CD68S-based retroviral vectors generate long-lasting gene expression in vivo.

(A) FACS analysis of EGFP expression by thioglycollate-elicited and bone marrow–derived macrophages from a single mouse. Macrophages in thioglycollate-elicited peritoneal cells were gated on the basis of forward- and side-scatter properties. The percentage of EGFP⁺ cells was determined by use of a gate set to exclude control cells from mice that had not received transplants (dotted line). The plots are representative of data from at least 5 mice per retroviral construct. (B-C) Analysis of the percentage of EGFP⁺ cells and the mean fluorescence intensity of thioglycollate-elicited macrophages from mice killed either 12 to 16 weeks (B) or 50 to 55 weeks (C) after HSC transplantation. Graphs represent mean ± SEM from groups of 5 (12-16 weeks) or 4 (50-55 weeks) mice per retroviral construct.