Saturable attachment sites for type 3 mammalian reovirus on murine L cells and human HeLa cells.
Attachment of [35S]methionine-labelled mammalian type 3 reovirus to murine L cells and human HeLa cells was studied under equilibrium conditions. Cellular attachment sites could be completely saturated with 35S-labelled reovirus, indicating that specific attachment sites for reovirus are present on the surface of these cells. We calculated that L cells possess about 86000-105000 attachment sites per cell while HeLa cells possess about 126000-147000 sites per cell for type 3 reovirus. Unlabelled reovirus was highly efficient in competing for attachment by 35S-labelled reovirus to the saturable attachment sites of both L and HeLa cells, further indicating the specificity of the interaction. We also found that unlabelled reovirus competed equally well for both binding and internalization of 35S-labelled reovirus into murine L cells, suggesting that the L cell attachment site may serve as a virus entry site. Phospholipase digestion of L cells had no effect on subsequent reovirus attachment, while treatment of L cells with moderate concentrations of bromelain (but not trypsin, proteinase K or pronase) and Vibrio cholerae neuraminidase reproducibly decreased subsequent reovirus attachment. These results and those of others (Epstein et al., 1984, Virology 133, 46-55) suggest that mammalian reoviruses attach to specific cell surface receptors on at least two species of mammalian cells to initiate the infectious cycle.
D000268:Adhesiveness; D000818:Animals; D001667:Binding, Competitive; D006367:HeLa Cells; D006801:Humans; D007739:L Cells / Q000187:drug effects; D012089:Mammalian orthoreovirus 3 / Q000502:physiology*; D051379:Mice; D009439:Neuraminidase / Q000494:pharmacology; D010447:Peptide Hydrolases / Q000494:pharmacology; D011991:Receptors, Virus / Q000032:analysis*; D012087:Reoviridae / Q000502:physiology*; D013462:Sulfur Radioisotopes; D010738:Type C Phospholipases / Q000494:pharmacology
D011991:Receptors, Virus; D013462:Sulfur Radioisotopes; D010738:Type C Phospholipases; D009439:Neuraminidase; D010447:Peptide Hydrolases