FIG. 3.
Effects of PTX-B on HIV-1 mRNA expression. PHA-activated PBMC cultures were infected with the X4 isolate HIV-1LAI. (A) Cells were cultured according to the scheme shown. AZT was used at a concentration of 1 μM, which completely blocked de novo infection, and PTX-B (B-ol.) was used at a concentration of 1 nM. Arrows indicate times at which the medium was changed and cells were thoroughly washed. (B) After the final wash, total RNA was analyzed by RT-PCR using an SPL-1–SPL-2 primer pair specific for spliced HIV-1 mRNA (product detected by Southern blot hybridization, upper panel) or β-actin mRNA (product detected by ethidium bromide staining of the gel, bottom panel). Results are for one representative experiment out of two performed with cells from different donors. The standards were prepared by extracting RNA from indicated numbers of TNF-α-stimulated U1 cells (each cell containing 2 copies of integrated HIV-1 provirus) and amplifying it in parallel with experimental samples.