Screening of single-cell clonal lines from Papilio demoleus Linnaeus cell lines for exogenous protein expression and adaptation in serum-free culture

In this paper, four established cell lines derived from newly hatched larvae of Papilio demoleus Linnaeus and 57 single-cell clones derived from the 3 lines were used as test materials. Recombinant β -galactosidase baculovirus AcMNPV-Gal was used to infect the P. demoleus L. cell lines and the single-cell clones, and recombinant protein expression in each cell line was detected and compared. Three clonal cell lines, RIRI-PaDe-1-C1, RIRI-PaDe-2-C6 and RIRI-PaDe-3-C52, which showed significantly higher β -galactosidase expression levels than those of the parental cell lines, were selected. Five types of commercial serum-free media for insect cells, Express Five SFM, Ex-Cell 405, Sf-900III SFM, Sf-900II SFM and HyClone Serum-Free Media, were used to adapt RIRI-PaDe-2-C6 cells and RIRI-PaDe-3-C52 cells to serum-free culture conditions, and the growth characteristics of the cells and the exogenous protein expression characteristics before and after adaptation were compared. The results showed that RIRI-PaDe-2-C6 cells could stably proliferate in Ex-Cell 405, RIRI-PaDe-3-C52 cells could stably proliferate in Express Five SFM and Ex-Cell 405, and the rate of proliferation of and the level of expression of β -galactosidase in RIRI-PaDe-3-C52 cells were significantly increased in Express Five SFM.