Cell engineering for the production of hybrid-type N-glycans in HEK293 cells.

Glycoprotein therapeutics are among the leading products in the biopharmaceutical industry. The heterogeneity of glycans in therapeutic proteins is an issue for maintaining quality, activity and safety during bioprocessing. In this study, we knocked out genes encoding Golgi α-mannosidase-II, MAN2A1 and MAN2A2 in human embryonic kidney 293 (HEK293) cells, establishing an M2D-KO cell line that can produce recombinant proteins mainly with hybrid-type N-glycans. Furthermore, FUT8, which encodes α1,6-fucosyltransferase, was knocked out in the M2D-KO cell line, establishing a DF-KO cell line that can express noncore fucosylated hybrid-type N-glycans. Two recombinant proteins, lysosomal acid lipase and constant fragment of human IgG1, were expressed in the M2D-KO and DF-KO cell lines. Glycan structural analysis revealed that complex-type N-glycans were removed in both M2D-KO and DF-KO cells. Our results suggest that these cell lines are suitable for the production of therapeutic proteins with hybrid-type N-glycans. Moreover, KO cell lines would be useful as models for researching the mechanism of antimetastatic effects in human tumours by swainsonine treatment.