EV71 viruses bind to MDDCs. (A) Expression of EV71 receptors or attachment factors in MDDCs. MDDCs cells were immunostained and measured with flow cytometry for expression of PSGL-1 and DC-SIGN. The positive expression percentage is noted. (B,C) Viral binding to MDDCs. MDDCs were incubated with EV71 or CVA16 viruses for 1 h at 4°C (MOI 0.3 or 0.1). Some samples were treated with trypsin. Surface-bound viruses were measured with flow cytometry through immunostaining with anti-VP1 polyclonal antibodies. One representative donor from four with similar results is shown.