COMPARISON OF THE BINDING CHARACTERISTICS TO BHK-21-CELLS OF VIRUSES REPRESENTING THE 2 THEILERS VIRUS NEUROVIRULENCE GROUPS

The binding characteristics of the highly virulent GDVII and less virulent BeAn strains of Theiler's murine encephalomyelitis viruses (TMEV) to whole BHK-21 cells were determined using a direct viral binding assay. The overall rates of association and dissociation of BeAn and GDVII viruses were similar. Using a saturation binding assay intended for multivalent ligands, such as picornaviruses, the number of binding sites per cell was calculated as 1.6 × 105. Competitive binding assays with both viruses showed one-way blocking. In addition, treatment of cell monolayers with neuraminidase reduced binding of BeAn virus by 90% but did not affect GDVII binding. Wheat germ agglutinin, a lectin which blocks binding to sialic acid and N-acetylglucosamine residues, substantially reduced binding of radiolabeled GDVII and BeAn viruses. Treatment of asialylated cells with O-glycanase further reduced the binding of BeAn virus, suggesting that O-linked oligosaccharides are involved in viral binding. These results suggest members of the two TMEV virulence groups share a common receptor but bind it differently. © 1991.