B7-DC Variants

• US 20090042292A1
• Filed: 07/11/2008
• Published: 02/12/2009
• Est. Priority Date: 07/13/2007
• Status: Active Grant

• Current Assignee: Johns Hopkins University
• Original Assignee: Johns Hopkins University
• Inventors: Chen, Lieping
• Granted Patent: US 8,153,595 B2
• Time in Patent Office: Days
• US Class Current: 435/375
• CPC Class Codes: A61K 38/00 Medicinal preparations containing peptides peptides containing beta-lactam rings A61K31/00; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, A61K31/00; ergot alkaloids of the cyclic peptide type A61K31/48; containing macromolecular compounds having statistically distributed amino acid units A61K31/74; medicinal preparations containing antigens or antibodies A61K39/00; medicinal preparations characterised by the non-active ingredients, e.g. peptides as drug carriers, A61K47/00
• CPC Class Codes: A61P 31/12 Antivirals
• CPC Class Codes: A61P 35/00 Antineoplastic agents
• CPC Class Codes: A61P 37/04 Immunostimulants
• CPC Class Codes: C07K 14/70532 B7 molecules, e.g. CD80, CD86

Abstract

Compositions and methods for costimulating T cells (i.e., increasing antigen-specific proliferation of T cells, enhancing cytokine production by T cells, stimulating differentiation ad effector functions of T cells and/or promoting T cell survival) are provided. Suitable compositions include variant B7-DC polypeptides, fragments and fusion proteins thereof. Variant B7-DC polypeptides have reduced binding affinity for the inhibitory PD-1 ligand and substantially retain the ability to costimulate T cells. Methods for using variant B7-DC polypeptides to stimulate immune responses in subjects in need thereof are provided.

Claims

1. An isolated variant B7-DC polypeptide or a costimulatory fragment thereof,

wherein the variant B7-DC polypeptide is a variant of wild-type B7-DC polypeptide,

wherein the variant B7-DC polypeptide has reduced binding affinity for PD-1 compared to wild-type B7-DC polypeptide, and

wherein the variant B7-DC polypeptide retains the ability to increase antigen-specific proliferation of T cells, enhance production of cytokines by T cells, stimulate differentiation and effector function of T cells or promote survival of T cells.

2. The isolated variant B7-DC polypeptide of claim 1, wherein the polypeptide comprises a substitution, deletion or insertion of one or more amino acids.

3. The isolated polypeptide of claim 1, wherein the B7-DC polypeptide is human B7-DC.

4. The isolated variant B7-DC polypeptide of claim 3, wherein the substitution, deletion or insertion of one or more amino acids is in the A′

, B, C, C′

, C″

, D, E, F, or G strand or any combination thereof.

5. The isolated polypeptide of claim 4, wherein the substitution comprises replacing the amino acid at position 111 of wild type murine B7-DC or human B7-DC with a serine residue.

6. The isolated polypeptide of claim 4, wherein the substitution comprises replacing the amino acid at position 113 of wild type human B7-DC with a serine residue.

7. The isolated polypeptide of claim 4, wherein the substitution comprises replacing the amino acid at position 56 of wild type human B7-DC with a serine residue.

8. The isolated polypeptide of claim 4, wherein the substitution comprises replacing the amino acid at position 67 of wild type human B7-DC with a tyrosine residue.

9. The isolated polypeptide of claim 4, wherein the substitution comprises replacing the amino acid at position 71 of wild type human B7-DC with a serine residue.

10. The isolated polypeptide of claim 4, wherein the substitution comprises replacing the amino acid at position 101 of wild type human B7-DC with a serine residue.

11. The isolated polypeptide of claim 4, wherein the substitution comprises replacing the amino acid at position 105 of wild type murine B7-DC or human B7-DC with an alanine residue.

12. An isolated fusion polypeptide comprising:

a) as a first fusion partner, the polypeptide of claim 1, and

b) as a second fusion partner, a second polypeptide,

wherein the first fusion partner is fused directly to the second fusion partner, or optionally, is fused to a linker sequence that is fused to the second fusion partner.

13. The fusion polypeptide of claim 12,

wherein the second polypeptide comprises one or more domains of an Ig heavy chain constant region.

14. The fusion polypeptide of claim 13,

wherein the second polypeptide comprises an amino acid sequence corresponding to the hinge, C_H2 and C_H3 regions of a human immunoglobulin Cγ

1 chain.

15. The fusion polypeptide of claim 14,

wherein the first polypeptide comprises the extracellular domain of B7-DC or a costimulatory fragment thereof, and

wherein the second polypeptide comprises an amino acid sequence corresponding to the hinge, C_H2 and C_H3 regions of a human immunoglobulin Cγ

1 chain.

16. A method for increasing antigen-specific proliferation of T cells, enhancing production of cytokines by T cells, stimulating differentiation and effector function of T cells or promoting survival of T cells,

wherein the method comprises contacting a T cell with an isolated fusion polypeptide comprising:

a) as a first fusion partner, an isolated variant B7-DC polypeptide or a costimulatory fragment thereof,

wherein the variant B7-DC polypeptide is a variant of wild-type B7-DC polypeptide,

wherein the variant B7-DC polypeptide has reduced binding affinity for PD-1 compared to wild-type B7-DC polypeptide, and

wherein the variant B7-DC polypeptide retains the ability to increase antigen-specific proliferation of T cells, enhance production of cytokines by T cells, stimulate differentiation and effector function of T cells or promote survival of T cells, and

b) as a second fusion partner, a second polypeptide,

wherein the first fusion partner is fused directly to the second fusion partner, or optionally, is fused to a linker sequence that is fused to the second fusion partner.

17. The method of claim 16,

wherein the second polypeptide comprises one or more domains of an Ig heavy chain constant region.

18. The method of claim 17,

wherein the second polypeptide comprises an amino acid sequence corresponding to the hinge, C_H2 and C_H3 regions of a human immunoglobulin Cγ

1 chain.

19. The method of claim 18,

wherein the first polypeptide comprises the extracellular domain of B7-DC or a costimulatory fragment thereof, and

wherein the second polypeptide comprises an amino acid sequence corresponding to the binge, C_H2 and C_H3 regions of a human immunoglobulin Cγ

1 chain.