Pathogenesis of HIV encephalitis.

A wide spectrum of infectious agents attack the central nervous system (CNS) of acquired immunodeficiency syndrome (AIDS) patients. Human immunodeficiency virus (HIV) itself, infects the CNS of a subgroup of these patients. The mechanism behind why HIV enters the CNS is unclear. We have observed an interesting association between HIV and opportunistic viral infections that may explain why HIV enters the brain. Infection of the CNS by opportunistic agents results in recruitment of latently HIV-infected monocytes. Upon differentiation into macrophages these cells produce abundant HIV. Latent HIV-infection of monocytes/macrophages provides a unique opportunity for cooperativity between opportunistic infections and HIV in mediating CNS damage.