Impaired Degranulation and Proliferative Capacity of Mycobacterium tuberculosis-Specific CD8+ T Cells in HIV-Infected Individuals With Latent Tuberculosis

Human immunodeficiency virus (HIV)-infected individuals with latent Mycobacterium tuberculosis infection have substantially higher rates of progression to active tuberculosis than HIV-uninfected individuals with latent tuberculosis. To explore HIV-induced deficits in M. tuberculosis-specific CD8(+) T-cell functions, we compared interferon. production, degranulation, and proliferation of CD8(+) T cells in response to M. tuberculosis peptides (ESAT-6/CFP-10) between HIV-infected (median CD4(+) T-cell count, 522 cells/mu L; interquartile range, 318-585 cells/mu L) and HIV-uninfected individuals with latent tuberculosis from South Africa. We found that M. tuberculosis-specific degranulation and proliferative capacities were impaired in the HIV-infected group. Thus, our results suggest that HIV coinfection compromises CD8(+) T-cell functions in latent tuberculosis.