SDF-1–induced transstromal migration of human SRCs.

(A) Migration of CD34⁺ cells across murine bone marrow–derived adipocyte 14F1.1 and MBA-15 stromal cells and primary human stroma (HS) cells toward SDF-1 is dependent on VLA-4 and VLA-5 but not on LFA-1. (B) Percent engraftment in the murine bone marrow by nonmigrating (NM) and migrating (M) cells, quantified 1 month after transplantation by FACS analysis using antibodies to human CD45. Each dot represents 1 mouse, and bars and numbers indicate the average time of engraftment. (*Indicates P < .05.) (C) Phenotype analysis of engrafted human cells in mice transplanted with transstromal migrating (M) cells. Lymphoid CD45⁺/CD19⁺ pre–B cells (EI, R1), as well as primitive CD34⁺/CD38^−/low cells (EII, R2), are shown.