(624d) Analysis of Post-Translational Regulation of Engineered CHO Using Proteomics

Cell engineering has been applied to improve the post-translational modification (PTM) by manipulating one or multiple enzymes in CHO. However, the effects of the interaction between intracellular proteins, heterologous protein expression and the regulation of host cells on PTM have not been fully investigated at systems biology level. In this study, the comparative and quantitative proteomics was performed to investigate seven host cells, including parental cells (CHO K1 and CHO S) and engineered cells (Pro^-5 CHO, Pro^-5Lec20, Gat^-2CHO, Gat^-2Lec20, and Lec13) expressing different β4-galactosyltransferase (β4GalT) or down-regulating α-1,6-fucosyltransferase, and their anti-cancer monoclonal antibody (mAb) production cell lines. The intracellular proteomic maps of these host cells and production lines were created. The expression of the proteins associated with PTM of mAb, the metabolism of glucose, glutamine and amino acids, and the transcription, translation and folding of mAb were investigated and compared. The PTM regulation of mAb and the interaction of intracellular proteins caused by the genetic engineering were analyzed. This study demonstrated that proteomics is a powerful tool to understand the mechanism of protein expression and protein quality regulation. The Omics knowledge developed could be used to optimize the cell engineering strategy to achieve high quality of biopharmaceuticals.