NEF AND GAG SYNTHETIC PEPTIDE PRIMING OF ANTIBODY-RESPONSES TO HIV TYPE-1 ANTIGENS IN MICE AND PRIMATES

T epitope mapping in human immunodeficiency virus proteins provides a useful tool for AIDS vaccine design. We have previously shown that fou r peptides selected from the Gag polyprotein of HIV-1 were able to pri me mice for in vitro lymphoproliferative responses. These responses we re shown to be MHC restricted, and a pool of these peptides was able t o prime mice for a subsequent humoral response to HIV-1 Gag proteins. Here we show that two of these Gag peptides are able to prime the anti -HIV-1 IgG response to heat-inactivated HIV-1 in B10Sc.Cr mice. Furthe rmore, we extended this study in the nonhuman primate model, and show efficient priming of the IgG response to heat-inactivated HIV-1 using the pool of four Gag peptides in baboons. Further mapping of ''nonself ' peptides is extended to the HIV-1 Nef protein. Three potential Nef T epitopes located at positions 137-145, 98-107, and 81-95 are also sho wn to prime the IgG response to HIV-1 in the mouse model, although T c ell proliferation to recall peptides' in vitro was not detectable. Alt hough they have not yet been defined as major helper T epitopes in hum ans, using classic in vitro stimulation assays, the fact that most of them are able to prime IgG responses in animals without detectable in vitro proliferative responses does not rule out their functional helpe r capacity in humans.