Glycosylation engineering of antibodies for improving antibody-dependent cellular cytotoxicity

1. A glycoengineered Chinese Hamster Ovary cell that expresses a recombinant antibody comprising an IgG Fc region or fragment thereof containing N-linked oligosaccharides, wherein said Chinese Hamster Ovary cell has been genetically manipulated to have altered activity of at least one glycoprotein-modifying glycosyltransferase, wherein said antibody has an altered pattern of glycosylation in the Fc region compared to the corresponding antibody produced by the same Chinese Hamster Ovary cell that has not been glycoengineered, and wherein said antibody has increased Fc-mediated cellular cytotoxicity as a result of said altered glycosylation.

2. A glycoengineered Chinese Hamster Ovary cell that expresses a recombinant antibody comprising an IgG Fc region or fragment thereof containing N-linked oligosaccharides, wherein said Chinese Hamster Ovary cell has been genetically manipulated to have altered activity of at least one glycoprotein-modifying glycosyltransferase, wherein said antibody has an altered pattern of glycosylation in the Fc region compared to the corresponding antibody produced by the same Chinese Hamster Ovary cell that has not been glycoengineered, and wherein said antibody has increased Fc receptor binding affinity as a result of said altered glycosylation.

3. A glycoengineered Chinese Hamster Ovary cell according to claim 1 or claim 2 , wherein said altered pattern of glycosylation comprises an increased proportion of nonfucosylated oligosaccharides.

4. A glycoengineered Chinese Hamster Ovary cell according to claim 1 or claim 2 , wherein the predominant N-linked oligosaccharide in the Fc region of said antibody is nonfucosylated.

5. A glycoengineered Chinese Hamster Ovary cell according to claim 1 or claim 2 , wherein said antibody is a chimeric antibody.

6. A glycoengineered Chinese Hamster Ovary cell according to claim 1 or claim 2 , wherein said antibody is a humanized antibody.

7. A glycoengineered Chinese Hamster Ovary cell according to claim 1 or claim 2 , wherein said antibody is a fusion protein that includes a Fc region of an immunoglobulin.

8. A glycoengineered Chinese Hamster Ovary cell according to claim 1 or claim 2 , wherein the predominant N-linked oligosaccharide in the Fc region is not a high-mannose structure.

9. A glycoengineered Chinese Hamster Ovary cell according to claim 3 , wherein said Fc region containing N-linked oligosaccharides further comprises an increased proportion of GlcNAc residues compared to the corresponding antibody produced by the same Chinese Hamster Ovary cell that has not been glycoengineered.

10. A glycoengineered Chinese Hamster Ovary cell that produces a recombinant antibody comprising an Fc region containing N-linked oligosaccharides, wherein said Chinese Hamster Ovary cell has been genetically manipulated to have altered activity of at least one glycoprotein-modifying glycosyltransferase, wherein said antibody has an increased proportion of GlcNAc residues in the Fc region relative to the proportion of fucose residues compared to the proportion of GlcNAc to fucose residues in the Fc region of a corresponding antibody produced by the same Chinese Hamster Ovary cell that has not been glycoengineered, and wherein said antibody has increased Fc-mediated cellular cytotoxicity as a result of said genetic manipulation.

11. A glycoengineered Chinese Hamster Ovary cell according to claim 10 , wherein said GlcNAc residues are bisecting.

12. A glycoengineered Chinese Hamster Ovary cell according to claim 10 , wherein said GlcNAc residues are bisecting and wherein said bisected oligosaccharides are of complex type.

13. A glycoengineered Chinese Hamster Ovary cell according to claim 10 , wherein said GlcNAc residues are bisecting and wherein said bisected oligosaccharides are of hybrid type.

14. A glycoengineered Chinese Hamster Ovary cell according to claim 10 , wherein said at least one glycoprotein-modifying glycosyltransferase is selected from the group consisting of: β(1,4)-N-acetylglucosaminyltransferase III, β(1,4)-N-acetylglucosaminyltransferase V, β(1,4) -galactosyltransferase, α-mannosidase II, and core α-1,6-fucosyltransferase.

15. A glycoengineered Chinese Hamster Ovary cell according to claim 14 , wherein said at least one glycoprotein-modifying glycosyltransferase is β(1,4)-N-acetylglucosaminyltransferase III.

16. A glycoengineered Chinese Hamster Ovary cell according to claim 14 , wherein said at least one glycoprotein-modifying glycosyltransferase is core α-1,6-fucosyltransferase.

17. A glycoengineered Chinese Hamster Ovary cell according to claim 14 , wherein said at least one glycoprotein-modifying glycosyltransferase is α-mannosidase II.

18. A glycoengineered Chinese Hamster Ovary cell according to claim 14 , wherein said altered activity is increased activity of said at least one glycoprotein-modifying glycosyltransferase.

19. A glycoengineered Chinese Hamster Ovary cell according to claim 14 , wherein said altered activity is decreased activity of said at least one glycoprotein-modifying glycosyltransferase.

