Interleukin 1 activity in the acquired immunodeficiency syndrome.

Interleukin 1 (IL-1) is a monocyte-derived mediator that participates in the regulation of various T-lymphocyte activities, among them IL-2 production. Since IL-2 deficiency is a central feature in the immunological profile of the acquired immunodeficiency syndrome (AIDS), the production of IL-1 from peripheral blood monocytes from male homosexuals with AIDS was investigated at the same time as the IL-1 responsiveness of monocyte-depleted mononuclear cells (MDC) from the same patients. The IL-1 was produced by lipopolysaccharide-stimulated monocytes and assayed by the capacity of monocyte supernatants to amplify the proliferation of phytohaemagglutinin-stimulated allogeneic MDC from healthy donors as well as murine thymocytes. The IL-1 responsiveness was measured by measuring the enhancing effect of an IL-1 standard on the proliferative response of patients' MDC. The IL-1 production was not reduced compared to the IL-1 production in a control group, but the IL-1 responsiveness of the patients' MDC was depressed. The results indicate that depressed IL-1 production is not one of the immunological disturbances in AIDS, but that the T-lymphocyte accessory properties of IL-1 are affected.