Functional evaluation for adequacy of MDCK-lineage cells in influenza research

OBJECTIVE: Influenza is an acute respiratory disease caused by the influenza virus which circulates annually in populations of different species. Madin-Darby Canine Kidney (MDCK) is the most widely utilized cell-line for conducting influenza research. However, the infectivity of various influenza strains in MDCK cells is not equivalent and the productivity of viral propagation is also limited. RESULTS: We tested the functional adequacy of two MDCK-lineage cell lines, conventional MDCK and MDCK/London, were evaluated by assessing their infectivity of different influenza viral strains with focus forming assays and the cellular toxicity caused by influenza infections by lactate dehydrogenase assay. Moreover, the sensitivity of cells in the presence of the antiviral agent ribavirin was assessed by MTT assay. Our results showed that MDCK/London cells efficiently propagate virus across all influenza viruses tested, are comparable to the utility of Mv1Lu cells, and are superior to conventional MDCK cells in replicating virus as indicated by an increase in virus of three to four logs, particularly in H3N2 infection. Also, the MDCK/London cells were more sensitive to the presence of antiviral drug than conventional MDCK cells. In conclusion, MDCK/London cell line could be a better platform for influenza studies and vaccine development.