Sustained multilineage transgene expression from an MMLV-based vector in peripheral blood for more than 8 months after transplantation of transduced bone marrow cells.

Data represented the mean percentage ± SEM of NGFR⁺cells in peripheral blood of mice at various time-points after transplantation of bone marrow cells transduced with the 1171 vector. Results are shown from 2 independent transductions, experiment 1 (top) and experiment 2 (bottom). NGFR expression was analyzed as in Figure 1with WBCs gated on live donor-type cells. Controls are nonirradiated, age-matched mice from the donor and recipient strains, mocks are mice transplanted with nontransduced cells otherwise prepared as for 1171 transduced cells. Eight mice were analyzed in experiment 1; 7 mice were analyzed in experiment 2 until day 161, and 3 were analyzed on day 249. Note that overall NGFR expression in RBCs, platelets, and donor WBCs declined with time then stabilized after the second month. In experiment 1, the percentage of NGFR⁺ cells was greater at day 31 than at any subsequent time-point (P < .03, except for donor WBCs at day 31 versus day 89). Similar results were obtained in experiment 2 (P < .05), except that fewer NGFR⁺ platelets were detected at day 38 than at later time-points. After the second month after transplantation, no other significant declines (P < .05) in the percentage of NGFR⁺ WBCs, RBCs, or platelets were observed between any of the time-points in either experiment. All other abbreviations are as in Figure 1.