On 2015 Sep 25, Amanda Capes-Davis commented:

Great to see a paper looking at reproducibility of cell culture systems, in this case for replication of HuNoVs, important for the study of acute gastroenteritis. The authors note in their Materials and Methods that two cell lines are used for viral growth, INT-407 and Caco-2, and correctly state that INT-407 has been cross-contaminated with HeLa. So it makes sense that INT-407 is not a good model for culture of HuNoVs. INT-407 was found to be cross-contaminated with HeLa in the 1960s and there are no known authentic stocks remaining for the original intestinal culture; INT-407 has been completely replaced by HeLa cells. HeLa may form microvilli as shown here, but HuNoV replication is likely to require additional tissue-specific factors that HeLa cannot supply.

Failure of Caco-2 is more puzzling, considering that the authors used a well-known intestinal (colorectal adenocarcinoma) cell line that was successful for the previous study, and obtained their stock of Caco-2 from the same source. However, it is worth noting that viral replication can vary across different strains or subclones e.g. Carson & Pirruccello, PMID 23408555. Caco-2 is well documented as a cell line that can change phenotype with passaging e.g. Briske-Anderson et al, PMID 9083258.

For a list of known misidentified cell lines, please refer to http://iclac.org/databases/cross-contaminations/. It is also important to authenticate cell line stocks before use. Setting up in vitro culture systems takes a great deal of time - testing can save a great deal of heartache!

On 2015 Sep 25, Amanda Capes-Davis commented:

Great to see a paper looking at reproducibility of cell culture systems, in this case for replication of HuNoVs, important for the study of acute gastroenteritis. The authors note in their Materials and Methods that two cell lines are used for viral growth, INT-407 and Caco-2, and correctly state that INT-407 has been cross-contaminated with HeLa. So it makes sense that INT-407 is not a good model for culture of HuNoVs. INT-407 was found to be cross-contaminated with HeLa in the 1960s and there are no known authentic stocks remaining for the original intestinal culture; INT-407 has been completely replaced by HeLa cells. HeLa may form microvilli as shown here, but HuNoV replication is likely to require additional tissue-specific factors that HeLa cannot supply.

Failure of Caco-2 is more puzzling, considering that the authors used a well-known intestinal (colorectal adenocarcinoma) cell line that was successful for the previous study, and obtained their stock of Caco-2 from the same source. However, it is worth noting that viral replication can vary across different strains or subclones e.g. Carson & Pirruccello, PMID 23408555. Caco-2 is well documented as a cell line that can change phenotype with passaging e.g. Briske-Anderson et al, PMID 9083258.

For a list of known misidentified cell lines, please refer to http://iclac.org/databases/cross-contaminations/. It is also important to authenticate cell line stocks before use. Setting up in vitro culture systems takes a great deal of time - testing can save a great deal of heartache!