Microbicidal activity of monocyte derived macrophages in AIDS and related disorders.

We have examined the ability of monocyte-derived macrophages from patients with AIDS and other HIV-related disorders to kill the intracellular pathogen Toxoplasma gondii. We have also examined the capacity of peripheral blood mononuclear cells from these patients to produce macrophage-activating and other lymphokines. The capacity to produce interleukin 2 and gamma interferon decreases from controls through asymptomatic seropositive subjects and lymphadenopathy groups A (benign) and B (prodromal) to AIDS. The decrease did not correlate precisely with the decrease in CD4+ cells in these patients. Monocyte-derived macrophages from asymptomatic HIV-infected subjects and lymphadenopathy patients showed a decreased ability to kill T. gondii after activation with recombinant gamma interferon; paradoxically, this was most striking for PGL group A. The defect was largely overcome by using Concanavalin A stimulated autologous supernatants. It was notable that macrophages from AIDS patients showed normal killing with recombinant gamma interferon, but that the supernatants from AIDS patients had reduced activity with normal macrophages. These studies confirm that functional defects of both lymphocytes and macrophages are found in HIV-infected subjects; they serve to emphasize the heterogeneity of the clinical and biological responses to this retrovirus, responses which have important implications in the pathogenesis and treatment of the immunodeficiency.