Nucleic acid molecules encoding B7-DC variants
View Patent ↗Variant costimulatory polypeptides, nucleic acids encoding such polypeptides, and methods for using the polypeptides and nucleic acids to enhance a T cell response are provided herein.
1. An isolated nucleic acid molecule encoding a variant B7-DC polypeptide comprising an IgV domain, wherein the variant polypeptide is a variant of wild-type B7-DC polypeptide, has altered binding affinity for PD-1 compared to the wild-type B7-DC polypeptide, and comprises a substitution of an amino acid in the A′, B, C, C′, C″, D, E, F, or G β strand of wild-type B7-DC polypeptide according to SEQ ID NO:5 or 6.
2. The isolated nucleic acid molecule of claim 1 , wherein the variant B7-DC polypeptide is a variant of murine B7-DC.
3. The isolated nucleic acid molecule of claim 1 , wherein the variant B7-DC polypeptide is a variant of human B7-DC.
4. The isolated nucleic acid molecule of claim 1 , wherein the variant B7-DC polypeptide or fragment thereof has decreased binding affinity for PD-1 compared to wild-type B7-DC polypeptide.
5. The isolated nucleic acid molecule of claim 4 , wherein the variant B7-DC polypeptide or fragment thereof enhances an immune response in a mammal.
6. The isolated nucleic acid molecule of claim 1 , wherein the variant B7-DC polypeptide or fragment thereof has increased binding affinity for PD-1 compared to wild-type B7-DC polypeptide.
7. The isolated nucleic acid molecule of claim 6 , wherein the variant B7-DC polypeptide or fragment thereof enhances an immune response in a mammal.
8. The isolated nucleic acid molecule of claim 1 , wherein the variant polypeptide comprises a substitution of the amino acid at position 111 numbered from the initiation methionine of wild-type murine B7-DC (SEQ ID NO:6) or human B7-DC (SEQ ID NO:5).
9. The isolated nucleic acid molecule of claim 8 , wherein the substitution is with a serine residue.
10. The isolated nucleic acid molecule of claim 1 , wherein the variant polypeptide comprises a substitution of the amino acid at position 113 numbered from the initiation methionine of wild-type murine B7-DC (SEQ ID NO:6) or human B7-DC (SEQ ID NO:5).
11. The isolated nucleic acid molecule of claim 10 , wherein the substitution is with a serine residue.
12. The isolated nucleic acid molecule of claim 1 , wherein the variant polypeptide comprises a substitution of the amino acid at position 56 numbered from the initiation methionine of wild-type murine B7-DC (SEQ ID NO:6) or human B7-DC (SEQ ID NO:5).
13. The isolated nucleic acid molecule of claim 12 , wherein the substitution is with a serine residue.
14. The isolated nucleic acid molecule of claim 1 , wherein the variant polypeptide comprises a substitution of the amino acid at position 67 numbered from the initiation methionine of wild-type murine B7-DC (SEQ ID NO:6) or human B7-DC (SEQ ID NO:5).
15. The isolated nucleic acid molecule of claim 14 , wherein the substitution is with a tyrosine residue.
16. The isolated nucleic acid molecule of claim 1 , wherein the variant polypeptide comprises a substitution of the amino acid at position 71 numbered from the initiation methionine of wild-type murine B7-DC (SEQ ID NO:6) or human B7-DC (SEQ ID NO:5).
17. The isolated nucleic acid molecule of claim 16 , wherein the substitution is with a serine residue.
18. The isolated nucleic acid molecule of claim 1 , wherein the variant polypeptide comprises a substitution of the amino acid at position 101 numbered from the initiation methionine of wild-type murine B7-DC (SEQ ID NO:6) or human B7-DC (SEQ ID NO:5).
19. The isolated nucleic acid molecule of claim 18 , wherein the substitution is with a serine residue.
20. The isolated nucleic acid molecule of claim 1 , wherein the variant polypeptide comprises a substitution of the amino acid at position 105 numbered from the initiation methionine of wild-type murine B7-DC (SEQ ID NO:6) or human B7-DC (SEQ ID NO:5).
21. The isolated nucleic acid molecule of claim 20 , wherein the substitution is with an alanine residue.
22. The isolated nucleic acid molecule of claim 1 , wherein the variant polypeptide comprises a substitution of the amino acid at position 58 number from the initiation methionine of wild-type murine B7-DC (SEQ ID NO:6) or human B7-DC (SEQ ID NO:5).
23. The isolated nucleic acid molecule of claim 22 , wherein the substitution is with a tyrosine residue.
24. An isolated nucleic acid molecule encoding a polypeptide fragment of murine B7-DC (SEQ ID NO:6) or human B7-DC (SEQ ID NO:5), the polypeptide fragment comprising amino acids 67-71, amino acids 101-105, or amino acids 111-113 of SEQ ID NO:6, wherein the polypeptide inhibits binding of endogenous B7-DC to PD-1.
25. The isolated nucleic acid molecule of claim 24 encoding a polypeptide comprising amino acids 101-113 of murine B7-DC (SEQ ID NO:6) or human B7-DC (SEQ ID NO:5).
26. A vector comprising the nucleic acid molecule of claim 1 .
27. The vector of claim 26 , wherein the nucleic acid molecule is operably linked to an expression control sequence.
28. An isolated host cell comprising the vector of claim 27 .
29. A method for enhancing an immune response in a mammal comprising administering to the mammal the vector of claim 27 .
