Cell-surface viral proteins most frequently enter the cell through clathrin or caveolae endocytosis. Respiratory syncytial virus antigen internalization by immune cells is via caveolin, however, uptake of paramyxovirus cell membrane proteins by non-immune cells is done through clathrin-coated pits. In this work, the uptake of respiratory syncytial virus cell surface glycoproteins by non-immune human epithelial cells was investigated through indirect immunofluorescence with polyclonal anti-RSV antibody and confocal lasser-scanner microscopy. Clathrin and caveolae internalization pathways were monitored through specific inhibitors monodansylcadaverine (MDC) and methyl-beta- cyclodextrin (MBCD), respectively. Internalization of RSV antigens was inhibited by MDC but not by MBCD, implying that clathrin-mediated endocytosis is the major uptake route of RSV antigens by an epithelial human cell line.
