infected with the PRRSV strain HN. Immunofluorescence staining for PRRSV GP5 and N proteins was carried out at 48 hpi using polyclonal antibodies (Cat #bs-4504R
and Cat #23941R, Bioss, Beijing, China). To detect the receptors of PRRSV, the PMECs were fixed with 4% paraformaldehyde after a 24-hr incubation, and a routine
indirect immunofluorescence method was performed. Anti-CD151 (Cat #sc-18753-R, Santa Cruz Biotechnology, Santa Cruz, CA, USA), anti-CD163 (Cat #MCA2311GA, AbD
Serotec, Kidlington, Oxford, UK), and anti-CD169 (Cat #MCA2316GA, AbD Serotec) antibodies and goat anti-mouse (Cat #bs-0296G-FITC, Bioss) and goat anti-rabbit
(Cat #bs-0296G-FITC, Bioss) FITC-conjugated secondary antibodies were used.