Analysis of the proliferative responses to peptides in individuals with vigorous Gag protein-specific proliferation

Proliferative responses to recombinant HIV proteins in infected individuals may represent a correlate of protection from disease progression. In this study, the proliferative responses to HIV p24, p55 and gp120 were evaluated in infected subjects. Whereas, vigorous proliferative responses directed at the Gag proteins were detected in several individuals, Env-specific proliferation was observed in only one subject. Epitope mapping using overlapping peptides demonstrated proliferative responses of PBMC to Gag peptides. Responses were broadly directed at multiple peptides in some subjects. Although several of the peptides that induced proliferative responses also contain CTL epitopes potentially relevant in the particular individuals, many additional Gag T cell epitopes were present in each subject. This finding may be relevant for the design and testing of HIV candidate vaccines.