NGF enhances HIV-1 transcription in macrophages. Macrophages were infected by an R5-tropic HIV-1 isolate (Ba-L) and treated with NGF (10 ng/mL) or TNF-α (10 ng/mL) for 48 hours. Total RNA was then extracted using the QIAamp RNA kit, and qRT-PCR for the detection of MS (A) and FL (B) HIV-1 transcripts were performed as described previously.²⁹  Data represent means ± SEM of 3 independent experiments. **P < .01.