Neuropathogenesis of HIV-1 infection: Interactions between interleukin-1 and transforming growth factor-1 beta

Cytokines are widely considered to function as major mediators of neuropathogenesis of HIV-1 infection. This view is based on a large amount of data obtained in vitro, in animal models and in human brain tissue obtained postmortem. Evidence for the involvement of interleukin-1 and transforming growth factor-beta 1, summarized here, indicates that these cytokines likely control HIV-1 expression in the brain and astrocytosis, the two hallmarks of brain in AIDS patients. Although the data do not reveal the precise time course of molecular and cellular changes in vivo, they strongly suggest a complex pattern of interactions whose ordering in time determines when and where HIV-1 is expressed in the brain. Further kinetic data are therefore urgently needed to shed light on the heterogeneity of HIV-1 expression in the brain.