Impaired induction of MxA and OAS in monocytes from HIV-1–infected persons. RNA was extracted from purified monocytes from uninfected and HIV-1–infected persons ex vivo or after culture for 18 hours with 1000 U/mL IFNα2a or without IFNα2a (“medium”), and mRNA for MxA or OAS was quantified by qRT-PCR and normalized to GAPDH. Results are expressed as fold induction (expression after 18-hour incubation versus ex vivo). Fold induction was significantly reduced for MxA mRNA (P < .001; A) and OAS mRNA (P < .001; B) in monocytes of HIV-1–infected persons in comparison to uninfected subjects. Boxes show median, 25th and 75th percentile values and whiskers show ranges.