Effect of HIV-1 and HIV-2 on DC activation. (A) CD86 surface expression in DCs after infection with HIV-1 and HIV-2 IRES-eGFP constructs alone or in combination with VSV-G-pseudotyped SIVmac239 particles. The levels of CD86 expression by virally infected (eGFP+) cells were measured at 3 days post-infection. Panels A and B show mean values (±SEM) derived from four experiments. HIV-1 alone did not infect DCs at detectable levels. (B) Levels of IFN-γ in the supernatant of the infected DC cultures.