Akio Shirasu

Transfection System Using a Cocktail of Totally Designed Lipidic Materials in Chinese Hamster Ovary Cells: Lipidic Cocktail as Potential Gene Carrier for CHO Cells

Attention has recently been focused on Chinese hamster ovary (CHO) cell line as a powerful tool for the production of therapeutic proteins, including cytokines and antibodies. CHO cells are becoming the prevailing expression system for the large-scale production of recombinant proteins because of their capacity for proper protein folding and post-translational modifications. These systems are essential for the cells genetically engineered for high level production of recombinant proteins. Therefore, a number of studies have reported various strategies for the efficient transfer process and high production of recombinant proteins. Efforts toward the development of transfection system based on nonpathogenic materials such as lipids or polymers are crucial for basic and therapeutic research. We are interested in studying the evolution of designed lipidic materials as potential gene carriers with high transfection efficiency and low cytotoxicity. Here, we demonstrate that a cocktail of novel lipidic materials that are designed by taking advantage of the chemical structure having double-stranded hydrophobic chains in major cell membrane lipids such as phospholipids and sphingolipids can provide an efficient transfection (˜90% of the transferred cells) with low cytotoxicity in CHO cells, no reduction in transfection efficiency in the presence of fetal bovine serum. Moreover, the transfer abilities of its lipid cocktail were estimated in the large scale culture of CHO cells in gas permeability bags. Our findings suggest that this approach can serve as a novel model for the development of the expression system for the large-scale production of recombinant proteins.