Effect of antibodies to CXCR4 and β1 integrins on engraftment of cord blood CD34⁺ cells in NOD/SCID mice BM.

(A) Expression of CXCR4 (i), VLA-4 (ii), and VLA-5 (iii) on enriched CD34⁺ cells. Expression levels of CXCR4, VLA-4, and VLA-5 on gated CD34⁺ population are shown. A representative FACS analysis of 3 independent experiments is shown. The white histogram indicates negative control staining with isotype control antibody; the black histogram indicates CXCR4 (i), VLA-4 (ii), and VLA-5 (iii). (B) Percentage of engraftment in murine BM by CB CD34⁺ cells pretreated with antibodies to either CXCR4 (R4), VLA-4 (α4), VLA-5 (α5), or VLA-4 + VLA-5 (α4 + α5) was quantified at 6 weeks after transplantation by immunostaining with antihuman CD45 mAb. Open circles (○) represent the mouse that received a transplant of 2 × 10⁵ of CD34⁺ cells intravenously. Filled circles (●) represent the mouse that received a transplant of 2 × 10⁴ CD34⁺ cells by iBM. Each circle represents 1 mouse, and bars indicate the average of engraftment. Results were combined from 3 independent experiments.