Derivatives of growth hormone and related proteins, and methods of use thereof
The growth hormone supergene family comprises greater than 20 structurally related cytokines and growth factors. A general method is provided for creating site-specific, biologically active conjugates of these proteins. The method involves adding cysteine residues to non-essential regions of the proteins or substituting cysteine residues for non-essential amino acids in the proteins using site-directed mutagenesis and then covalently coupling a cysteine-reactive polymer or other type of cysteine-reactive moiety to the proteins via the added cysteine residue. Disclosed herein are preferred sites for adding cysteine residues or introducing cysteine substitutions into the proteins, and the proteins and protein derivatives produced thereby. Also disclosed are therapeutic methods for using the cysteine variants of the invention.
1. A method to stimulate proliferation and differentiation of hematopoietic cells in an animal, comprising administering to said animal a composition comprising a granulocyte-macrophage colony stimulating factor (GM-CSF) cysteine mutein of SEQ ID NO:8, wherein a cysteine residue is substituted for an amino acid selected from the group consisting of: A1, A3, S5, S7, N27, T32, A33, E51, R67, S69, E93, T94, T98, Q99, T102, E123, V125, Q126, and E127, and wherein said variant has biological activity in vitro as measured by proliferation of a cell line that proliferates in response to granulocyte-macrophage colony-stimulating factor.
2. The method of claim 1 , wherein a cysteine residue is substituted for an amino acid selected from the group consisting of: A1, A3, S5, and S7.
3. The method of claim 1 , wherein a cysteine residue is substituted for A1.
4. The method of claim 1 , wherein a cysteine residue is substituted for A3.
5. The method of claim 4 , wherein said GM-CSF cysteine mutein is modified with at least one polyethylene glycol.
6. The method of claim 1 , wherein a cysteine residue is substituted for S5.
7. The method of claim 1 , wherein a cysteine residue is substituted for S7.
8. The method of claim 1 , wherein a cysteine residue is substituted for N27.
9. The method of claim 1 , wherein a cysteine residue is substituted for T32.
10. The method of claim 1 , wherein a cysteine residue is substituted for A33.
11. The method of claim 1 , wherein a cysteine residue is substituted for E51.
12. The method of claim 1 , wherein a cysteine residue is substituted for R67.
13. The method of claim 1 , wherein a cysteine residue is substituted for S69.
14. The method of claim 1 , wherein a cysteine residue is substituted for E93.
15. The method of claim 1 , wherein a cysteine residue is substituted for T94.
16. The method of claim 1 , wherein a cysteine residue is substituted for T98.
17. The method of claim 1 , wherein a cysteine residue is substituted for Q99.
18. The method of claim 1 , wherein a cysteine residue is substituted for T102.
19. The method of claim 1 , wherein a cysteine residue is substituted for E123.
20. The method of claim 1 , wherein a cysteine residue is substituted for V125.
21. The method of claim 1 , wherein a cysteine residue is substituted for Q126.
22. The method of claim 1 , wherein a cysteine residue is substituted for E127.
23. The method of claim 1 , wherein said composition is administered by a route selected from the group consisting of intravenous administration, intraperitoneal administration, intramuscular administration, intranodal administration, intracoronary administration, intraarterial administration, subcutaneous administration, transdermal delivery, intratracheal administration, intraarticular administration, intraventricular administration, inhalation, intranasal administration, intracranial administration, intraspinal administration, intraocular administration, aural administration, oral administration, pulmonary administration, impregnation of a catheter, and direct injection into a tissue.
24. The method of claim 1 , wherein said composition is administered by intravenous administration.
25. The method of claim 1 , wherein said composition is administered by subcutaneous administration.
26. The method of claim 1 , wherein said animal has a deficiency of hematopoietic cells.
27. The method of claim 26 , wherein said deficiency of hematopoietic cells is associated with myclosuppressive chemotherapy.
28. The method of claim 26 , wherein said deficiency of hematopoietic cells is associated with bone marrow transplantation.
29. The method of claim 26 , wherein said deficiency of hematopoietic cells is associated with infection with the human immunodeficiency virus.
30. The method of claim 26 , wherein said deficiency of hematopoietic cells is associated with chronic neutropenia.
31. The method of claim 1 , wherein said GM-CSF cysteine mutein is modified with at least one polyethylene glycol.
32. The method of claim 1 , wherein said GM-CSF cysteine mutein is modified with a cysteine-reactive moiety.
33. The method of claim 32 , wherein said cysteine-reactive moiety is a polyethylene glycol.
34. The method of claim 1 , wherein said hematopoietic cell is selected from the group consisting of a granulocyte, a neutrophil, an eosinophil, a monocyte, a macrophage, a white blood cell and a lymphocyte.
35. The method of claim 34 , wherein said hematopoietic cell is a neutrophil.
36. The method of claim 34 , wherein said hematopoietic cell is a white blood cell.