Production of CD8⁺ T cell nonlytic suppressive factors by CD28, CD38, and HLA-DR subpopulations

HIV infection may be modified by CD8⁺ T cells by the production of nonlytic antiviral factors. To determine subpopulations that mediate nonlytic, antiviral activity, we examined the production of β chemokines and of CD8 antiviral factor (CAF) by different subsets, using CD8⁺ cells derived from 24 HIV-1-infected and 25 uninfected individuals. Subjects with CD8⁺ cell counts greater than 200/μl produced increased levels of MIP-1α by CD8⁺CD28⁺, CD8⁺CD38^-, and CD8⁺HLA-DR⁺ subsets as compared with uninfected controls. CD8⁺CD38^- cells produced higher levels of MIP-1β and RANTES. CAF production was increased by CD8⁺CD38⁺ and CD8⁺HLA-DR⁺ cells of HIV-infected individuals as compared with uninfected controls. Chemokine production was increased by cells that do not express activation markers, whereas CAF activity was increased by cells expressing CD38 or HLA-DR. These findings shed light on CD8⁺ T cell noncytotoxic antiviral factor production during HIV infection.