Multiplication of the Recombinant Strain Re-7 of Avian Influenza Virus Subtype H5 in MDCK Cells

摘要

This study was conducted to explore the multiplication pattern of the recombinant strain Re-7 of avian influenza virus subtype H5 in Madin Darby Canine Kidney(MDCK) cells and to determine the optimal multiplicity of infection(MOI) and the optimal time for virus harvest. The recombinant strain Re-7 was inoculated at different MOIs into MDCK cells grown in serum-free medium in 100 L bioreactors for replication. Then,the hemagglutination(HA) titer, 50% tissue culture infectious dose(TCID50) and 50% embryo infectious dose(EID50) of culture medium were measured once every 12 h from 24 h after virus inoculation to determine the optimal MOI. After that, virus was inoculated at the optimal MOI deter-mined above into MDCK cells for large-scale virus replication to determine the optimal time for virus harvest. The results showed that the optimal MOI was 10^(-2), and the optimal time for virus harvest was 60 h after inoculation. Under these conditions, the HA titer, TCID_(50) per 1 m L and EID50 per 0.1 m L were increased to 1∶102 4, 10^(7.33) and 10^(6.83), respectively. This study provides relatively stable parameters for large-scale production of the recombinant strain Re-7 of avian influenza virus subtype H5.