Reduction of Cell Death by Using Storage-protein 2 from Silkworm Hemolymph in Chinese Hamster Ovary Cell Culture

초록

Chinese hamster ovary (CHO) cells have been widely used in recombinant protein production. Cell death is one of the major problems in mammalian cell cultures. Many factors cause the cell death during culture processes. To increase cell viability and productivity, various anti-apoptotic agents have been used to extend the culture period. Storage-protein 2 (SP2) is a soluble protein derived from silkworm hemolymph. Molecular weight of SP2 is approximately 70 kDa and amino acid sequence is confirmed. In this study, we investigated the effects of SP2 addition in recombinant CHO cell culture. When SP2 was added to culture media, viable cell density and viability were enhanced. Productivity was increased up to 1.48-fold than the control. It was found that cell aggregation rate was decreased by 20% with 2 mg/mL of SP2. To identify the effect of SP2 as an anti-apoptotic agent, annexin V-FITC/propidium iodide staining was performed to detect cell death. Compared with the control, the fraction of apoptotic cells was reduced by 80%. In conclusion, utilization of SP2 inhibited cell death, thereby enhanced the productivity.