Chemokine and chemokine-receptor expression in human glial elements: induction by the HIV protein, Tat, and chemokine autoregulation.

Human immunodeficiency virus (HIV) encephalitis is a prominent pathology seen in children infected with HIV. Immunohistochemical analyses of pediatric brain tissue showed distinct differences in expression of C-C chemokines and their receptors between children with HIV encephalitis and those with non-CNS-related pathologies. Evidence suggests that soluble factors such as HIV Tat released from HIV-infected cells may have pathogenic effects. Our results show Tat effects on chemokines and their receptors in microglia and astrocytes as well as chemokine autoregulation in these cells. These results provide evidence for the complex interplay of Tat, chemokines, and chemokine receptors in the inflammatory processes of HIV encephalitis and illustrate an important new role for chemokines as autocrine regulators.