An αIIbβ3 ligand-mimetic murine monoclonal antibody that produces platelet activation by engaging the FcγIIa receptor.

ABSTRACT:

Abstract

To produce a murine monoclonal antibody (mAb) that binds to glycoprotein IIb/IIIa (αIIbβ3) and inhibits clot retraction (CR), we immunized mice with human platelets and tested hybridoma supernatants for their ability to bind to αIIbβ3 and inhibit CR. The immunoglobulin G1 (IgG1) mAb R6H8 completely inhibited CR at 20 μg/mL. Paradoxically, at 5 μg/mL, R6H8 initiated platelet aggregation and induced P-selectin expression, fibrinogen binding, and PAC-1 binding. At 20 μg/mL, however, R6H8 completely inhibited aggregation induced by thrombin PAR-1 receptor activating peptide SFLLRN (T6; 25 μg/mL) and T6-induced fibrinogen and PAC-1 binding to platelets. Platelet aggregation induced by R6H8 was inhibited by mAb IV.3, which blocks the FcγIIa receptor (FcγRIIa), and the Fab fragme

SUBMITTER: Wang J 

PROVIDER: S-EPMC12274674 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature