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.