CHIMERIC ANTIBODIES WITH PART NEW WORLD PRIMATE BINDING REGIONS
The present invention provides a chimeric antibody polypeptide comprising an antigen binding site, wherein the antigen binding site comprises a human variable domain having at least one New World Primate CDR.
1 . A chimeric antibody polypeptide comprising an antigen binding site, wherein the antigen binding site comprises a human variable domain having at least one New World Primate CDR.
2 . The antibody polypeptide of claim 1 , wherein the human variable domain comprises at least one human framework region having an amino acid sequence encoded by a human germline antibody gene segment, or an amino acid sequence comprising up to 5 amino acid differences relative to the amino acid sequence encoded by a human germline antibody gene segment.
3 . The antibody polypeptide of claim 2 , wherein the human variable domain comprises four human framework regions, FR1, FR2, FR3 and FR4 having amino acid sequences encoded by a human germline antibody gene segment, or the amino acid sequences of FR1, FR2, FR3 and FR4 collectively containing up to 10 ammo acid differences relative to the amino acid sequences by said human germline antibody gene segment.
4 . The antibody polypeptide according to claim 2 , wherein the framework regions are encoded by a human germline antibody gene segment selected from the group consisting of DP47, DP45, DP48 and DPK9.
5 . The antibody polypeptide of claim 1 , wherein said New World Primate CDR is CDR2.
6 . The antibody polypeptide of claim 1 , wherein said New World Primate CDR is CDR1 or CDR3.
7 . The antibody polypeptide of claim 1 , wherein said New World Primate CDR sequence is a germline New World Primate CDR sequence.
8 . The antibody polypeptide of claim 1 , wherein the antibody polypeptide is selected from the group consisting of a dAb, scFv, Fab, (Fab′) 2 , Fv, disulphide bonded Fv, IgG, and a diabody.
9 . The antibody polypeptide of claim 1 , wherein the antigen is TNF-α.
10 . The antibody polypeptide of claim 1 , wherein the New World Primate is a Callithricidae.
11 . The antibody polypeptide of claim 10 , wherein the New World Primate is a marmoset.
12 . The antibody polypeptide of claim 1 , wherein the human variable domain amino acid sequence comprises a Kpn1 restriction site spaced from a SanD1 restriction site, said CDR of the human variable domain being between the restriction sites.
13 . The antibody polypeptide of claim 1 , wherein said New World Primate CDR sequence is obtainable from New World Primate DNA by PCR using primer pair VK1BL (SBQ ID No:11)/VK1BL35a (SEQ ID No:12) or primer pair VK1BL (SEQ ID No:11)/VK1BL35b (SEQ ID No:13).
14 . A chimeric domain antibody (dAb) which binds to human TNF-α, wherein the dAb is a human dAb that binds human TNF-α in which at least one of the CDRs is replaced with the corresponding CDR from a New World Primate.
15 . A chimeric dAb according to claim 14 wherein the replaced CDR is CDR2.
16 . A chimeric dAb according to claim 14 wherein the New World Primate is a marmoset.
17 . A method of producing an antibody polypeptide as defined in claim 1 , the method comprising
(i) Providing an acceptor sequence encoding a human variable domain; and
(ii) Replacing a CDR sequence of the variable domain with a donor CDR sequence, wherein the donor CDR sequence is a New World Primate CDR.
18 . The method of claim 17 , wherein in step (ii) said CDR of said human variable domain is replaced by said donor New World Primate CDR using restriction digestion and annealing of an oligonucleotide encoding the donor CDR into the acceptor sequence.
19 . The method of claim 17 , further comprising (iii) affinity maturing the variable domain produced in step (ii).
20 . A method of producing a chimeric dAb as defined in claim 14 , the method comprising
(i) Providing an acceptor sequence encoding a human variable domain; and
(ii) Replacing a CDR sequence of the variable domain with a donor CDR sequence, wherein the donor CDR sequence is a New World Primate CDR.
21 . The method of claim 20 , wherein in step (ii) said CDR of said human variable domain is replaced by said donor New World Primate CDR using restriction digestion and annealing of an oligonucleotide encoding the donor CDR into the acceptor sequence.
22 . The method of claim 20 , further comprising (iii) affinity maturing the variable domain produced in step (ii).