Suppression of concanavalin A-induced blastogenesis by HTLV-III-infected H9 cells

The ability of cells infected with human T lymphotropic virus type III (HTLV-III) to suppress lymphocyte responses to concanavalin A (ConA) was evaluated. Thirty homosexual men, both HTLV-III seropositive and seronegative, and 11 seronegative laboratory personnel were studied. Peripheral blood lymphocytes from all groups had lower responses to ConA in the presence of HTLV-III-infected H9 cells than in the presence of uninfected H9 cells. Among HTLV-III-seropositive males, responses to ConA in the presence of infected or uninfected H9 cells correlated with the number of T4 cells present. The studies suggest that HTLV-III-infected cells can suppress normal lymphocyte responses. Possible mechanisms of this suppression are discussed.