Stable transgene expression in human primary PBLs by the SB transposon trans construct and functional transposase. (A) SB trans delivery. Freshly isolated PBLs (5 × 10⁶) were co-nucleofected with 5 μg of pT2/DsRed and different amounts of pUbSB10 or pUbSB11 (donors 7 and 8 only) (20, 10, 5, 2.5, and 0 μg). DsRed expression was analyzed on days 1, 2, 7, 14, 21, and 28. The data from 8 individual PBLs are shown. (B) Comparison of wild-type and mutant SB10 in trans delivery. Columns represent geometric means with 95% confidence intervals of 6 independent experiments. P values to compare SB10 and SB10ΔDDE on days 21 and 28 were all less than .001.