Dimeric fusion proteins and materials and methods for producing them
Polypeptide fusions, dimeric fusion proteins, and materials and methods for making them are disclosed. One of the polypeptide fusions consists of a non-immunoglobulin polypeptide, a polypeptide linker, a dimerizing domain, and, optionally, a linking polypeptide. Another of the polypeptide fusions consists of a non-immunoglobulin polypeptide, a polypeptide linker, and a second dimerizing domain.
1. A dimeric protein consisting of a first polypeptide fusion disulfide bonded to a second polypeptide fusion, wherein said first polypeptide fusion consists of, from amino terminus to carboxyl terminus, P1-L1-D1-(P2) n , wherein said second polypeptide fusion consists of, from amino terminus to carboxyl terminus, P3-L2-D2, and wherein:
P1 is a first non-immunoglobulin polypeptide;
L1 is a first polypeptide linker consisting of from 18 to 32 amino acid residues, wherein x of said residues are cysteine residues;
P2 is a linking polypeptide consisting of from 1 to 29 amino acid residues, wherein at least one of said residues is a cysteine residue;
n is 0 or 1;
P3 is a second non-immunoglobulin polypeptide different from P1;
L2 is a second polypeptide linker consisting of from 18 to 32 amino acid residues, wherein y of said residues are cysteine residues;
D1 and D2 are dimerizing domains capable of dimerizing with each other, wherein D1 and D2 are respectively selected from the following dimerizing domain pairs:
(a) an immunoglobulin CH1 domain and an immunoglobulin light chain constant domain;
(b) a TCR Cα domain and a TCR Cβ domain;
(c) a TCR Cβ domain and a TCR Cα domain;
(d) an MHC class I α 3 domain and a β2-microglobulin;
(e) a β2-microglobulin and an MHC class I α 3 domain;
(f) an MHC class II α 2 domain and an MHC class II β 2 domain; and
(g) an MHC class II β 2 domain and an MHC class II α 2 domain;
each of P1 and P3 is an extracellular domain of a cell-surface receptor requiring, in its native state, dimerization in order to initiate intracellular signal transduction;
each of x and y is an integer from 1 to 8; and
x=y.
2. The dimeric protein of claim 1 wherein n=1.
3. The dimeric protein of claim 1 wherein x=2 and y=2.
4. The dimeric protein of claim 1 , wherein each of P1 and P3 is an extracellular domain of a human cell-surface receptor.
5. The dimeric protein of claim 1 , wherein each of P1 and P3 is not a member of the immunoglobulin superfamily.
6. The dimeric protein of claim 1 wherein each of P1 and P3 is individually selected from the group consisting of IL-17R, IL-20RA, IL-20RB, IL-21R, IL-28RA, IL-31RA, CRF2-4, and γC.
7. The dimeric protein of claim 1 wherein each of L1 and L2 contains exactly two cysteine residues.
8. The dimeric protein of claim 1 wherein each of L1 and L2 comprises an immunoglobulin hinge variant wherein the cysteine residue corresponding to residue 103 of SEQ ID NO:1 is replaced by serine.
9. The dimeric protein of claim 1 wherein each of L1 and L2 comprises a human γ1 hinge wherein the cysteine residue corresponding to residue 103 of SEQ ID NO:1 is replaced by serine.
10. The dimeric protein of claim 1 wherein each of L1 and L2 consists of 18 amino acid residues.
11. The dimeric protein of claim 1 wherein each of L1 and L2 comprises a plurality of glycine residues.
12. The dimeric protein of claim 1 wherein each of L1 and L2 comprises a plurality of serine residues.
13. The dimeric protein of claim 1 wherein each of L1 and L2 comprises [Gly-Ser-Gly-Ser] a (SEQ ID NO:2), wherein a is 1 or 2; or [Gly-Gly-Gly-Ser] b (SEQ ID NO:3), wherein b is 1 or 2.
14. The dimeric protein of claim 1 wherein each of L1 and L2 comprises a proteolytic cleavage site.
15. The dimeric protein of claim 1 wherein:
D1 is an immunoglobulin CH1 domain; and
D2 is an immunoglobulin κ light chain constant domain or immunoglobulin λ light chain constant domain.
16. The dimeric protein of claim 15 wherein D2 is an immunoglobulin κ light chain constant domain.
17. The dimeric protein of claim 1 wherein:
a) one of P1 and P3 is an IL-20RA extracellular domain and the other of P1 and P3 is an IL-20RB extracellular domain;
b) one of P1 and P3 is an IL-22RA1 extracellular domain and the other of P1 and P3 is an IL-20RB extracellular domain;
c) one of P1 and P3 is an IL-21R extracellular domain and the other of P1 and P3 is an IL-2 receptor γ common extracellular domain; or
d) one P1 and P3 is a PDGF α receptor extracellular domain and the other of P1 and P3 is a PDGF β receptor extracellular domain.
18. A polypeptide fusion consisting of, from amino terminus to carboxyl terminus, P1-L-D1-(P2) n , wherein:
P1 is a non-immunoglobulin polypeptide, wherein said non-immunoglobulin polypeptide is an extracellular domain of a cell-surface receptor requiring, in its native state, dimerization in order to initiate intracellular signal transduction;
L is a polypeptide linker consisting of from 18 to 32 amino acid residues, wherein from 1 to 8 of said residues are cysteine residues;
D1 is a dimerizing domain selected from the group consisting of an immunoglobulin CH1 domain, a T-cell receptor Cα domain, a T-cell receptor Cβ domain, a major histocompatibility complex class I α3 domain, β2-microglobulin, a major histocompatibility complex class II α2 domain, and a major histocompatibility complex class II β2 domain;
P2 is a linking polypeptide consisting of from 1 to 29 amino acid residues, wherein at least one of said residues is a cysteine residue; and
n is 0 or 1.
19. The polypeptide fusion of claim 18 wherein D1 is an immunoglobulin γ1 CH1 domain.
20. The polypeptide fusion of claim 19 wherein the γ1 CH1 domain is a human γ1 CH1 domain.
21. The polypeptide fusion of claim 18 wherein P2 is a portion of an immunoglobulin hinge comprising a cysteine residue.
22. The polypeptide fusion of claim 18 wherein n is 1 and P2 consists of from 5 to 15 amino acid residues.
23. The polypeptide fusion of claim 18 wherein n is 1 and P2 contains exactly one cysteine residue.
24. A polypeptide fusion consisting of, from amino terminus to carboxyl terminus, P3-L-D2, wherein:
P3 is a non-immunoglobulin polypeptide, said non-immunoglobulin polypeptide being an extracellular domain of a cell-surface receptor requiring, in its native state, dimerization in order to initiate intracellular signal transduction;
L is a polypeptide linker consisting of from 18 to 32 amino acid residues, wherein from 1 to 8 of said residues are cysteine residues; and
D2 is a dimerizing domain selected from the group consisting of an immunoglobulin light chain constant domain, a T-cell receptor Cα domain, a T-cell receptor Cβ domain, a major histocompatibility complex class I α3 domain, β2-microglobulin, a major histocompatibility complex class II α2 domain, and a major histocompatibility complex class II β2 domain.