EBV-stimulated, but not CD40L-stimulated, primary B cells were transduced by HIV vectors.

B cells were cultured in parallel either in the EL-4 system (EL-4) or in the presence of CD40L, IL-4, IL-2, and IL-10 (CD40L) or with EBV containing B95-8 cell supernatant (EBV). B cells were transduced after 4 or 5 days (EL-4 system) or after 3 to 5 days (CD40L, EBV) with the same vector preparations, using CMV or EF1-α promoters. Columns show means of the percentages of GFP⁺ cells found among 1000 or more gated CD19⁺ 7-AAD^low cells, 3 or 4 days later; numbers of experiments are indicated (n); bars indicate ± 1 SD.