Preliminary analysis of isolation effect of influenza virus by recombinant MDCK cells stably expressing trypsinogen / 中国生物制品学杂志

ABSTRACT

@#ObjectiveTo investigate the isolation effect of influenza virus by recombinant MDCK cells(MTY6 cells)stably expressing trypsinogen.MethodsAccording to the virus isolation method recommended by the World Health Organization(WHO)Global Influenza Surveillance Network(GISN)and the National Influenza Centers(NICs),a total of 20 throat swab specimens containing positive nucleic acid for H1N1,H3N2 and B influenza virus were isolated simultaneously using MDCK and MTY6 cells. Guinea pig red blood cells and chicken red blood cells were used for agglutination test respectively and the agglutination effects of different types of red blood cells,the positive rate of virus and the titer of hemagglutinin isolated from different cells were statistically compared.ResultsThe agglutination effect of the same virus isolate on the two types of red blood cells was different. The complete agglutination time of guinea pig red blood cells was about 2 times that of chicken red blood cells,and the deposition shape showed a ring shape. The average hemag-glutinin titer was 23. 6 ± 1. 2times that of chicken red blood cells. Under the same conditions,3 samples were negative for both types of cells,11 samples were positive for both types of cells,and the other 6 samples were negative for MDCK cells while positive for MTY6 cells. The positive rate of MTY6 cells was 30% higher than that of MDCK cells. The isolated positive samples included 8 cases of H1N1 subtype and the hemagglutinin titer of virus isolated by MTY6 cells was significantly higher than that by MDCK cells[13. 0(1. 7,23. 0)times on average]. 2 cases of H3N2 and 2 cases of B were isolated,the hemagglutinin titer of each virus isolated by MTY6 cells was 11. 3 and 32. 0 times higher than that by MDCK cells on average respectively.ConclusionIn conclusion,guinea pig red blood cells were superior to chicken red blood cells for influenza virus detection by cell isolation. Under the same conditions,MTY6 cells were more sensitive than MDCK cells for influenza virus isolation,and had the potential to be used as a high-quality cell matrix for influenza virus isolation.