RESUMEN
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.
RESUMEN
The High Five cell line (BTI-TN-5B1-4) isolated from the cabbage looper, Trichoplusia ni is an insect cell line widely used for baculovirus-mediated recombinant protein expression. Despite its widespread application in industry and academic laboratories, the genomic background of this cell line remains unclear. Here we sequenced the transcriptome of High Five cells and assembled 25,234 transcripts. Codon usage analysis showed that High Five cells have a robust codon usage capacity and therefore suit for expressing proteins of both eukaryotic- and prokaryotic-origin. Genes involved in glycosylation were profiled in our study, providing guidance for engineering glycosylated proteins in the insect cells. We also predicted signal peptides for transcripts with high expression abundance in both High Five and Sf21 cell lines, and these results have important implications for optimizing the expression level of some secretory and membrane proteins.