Fusion constructs and use of same to produce antibodies with increased Fc receptor binding affinity and effector function

1. A method for modifying the glycosylation of a polypeptide produced by a host cell, comprising introducing into said host cell a nucleic acid comprising a sequence encoding a fusion polypeptide, wherein said fusion polypeptide has β(1,4)-galactosyltransferase activity and comprises a Golgi localization domain selected from the group consisting of: the localization domain of mannosidase II, the localization domain of β(1,2)-N-acetylglucosaminyltransferase I, the localization domain of mannosidase I, the localization domain of β(1,2)-N-acetylglucosaminyltransferase II, and the localization domain of α1-6 core fucosyltransferase, and wherein said modified polypeptide has increased Fc-receptor binding or effector function as a result of said modification.

2. A method according to claim 1 , wherein said nucleic acid comprising a sequence encoding a fusion polypeptide is expressed from an expression vector.

3. A method according to claim 1 , wherein said polypeptide produced by said host cell is IgG or a fragment thereof.

4. A method according to claim 3 , wherein said polypeptide produced by said host cell is IgG1 or a fragment thereof.

5. A method according to claim 3 , wherein said polypeptide produced by said host cell is a fusion protein that includes a region equivalent to the Fc region of a human IgG.

6. A method for producing a polypeptide in a host cell, comprising:

a. culturing a host cell engineered to express at least one nucleic acid encoding a fusion polypeptide having β(1,4)-galactosyltransferase activity under conditions which permit the production of a polypeptide selected from the group consisting of a whole antibody molecule, an antibody fragment, and a fusion protein that includes a region equivalent to the Fc region of an immunoglobulin, wherein said fusion polypeptide is expressed in an amount sufficient to modify the oligosaccharides in the Fc region and increase Fc-receptor binding or effector function of said polypeptide produced by said host cell, and wherein said fusion polypeptide having β(1,4)-galactosyltransferase activity comprises a Golgi localization domain selected from the group consisting of: the localization domain of mannosidase II, the localization domain of β(1,2)-N-acetylglucosaminyltransferase I, the localization domain of mannosidase I, the localization domain of β(1,2)-N-acetylglucosaminyltransferase II, and the localization domain of α1-6 core fucosyltransferase; and

b. isolating said polypeptide.

7. A method according to claim 6 wherein said fusion polypeptide consists essentially of the catalytic domain of β(1,4)-galactosyltransferase and a Golgi localization domain selected from the group consisting of: the localization domain of mannosidase II, the localization domain of β(1,2)-N-acetylglucosaminyltransferase I, the localization domain of mannosidase I, the localization domain of β(1,2)-N-acetylglucosaminyltransferase II, and the localization domain of α1-6 core fucosyltransferase.

8. A method according to claim 6 , wherein said Golgi localization domain is the localization domain of mannosidase II.

9. A method according to claim 6 , wherein said produced polypeptide selected from the group consisting of a whole antibody molecule, an antibody fragment, and a fusion protein that includes a region equivalent to the Fc region of an immunoglobulin exhibits at least 15% greater antibody-dependent cellular cytotoxicity compared to polypeptides produced in a host cell expressing wild-type β(1,4)-galactosyltransferase.

10. A method according to claim 6 , wherein said increased effector function is selected from the group consisting of: increased Fc-mediated cellular cytotoxicity, increased binding to NK cells, increased binding to macrophages, increased binding to monocytes, increased binding to polymorphonuclear cells, increased direct signaling inducing apoptosis, increased dendritic cell maturation, and increased T cell priming.

11. A method according to claim 6 , wherein said produced polypeptide selected from the group consisting of a whole antibody molecule, an antibody fragment, and a fusion protein that includes a region equivalent to the Fc region of an immunoglobulin exhibits increased Fc receptor binding affinity as a result of said modification.

12. A method according to claim 11 , wherein said Fc receptor is Fc activating receptor.

13. A method according to claim 11 , wherein said Fc receptor is FcγRIIIA receptor.

14. A method according to claim 6 , wherein said produced polypeptide selected from the group consisting of a whole antibody molecule, an antibody fragment, and a fusion protein that includes a region equivalent to the Fc region of an immunoglobulin has an increased proportion of bisected oligosaccharides in the Fc region of said polypeptide.

15. A method according to claim 6 , wherein said produced polypeptide selected from the group consisting of a whole antibody molecule, an antibody fragment, and a fusion protein that includes a region equivalent to the Fc region of an immunoglobulin has an increased proportion of nonfucosylated oligosaccharides in the Fc region of said polypeptide.

16. A method according to claim 15 , wherein said nonfucosylated oligosaccharides are hybrid bisected or complex bisected.

17. A method according to claim 6 , wherein said produced polypeptide selected from the group consisting of a whole antibody molecule, an antibody fragment, and a fusion protein that includes a region equivalent to the Fc region of an immunoglobulin has an increased proportion of bisected, nonfucosylated oligosaccharides in the Fc region of said polypeptide.

