Video 3.
Increased TLR9 PLT surface expression results in type C CpG-mediated PLT clumping. Washed human PLTs were transferred onto video chambers maintained at 37°C. Specific up-regulation of TLR9 surface expression in PLTs with 50 µg/ml type IV collagen preincubation had no effect on PLT morphology over a course of 20 min. Addition of 5 µM type C CpG to this PLT culture resulted in immediate PLT shape change and significant PLT clumping (characteristic of activation). Images were captured at 30-s intervals over the course of 72 min. Cells were viewed on an inverted microscope (TE-200) equipped with a 63× oil immersion objective, and images were obtained using a CCD camera (ORCA-ER).