Gp96 binds to nonactivated and thrombin-activated human platelets.

Freshly prepared platelets from human blood were incubated for 3 minutes at 37°C with 0.2 U/mL thrombin or without effector and were fixed with paraformaldehyde. (A) After extensive washing, platelets were stained with antibodies specific for CD41, CD40L, CD91, and CD36 or with 50 μg/mL FITC-labeled Gp96 and were analyzed by flow cytometry. Isotypic controls are shown as dotted lines, stainings of nonactivated platelets are shown as solid lines, and thrombin-activated platelets are shown as filled gray lines. Nonactivated (B) or thrombin-activated (C) platelets were stained with different concentrations of Gp96-FITC for 30 minutes at 4°C and were analyzed by flow cytometry. Data shown are representative for at least 4 independent experiments.