Alteration of Macrophage Functions by Cocaine

Abstract

Studies elucidating the effects of cocaine on immune cells and immune function are relatively recent. Although immunomodulation by cocaine has been reported by a number of investigators, it is not consistently associated with immunosuppression. A review sum­marized many of the earlier studies of cocaine on the immune system (1). Another study (2) describes a number of immune abnormalities in mice exposed to cocaine including an enhancement of neutrophil phagocytosis, a reduction of T-cell responses to the mitogen phytohemagglutinin, and cytotoxic activity of immune spleen cells. Other reports have described alteration of spleen cell subsets following injection with cocaine (3,4). A number of reports have described a reduction or alteration in the production of certain cytokines (5–7). In a series of publications, Peterson et al. (8–10) have reported an enhancement of HIV replication in cultures of human monocytes via the induction of transforming growth factor β (TGFβ) and tumor necrosis factor (TNFα). An increase in p24, one of the internal viral proteins, was used to quantify viral replication. A recent study (11) reported that Me culture supernatants from cells exposed to cocaine, modulate mesangial cell proliferation in vitro altering TGFβ, as well as IL-6.