Chim3-LV confers survival advantage to transduced CD4⁺ T lymphocytes under HIV-1 selective pressure. (A) Empty-LV– and (B) Chim3-LV–transduced CD4⁺ T lymphocytes were selected to 95% or greater ΔLNGFR⁺ by anti-ΔLNGFR Ab and then mixed at a 1:1 ratio with mock-transduced cells. Mixtures were either infected with the AD8 HIV-1 molecular clone at an MOI of 1 or left uninfected. FACS staining of ΔLNGFR⁺ cells of infected and uninfected cultures was performed after 40 days of cell cultivation. The results are representative of a triplicate culture for infected cells and of a duplicate culture for uninfected cells. Numbers in the quadrants indicate the percent of single and double positive cells. (C) GFP-LV– and Chim3-LV–transduced CD4⁺ T lymphocytes were infected with VSV-G–pseudotyped Vif-proficient NL4-3–based HIV-1 at an MOI of 3. At 72 hours after viral challenge, intracellular p24Gag level was evaluated by FACS using an anti-p24Gag Ab on fixed and permeabilized cells. Values express means ± SEM percentage of p24Gag expression (n = 16).