Interleukin-12 enhancement of antigen-specific lymphocyte proliferation correlates with stage of human immunodeficiency virus infection

The effect of interleukin (IL)-12 on T lymphocyte function was assessed in 47 human immunodeficiency virus (HIV)-infected persons of different disease stages and 16 seronegative controls. Lymphoproliferative responses (LPR) were measured to various HIV and non-HIV antigens and mitogens using peripheral blood mononuclear cells cultured with or without IL-12. Without exogenous IL-12, 96% of HIV-seropositive persons responded to mitogens, 77% to sl non-HIV antigen, and 11% to greater than or equal to 1 HIV antigen. Supplementation with IL-12 augmented LPR of HIV-seropositive persons to non-HIV antigens; however, the effect was greatest for those with higher CD4 cells (40% vs. 9% for those with >200 vs. less than or equal to 200 CD4 cells/mm(3)). Addition of IL-12 also enhanced LPR to HIV antigens in 30% of subjects. This effect was most pronounced for those with >500 CD4 cells/mm(3) (56% [P < .05]). These findings suggest that impaired T lymphocyte recognition of foreign antigen, including HIV, can be reconstituted in part for selected HIV-seropositive persons.