Hetero-dimeric immunoglobulins

1. A hetero-dimeric immunoglobulin or hetero-dimeric fragment thereof, wherein the hetero-dimeric immunoglobulin or hetero-dimeric fragment thereof comprises a first and a second engineered immunoglobulin chain, wherein the first and second immunoglobulin chains are engineered with substitutions in amino acids in a protein interface that promote dimerization between the first and second immunoglobulin chains

wherein the first engineered immunoglobulin chain and the second engineered immunoglobulin chain are not identical and,

wherein the first and second engineered domain each comprise a CH3 domain,

wherein the substitutions in the engineered domains are from an equivalent position in a naturally-occurring TCR constant domain hetero-dimer or homo-dimer

wherein the amino acid residues which are substituted in the protein-protein interface of the first and second engineered immunoglobulin chains comprise the following amino acid residues:

(20, 22, 26, 79, 85.1, 86, 88, 90) in the first engineered immunoglobulin chain and (3, 5, 7, 20, 22, 26, 81, 84, 84.2, 85.1, 86, 88, 90) in the second engineered immunoglobulin chain; or

(7, 20, 22, 27, 79, 81, 84.2, 85.1, 86, 88, 90) in the first engineered immunoglobulin chain, and (3, 5, 20, 22, 26, 27, 81, 84, 85.1, 86, 88) in the second engineered immunoglobulin chain;

wherein the amino acid position of each group member is indicated according to the IMGT® numbering.

2. The hetero-dimeric immunoglobulin or hetero-dimeric fragment thereof of claim 1 , wherein the amino acid residue substitution at position 20 in the protein-protein interface of the first engineered immunoglobulin chain is selected from the group consisting of 20N and 20T, and conservative amino acid substitutions thereof, wherein the amino acid position is indicated according to the IMGT® numbering.

3. The hetero-dimeric immunoglobulin or hetero-dimeric fragment thereof of claim 1 , wherein the amino acid residue substitution at position 26 in the protein-protein interface of the second engineered immunoglobulin chain is selected from the group consisting of 26T and 26E, and conservative amino acid substitutions thereof, wherein the amino acid position is indicated according to the IMGT® numbering.

4. The hetero-dimeric immunoglobulin or hetero-dimeric fragment thereof of claim 1 , wherein the amino acid residue substitution at position 20 in the protein-protein interface of the first engineered immunoglobulin chain is selected from the group consisting of 20V, 20T, 20A, 20N, 20Q, 20K, 20S, 20W and 20E and/or wherein the amino acid residue substitutions in the protein-protein interface of the first engineered immunoglobulin chain are selected from the group consisting of 22A, 22G, 22L, 22I, 22V, 22T, 26K, 26R, 26Q, 26T, 26V, 26S, 26N, 26E, 85.1W, 85.1F, 85.1T, 85.1M, 85.1A, 85.1S, 85.1R, 85.1H, 85.1K, 85.1C, 85.1N, 86W, 86Y, 86S, 861, 86H, 86Q, 86V, 86T, 86F, 88Q, 88L, 88V, 88R, 88E, 88T, 881, 88Y, 88K and 88W, wherein the amino acid position of each group member is indicated according to the IMGT® numbering.

5. The hetero-dimeric immunoglobulin or hetero-dimeric fragment thereof of claim 1 , wherein the amino acid residue substitution at position 20 in the protein-protein interface of the first engineered immunoglobulin chain is selected from the group consisting of 20V, 20T, 20A, 20N, 20Q, 20K, 20S and 20E and/or wherein the amino acid residue substitutions in the protein-protein interface of the first engineered immunoglobulin chain are selected from the group consisting of 22A, 22G, 22L, 22I, 22V, 26K, 26Q, 26T, 26V, 26S, 26N, 26E, 85.1T, 85.1M, 85.1A, 85.1S, 85.1R, 85.1H, 85.1K, 85.1C, 85.1N, 86S, 861, 86H, 86Q, 86V, 86T, 86F, 88Q, 88L, 88V, 88R, 88E, 88T, 881, 88Y, and 88W, and conservative amino acid substitutions thereof, wherein the amino acid position of each group member is indicated according to the IMGT® numbering.

6. The hetero-dimeric immunoglobulin or hetero-dimeric fragment thereof of claim 1 , wherein the amino acid residue substitutions in the protein-protein interface of the first engineered immunoglobulin chain are selected from the group consisting of 3E, 3K, 5A, 5T, 7F, 7M, 22A, 22L, 22V, 26E, 26T, 27E, 27K, 79F, 79Y, 81A, 81G, 81D, 84L, 84M, 84.2E, 84.2S, 85.1A, 85.1C, 85.1M, 85.1N, 85.1S, 86F, 86S, 86V, 88L, 88R, 88W, 90K, 90N, and 90R and conservative amino acid substitutions thereof, wherein the amino acid position of each group member is indicated according to the IMGT® numbering.

7. The hetero-dimeric immunoglobulin or hetero-dimeric fragment thereof claim 1 , wherein the first engineered immunoglobulin chain is an IgG1 CH3 domain and the second engineered immunoglobulin chain is an IgG3 CH3 domain or wherein the first engineered immunoglobulin chain is an IgG3 CH3 domain and the second engineered immunoglobulin chain is an IgG1 CH3 domain.

8. The hetero-dimeric immunoglobulin or hetero-dimeric fragment thereof of claim 1 , wherein the hetero-dimeric immunoglobulin or hetero-dimeric fragment thereof is bispecific.

9. The hetero-dimeric immunoglobulin or hetero-dimeric fragment thereof of claim 1 , wherein at least one additional polypeptide is fused to the first and/or second engineered immunoglobulin chain, and wherein said additional polypeptide is selected from the group consisting of Fab, scFv, diabody, domain antibody, pharmacologically active peptide or protein, receptor extracellular domain, CDR grafted polypeptide, and therapeutic engineered protein scaffold.

10. The hetero-dimeric immunoglobulin or hetero-dimeric fragment thereof according to claim 1 , wherein the amino acid residue substitutions in the protein-protein interface of the first and second engineered immunoglobulin chains comprise the following residue groups:

(S20K, T22V, K26T, K79Y, F85.1S, Y86V, K88W, T90N) in the first engineered immunoglobulin chain, and (Q3E, Y5A, L7F, S20T, T22V, K26T, T81D, V84L, D84.2E, F85.1C/S/A, Y86S, K88R, T90R) in the second engineered immunoglobulin chain; or

(L7M, S20N, T22A, G27E, K79F, T81A, D84.2S, F85.1N, Y86V, K88L, T90K) in the first engineered immunoglobulin chain, and (Q3K, Y5T, S20T, T22L, K26E, G27K, T81G, V84M, F85.1M, Y86F, K88W) in the second engineered immunoglobulin chain.