Dysfunctional bronchoalveolar effector memory CD8 T cells in tuberculosis-exposed people living with antiretroviral-naïve HIV infection.

HIV causes susceptibility to respiratory pathogens, including tuberculosis (TB), but the underlying immunological mechanisms remain incompletely understood. We obtained whole blood and bronchoalveolar lavage (BAL) from TB-exposed people in the presence or absence of antiretroviral-naïve HIV co-infection. Bulk transcriptional profiling demonstrated compartment-specific enrichment of immunological processes. Systems-level deconvolution of whole blood from people living with HIV identified elevated type I and type II interferon cytokine activity and T cell proliferation. Transcriptional modules derived from both peripheral blood and sorted BAL immune cells demonstrated an increased frequency of effector memory CD8 T cells in whole BAL samples. Both compartments displayed reduced induction of CD8 T-cell-derived interleukin-17A (IL-17A) in people with HIV, associated with elevated T cell regulatory molecule expression. The data suggest that dysfunctional CD8 T cell responses in uncontrolled HIV may contribute to compromised respiratory immunity to pathogens, a process that could be modulated by host-directed therapies that target CD8 T cell effector functions.