TAT and HIV-1 infection: To determine if chronic exposure to HIV-1 Tat could stimulate production of A1-associated signals independent of simulated microglia signaling, astrocytes were treated with low and high doses of HIV-1 Tat, as well as a combination of TIC and HIV-1 Tat (50 ng/ml) to serve as a more representative model of a chronic low-level inflammatory environment in the context of HIV-1 infection.