Detection of In Vivo Activated Platelets in Experimental Cerebral Thrombosis: Studies Using a New Monoclonal Antibody 2T60, Specific for Activated Human and Rabbit Platelets.

To detect in vivo activated platelets in humans as well as in animal models of thrombosis, we developed a new murine monoclonal antibody, 2T60, specific for activated human and rabbit platelets by immunizing with human thronibin-activated platelets. 2T60 (IgG1 subclass) showed a great difference between binding to the thrombin-activated and resting human and rabbit platelets on ELISA and flow cytometer analysis. Immunoblotting analysis revealed that 2T60 reacted with a 130 or 106 kDa protein of human or rabbit platelets, respectively, only under non-reducing conditions. 125I-labeled 2T60 inserted into the intermediate gel of CIE of solubilized human platelets was incorporated into a immunoprecipitation line. 2T60 immunoprecipitated a protein of 130 or 115 kDa from human or rabbit platelets, respectively, which had been activated and 125I-surface-labeled. The N-terminal sequence of the affinity purified 2T60 antigen of human platelets was identical to that of GMP 140. There were differences in the carbohyd...