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 determined 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, TCIDso per 1 mL and EIDso per 0.1 mL 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.
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 determined 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, TCIDso per 1 mL and EIDso per 0.1 mL 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.
