Comparison of sensitivities of three commercial MRC-5 cell lines grown in shell vials to cytomegalovirus and responses to enhancing agents.

MRC-5 cells grown in shell vials from three suppliers (Whittaker Bioproducts, Bartels, and ViroMed) were evaluated for sensitivity to human cytomegalovirus. Previous studies done in our laboratory showed that treatment of the cells with dexamethasone (DEX) and dimethyl sulfoxide (DMSO) or these agents plus calcium improved the sensitivity of cells from Whittaker. In this study, we compared the response of the Whittaker cells with those of the cells from Bartels and ViroMed, both treated and untreated, when tested with strain AD169, a strain of wild-type virus, and 41 clinical specimens from various sources. A progressive improvement in sensitivity to AD169 and the wild-type virus was seen for all cell lines with DEX-DSMO and DEX-DMSO-calcium treatments, although even untreated, the Whittaker cells were much more sensitive. Detection of most of the positive clinical specimens was enhanced by both treatments with the Whittaker cells. DEX-DMSO had little or no effect on Bartels or ViroMed cells, while DEX-DMSO-calcium usually effected some increase in the number of inclusions. Six specimens were recovered only on Whittaker cells. Protein studies were done on all groups to determine the effect, if any, of the treatments on the metabolism of the cells.