hand, acidification of mycobacterial phagosomes was more efficient at a low MOI with both mycobacterial strains, consistent with a role for phagosomal acidification in restricting M. tuberculosis growth. Inhibition of the vacuolar H+-ATPase as well as of cathepsin D led to enhanced mycobacterial replication inside the macrophage. We conclude that acidification and related functional aspects of the mature phagosome are important factors for restriction of M. tuberculosis replication in human macrophages.

  • 40.
    Kälvegren, Hanna
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Hälsouniversitetet.
    Skoglund, Caroline
    Linköpings universitet, Institutionen för medicin och hälsa, Farmakologi. Linköpings universitet, Hälsouniversitetet.
    Helldahl, Christian
    Linköpings universitet, Institutionen för medicin och hälsa, Farmakologi. Linköpings universitet, Hälsouniversitetet.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Grenegård, Magnus
    Linköpings universitet, Institutionen för medicin och hälsa, Farmakologi. Linköpings universitet, Hälsouniversitetet.
    Bengtsson, Torbjörn
    Linköpings universitet, Institutionen för medicin och hälsa, Farmakologi. Linköpings universitet, Hälsouniversitetet.
    Toll-like receptor 2 stimulation of platelets is mediated by purinergic P2X1-dependent Ca2+ mobilisation, cyclooxygenase and purinergic P2Y1 and P2Y12 receptor activation2010Ingår i: Thrombosis and Haemostasis, ISSN 0340-6245, Vol. 103, nr 2, s. 398-407Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Toll-like receptor 2 (TLR2), which recognise and respond to conserved microbial pathogen-associated molecular patterns, is expressed on the platelet surface. Furthermore, it has recently been shown that the TLR2/1 agonist Pam(3)CSK(4) stimulates platelet activation. The aim of the present study was to clarify important signalling events in Pam(3)CSK(4)-induced platelet aggregation and secretion. Platelet interaction with Pam(3)CSK(4) and the TLR2/6 agonist MALP-2 was studied by analysing aggregation, ATP-secretion, [Ca2+](i) mobilisation and thromboxane B2 (TxB(2)) production. The results show that Pam(3)CSK(4) but not MALP-2 induces [Ca2+](i) increase, TxB(2) production, dense granule secretion and platelet aggregation. Preincubation of platelets with MALP-2 inhibited the Pam(3)CSK(4)-induced responses. The ATP-secretion and aggregation in Pam(3)CSK(4)-stimulated platelets was impeded by the purinergic P2X(1) inhibitor MRS 2159, the purinergic P2Y(1) and P2Y(12) antagonists MRS 2179 and cangrelor, the phospholipase C inhibitor U73122, the calcium chelator BAPT-AM and aspirin. The calcium mobilisation was lowered by MRS 2159, aspirin and U73122 whereas the TxB(2) production was antagonised by MRS 2159, aspirin and BAPT-AM. When investigating the involvement of the myeloid differentiation factor-88 (MyD88) -dependent pathway, we found that platelets express MyD88 and interleukin 1 receptor-associated kinase (IRAK-1), which are proteins important in TLR signalling. However, Pam(3)CSK(4) did not stimulate a rapid (within 10 minutes) phosphorylation of IRAK-1 in platelets. In conclusion, the results show that Pam(3)CSK(4)-induced platelet aggregation and secretion depends on a P2X(1)-mediated Ca2+ mobilisation, production of TxA(2) and ADP receptor activation. The findings in this study further support a role for platelets in sensing bacterial components.

  • 41.
    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.

  • 42.
    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.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    A medium-throughput microplate-based ex vivo model for measuring intramacrophage growth of mycobacterium tuberculosis in CYTOKINE, vol 48, issue 1-2, pp 14-142009Ingår i: CYTOKINE, 2009, Vol. 48, nr 1-2, s. 14-14Konferensbidrag (Refereegranskat)
    Abstract [en]

    n/a

  • 43.
    Schoultz, Ida
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Kirurgi. Linköpings universitet, Hälsouniversitetet.
    Verma, Deepti
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Cellbiologi. Linköpings universitet, Hälsouniversitetet.
    Halfvarsson, Jonas
    Örebro University Hospital.
    Torkvist, Leif
    Karolinska University Hospital.
    Fredrikson, Mats
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Yrkes- och miljömedicin. Linköpings universitet, Hälsouniversitetet.
    Sjoqvist, Urban
    Karolinska University Hospital.
    Lordal, Mikael
    Karolinska University Hospital.
    Tysk, Curt
    Örebro University Hospital.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Söderkvist, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Cellbiologi. Linköpings universitet, Hälsouniversitetet.
    Söderholm, Johan D
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Kirurgi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Kirurgiska kliniken i Östergötland med verksamhet i Linköping, Norrköping och Motala.
    Combined Polymorphisms in Genes Encoding the Inflammasome Components NALP3 and CARD8 Confer Susceptibility to Crohns Disease in Swedish Men2009Ingår i: American Journal of Gastroenterology, ISSN 0002-9270, E-ISSN 1572-0241, Vol. 104, nr 5, s. 1180-1188Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    OBJECTIVES : Crohns disease (CD) is characterized by overproduction of proinflammatory cytokines like interleukin (IL)-1 beta. Production of mature IL-1 beta is dependent on a caspase-1-activating protein complex called the NALP3 inflammasome, composed of NALP3, ASC, and CARD8. NALP3 shares structural similarities with Nod2, and both of these proteins are required for bacteria-induced IL-1 beta secretion. The combination of the polymorphisms CARD8 (C10X) and NALP3 (Q705K) was recently shown to be associated with rheumatoid arthritis. Our aim was to investigate whether these combined polymorphisms play a role in the susceptibility to CD.

    METHODS: The study included 498 CD patients in two cohorts from different regions and 742 control individuals from a Swedish population. DNA was isolated from whole blood. Polymorphisms of (Q705K) NALP3 and (C10X) CARD8, as well as the Nod2 variants, R702W and G908R, were genotyped using the Taqman single nucleotide polymorphism assay. The Nod2 frameshift mutation, L1007fs, was detected by Megabace SNuPe genotyping.

    RESULTS: Our results show that men who have both the C10X and Q705K alleles in CARD8 and NALP3, and who express wild-type alleles of Nod2 are at an increased risk of developing CD (odds ratio, OR: 3.40 range: 1.32-8.76); P = 0.011). No association with these polymorphisms was found in women (OR: 0.89 (range: 0.44-1.77); P = 0.74).

    CONCLUSIONS: We suggest a role for combined polymorphisms in CARD8 and NALP3 in the development of CD in men, with obvious sex differences in the genetic susceptibility pattern. These findings give further support to the importance of innate immune responses in CD.

  • 44.
    Winberg Tinnerfelt, Martin
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Holm, Åsa
    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.
    Vinet, Adrien F
    INRS, Canada.
    Descoteaux, Albert
    INRS, Canada.
    Magnusson, Karl-Eric
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Rasmusson, Birgitta
    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.
    Leishmania donovani lipophosphoglycan inhibits phagosomal maturation via action on membrane rafts2009Ingår i: Microbes and infection, ISSN 1286-4579, E-ISSN 1769-714X, Vol. 11, nr 2, s. 215-222Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Lipophosphoglycan (LPG), the major surface glycoconjugate on Leishmania donovani promastigotes, is crucial for the establishment of infection inside macrophages. LPG comprises a polymer of repeating Gal beta 1,4Man alpha-PO4 attached to a lysophosphatidylinositol membrane anchor. LPG is transferred from the parasite to the host macrophage membrane during phagocytosis and induces periphagosomal F-actin accumulation correlating with an inhibition of phagosomal maturation. The biophysical properties of LPG suggest that it may be intercalated into membrane rafts of the host-cell membrane. The aim of this study was to investigate if the effects of LPG on phagosomal maturation are mediated via action on membrane rafts. We show that LPG accumulates in rafts during phagocytosis of L. donovani and that disruption of membrane rafts abolished the effects of LPG on periphagosomal F-actin and phagosomal maturation, indicating that LPG requires intact membrane rafts to manipulate host-cell functions. We conclude that LPG associates with membrane rafts in the host cell and exert its actions on host-cell actin and phagosomal maturation through subversion of raft function.

