The CD160+ CD8high cytotoxic T cell subset correlates with response to HAART in HIV-1+ patients

We investigated the circulating cytotoxic CD160+ CD8high subset in correlation to antiviral immunity and response to highly active antiretroviral therapy (HAART) in HIV+ subjects. The study included 45 treatment-naive patients receiving HAART for 18 months, retrospectively defined as good (n = 29) and transient (n = 16) responders. HIV-specific CD8 T lymphocyte levels were measured by IFNγ production in response to p17 Gag, in the presence of immobilized anti-CD160 mAb. We report a significantly increased baseline level of CD160+ CD8high subset in good therapy responders. CD160+ CD8high subset correlates with CD4+ T cell count, immune activation, and viral load. CD160+ CD8high lymphocytes contain a high amount of Granzyme B and include virus-specific T lymphocytes in HIV-1+ subjects. Co-stimulation through CD160 molecules enhances IFNγ production in response to p17 Gag. Therefore, the CD160+ CD8high subset may be useful for monitoring of virus-specific cellular immunity and predicting response to antiretroviral therapy in chronic HIV-1 infection.