Displacement of TM11: association to P-selectin by blocking antibodies and rPSGL-Ig.

Human P-selectin (20 nM, 50 μL) was injected over the TM11 surface, followed by blocking or non–blocking antibodies (10 μg/mL). In the same figures, coinjections of P-selectin and antibodies or rPSGL-Ig are shown. The horizontal bars indicate the infusion periods. (A) Non–blocking antibody AC1.2 was able to bind TM11-associated P-selectin as indicated by an increase in response units. Coinjection of P-selectin with AC1.2 resulted in a higher response than injection of P-selectin alone, due to the formation of a P-selectin/AC1.2 complex. (B) Blocking antibody WASP 12.2 displaced P-selectin from TM11. (C) Blocking antibody AK-4 was not able to bind or displace TM11-bound P-selectin when it was injected after P-selectin, although coinjection with P-selectin led to complete inhibition of TM11 binding. (D) rPSGL-Ig displaced P-selectin from TM11. Results represent typical sensorgrams of at least 2 experiments.