Immunoregulatory circuits in the acquired immune deficiency syndrome and related complex. Production of and response to interleukins 1 and 2, NK function and its enhancement by interleukin-2 and kinetics of the autologous mixed lymphocyte reaction.

The production of the T cell lymphokine interleukin-2 (IL-2) was found to impaired in all of seven male patients with AIDS or homosexuals with persistent generalized lymphadenopathy (AIDS related complex, AIDS-RC) whom we studied. Conversely the T cell response to IL-2 was found unimpaired as was the production of the monocyte factor interleukin-1 (IL-1). The response of T cells to IL-1 was found markedly decreased in two of the four patients with AIDS and in two of the three patients with AIDS-RC. Five of six patients had flat curves in autologous mixed lymphocyte cultures with no significant proliferative response throughout 7 days. The exception was a Haitian heterosexual patient with AIDS. Natural killer cell function was decreased in three of four patients with AIDS and two of three patients with AIDS-RC but it augmented normally in the presence of IL-2 in four, including the two who had it normal basally. Responses to pokeweed mitogen were within normal limits in all seven patients despite decreased responses to concanavalin A and phytohaemagglutinin. These findings help pinpoint the defect in AIDS to the T4+ cell, and perhaps even to one of its subpopulations, and suggest a role for IL-2 in the treatment of AIDS.