Figure 5.

Individual pneumococcal proteins and pneumococcal lysates directly activate human platelets. Washed platelets of a defined set of donors were incubated with different concentrations of pneumococcal proteins (A) (Table 1) for 30 min or pneumococcal lysates (B) with the indicated genetic backgrounds for 60 min at 37 °C. CD62P was used as an activation marker and was detected by flow cytometry, using a PE-Cy5-labelled P-selectin antibody. PBS was used as negative control, and 20 µM TRAP-6 was used as a positive control. The data are presented as geometric mean of fluorescence intensity (GMFI) of positive gated events multiplied with the percentage of positive gated events in the dot plots.