Leukemic blast were cultured in serum-free medium with SCF, GM-CSF, FL, IL-3, and TNFalpha for 48 hours before 3 rounds of infection with viral supernatants containing either the IL-7 cytokine (IL-7LN) or the reporter gene alone (LXLN). Transduction efficiency was monitored by flow cytometry using specific LNGFr mAb, 48 to 72 hours after the last transduction (n = 8, mean ± SD). Mean % LNGFr⁺ values (± SDs) were 19.8 ± 9 for LXLN and 12.7 ± 8.3 for IL-7LN.

FAB indicates French-American-British; ND, not done.