Methods for controlling fucosylation levels in proteins

A method for decreasing fucosylation and increasing Mannose 5 and GlcNAc2Man3GlcNAc2 (G0) in the glycosylation pattern of an expressed antibody in an eukaryotic protein expression system, the method comprising:

• providing a culturing medium;
• introducing into the culturing medium the eukaryotic protein expression system, wherein the eukaryotic protein expression system comprises an expression cassette encoding the expressed antibody, wherein the expressed antibody is Itolizumab, wherein the eukaryotic protein expression system comprises mammalian cells, wherein the mammalian cells are CHO hamster cells;
• adding manganese or manganese ions into the culture medium to form a manganese containing culture medium, wherein the manganese or manganese ions is in a concentration range of ≥0.075 mM-≤0.5 mM;
• culturing the eukaryotic protein expression system in the manganese containing medium to obtain the expressed antibody;
• and
• recovering the expressed antibody from the manganese containing medium, wherein the expressed antibody exhibits decreased fucose and increased levels of Mannose 5 and GlcNAc2Man3GlcNAc2 (G0) in the glycosylation pattern compared to an expressed antibody cultured in a medium wherein no manganese or manganese ions were introduced into the culture medium.