Exchange of the cellular growth medium supplement from fetal bovine serum to Ultroser G increases the affinity of adenovirus for HeLa cells.

A comparative investigation was performed on the process of attachment of adenovirus type 2 to HeLa cells cultivated in the presence of 3.5% fetal bovine serum (FBS-cells) or 2% Ultroser G (USG-cells). The initial rates of virus attachment were markedly higher at temperatures between 10 and 35 degrees C for the virus binding to USG-cells than to FBS-cells. This was not caused by a higher amount of available virus-recognizing cellular receptor sites or cellular receptor units recognizing the viral fiber, but could be explained by a higher affinity of virions for USG-cells as compared to FBS-cells. Studies of virus attachment to cells, pretreated with neuraminidase and/or wheat germ agglutinin, suggested that the cellular receptor sites of FBS-cells were masked to a higher extent by sialic acid than the cellular receptor sites of USG-cells.