Tuberculosis (TB) and sarcoidosis are both granulomatous diseases. Here, we compared the immunological microenvironments of granulomas from TB and sarcoidosis patients using sequencing (ISS) transcriptomic analysis and multiplexed immunolabeling of tissue sections. TB lesions consisted of large necrotic and cellular granulomas, whereas "multifocal" granulomas with macrophages or epitheloid cell core and a T-cell rim were observed in sarcoidosis samples.
View Article and Find Full Text PDFMatrix-M™ adjuvant is a key component of several novel vaccine candidates. The Matrix-M adjuvant consists of two distinct fractions of saponins purified from the Molina tree, combined with cholesterol and phospholipids to form 40-nm open cage-like nanoparticles, achieving potent adjuvanticity with a favorable safety profile. Matrix-M induces early activation of innate immune cells at the injection site and in the draining lymph nodes.
View Article and Find Full Text PDFDiabetes mellitus (DM) increases the risk of developing tuberculosis (TB), but the mechanisms behind diabetes-TB comorbidity are still undefined. Here, we studied the role of hypoxia-inducible factor-1 (HIF-1), a main regulator of metabolic and inflammatory responses, in the outcome of Mycobacterium tuberculosis infection of bone marrow-derived macrophages (BMM). We observed that M.
View Article and Find Full Text PDFThe hypoxia-inducible factors (HIFs) regulate the main transcriptional pathway of response to hypoxia in T cells and are negatively regulated by von Hippel-Lindau factor (VHL). But the role of HIFs in the regulation of CD4 T cell responses during infection with M. tuberculosis isn't well understood.
View Article and Find Full Text PDF(Mtb) bacilli are the causative agent of tuberculosis (TB), a major killer of mankind. Although it is widely accepted that local interactions between Mtb and the immune system in the tuberculous granuloma determine whether the outcome of infection is controlled or disseminated, these have been poorly studied due to methodological constraints. We have recently used a spatial transcriptomic technique, sequencing (ISS), to define the spatial distribution of immune transcripts in TB mouse lungs.
View Article and Find Full Text PDFThe suppressor of cytokine signaling 3 (SOCS3) is a major regulator of immune responses and inflammation as it negatively regulates cytokine signaling. Here, the role of SOCS3 in thymic T cell formation was studied in mice (Δ with a tamoxifen inducible and ubiquitous deficiency. Δ thymi showed a 90% loss of cellularity and altered cortico-medullary organization.
View Article and Find Full Text PDFSpecific T cell responses are central for protection against infection with . Here we show that mycobacteria-specific CD4 and CD8 T cells accumulated in the lung but not in the mediastinal lymph node (MLN) at different time points after infection or BCG immunization. Proliferating specific T cells were found in the lung after infection and immunization.
View Article and Find Full Text PDFTRIM21 is an interferon-stimulated E3 ligase that controls the activity of pattern-recognition signaling via ubiquitination of interferon regulatory factors and DDX41. Previous studies on the role of TRIM21 in innate immune responses have yielded contradictory results, suggesting that the role of TRIM21 is cell specific. Here, we report that bone-marrow-derived macrophages (BMDMs) generated from Trim21 mice have reduced expression of mature macrophage markers.
View Article and Find Full Text PDFGranulomas are the pathological hallmark of tuberculosis (TB) and the niche where bacilli can grow and disseminate or the immunological microenvironment in which host cells interact to prevent bacterial dissemination. Here we show 34 immune transcripts align to the morphology of lung sections from Mycobacterium tuberculosis-infected mice at cellular resolution. Colocalizing transcript networks at <10 μm in C57BL/6 mouse granulomas increase complexity with time after infection.
View Article and Find Full Text PDFSTAT3 is a master regulator of the immune responses. Here we show that M. tuberculosis-infected stat3fl/fl lysm cre mice, defective for STAT3 in myeloid cells, contained lower bacterial load in lungs and spleens, reduced granuloma extension but higher levels of pulmonary neutrophils.
View Article and Find Full Text PDFTuberculosis (Edinb)
December 2017
CISH gene has been associated with increased susceptibility to human tuberculosis. We found that cish mice had higher M. tuberculosis load in spleens and lungs up to 2.
View Article and Find Full Text PDFThe obligate intracellular parasite can actively infect any nucleated cell type, including cells from the immune system. The rapid transfer of from infected dendritic cells to effector natural killer (NK) cells may contribute to the parasite's sequestration and shielding from immune recognition shortly after infection. However, subversion of NK cell functions, such as cytotoxicity or production of proinflammatory cytokines, such as gamma interferon (IFN-γ), upon parasite infection might also be beneficial to the parasite.
View Article and Find Full Text PDFConditional gene targeting using the bacteriophage-derived Cre recombinase is widely applied for functional gene studies in mice. Mice transgenic for Cre under the control of the lck gene promoter are used to study the role of loxP-targeted genes in T cell development and function. In this article, we show a striking 65% reduction in cellularity, preferential development of γδ versus αβ T cells, and increased expression of IL-7R in the thymus of mice expressing Cre under the proximal lck promoter (lck-cre(+) mice).
