ABSTRACT
Objective To observe the tumorigenicity of High Five insect cell line in Balb/c nude mice,and make sure the safety of the cells when used in vaccine production.Methods Balb/c nude mice were randomly divided into 5 groups:the basic cell bank of High Five group,the highest limited passages of High Five group,HEp-2 cell group as positive control,CEF cell group as negative control,and blank control.Except of the blank control,cell suspension was injected subcutaneously into the nude mice in the different groups,respectively.At 3 and 12 weeks after injection,anatomical observation and histopathologic examination were performed to detect the tumor formation.Results At 3 and 12 weeks after injection,the tumorigenicity study results showed that no tumor developed at the transplantation site in the blank control group,negative group,and High Five groups.Histopathological examinations also showed no abnormality in these groups.Otherwise,squamous cell carcinoma was developed in the positive group at 3 weeks after injection.Conclusions High Five cells of basic cell bank and highest limited passages are not tumorigenic,and can be used in vaccine production safely.