Partial inhibition of gingipain-induced calcium changes in platelets by an anti–PAR-1 antibody.

Calcium mobilization in platelets induced by RgpB or HRgpA in the presence of rabbit anti–PAR-1 antibody (bold line) or a control rabbit antibody (thin line). Platelets from one donor were incubated with the antibodies (30 μg/mL) for 15 minutes, before treatment with (A) 1 nM thrombin or (B) 12.5 nM RgpB, both followed by treatment with 138 μM ADP. Platelets from another donor were incubated with the antibodies (60 μg/mL) for 15 minutes, and then treated with (C) 1 nM thrombin or (D) 0.25 nM HRgpA, both followed by treatment with 100 μM ADP. These data are representative of 3 experiments.