ASSAY FOR EVALUATION OF ROTAVIRUS-CELL INTERACTIONS - IDENTIFICATION OF AN ENTEROCYTE GANGLIOSIDE FRACTION THAT MEDIATES GROUP-A PORCINE ROTAVIRUS RECOGNITION

A virus-host cell-binding assay was developed and used to investigate specific binding group A porcine rotavirus and MA-104 cells or porcine enterocytes. A variety of glycoconjugates and cellular components wer e screened for their ability to block rotavirus binding to cells. Duri ng these experiments a crude ganglioside mixture was observed to speci fically block rotavirus binding. On the basis of these results, entero cytes were harvested from susceptible piglets and a polar lipid fracti on was isolated by solvent extraction and partitioning. Thougout subse quent purification of this fraction by Sephadex partition, ion-exchang e, silicic acid, and thin-layer chromatography, blocking activity beha ved as a monosialoganglioside (GMX) that displayed a thin-layer chroma tographic mobility between those of GM2 and GM3. The blocking activity of GMX was inhibited by treatment with neuraminidase and ceramide gly canase but not by treatment with protease or heat (100 degrees C). Fur ther purification of GMX by high-pressure liquid chromatography result ed in the resolution of two monosialogangliosides, GMX and a band whic h comigrated with GM1 on thin-layer chromatography. These data suggest that a cell surface monosialoganglioside or family of monosialogangli osides may function as an in vivo relevant receptor for group A porcin e rotavirus and that sialic acid is a required epitope for virus-bindi ng activity.