Glycosylation engineering of antibodies for improving antibody-dependent cellular cytotoxicity

1. A glycoengineered mammalian host cell that expresses a recombinant antibody comprising an Fc region or fragment thereof containing N-linked oligosaccharides, wherein said host 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 host 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 mammalian host cell that expresses a recombinant antibody comprising an Fc region or fragment thereof containing N-linked oligosaccharides, wherein said host 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 host 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 host cell according to claim 1 , wherein said altered pattern of glycosylation comprises an increased proportion of nonfucosylated oligosaccharides.

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

5. A glycoengineered host cell according to claim 1 , wherein said antibody is a chimeric antibody.

6. A glycoengineered host cell according to claim 1 , wherein said antibody is a humanized antibody.

7. A glycoengineered host cell according to claim 1 , wherein said antibody is an antibody fragment that contains a Fc region.

8. A glycoengineered host cell according to claim 1 , wherein said antibody is a fusion protein that includes a Fc region of an immunoglobulin.

9. A glycoengineered host cell according to claim 1 , wherein the predominant N-linked oligosaccharide in the Fc region is not a high-mannose structure.

10. A glycoengineered host 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 host cell that has not been glycoengineered.

11. A glycoengineered mammalian host cell that produces a recombinant antibody comprising an Fc region containing N-linked oligosaccharides, wherein said host 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 host cell that has not been glycoengineered, and wherein said antibody has increased Fc-mediated cellular cytotoxicity as a result of said glycoengineering.

12. A glycoengineered host cell according to claim 11 , wherein said GlcNAc residues are bisecting.

13. A glycoengineered host cell according to claim 11 , wherein said GlcNAc residues are bisecting and wherein said bisected oligosaccharides are of complex type.

14. A glycoengineered host cell according to claim 11 , wherein said GlcNAc residues are bisecting and wherein said bisected oligosaccharides are of hybrid type.

15. A glycoengineered host cell according to claim 1 , wherein said host cell is selected from the group consisting of an engineered CHO cell, and engineered BHK cell, an engineered NS0 cell, and an engineered SP2/0 cell.

16. A glycoengineered host cell according to claim 15 , wherein said host cell is an engineered CHO cell.

17. A glycoengineered host cell according to claim 1 , wherein said host cell has been genetically manipulated to have altered expression of at least one glycoprotein-modifying glycosyl transferase.

18. A glycoengineered host cell according to claim 17 , 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, a-mannosidase II, and core α-1,6-fucosyltransferase.

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

20. A glycoengineered host cell according to claim 18 wherein said at least one glycoprotein-modifying glycosyltransferase is core α1,6-fucosyltransferase.

21. A glycoengineered host cell according to claim 18 , wherein said at least one glycoprotein-modifying glycosyltransferase is α-mannosidase II.

22. A glycoengineered host cell according to claim 18 , wherein said altered expression is increased expression of said at least one glycoprotein-modifying glycosyltransferase.

23. A glycoengineered host cell according to claim 18 , wherein said altered expression is decreased expression of said at least one glycoprotein-modifying glycosyltransferase.

24. A glycoengineered host cell according to claim 22 , wherein said at least one glycoprotein-modifying glycosyltransferase is β(1,4)-N-acetylglucosaminyltransferase III.

25. A glycoengineered host cell according to claim 24 , wherein said increased activity is increased expression of β(1,4)-N-acetylglucosaminyltransferase III.

26. A glycoengineered host cell according to claim 23 , wherein said at least one glycoprotein-modifying glycosyltransferase is core α-1,6-fucosyltransferase.

27. A glycoengineered host cell according to claim 21 , wherein said altered expression is increased expression of β(1,4)-N-acetylglucosaminyltransferase III and α-mannosidase II.

28. A glycoengineered host cell according to claim 21 , wherein said altered expression is increased expression of β(1,4)-N-acetylglucosaminyltransferase III and α-mannosidase II and β(1,4)-galactosyltransferase.

29. A glycoengineered host cell according to claim 1 , wherein said antibody is a therapeutic antibody.

30. A glycoengineered host cell according to claim 1 , wherein said antibody selectively binds to an antigen expressed by cancer cells.

31. A glycoengineered host cell according to claim 29 , wherein said antibody is a monoclonal antibody.

32. A glycoengineered host cell according to claim 29 , wherein said antibody is a selected from the group consisting of: an antiCD20 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.

33. A glycoengineered host cell according to claim 1 , wherein said antibody is an IgG.

34. A glycoengineered host cell according to claim 1 , wherein the majority of the N-linked oligosaccharides in the Fc region of said antibody are bisected.

35. A glycoengineered host cell according to claim 1 , wherein the majority of the N-linked oligosaccharides in the Fc region of said antibody are nonfucosylated.

36. A glycoengineered host cell according to claim 1 , wherein the majority of the N-linked oligosaccharides in said Fc region of said antibody are bisected, nonfucosylated.

37. A glycoengineered host cell according to claim 1 , wherein said host cell is produced by a process comprising:

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

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

38. A glycoengineered host cell according to claim 37 , wherein said genetic manipulation is achieved by introducing into said host cell at least one gene encoding an exogenous glycoprotein-modifying glycosyltransferase.

39. A glycoengineered host cell according to claim 29 , 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.

40. A glycoengineered host cell according to claim 1 , wherein at least 45% of the oligosaccharides in the Fc region are complex structures.

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

42. A glycoengineered host cell according to claim 17 , wherein said at least one glycoprotein-modifying glycosyl transferase is mammalian.

43. A glycoengineered host cell according to claim 42 , wherein said at least one glycoprotein-modifying glycosyl transferase is human.

44. A glycoengineered host cell according to claim 38 , wherein said exogenous glycoprotein-modifying glycosyltransferase is β(1,4)-N-acetylglucosaminyltransferase III and α-mannosidase II.

45. A glycoengineered host cell according to claim 38 , wherein said exogenous glycoprotein-modifying glycosyltransferase is α-mannosidase II.