30. An isolated nucleic acid molecule encoding a fusion polypeptide comprising a first fusion partner comprising a variant B7-DC polypeptide comprising an IgV domain, wherein the variant polypeptide is a variant of wild-type B7-DC polypeptide, has altered binding affinity for PD-1 compared to the wild-type B7-DC polypeptide, and comprises a substitution of an amino acid in the A′, B, C, C′, C″, D, E, F, or G β strand of wild-type B7-DC polypeptide according to SEQ ID NO:5 or 6, and a second fusion partner.
31. The isolated nucleic acid molecule of claim 30 , wherein the second fusion partner comprises one or more domains of an Ig heavy chain constant region.
32. The isolated nucleic acid molecule of claim 30 , wherein the second polypeptide comprises an amino acid sequence corresponding to the hinge, CH2 and CH3 regions of a human immunoglobulin chain.
33. The isolated nucleic acid molecule of claim 30 , wherein the first polypeptide comprises the extracellular domain of B7-DC or a fragment thereof, and wherein the second polypeptide comprises an amino acid sequence corresponding to the hinge, CH2 and CH3 regions of a human immunoglobulin chain.
34. The isolated nucleic acid molecule of claim 30 , wherein the variant B7-DC polypeptide is a variant of murine B7-DC.
35. The isolated nucleic acid molecule of claim 30 , wherein the variant B7-DC polypeptide is a variant of human B7-DC.
36. The isolated nucleic acid molecule of claim 30 , wherein the variant B7-DC polypeptide or fragment thereof has decreased binding affinity for PD-1 compared to wild-type B7-DC polypeptide.
37. The isolated nucleic acid molecule of claim 36 , wherein the variant B7-DC polypeptide or fragment thereof enhances an immune response in a mammal.
38. The isolated nucleic acid molecule of claim 30 , wherein the variant B7-DC polypeptide or fragment thereof has increased binding affinity for PD-1 compared to wild-type B7-DC polypeptide.
39. The isolated nucleic acid molecule of claim 38 , wherein the variant B7-DC polypeptide or fragment thereof enhances an immune response in a mammal.
40. An isolated nucleic acid molecule encoding a fusion polypeptide comprising the IgV domain of B7-DC fused to a second polypeptide, wherein the IgV domain of B7-DC is from human (SEQ ID NO:5) or murine B7-DC (SEQ ID NO:6) and comprises an amino acid substitution relative to wildtype human (SEQ ID NO:5) or murine (SEQ ID NO:6) B7-DC IgV domain, wherein the substitution alters binding affinity for PD-1 compared to the wild-type B7-DC polypeptide.
41. The isolated nucleic acid of claim 40 , wherein the second polypeptide comprises an amino acid sequence corresponding to the hinge, CH2 and CH3 regions of a human immunoglobulin chain.
42. The isolated nucleic acid molecule of claim 41 , wherein the IgV domain of B7-DC comprises an amino acid substitution at position 111 numbered from the initiation methionine of wild-type murine B7-DC (SEQ ID NO:6) or human B7-DC (SEQ ID NO:5).
43. The isolated nucleic acid molecule of claim 42 , wherein the substitution is with a serine residue.
44. The isolated nucleic acid molecule of claim 41 , wherein the IgV domain of B7-DC comprises an amino acid substitution at position 113 numbered from the initiation methionine of wild-type murine B7-DC (SEQ ID NO:6) or human B7-DC (SEQ ID NO:5).
45. The isolated nucleic acid molecule of claim 44 , wherein the substitution is with a serine residue.
46. The isolated nucleic acid molecule of claim 41 , wherein the IgV domain of B7-DC comprises an amino acid substitution at position 56 numbered from the initiation methionine of wild-type murine B7-DC (SEQ ID NO:6) or human B7-DC (SEQ ID NO:5).
47. The isolated nucleic acid molecule of claim 46 , wherein the substitution is with a serine residue.
48. The isolated nucleic acid molecule of claim 41 , wherein the IgV domain of B7-DC comprises an amino acid substitution at position 67 numbered from the initiation methionine of wild-type murine B7-DC (SEQ ID NO:6) or human B7-DC (SEQ ID NO:5).
49. The isolated nucleic acid molecule of claim 48 , wherein the substitution is with a tyrosine residue.
50. The isolated nucleic acid molecule of claim 41 , wherein the IgV domain of B7-DC comprises an amino acid substitution at position 71 numbered from the initiation methionine of wild-type murine B7-DC (SEQ ID NO:6) or human B7-DC (SEQ ID NO:5).
51. The isolated nucleic acid molecule of claim 50 , wherein the substitution is with a serine residue.
52. The isolated nucleic acid molecule of claim 41 , wherein the IgV domain of B7-DC comprises an amino acid substitution at position 101 numbered from the initiation methionine of wild-type murine B7-DC (SEQ ID NO:6) or human B7-DC (SEQ ID NO:5).
53. The isolated nucleic acid molecule of claim 52 , wherein the substitution is with a serine residue.
54. The isolated nucleic acid molecule of claim 41 , wherein the IgV domain of B7-DC comprises an amino acid substitution at position 105 numbered from the initiation methionine of wild-type murine B7-DC (SEQ ID NO:6) or human B7-DC (SEQ ID NO:5).
55. The isolated nucleic acid molecule of claim 54 , wherein the substitution is with an alanine.
56. A vector comprising the nucleic acid molecule of claim 41 .
57. The vector of claim 56 , wherein the nucleic acid molecule is operably linked to an expression control sequence.
58. An isolated host cell comprising the vector of claim 57 .
59. A method for enhancing an immune response in a mammal comprising administering to the mammal the vector of claim 57 .
60. A method for enhancing an immune response in a mammal comprising administering to the mammal a polypeptide encoded by a polynucleotide of claim 40 .
61. A method for enhancing an immune response in a mammal comprising administering to the mammal a polypeptide produced by the host cell of claim 58 .