Reply to “Contamination of SVG p12 Cells with BK Polyomavirus Occurred after Deposit in the American Type Culture Collection”

REPLY

We thank Michael W. Ferenczy and Eugene O. Major for their informative historical background regarding the origins of various SVG cell lines and subclones. In their letter, the authors also provide independent confirmation of our results that SVG p12 cells (ATCC CRL-8621) are positive for BK polyomavirus (BKPyV) DNA (1). Their letter is particularly important since the laboratory of the authors is one of the pioneers in JC polyomavirus (JCPyV) research and is also the place where the SVG cells originated.

We disagree that our recent paper (1) implies that all SVG-derived cell lines are BKPyV contaminated. On the contrary, in our paper we concluded that SVG-A cells, derived by limiting dilution of the original SVG cell line, are BKPyV negative, which suggests that the source of the SVG-A cell line was BKPyV negative. This observation was confirmed by Ferenczy and Major.

The impact of the BKPyV contamination on SVG research is presently difficult to estimate since many studies utilizing SVG-derived cell lines lack a clear specification of the source of the cells (1, 2). This leads us to reemphasize the implications of our recent paper: researchers who have been using or are using SVG-derived cell lines should test their cells for the presence of BKPyV, and reviewers of such work should demand this testing in case this has not been performed.

Finally, the evidence provided by Ferenczy and Major showing that the SVG cells in their possession do not contain BKPyV DNA certainly raises concerns about previous and present routines for cell handling at the ATCC.