NFYPs after MWReg30-induced thrombocytopenia display impaired GPVI signaling. (A) Platelet count in circulation on day 5 after MWReg30 treatment was determined by flow cytometry. Data bars are represented as percent values ± SD compared with vehicle-treated controls (100%) on day 5 after depletion by gating on anti-GPIb/phycoerythrin and anti-GPV/fluorescein isothiocyanate antibody. **P<.001. Flow cytometric analysis of (B) platelet integrin αIIbβ3 activation and (C) P-selectin exposure of control and MWReg30-treated mice on day 5 (n = 4). CVX, convulxin. *P < .05, **P < .01. (D) Integrin αIIbβ3 activation (binding of JON/A-phycoerythrin) and (E) P-selectin exposure on day 5 after anti-GPIbα antibody or MWReg30 (anti-αIIbβ3) treatment in response to indicated agonists (n = 5). Epi, epinephrine; FITC, fluorescein isothiocyanate; MFI, mean fluorescence intensity; RC, rhodocytin; U46, U46619.