View Article and Find Full Text PDFIn our review, we address the role of signal transducer and activator of transcription-3 (STAT3) and suppressor of cytokine signaling-3 (SOCS3) in the outcome of Mycobacterium tuberculosis infection, focusing on functions of these molecules in regulating the biology of myeloid and lymphoid cells. The STAT3 transcription factor has paradoxical roles: mainly activating an anti-inflammatory program in myeloid cells while promoting the differentiation and activation of inflammatory T cells. STAT3 is a major player in all phases of T cell responses, including T cell subset differentiation, T cell activation, and generation of memory.
View Article and Find Full Text PDFIn this review, we describe the role of suppressor of cytokine signaling-3 (SOCS3) in modulating the outcome of infections and autoimmune diseases as well as the underlying mechanisms. SOCS3 regulates cytokine or hormone signaling usually preventing, but in some cases aggravating, a variety of diseases. A main role of SOCS3 results from its binding to both the JAK kinase and the cytokine receptor, which results in the inhibition of STAT3 activation.
View Article and Find Full Text PDFIn this study, we explored the local cytokine/chemokine profiles in patients with active pulmonary or pleural tuberculosis (TB) using multiplex protein analysis of bronchoalveolar lavage and pleural fluid samples. Despite increased pro-inflammation compared to the uninfected controls; there was no up-regulation of IFN-γ or the T cell chemoattractant CCL5 in the lung of patients with pulmonary TB. Instead, elevated levels of IL-4 and CCL4 were associated with high mycobacteria-specific IgG titres as well as SOCS3 (suppressors of cytokine signaling) mRNA and progression of moderate-to-severe disease.
View Article and Find Full Text PDFSuppressor of cytokine signalling 3 (SOCS3) negatively regulates STAT3 activation in response to several cytokines such as those in the gp130-containing IL-6 receptor family. Thus, SOCS3 may play a major role in immune responses to pathogens. In the present study, the role of SOCS3 in M.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
April 2013
We have used humanized mice, in which human immune cells differentiate de novo from transplanted cord blood progenitor cells, to study the human immune responses to infection with Mycobacterium bovis bacillus Calmette-Guérin and Mycobacterium tuberculosis. Granulomas with a core containing giant cells, human CD68(+) macrophages, and high bacilli numbers surrounded by a layer of CD3(+) T cells and a fibrotic response encapsulating the lesions were observed in livers and lungs from bacillus Calmette-Guérin-infected humanized mice but not in nonhumanized infected controls. Paradoxically, humanized mice contained higher mycobacterial numbers in organs than nonhumanized controls.
View Article and Find Full Text PDFBackground: Appropriate immune activation of T cells and macrophages is central for the control of Mycobacterium tuberculosis infections. IFN-γ stimulated responses are lowered in tuberculosis (TB), while expression of Suppressor of Cytokine Signaling (SOCS) molecules - 1 and 3 and CD4+CD25+FoxP3+T regulatory cells is increased. Here we investigated the association of these molecules in regard to clinical severity of TB.
View Article and Find Full Text PDFHepatic steatosis is a prominent feature in patients with growth hormone (GH) deficiency. The ubiquitin ligase SOCS2 attenuates hepatic GH signaling by inhibiting the Janus kinase 2 (JAK2)-signal transducer and activator of transcription 5b (STAT5b) axis. Here, we investigated the role of SOCS2 in the development of diet-induced hepatic steatosis and insulin resistance.
View Article and Find Full Text PDFRecent studies suggest that SOCS2 is involved in the regulation of TLR signaling. In this study, we found that the expression of SOCS2 is regulated in human monocyte-derived DC by ligands stimulating TLR2, 3, 4, 5, 8 and 9 signaling. SOCS2 induction by LPS was dependent on the type I IFN regulated transcription factors IRF1 and IRF3 as shown by using silencing RNAs for IRFs.
View Article and Find Full Text PDFProtection against infection with Mycobacterium tuberculosis demands IFN-γ. SOCS1 has been shown to inhibit responses to IFN-γ and might thereby play a central role in the outcome of infection. We found that M.
View Article and Find Full Text PDFMonitoring the spread of mycobacterium in vivo using biophotonic imaging provides a fast, reliable and sensitive method to evaluate the distribution of the infection. Moreover, this technique allows for a significant reduction in the number of animals required in comparison to conventional anatomopathological studies. Here, we describe for the first time and validate the use of a luciferase-tagged recombinant Mycobacterium bovis BCG for non-invasive bioluminescent imaging of 1) bacterial dissemination in tissues, 2) the efficacy of treatment with anti-mycobacterial drugs and 3) the role of adaptive immune responses in controlling mycobacterial infection in vivo.
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