IL-1β expression and release from primary human microglia following HIV-1 infection or exposure. A. Viral p24 and B. IL-1β release from microglia at days 4, 7 and 10 following infection with HIV-1SF162.C. IL-1β induction and D. release from microglia cultures over 24 hr following exposure to HIV-1SF162. E. Induction, processing and F. release of IL-1β following 24 hr exposure to HIV-1SF162 +/- the caspase inhibitor YVAD-fmk (80 μM). G. Induction and H. release of IL-1β from microglia cultures exposed to recombinant gp120 (80 nM) for 24 hr +/- YVAD-fmk. Mean levels are reported for each ELISA. Bars indicate standard error. We compared the effect of HIV-1gp120 exposure on IL-1β release +/- YVAD-fmk using two-tailed Student t-test (*p < 0.05).