Abstract
Background: The application (WO 2010/141478) is in the field of glycobiology and deals with the synthesis of recombinant proteins with a reduced rate of fucosylation.
Objective: It aims at generating mammalian cell lines that express mutant forms of GDP-4-keto-deoxy-mannose-3,5,-epimerase-4-reductase (FX) and cells that conditionally fucosylate proteins.
Methods: Mutant forms of FX were synthesized, and mammalian cell lines genetically engineered to express mutant FX proteins and the protein of interest. Cell lines that conditionally fucosylate proteins were generated from a mutant FX form that has reduced ability to fucosylate glycoproteins at 37oC and not at 34oC.
Results: Cells genetically engineered to express mutant forms of FX protein show reduced ability to fucosylate proteins, particularly antibodies, with rates as low as 5 – 0.5% fucosylation, compared to cells expressing wild-type FX.
Conclusion: Cells genetically engineered to express the mutant forms of FX protein provide a means to synthesize and express proteins with a reduced rate of fucosylation. The paradigm may be used to synthesize antibodies that mediate antibody-dependent cell-mediated cytotoxicity more efficiently. The application uses mammalian cell lines, genetically engineered to express mutant FX proteins, to synthesize and produce proteins with a reduced rate of fucosylation. The application claims the conditional control of protein fucosylation by FX mutant proteins.