18. A method according to claim 17 , wherein said bisected, nonfucosylated oligosaccharides are hybrid or complex.

19. A method according to claim 17 , wherein at least 45% of the oligosaccharides in the Fc region of said produced polypeptide are nonfucosylated.

20. A method for producing a polypeptide in a host cell, comprising:

a. culturing a host cell engineered to express at least one nucleic acid encoding a fusion polypeptide having GalT activity and at least one a nucleic acid encoding a polypeptide having Man II activity under conditions which permit the production of a polypeptide selected from the group consisting of a whole antibody molecule, an antibody fragment, and a fusion protein that includes a region equivalent to the Fc region of an immunoglobulin, wherein said fusion polypeptide is expressed in an amount sufficient to modify the oligosaccharides in the Fc region and increase the Fc-receptor binding or effector function of said polypeptide produced by said host cell, and wherein said fusion polypeptide having GalT activity comprises a Golgi localization domain selected from the group consisting of: the localization domain of mannosidase II, the localization domain of β(1,2)-N-acetylglucosaminyltransferase I, the localization domain of mannosidase I, the localization domain of β(1,2)-N-acetylglucosaminyltransferase II, and the localization domain of α1-6 core fucosyltransferase; and

b. isolating said polypeptide.

21. A method according to claim 20 , wherein said host cell is further engineered to express at least one nucleic acid encoding a polypeptide having GnT II activity.

22. A method according to claim 20 wherein said fusion polypeptide consists essentially of the catalytic domain of GalT and a Golgi localization domain selected from the group consisting of: the localization domain of mannosidase II, the localization domain of β(1,2)-N-acetylglucosaminyltransferase I, the localization domain of mannosidase I, the localization domain of β(1,2)-N-acetylglucosaminyltransferase II, and the localization domain of α1-6 core fucosyltransferase.

23. A method according to claim 20 , wherein said Golgi localization domain is the localization domain of mannosidase II.

24. A method according to claim 20 , wherein said produced polypeptide selected from the group consisting of a whole antibody molecule, an antibody fragment, and a fusion protein that includes a region equivalent to the Fc region of an immunoglobulin exhibits at least 15% greater antibody-dependent cellular cytotoxicity compared to polypeptides produced in a host cell expressing wild-type β(1,4)-galactosyltransferase.

25. A method according to claim 20 , wherein said produced polypeptide selected from the group consisting of a whole antibody molecule, an antibody fragment, and a fusion protein that includes a region equivalent to the Fc region of an immunoglobulin has an increased proportion of, nonfucosylated oligosaccharides in the Fc region of said polypeptide.

26. A method according to claim 25 , wherein said nonfucosylated oligosaccharides are hybrid bisected or complex bisected.

27. A method according to claim 25 , wherein at least 45% of the oligosaccharides in the Fc region of said produced polypeptide are nonfucosylated.

28. A method according to claim 20 , wherein in step (a), said host cell comprises at least one nucleic acid encoding a polypeptide selected from the group consisting of an antibody, an antibody fragment, or a fusion protein that includes a region equivalent to the Fc region of an immunoglobulin.

29. A method according to claim 20 , wherein the expression level of GalT produces an antibody molecule, antibody fragment, or a fusion protein that includes a region equivalent to the Fc region of an immunoglobulin having increased Fc-mediated cellular cytotoxicity.

30. A method according to claim 20 , wherein said host cell further comprises at least one nucleic acid encoding GnT III, wherein said GnT III is expressed in an amount sufficient to modify the oligosaccharides in the Fc region of said produced polypeptide selected from the group consisting of a whole antibody molecule, an antibody fragment, and a fusion protein that includes a region equivalent to the Fc region of an immunoglobulin and wherein said produced polypeptide has increased Fc-mediated cellular cytotoxicity as a result of said modification.

31. A method according to claim 30 , wherein the expression level of one or more of GalT, Man II or GnT III is sufficient to form nonfucosylated oligosaccharides in the Fc region of said produced polypeptide.

32. A method according to claim 31 , wherein the proportion of nonfucosylated oligosaccharides in the Fc region to total oligosaccharides in the Fc region is at least 45 percent.

33. A method according to claim 31 , wherein said nonfucosylated oligosaccharides are hybrid bisected or complex bisected.

34. A method according to claim 30 , wherein said host cell is selected from the group consisting of: a mammalian cell, a yeast cell, an insect cell, and a plant cell.

35. A method according to claim 30 , wherein said host cell is selected from the group consisting of: a CHO cell, a BHK cell, a NSO cell, an SP2/0 cell, a YO myeloma cell, a P3X63 mouse myeloma cell, a PER cell, a PER.C6 cell, and a hybridoma cell.

36. A method according to claim 20 , wherein said host cell is selected from the group consisting of a mammalian cell, a yeast cell, an insect cell, and a plant cell.

37. A method according to claim 20 , wherein said host cell is selected from the group consisting of: a CHO cell, a BHK cell, a NSO cell, an SP2/0 cell, a YO myeloma cell, a P3X63 mouse myeloma cell, a PER cell, a PER.C6 cell, and a hybridoma cell.