Clonal analysis of T-cell responses to the HIV-1 envelope proteins in AIDS vaccine recipients.

Both CD4+ and CD8+ CTL responses specific for the HIV-1 envelope proteins can be elicited in seronegative humans by candidate AIDS vaccines. The phenotype of the responding CTL depends upon the nature of the vaccine, with CD8+ CTL being found exclusively in recipients of live virus vaccines. Both types of CTL are active against HIV-1-infected cells in vitro. However, the potential efficacy of vaccine-induced CTL in preventing infection in vaccinated individuals exposed to HIV-1 is unknown and is likely to be dependent upon complex factors including lytic activity against divergent strains, cytokines produced, and the lysis of noninfected CD4+ T cells.