Granulocytes act as a niche for Mycobacterium tuberculosis growth
Autor: | Rustin R. Lovewell, Christina E. Baer, Christopher M. Sassetti, Bibhuti B. Mishra, Clare M. Smith |
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Rok vydání: | 2021 |
Předmět: |
0301 basic medicine
Tuberculosis Immunology Granulocyte Severity of Illness Index Article Lymphocyte Depletion Immunophenotyping Mycobacterium tuberculosis Mice 03 medical and health sciences 0302 clinical medicine Immunopathology medicine Animals Immunology and Allergy Pathogen Mice Knockout Lung biology Gene Expression Profiling Acquired immune system medicine.disease biology.organism_classification Bacterial Load Chemotaxis Leukocyte 030104 developmental biology medicine.anatomical_structure Host-Pathogen Interactions Cytokines Disease Susceptibility Inflammation Mediators Biomarkers Intracellular Granulocytes 030215 immunology |
Zdroj: | Mucosal immunology |
ISSN: | 1933-0219 |
Popis: | Granulocyte recruitment to the pulmonary compartment is a hallmark of progressive tuberculosis (TB). This process is well-documented to promote immunopathology, but can also enhance the replication of the pathogen. Both the specific granulocytes responsible for increasing mycobacterial burden and the underlying mechanisms remain obscure. We report that the known immunomodulatory effects of these cells, such as suppression of protective T-cell responses, play a limited role in altering host control of mycobacterial replication in susceptible mice. Instead, we find that the adaptive immune response preferentially restricts the burden of bacteria within monocytes and macrophages compared to granulocytes. Specifically, mycobacteria within inflammatory lesions are preferentially found within long-lived granulocytes that express intermediate levels of the Ly6G marker and low levels of antimicrobial genes. These cells progressively accumulate in the lung and correlate with bacterial load and disease severity, and the ablation of Ly6G-expressing cells lowers mycobacterial burden. These observations suggest a model in which dysregulated granulocytic influx promotes disease by creating a permissive intracellular niche for mycobacterial growth and persistence. |
Databáze: | OpenAIRE |
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