High level expression of recombinant protein in a cell line derived from Spodoptera litura (Lepidoptera: Noctuidae)

Cell lines were established from pupal ovaries of the common cutworm, Spodoptera litura, SL7B cells, one of the cell lines established had a doubling time of about 20.8 h at 28 degrees C in TNM-FH medium. Results of isozyme analysis showed that this cell line differed from five other lepidopteran cell lines. The karyotype was typical of lepidopteran cells, containing numerous microchromosomes, with an average of about 147+/-60. Wild type Autographa californica NPV and recombinant viruses containing chloramphenical acetyl transferase (CAT) and hepatitis B surface antigen (HBsAg) gene were used to evaluate the expression of enzyme and virus occlusion body formation in SL7B, SF21AE, and SF9 cells. The SL7B cell produced 2-3 fold more CAT protein than did SF21AE and SF9 cell lines, and produced 1.5-2 fold more occlusion bodies than the other two cell lines.