  • 45.
    Verma, Deepti
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Blomgran Julinder, Robert
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Eriksson, Per
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Reumatologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Medicincentrum, Länskliniken för Reumatologi i Östergötland.
    Söderkvist, Peter
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Cellbiologi.
    Särndahl, Eva
    Örebro Universitet, Örebro.
    Gene polymorphisms in the NALP3 inflammasome are associated with interleukin-1 production and severe inflammation: Relation to Common Inflammatory Diseases?2008Ingår i: Arthritis and Rheumatism, ISSN 0004-3591, E-ISSN 1529-0131, Vol. 58, nr 3, s. 888-894Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objective: NALP3, ASC, and TUCAN are components of the NALP3 inflammasome, which triggers caspase 1-mediated interleukin-1β (IL-1β) release. Activating mutations in the gene encoding NALP3 (NLRP3) have recently been linked to familial periodic fever syndromes. We undertook this study to determine whether a patient with arthritis and antibiotic-resistant fever carried mutations in the genes encoding the NALP3 inflammasome.

    Methods: Genetic analysis of NLRP3 and the gene encoding TUCAN (CARD-8) was performed on genomic DNA from the patient and from a population-based collection of DNA (806 subjects). For in vitro studies of IL-1β production and caspase 1 activity, blood was obtained from the patient at different time points after administration of anakinra, an IL-1 receptor antagonist, as well as from 5 healthy age- and sex-matched control subjects.

    Results: Mutation analysis of the patient's genes encoding NALP3, ASC, and TUCAN revealed variations in the NLRP3 (Q705K) and CARD-8 (C10X) genes. The allele frequencies of these single-nucleotide polymorphisms (SNPs) in the population were 6.5% and 34%, respectively. The elevated activity of caspase 1 and the high levels of IL-1β measured in samples from the patient returned to normal levels after treatment with anakinra.

    Conclusion: Our results indicate that the patient's symptoms were due to elevated levels of IL-1β, since treatment with anakinra effectively abolished the symptoms. The compound SNPs may explain the increased IL-1β levels and inflammatory symptoms observed, but further studies are needed to reveal a functional relationship. The prevalence of the polymorphisms (4% of the population carry both SNPs) in the general population may suggest a genetic predisposition for common inflammatory disorders.

  • 46.
    Welin, Amanda
    et al.
    Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Winberg Tinnerfelt, Martin
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Abdalla, Hana
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Särndahl Lindblom, Eva
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Rasmusson, Birgitta
    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.
    Lerm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Incorporation of Mycobacterium tuberculosis lipoarabinomannan into macrophage membrane rafts is a prerequisite for the phagosomal maturation block.2008Ingår i: Infection and Immunity, ISSN 0019-9567, E-ISSN 1098-5522, Vol. 76, nr 7, s. 2882-2887Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Lipoarabinomannan (LAM) is one of the key virulence factors for Mycobacterium tuberculosis, the etiological agent of tuberculosis. During uptake of mycobacteria, LAM interacts with the cell membrane of the host macrophage and can be detected throughout the cell upon infection. LAM can inhibit phagosomal maturation as well as induce a proinflammatory response in bystander cells. The aim of this study was to investigate how LAM exerts its action on human macrophages. We show that LAM is incorporated into membrane rafts of the macrophage cell membrane via its glycosylphosphatidylinositol anchor and that incorporation of mannose-capped LAM from M. tuberculosis results in reduced phagosomal maturation. This is dependent on successful insertion of the glycosylphosphatidylinositol anchor. LAM does not, however, induce the phagosomal maturation block through activation of p38 mitogen-activated protein kinase, contradicting some previous suggestions.

