Interleukin-1 and tumor necrosis factor alpha can be induced from mononuclear phagocytes by human immunodeficiency virus type 1 binding to the CD4 receptor

Abstract

Cytokines such as interleukin-1 (IL-1) and tumor necrosis factor alpha (TNF alpha) are important in normal immune processes. In this study, we demonstrate that human immunodeficiency virus type 1 (HIV-1) virions induce normal peripheral blood mononuclear phagocytes to produce both IL-1 and TNF within a few hours after their exposure to virus. The induction of these cytokines by HIV-1 does not require a productive infection. Blocking studies with soluble CD4 indicate that the effect is mediated through the CD4 molecule. In addition, the treatment of mononuclear phagocytes with OKT4A monoclonal antibody mimics the effects of HIV-1. Thus, these results indicate that induction of IL-1 and TNF alpha can occur via signals mediated through the CD4 molecule on mononuclear phagocytes. TNF has been shown by other investigators to induce HIV-1 expression. Therefore, TNF alpha may play a role in autocrine and paracrine regulation of HIV-1 expression. In addition, the induction of IL-1 and TNF by HIV-1 may also contribute to some of the neurologic and physiologic disorders associated with acquired immunodeficiency syndrome.