Mucosal‐associated invariant T cells and Vδ2+ γδ T cells in community acquired pneumonia: association of abundance in sputum with clinical severity and outcome. (24th October 2019)

• Record Type: Journal Article
• Authors: Hannaway, R. F.; Wang, X.; Schneider, M.; Slow, S.; Cowan, J.; Brockway, B.; Schofield, M. R.; Morgan, X. C.; Murdoch, D. R.; Ussher, J. E.
• Is Part Of: Clinical and experimental immunology. Volume 199:Number 2(2020)
• Page Start: 201
• Page End: 215
• Publication Date: 2019-10-24
• Subjects: community‐acquired pneumonia -- gamma delta T cells -- MAIT cells -- qPCR -- severity -- Vδ2+ T cells; Immunopathology -- Periodicals; 616.079
• DOI: 10.1111/cei.13377
• Languages: English
• ISSNs: 0009-9104

Abstract

Summary: Mucosal‐associated invariant T (MAIT) cells and Vδ2 + γδ T cells are anti‐bacterial innate‐like lymphocytes (ILLs) that are enriched in blood and mucosa. ILLs have been implicated in control of infection. However, the role of ILLs in community‐acquired pneumonia (CAP) is unknown. Using sputum samples from a well‐characterized CAP cohort, MAIT cell and Vδ2 + T cell abundance was determined by quantitative polymerase chain reaction (qPCR). Cytokine and chemokine concentrations in sputum were measured. The capacity of bacteria in sputum to produce activating ligands for MAIT cells and Vδ2 + T cells was inferred by 16S rRNA sequencing. MAIT cell abundance in sputum was higher in patients with less severe pneumonia; duration of hospital admission was inversely correlated with both MAIT and Vδ2 + T cell abundance. The abundance of both ILLs was higher in patients with a confirmed bacterial aetiology; however, there was no correlation with total bacterial load or the predicted capacity of bacteria to produce activating ligands. Sputum MAIT cell abundance was associated with interferon (IFN)‐α, IFN‐γ, and sputum neutrophil abundance, while Vδ2 + T cell abundance was associated with CXCL11 and IFN‐γ. Therefore, MAIT and Vδ2 + T cells can be detected in sputum in CAP, where they may contribute to improved clinical outcome. Abstract : Mucosal‐associated invariant T (MAIT) cells and Vδ2 + γδ T cells are innate‐like lymphocytes that are abundant in humans in blood and at mucosal surfaces, including the lungs. They provide rapid effector responses upon activation by specific ligands produced by a broad range of bacteria, including numerous pulmonary pathogens. Here we show that MAIT and Vδ2 + γδ T cells can be detected in sputum in patients with community acquired pneumonia, where they may contribute to improved clinical outcome.