Mycobacterium tuberculosis resisters despite HIV exhibit activated T cells and macrophages in their pulmonary alveoli

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Abstract

BACKGROUND Natural resistance to Mycobacterium tuberculosis (Mtb) infection in some people with HIV (PWH) is unexplained.METHODS We performed single cell RNA-sequencing of bronchoalveolar lavage cells, unstimulated or ex vivo stimulated with Mtb, for 7 PWH who were tuberculin skin test (TST) and IFN-γ release assay (IGRA) positive (called LTBI) and 6 who were persistently TST and IGRA negative (called resisters).RESULTS Alveolar macrophages (AM) from resisters displayed a baseline M1 macrophage phenotype while AM from LTBI did not. Resisters displayed alveolar lymphocytosis, with enrichment of all T cell subpopulations including IFNG-expressing cells. In both groups, mycobactericidal granulysin was expressed almost exclusively by a T cell subtype that coexpressed granzyme B, perforin and NK cell receptors. These poly-cytotoxic T lymphocytes (poly-CTL) overexpressed activating NK cell receptors and were increased in resister BAL. Following challenge with Mtb, only intraepithelial lymphocyte-like cells from LTBI participants responded with increased transcription of IFNG. AM from resisters responded with a stronger TNF signature at 6 hours after infection while at 24 hours after infection, AM from LTBI displayed a stronger IFN-γ signature. Conversely, at 24 hours after infection, only AM from resisters displayed an upregulation of MHC class I polypeptide–related sequence A (MICA) transcripts, which encode an activating ligand for poly-CTL.CONCLUSION These results suggest that poly-CTL and M1-like pre-activated AM mediate the resister phenotype in PWH.FUNDING National Institutes of Health. Canadian Institutes of Health Research. Digital Research Alliance of Canada. French National Research Agency. French National Agency for Research on AIDS and Viral Hepatitis. St. Giles Foundation. General Atlantic Foundation. South African Medical Research Council Centre for Tuberculosis Research.

Authors

Monica Dallmann-Sauer, Vinicius M. Fava, Stephanus T. Malherbe, Candice E. MacDonald, Marianna Orlova, Elouise E. Kroon, Aurélie Cobat, Stéphanie Boisson-Dupuis, Eileen G. Hoal, Laurent Abel, Marlo Möller, Jean-Laurent Casanova, Gerhard Walzl, Nelita Du Plessis, Erwin Schurr