Compositions and methods related to IL27 receptor binding

1. An IL27 receptor (IL27R) binding protein that specifically binds to IL27Rα subunit (IL27Rα) and glycoprotein 130 subunit (gp130),

wherein the binding protein causes the multimerization of IL27Rα and gp130 when bound to IL27Rα and gp130, and

wherein the binding protein comprises a single-domain antibody (sdAb) that specifically binds to IL27Rα (an anti-IL27Rα sdAb) and a sdAb that specifically binds to gp130 (an anti-gp130 sdAb) and wherein the anti-IL27Rα sdAb is an anti-IL27Rα V H H antibody and the anti-gp130 sdAb is an anti-gp130 V H H antibody and

wherein the anti-gp130 V H H antibody comprises a set of a CDR1, a CDR2, and a CDR3, wherein the set is selected from the group consisting of:

SEQ ID NO: 193, SEQ ID NO: 199, SEQ ID NO: 205, respectively;

SEQ ID NO: 194, SEQ ID NO: 200, SEQ ID NO: 206, respectively;

SEQ ID NO: 195, SEQ ID NO: 201, SEQ ID NO: 207, respectively;

SEQ ID NO: 196, SEQ ID NO: 202, SEQ ID NO: 208, respectively;

SEQ ID NO: 197, SEQ ID NO: 203, SEQ ID NO: 209, respectively; and

SEQ ID NO: 198, SEQ ID NO: 204, SEQ ID NO: 210, respectively; and

the anti-IL27Rα V H H antibody comprises a set of a CDR1, a CDR2, and a CDR3, wherein the set is selected from the group consisting of

SEQ ID NO: 211, SEQ ID NO: 218, SEQ ID NO: 225, respectively;

SEQ ID NO: 212, SEQ ID NO: 219, SEQ ID NO: 226, respectively;

SEQ ID NO: 213, SEQ ID NO: 220, SEQ ID NO: 227, respectively;

SEQ ID NO: 214, SEQ ID NO: 221, SEQ ID NO: 228, respectively;

SEQ ID NO: 215, SEQ ID NO: 222, SEQ ID NO: 229, respectively;

SEQ ID NO: 216, SEQ ID NO: 223, SEQ ID NO: 230, respectively; and

SEQ ID NO: 217, SEQ ID NO: 224, SEQ ID NO: 231, respectively.

2. The IL27R binding protein of claim 1 , wherein the anti-gp130 V H H antibody comprises the set of CDR1, CDR2, and CDR3 comprising amino acid sequences of SEQ ID NO: 196, SEQ ID NO: 202, and SEQ ID NO: 208, respectively.

3. The IL27R binding protein of claim 2 , wherein the anti-IL27Rα V H H antibody CDR1 comprises the set of CDR1, CDR2, and CDR3 comprising amino acid sequences of SEQ ID NO: 214, SEQ ID NO: 221, SEQ ID NO: 228, respectively.

4. The IL27R binding protein of claim 2 , wherein the anti-IL27Rα V H H antibody CDR1 comprises the set of CDR1, CDR2, and CDR3 comprising amino acid sequences of SEQ ID NO: 216, SEQ ID NO: 223 and SEQ ID NO: 230, respectively.

5. An IL27 receptor (IL27R) binding protein that specifically binds to IL27Rα subunit (IL27Rα) and glycoprotein 130 subunit (gp130),

wherein the binding protein causes the multimerization of IL27Rα and gp130 when bound to IL27Rα and gp130, and

wherein the binding protein comprises a single-domain antibody (sdAb) that specifically binds to IL27Rα (an anti-IL27Rα sdAb) and a sdAb that specifically binds to gp130 (an anti-gp130 sdAb) and wherein the anti-IL27Rα sdAb is an anti-IL27Rα V H H antibody and the anti-gp130 sdAb is an anti-gp130 V H H antibody, and

wherein the IL27 receptor (IL27R) binding protein comprises an amino acid sequence of SEQ ID NO: 64.

6. An IL27 receptor (IL27R) binding protein that specifically binds to IL27Rα subunit (IL27Rα) and glycoprotein 130 subunit (gp130),

wherein the binding protein causes the multimerization of IL27Rα and gp130 when bound to IL27Rα and gp130, and

wherein the binding protein comprises a single-domain antibody (sdAb) that specifically binds to IL27Rα (an anti-IL27Rα sdAb) and a sdAb that specifically binds to gp130 (an anti-gp130 sdAb) and wherein the anti-IL27Rα sdAb is an anti-IL27Rα V H H antibody and the anti-gp130 sdAb is an anti-gp130 V H H antibody, and

wherein the IL27 receptor (IL27R) binding protein comprises an amino acid sequence of SEQ ID NO: 76.