Use of well-defined HIV-derived epitopes to evaluate CD4(+) and CD8(+) T cell responses in patients with chronic HIV-1 infection treated with HAART.

Highly active antiretroviral therapy (HAART) is associated with a dramatic clinical benefit to HIV-infected patients through significant plasma viremia reduction and CD4+ T cells increase. In previous reports, HIV-specific CD4+ and/or CD8+ T cell responses have been studied separately during HAART; therefore the relationship between these two virus-specific populations is currently not well understood. In this study, both HIV-specific CD4+ and CD8+ T cell responses were investigated using a large panel of well-defined T cell epitope peptides in 24 HIV-1-infected patients undergoing HAART, with undetectable viral load and CD4+ T cell count ≥ 350/mm3. One-third of the patients had CD4+ T cells able to proliferate when exposed to HIV-1 protein fragments but only two patients displayed polyclonal responses. In addition the majority (78%) of HAART-treated patients displayed no or monospecific CD8+ T cell responses and the phenotypic analysis of these HIV-specific CD8+ T cells demonstrated the absence of termin...