  • 47.
    Ragnarsson, Eva Ge
    et al.
    Uppsala University.
    Schoultz, Ida
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Kirurgi.
    Gullberg, Elisabet
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Kirurgi.
    Carlsson, Anders
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Kirurgi.
    Tafazoli, Farideh
    Linköpings universitet, Institutionen för hälsa och miljö. Linköpings universitet, Hälsouniversitetet.
    Lerm, Maria
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi.
    Magnusson, Karl-Eric
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi.
    Söderholm, Johan D
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Kirurgi. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Kirurgiska kliniken i Östergötland med verksamhet i Linköping, Norrköping och Motala.
    Artursson, Per
    Uppsala University.
    Yersinia pseudotuberculosis induces transcytosis of nanoparticles across human intestinal villus epithelium via invasin-dependent macropinocytosis2008Ingår i: Laboratory Investigation, ISSN 0023-6837, E-ISSN 1530-0307, Vol. 88, nr 11, s. 1215-1226Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Crohns disease is characterized by a defect in intestinal barrier function, where bacteria are considered the most important inflammation-driving factor. Enteric bacteria, including E. coli and Yersinia spp, affect tight junctions in enterocytes, but little is known about bacterial effects on the transcellular pathway. Our objective was to study the short-term effects of Y. pseudotuberculosis on uptake of nanoparticles across human villus epithelium. Monolayers of human colon epithelium-derived Caco-2 cells and biopsies of normal human ileum were studied after 2 h exposure to Y. pseudotuberculosis expressing (inv+) or lacking (inv-) the bacterial adhesion molecule, invasin. Transepithelial transport of fluorescent nanoparticles (markers of transcytosis) was quantified by flow cytometry, and mechanisms explored by using inhibitors of endocytosis. Epithelial expressions of beta 1-integrin and particle uptake pathways were studied by confocal microscopy. The paracellular pathway was assessed by electrical resistance (TER), mannitol flux, and expression of tight junction proteins occludin and caludin-4 by confocal microscopy. Inv + Y. pseudotuberculosis adhered to the apical surface of epithelial cells and induced transcytosis of exogenous nanoparticles across Caco-2 monolayers (30-fold increase, P < 0.01) and ileal mucosa (268 +/- 47% of control; P < 0.01), whereas inv-bacteria had no effect on transcytosis. The transcytosis was concentration-, particle size-and temperature-dependent, and possibly mediated via macropinocytosis. Y. pseudotuberculosis also induced apical expression of beta 1-integrin on epithelial cells. A slight drop in TER was seen after exposure to inv+ Y. pseudotuberculosis, whereas mannitol flux and tight junction protein expression was unchanged. In summary, Y. pseudotuberculosis induced apical expression of beta 1-integrin and stimulated uptake of nanoparticles via invasin-dependent transcytosis in human intestinal epithelium. Our findings suggest that bacterial factors may initiate transcytosis of luminal exogenous particles across human ileal mucosa, thus presenting a novel mechanism of intestinal barrier dysfunction.

  • 48.
    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.

  • 49.
    Lerm, Maria
    et al.
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi.
    Holm, Åsa
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi.
    Seiron, Å
    Särndahl, Eva
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi.
    Magnusson, Karl-Eric
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi.
    Rasmusson, Birgitta
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för molekylär och klinisk medicin, Medicinsk mikrobiologi.
    Leishmania donovani requires functional Cdc42 and Rac1 to prevent phagosomal maturation2006Ingår i: Infection and Immunity, ISSN 0019-9567, E-ISSN 1098-5522, Vol. 74, nr 5, s. 2613-2618Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Leishmania donovani promastigotes survive inside macrophage phagosomes by inhibiting phagosomal maturation. The main surface glycoconjugate on promastigotes, lipophosphoglycan (LPG), is crucial for survival and mediates the formation of a protective shell of F-actin around the phagosome. Previous studies have demonstrated that this effect involves inhibition of protein kinase Cα. The present study shows that functional Cdc42 and Rac1 are required for the formation of F-actin around L. donovani phagosomes. Moreover, we present data showing that phagosomes containing LPG-defective L. donovani, which is unable to induce F-actin accumulation, display both elevated levels of periphagosomal F-actin and impaired phagosomal maturation in macrophages with permanently active forms of Cdc42 and Rac1. We conclude that L. donovani engages Cdc42 and Rac1 to build up a protective coat of F-actin around its phagosome to prevent phagosomal maturation. Copyright © 2006, American Society for Microbiology. All Rights Reserved.

  • 50.
    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.

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