Development of Skewed Functionality of HIV-1-Specific Cytotoxic CD8+ T Cells from Primary to Early Chronic Phase of HIV Infection

In recent years, the prevalence of HIV-1 infection has been rapidly increasing among men who have sex with men (MSM). However, it remains unknown how the host immune system responds to the infection in this population. We assessed the quantity of HIV-specific CD8(+) T-cell responses by using Elispot assay and their functionalities by measuring 5 CD8(+) T-cell evaluations (IL-2, MIP-1β, CD107a, TNF-α, IFN-γ) with flow cytometry assays among 18 primarily and 37 early chronically HIV-infected MSM. Our results demonstrated that subjects at early chronic phase developed HIV-specific CD8(+) T-cell responses with higher magnitudes and more diversified functionalities in comparison with those at primary infection. However, populations with IL-2(+) CD107a(+) or in combination with other functionality failed to develop in parallel. The multifunctional but not monofunctional HIV-specific CD8(+) T cells were associated with higher CD4(+) T -cell counts and lower viral loads. These data revealed that prolonged infection from primary to early chronic infection could selectively increase the functionalities of HIV-specific CD8(+) T cells in HIV-infected MSM population, the failure to develop IL-2 and cytotoxic functionalities in parallel may explain why the increased HIV-specific CD8(+) T cells were unable to enhance the containment of HIV-1 replication at the early chronic stage.