Co-infection with Mycobacterium tuberculosis impairs HIV-Specific CD8+ and CD4+ T cell functionality

The ability of antigen-specific T cells to simultaneously produce multiple cytokines is thought to correlate with the functional capacity and efficacy of T cells. These 'polyfunctional' T cells have been associated with control of HIV. We aimed to assess the impact of co-infection with Mycobacterium tuberculosis (MTB) on HIV-specific CD8+ and CD4+ T cell function. We assessed T cell functionality in 34 South African adults by investigating the IFN-y, IL-2, TNF-α, IL-21 and IL-17 cytokine secretion capacity, using polychromatic flow cytometry, following HIV Gag-specific stimulation of peripheral blood mononuclear cells. We show that MTB is associated with lower HIV-specific T cell function in co-infected as compared to HIV mono-infected individuals. This decline in function was greatest in co-infection with active Tuberculosis (TB) compared to co-infection with latent MTB (LTBI), suggesting that mycobacterial load may contribute to this loss of function. The described impact of MTB on HIV-specific T cell function may be a mechanism for increased HIV disease progression in co-infected subjects as functionally impaired T cells may be less able to control HIV.

Authors: 
S Chetty
P Govender
J Zupkosky
M Pillay
M Ghebremichael
MY Moosa
T Ndung'u
F Porichis
VO Kasprowicz
Journal: 
PLoS One
Volume: 
10
Issue: 
3
Publication Date: 
March, 2015
IBN number: 
10.1371/journal.pone.0118654