Presence of CCR4 on megakaryocytes and platelets.

(A) Unlabeled MDC competition study of ¹²⁵I-MDC binding to nonactivated platelets. The number of binding sites (approximately 4000 sites per platelet), with a kd of 30 nmol/L, were determined as described in “Material and methods.” (B) RT-PCR data from megakaryocytes and platelets shows the presence of a detectable CCR4 message in both. The anticipated 500–base pair (500-bp) band is seen in both platelet and megakaryocyte RT-PCR. Platelet preparation was the same for both Figures 2 and 3.