Cellular immune response to viral peptides in patients exposed to HIV.

In efforts to identify B cell and T cell epitopes of HIV-1 structural components, serum as well as lymphocytes from HIV-1-seropositive individuals were reacted with several recombinant and native peptides representing defined viral gag and env determinants. Several areas of discordance between humoral and cellular reactivity were identified. Specifically, the principal neutralizing site within HIV-1, the major envelope glycoprotein gp120, failed to elicit detectable cellular reactivities. The carboxyl portion of gp120 and the transmembrane gp41 region were uniformly recognized by patient antibodies but did not produce significant lymphocyte blastogenesis. However, the amino half of gp120 elicited cellular responses in a majority of the immunocompetent individuals tested, despite its extremely low reactivity with patient sera. Last, the major HIV-1 structure component p24 was found to be the most consistent T cell activation antigen among the panel tested.