A Phase I Safety and Immunogenicity Trial of HIV-1 gp120 C4-V3 Hybrid Polyvalent Peptide Immunogen Mixed in Mineral Oil Containing Mannose Mono-Oleate (IFA)

To evaluate the safety of HIV-1 gp120 C4-V3 hybrid polyvalent peptide immunogen (C4-V3 peptides) formulated in mineral oil containing mannose mono-oleate (IFA) in HIV-1 uninfected volunteers. To evaluate the humoral and cellular immune responses to the C4-V3 peptides as measured by the induction of 1 or more of the following: neutralizing antibodies to HIV-1 MN and RF, cross-neutralizing antibodies to primary isolates of HIV-1, HIV-1 antigen-specific lymphoproliferation, CD8+ and CD4+ cytotoxic T lymphocyte (CTL) activity specific for HIV-1 gp120 or V3 peptides corresponding to the vaccine strains of HIV-1, induction of HLA-B7 and HLA-A2 restricted CD8+CTLs, and induction of HIV-specific DTH responses. The test immunogen (C4-V3 peptides) is constructed from 4 sequences of the HIV-1 V3 gp120 loop shared by approximately 80% of North American HIV-1 strains. Because of the critical role that this region plays in generating anti-HIV sequences, it is hypothesized that the test immunogen (C4-V3 peptides) will be capable of inducing a broad range of cross-reactive neutralizing antibodies in the majority of recipients. The test immunogen (C4-V3 peptides) is constructed from 4 sequences of the HIV-1 V3 gp120 loop shared by approximately 80% of North American HIV-1 strains. Because of the critical role that this region plays in generating anti-HIV sequences, it is hypothesized that the test immunogen (C4-V3 peptides) will be capable of inducing a broad range of cross-reactive neutralizing antibodies in the majority of recipients. Twenty-eight volunteers are randomized to receive two 0.5 ml injections of C4-43 peptides in IFA or placebo (IFA alone) administered intramuscularly at 0, 1, 6, and 12 months. At least 50% of all volunteers (6 per Groups I and II; 2, Group III) must be HLA-B7 phenotype.