Fig. 4.
Effect of a CXCR-4 blocking antibody on transendothelial migration of CXCR-4–positive primary AML blasts. Migration was expressed as relative transendothelial migration compared with migration in response to MS-5–conditioned medium (CM [MS-5] = 100%). The CXCR-4 antibody (mAb) 12G5 markedly reduced migration of CXCR-4–positive, primary AML blasts (AML no. 7, 8, 11, and 12) in response to SDF-1–containing conditioned medium (CM + mAb). Transendothelial migration induced by 500 ng/mL rhSDF-1β was nearly as efficient as migration induced by the conditioned medium. The chemotactic effect of both MS-5–conditioned medium and recombinant SDF-1 was reduced by the partially blocking CXCR-4 antibody to a similar extent.