T cell immune responses to HIV-1.

The recent use of multiparametric flow cytometry to monitor T cell immune responses complements traditional assays, such as IFN-gamma ELISPOT, to provide more information on the functional complexity of CD4+ and CD8+ T cell immune responses induced either by natural infection, or by immunization. In this review, we provide a general background on T cell subsets, and describe the cellular immune response during natural HIV-1 infection. We then review T cell responses to current candidate HIV-1 vaccines. Taken together, this helps to formulate our understanding of the immune correlates of protection required for an effective prophylactic HIV-1 vaccine. Finally, we emphasize current dendritic cell based vaccine strategies designed to modulate immunity to establish immune protection against HIV-1.