Production of cytokines by peripheral blood monocytes/macrophages infected with human immunodeficiency virus type I

The study of monocyte/macrophage functions after human immunodeficiency virus type 1(HIV-1) infection may help in understanding the pathogenesis of AIDS. The production of four cyto-kines, tumor necrosis factor alpha (TNFa), interleukin-Id (IL-1~), interleukin-6 (IL-6), and granulocyte-macrophage colony-stimulating factor (GM-CSF), byperipheral blood monocytes/mac-rophages was evaluated after in vitro infection with HIV-l. HIV-1 infection ofthese monocytes/mac-rophages did not result in release of any of these cytokines. Similarly, treatment of uninfected cells with purified recombinant HIV-1 envelope protein did not result in cytokine production. After stimulation with endotoxin or endotoxin plus interferon-y, HIV-1-infected monocytes/mac-rophages produced amounts of TNFa, IL-6, GM-CSF, and IL-1 ~ comparable to that of unin-fected cells. HIV-1 infection does not appear to induce or alter cytokine production by mononuclear phagocytes, which retain the capacity to produce these cytokines after endotoxin stimulation. Monocytes/macrophages play an important role in host de-fense both by their direct microbicidal capacity and by their synthesis of regulatory proteins termed cytokines [I]. These cells also represent an important cellular target of human im