HIV type 1 vaccine-induced T cell memory and cytotoxic T lymphocyte responses in HIV type 1-uninfected volunteers

T cell memory to human immunodeficiency virus type 1 (HIV-1) antigens and a nti-HIV-1 cytotoxic T lymphocyte (CTL) activity were assessed after adminis tration of live canarypox virus (ALVAC) expressing HIV-1 env, gag, and prot ease (vCP205) vaccine given alone, vCP205 given with SF-2 recombinant gp120 (rgp120) vaccine, and placebos at 0, 1, 3, and 6 months. Healthy, HIV-1-un infected subjects reporting high-risk and low-risk behavior for HIV-1 were enrolled. Anti-HIV-1 Env CD8(+) CTLs (HIV-1(MN) and/or HIV-1 subtype B and C primary isolate sequences) were detected in 12 (60%) and anti-HIV-1 Gag C D8(+) CTLs in 7 (35%) of the 20 vCP205 vaccine recipients tested by CTL ass ay 3.5 months after the final immunization. Fourteen days after the fourth immunization, lymphocyte proliferation in response to HIV-1 Gag antigen was detected in 14 (48%) of 29 vCP205 vaccine recipients, but secreted cytokin e levels to HIV-1 Gag antigen were not above unstimulated levels. Coadminis tration of SF-2 rgp120 vaccine with vCP205 vaccine enhanced lymphocyte prol iferation in response to HIV-1 envelope glycoprotein and broadened the enve lope-stimulated cytokine secretion pattern, so that it consisted of both Th 1 and Th2 cytokines compared with only interferon gamma (IFN-gamma) after v CP205 vaccine given alone. There was a possible association between HIV-1 e nvelope glycoprotein-stimulated interleukin 2 secretion and CD8(+) CTLs aga inst HIV-1 envelope glycoprotein, and an inverse relation between lymphocyt e proliferation and CTLs against HIV-1 Gag antigens. Thus, a durable anti-H IV-1 CD8+ CTL response was detected after immunization with the live canary pox virus vaccine and preexisting helper T cell memory responses did not ne cessarily predict later CD8(+) CTL activity.