Effect of concanavalin A on early interactions of Sindbis virus with goose erythrocytes and BHK 21 cells.

The role of mannose containing molecules in Sindbis virus envelope glycoproteins and cell membrane receptors was investigated by means of concanavalin A (con A). Treatment of virus or BHK 21 cells with the lectin before infection reduced viral infectivity. Hemagglutination and hemolysis showed a different sensitivity to con A. Hemagglutination was not affected by the lectin and treatment of erythrocytes with con A produced an enhancement of agglutinability by the virus. Hemolytic activity was, on the contrary, strongly reduced by the lectin. The inhibition observed is due to an action on viral structures and not to an interaction with erythrocyte receptors because con A did not affect the hemolysis when preincubated with erythrocytes.