Patent ID: 7381794

Claim:
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.