INU1-induced thrombocytopenia is independent of platelet integrin activation and FcγRs. (A) Wt, FcRγ^−/−, and Tln1^−/− mice were IV injected with 100 µg of INU1 and platelet counts were determined on a FACSCalibur at the indicated time points. Results are mean ± SD in percentage of the initial platelet counts (n = 5 mice per group). (B) Western blot analysis of CLEC-2 levels, before and on day 5 post-INU1 injection in platelet lysates of FcRγ^−/− and Tln1^−/− mice. GPIIIa served as a loading control. (C) Flow cytometric analysis of αIIbβ3 activation (JON/A-PE) and degranulation-dependent P-selectin exposure on platelets on day 5 post-INU1 injection (RC, 0.12 µg/mL; Thr, 0.1 U/mL). Results are representative of 3 individual experiments.