LYMPHOPROLIFERATIVE RESPONSE TO SYNTHETIC V3 LOOP P18 PEPTIDE AND HIV-1 ENVELOPE GLYCOPROTEIN AMONG INDIVIDUALS IMMUNIZED WITH GP160 CANDIDATE VACCINES

Because T-cell responses are critical for defense against viral infect ions, the synthetic P18 peptide (RIQRGPGRAFVTIGK) and active component of gp160 protein has previously been shown to induce cytotoxic and he lper T-lymphocyte responses. In order to further define the T-helper c ells, responses which are known to play a role in enhancing the immuno logical response to foreign antigen, we studied the response of indivi duals immunized with HIV gp160 candidate vaccines. We investigated the proliferative cellular response of peripheral blood mononuclear cells (PBMC) derived from individuals immunized with gp160 antigens in thre e different protocols. We found a PBMC proliferative response to synth etic P18 peptide in healthy immunized individuals induced by Sp160 ant igen with or without vaccinia virus, There was correlation between the proliferative response to P18 peptide and other antigens such as HIV- like proteins and gp160 molecule, HLA-DR typing revealed the possible presentation of P18 peptide by several different class II molecules, S ince these class II molecules occur frequently in the general populati on, P18 peptide appears to contain broadly reactive epitopes and thus is presented by mutiple HLA class II molecules. Due to its broad react ivity P18 peptide is one of the candidates For inclusion as a subunit vaccine against HIV-1.