Blocking of DL1-platelet binding by Hsa-BR in whole human blood.

(A) Representative FSC/SSC plot showing whole blood with added DL1-Cy3. Platelets and bacteria are gated as R1. (B–E) are gated from R1: (B) Whole blood with DL1-Cy3 and CD41a-APC. Non-DL1-bound platelets appear in Q1 and DL1-bound in Q2, while free DL1-Cy3 in Q3. (C–E) Whole blood with different concentrations of Hsa-BR added first, followed by DL1-Cy3 and CD41a-APC. Increasing amount of Hsa-BR results in decreasing count of DL1-bound platelets (Q2 percentages) and increasing numbers of free bacteria (Q3 percentages). (F) Quantification of Hsa-BR blocking of DL1 binding to platelets in whole blood. The percentage values of DL1-bound platelets were normalized, with the highest single value being 100%. (n = 6, SEM). *P<0.05, ***P<0.001.