Cell culture medium influences RSV G protein glycosylation and recognition by monoclonal antibodies

Respiratory syncytial virus (RSV) glycoprotein G is heavily glycosylated and of variable size following virus growth in transformed cell lines or primary cells. However, it is unknown if the cell culture medium can influence the patterns of glycosylation. Therefore, we tested whether the choice of culture medium can affect the glycosylation of RSV G protein, viral infectivity and antibody recognition. The RSV G ectodomain was produced in HEK293T cells cultured in three different media. Marked differences in molecular weight were observed that were abolished in glycosylation-deficient knockout cells. RSV produced in A549 cells cultured in the same media also differed in relative G protein signals in virus stocks and virus spread. Higher apparent G protein glycosylation was associated with lower binding signals of human F protein-specific monoclonal antibodies to RSV-infected cells. These data show that the cell culture medium can influence biological properties of RSV preparations with consequences for antibody recognition and viral spread.