Submitted to: Journal of Virological Methods
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/19/2008
Publication Date: 7/30/2008
Citation: Lee, C., Jung, K., Jadhao, S., Suarez, D.L. 2008. Evaluation of chicken-origin (DF-1) and quail-origin (QT-6) fibroblast cell lines for replication of avian influenza viruses. Journal of Virological Methods. 153:22-28. Interpretive Summary: Type A influenza viruses are important viral diseases of man and animals. In veterinary medicine avian influenza virus is a problem in poultry including chickens and turkeys. Currently, most avian influenza viruses are grown in chicken eggs. However, not all avian influenza viruses and recent swine influenza viruses grow well in chicken eggs. In addition, it is difficult and costly to maintain a supply of chicken eggs for routine virological analysis. For these reasons alternative ways to grow influenza viruses were investigated, including two cell lines of chicken and quail origin. Both cell lines allowed good growth for the avian influenza viruses tested, but problems with swine viruses were still observed. The cell lines were also evaluated for the expression of a reporter protein in a plasmid. Both the chicken and quail cell lines performed well with a high percentage of cells expressing protein after transfection. Both cell lines appear to be reasonable alternatives for some purposes to chicken eggs, and further comparisons should be performed.
Technical Abstract: The characteristics of two avian cell lines, DF-1 (chicken-origin) and QT-6 (quail-origin), and their ability to support the growth of influenza viruses from different species were evaluated. The replication efficiency of 19 avian influenza viruses of 9 different hemagglutinin subtypes in QT-6 and DF-1 cells was comparable in general to those in primary CEF and Madin-Darby canine kidney (MDCK) cells. Receptor distribution analysis demonstrated high prevalence of SA alpha2,6-gal linked receptors in QT-6 and DF-1 cells which further validates the high growth of avian influenza viruses. We also confirmed high plaque forming ability of selected highly pathogenic avian influenza viruses in QT-6 and DF-1 cells in the absence of the exogenous trypsin. In addition, these two avian cell lines showed high transfection efficiency. Taken together, we expect DF-1 and QT-6 cell lines will be useful as a complementary substrate for avian-origin influenza virus isolation and also for many other influenza researches such as pathogenesis and host range studies.