20. A glycoengineered Chinese Hamster Ovary cell according to claim 18 , wherein said at least one glycoprotein-modifying glycosyltransferase is β(1,4)-N-acetylglucosaminyltransferase III.

21. A glycoengineered Chinese Hamster Ovary cell according to claim 20 , wherein said increased activity is increased expression of β(1,4)-N-acetylglucosaminyltransferase III.

22. A glycoengineered Chinese Hamster Ovary cell according to claim 19 , wherein said at least one glycoprotein-modifying glycosyltransferase is core α1,6-fucosyltransferase.

23. A glycoengineered Chinese Hamster Ovary cell according to claim 17 , wherein said altered activity is increased expression of β(1,4)-N-acetylglucosaminyltransferase III and α-mannosidase II.

24. A glycoengineered Chinese Hamster Ovary cell according to claim 17 , wherein said altered activity is increased expression of β(1,4)-N-acetylglucosaminyltransferase III and α-mannosidase II and β(1,4)-galactosyltransferase.

25. A glycoengineered Chinese Hamster Ovary cell according to claim 1 or claim 2 , wherein said antibody is a therapeutic antibody.

26. A glycoengineered Chinese Hamster Ovary cell according to claim 1 or claim 2 , wherein said antibody selectively binds to an antigen expressed by cancer cells.

27. A glycoengineered Chinese Hamster Ovary cell according to claim 25 , wherein said antibody is a monoclonal antibody.

28. A glycoengineered Chinese Hamster Ovary cell according to claim 25 , wherein said antibody is a selected from the group consisting of: an anti-CD20 antibody, an anti-human neuroblastoma antibody, an anti-human renal cell carcinoma antibody, an anti-HER2 antibody, an anti-human colon, lung, and breast carcinoma antibody, an anti-human 17-1A antigen antibody, a humanized anti-human colorectal tumor antibody, an anti-human melanoma antibody, and an anti-human squamous-cell carcinoma antibody.

29. A glycoengineered Chinese Hamster Ovary cell according to claim 1 or claim 2 , wherein the majority of the N-linked oligosaccharides in the Fc region of said antibody are bisected.

30. A glycoengineered Chinese Hamster Ovary cell according to claim 1 or claim 2 , wherein the majority of the N-linked oligosaccharides in the Fc region of said antibody are nonfucosylated.

31. A glycoengineered Chinese Hamster Ovary cell according to claim 1 or claim 2 , wherein the majority of the N-linked oligosaccharides in said Fc region of said antibody are bisected, nonfucosylated.

32. A glycoengineered Chinese Hamster Ovary cell according to claim 1 or claim 2 , wherein said Chinese Hamster Ovary cell is produced by a process comprising:

(a) providing a Chinese Hamster Ovary cell comprising at least one nucleic acid encoding a recombinant antibody; and

(b) genetically manipulating said Chinese Hamster Ovary cell to alter the activity in said cell of at least one glycoprotein-modifying glycosyltransferase.

33. A glycoengineered Chinese Hamster Ovary cell according to claim 32 , wherein said genetic manipulation is achieved by introducing into said cell at least one gene encoding an exogenous glycoprotein-modifying glycosyltransferase.

34. A glycoengineered Chinese Hamster Ovary cell according to claim 25 , wherein said antibody is a therapeutic monoclonal antibody having a human Fc region and that selectively binds an antigen expressed by cancer cells, and wherein the majority of oligosaccharides in the Fc region of said antibody are nonfucosylated.

35. A glycoengineered Chinese Hamster Ovary cell according to claim 1 or claim 2 , wherein at least 45% of the oligosaccharides in the Fc region are complex structures.

36. A glycoengineered Chinese Hamster Ovary cell according to claim 1 or claim 2 , wherein said recombinant antibody exhibits at least an 80% increase in maximal ADCC activity compared to the same antibody produced by the same Chinese Hamster Ovary cell under identical culture and purification conditions, but which has not been glycoengineered.

37. A glycoengineered Chinese Hamster Ovary cell according to claim 1 or claim 2 , wherein said at least one glycoprotein-modifying glycosyl transferase is mammalian.

38. A glycoengineered Chinese Hamster Ovary cell according to claim 37 , wherein said at least one glycoprotein-modifying glycosyl transferase is human.

39. A glycoengineered Chinese Hamster Ovary cell according to claim 33 , wherein said exogenous glycoprotein-modifying glycosyltransferase is β(1,4)-N-acetylglucosaminyltransferase III and α-mannosidase II.

40. A glycoengineered Chinese Hamster Ovary cell according to claim 33 , wherein said exogenous glycoprotein-modifying glycosyltransferase is α-mannosidase II.

41. A glycoengineered Chinese Hamster Ovary cell according to claim 1 or claim 2 , wherein said IgG Fc region containing N-linked oligosaccharides comprises an entire IgG Fc region.

42. A glycoengineered Chinese Hamster Ovary cell according to claim 1 or claim 2 , wherein said IgG Fc region containing N-linked oligosaccharides comprises an IgG fragment.

43. A glycoengineered Chinese Hamster Ovary cell according to claim 42 , wherein said IgG fragment comprises a CH2 domain.