Platelet binding to dendritic cells. Platelet (PLT) binding to dendritic cells (DCs) was evaluated by flow cytometry (A-D) or by confocal microscopy (E-G). DCs and PLTs were cultured for 48 h alone (A-B) or together, either in two 0.4-μm pore-sized filter-separated compartments (C) or in the same compartment (D). DCs and PLTs were stained for CD1a and CD41, respectively, and analyzed by flow cytometry (A-D). For PLTs cultured alone, flow cytometry plots are not gated on any marker. For DCs, flow cytometry plots are gated on CD1a+ events only. Plots are representative of five independent experiments. (E-G) DCs cultured with PLTs in the same compartment were stained for CD209 and CD41 and analyzed by confocal microscopy (E, anti-CD41-FITC; F, anti-CD209- Alexa Fluor® 555 and G, anti-CD41-FITC, and anti-CD209- Alexa Fluor® 555). The confocal microscopy photograph is representative of three independent experiments.