HΔ24/FΔ30-displaying LVs outperform VSV-G-LVs for the transduction of IL-7–prestimulated adult T cells. (A) Surface expression of SLAM or CD46 receptors on unstimulated PBLs or on PBLs stimulated for 3 days with anti-CD3⁺ anti-CD28 antibodies in the presence of IL-2. (B) PBLs were stimulated for 3 days with anti-CD3 and anti-CD28 antibodies in the presence of IL-2 and subsequently transduced with HΔ24/FΔ30- or VSV-G–pseudotyped HIV-GFP vectors at the indicated vector doses. Transduced cells were kept in culture for 3 days in the presence of IL-2 and the percentage of GFP expression was monitored by FACS (means ± SD; n = 3). (C,E) The surface expression of SLAM or CD46 receptors on resting adult or cord blood CD3⁺ T cells, respectively, immediately upon isolation by negative antibody-mediated selection or upon incubation of these T cells with rIL-7 for 3 days. Purified resting adult (D) or cord blood (F) CD3⁺ T cells were stimulated for 3 days with rIL-7 and subsequently transduced with HΔ24/FΔ30- or VSV-G–pseudotyped HIV-GFP vectors in the presence of rIL-7 at the indicated vector doses. Transduced cells were maintained in culture for 3 days and GFP expression was then monitored by FACS analysis (means ± SD; n = 5).