Figure 6.

In vivo treatment of primary mice with SDF-1 results in similar levels of engraftment in secondary recipients of either control or [³H]thymidine-treated cells. 18 to 21 d after transplant, human fetal liver–engrafted primary mice were given two intraperitoneal injections, 24 h apart, of 10 μg of SDF-1 and 2 d later the marrow cells from both femurs and tibias of all mice in each experiment (7–9 mice per experiment, four experiments) were pooled and then incubated with [³H]thymidine (filled symbols) or medium (open symbols) for 16 h in vitro. The cells were then harvested and equal aliquots of each pool injected into secondary NOD/SCID mice (25–.33 primary mouse marrow equivalents per secondary mouse). Levels of different types of human cells detected in the secondary mice were determined 6–8 wk later.