| Poliomyelitis(Polio)is an acute contagious fecal-oral transmitted disease caused by polio virus,commonly known as infantile paralysis.Vaccine is the only effective method.for prevention.The ability supporting cells growth and reproduction in the process of cell culture of serum is one of the primary indicator of its quality.Choosing a kind of high quality serum using in cells and virus culture is significant.The immunogenicity of vaccines dues to its virus contents thus,precise measurement of the virus contented in the vaccine ensures the immune effects of vaccines.At the present,the possible effects of using serum reagents for polio virus culturing and testing cannot be ignored.There have being some difference between different batch of serum selling on the market,which has increased the instability of vaccine production and verification and has increased the difficulty of vaccine quality control.Objective:Study serum influence on poliovirus culture and poliovirus titer test.Method:(1)Each serum adapt to Vero cell,poliovirus was inoculated in Vero cells with 3 different M.O.I and harvested,the influence of different serum to poliovirus culture was analyzed by measuring infectious titer of virus harvest fluid by micro measurement method and D antigen by ELISA method.(2)By using 6 kinds of untreated serum and 6 kinds of pretreatment serum group respectively,the degree of polio virus infectious droplets had been tested.Also,the poliovirus neutralization antibody titer of different group had been tested.After that,we presented the cell growth experiment in the pretreatment serum group.We analyzed the influence on CCID50(cell culture infective dose 50%)data from different chosen serum.Results:(1)Different serum culturing Vero cell,cell morphology,cell calculation result difference was not eminent(P>0.05),doubling time has no significant difference(P>0.05).Virus titer has no significant difference(P>0.05).D antigen test shows type one and type three imported fetal calf serum has significant difference with imported new-born calf serum,imported calf serum and domestic new-born calf serum the rest have significant difference(P<0.05),type two the rest have no significant difference(P>0.05).When inoculating poliovirus with same serum but different M.O.I,virus titer and D antigen content was not influenced and virus lesion time was influenced.(2)According to the final results,the difference of polio virus CCID50between these 6 kind of untreated serum groups were significant(P<0.01),however,the contrary results could be seen in the pretreatment serum groups,which had an significant difference(P>0.05).In these untreated serum groups,NO.2 serum sample had a 1:4 neutralizing antibody titer,the NO.6 serum sample had a 1:8 neutralizing antibody titer,and the others had a neutralizing antibody titer less than 1:4.The neutralizing antibody titer all the 6 kinds of pretreatment serum were 1:2.In the cell growth experiments,6 kinds of pretreatment serum could maintain the cell normal growth.Conclusions:(1)In analysis on different calf serum influence Vero cell growth in Vero cell culture leads to influence virus production and quality,we can optimize culture condition in a better way.By optimizing cell density augment and may lead to more effective capacity of Sabin IPV production in bioreactor.(2)Influence on poliovirus CCID50(cell culture infective dose 50%)by different serum has been compared.Using the serum immune adsorption method to pretreat the serum before Polio virus infectious droplets degree testing can reduce the influence of neutralizing antibody in the serum,which could be a possibility to comparing different experiment data between different laboratory. |
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