Antibodies directed against the alpha chain of IL7 receptor—their use for the preparation of drug candidates
The invention concerns antibodies directed against CD127, I.e. the alpha chain of the receptor for interleukin7 (IL-7), especially the receptor for human IL-7 expressed on human cells (designated human IL-7R alpha or IL-7Ra) or the TSLP receptor. The antibodies of the invention have cytotoxic activity against CD127 positive cells. The invention also relates to the use of these antibodies in order to deplete subpopulations of T lymphocytes as a result of cytotoxic action of the antibodies, through ADCC and optionally through CDC. Accordingly the invention concerns the use of the antibodies in the treatment of transplant rejection, autoimmune diseases, allergic diseases, lymphoma or cancer when these pathologies are associated with CD127 positive cells.
1. An antibody or a functional fragment thereof whose antigen-binding site comprises a Variable Heavy chain and a Variable Light chain, wherein the Variable Heavy chain comprises the following polypeptides:
(a) (i) VHCDR 1 having the amino acid sequence of SEQ ID No 38;
(ii) VHCDR 2 having the amino acid sequence of SEQ ID No 40; and
(iii) VHCDR 3 having the amino acid sequence of SEQ ID No 42; or
(b) VH having amino acid sequence from position 22 to position 135 of SEQ ID No 34; and
wherein the Variable Light chain comprises the following polypeptides:
(c) (i) VLCDR 1 having the amino acid sequence of SEQ ID No 44;
(ii) VLCDR 2 having the amino acid sequence of SEQ ID No 46; and
(iii) VLCDR 3 having the amino acid sequence of SEQ ID No 48; or
(d) VL having amino acid sequence from position 22 to position 129 of SEQ ID No 36.
2. The antibody or the functional fragment thereof according to claim 1 which binds the alpha chain of the receptor to IL-7 (designated CD127), and which exhibits Antibody-Dependent Cellular Cytotoxicity (ADCC) or both ADCC and Complement-Dependent Cytotoxicity (CDC) against human CD127 positive cells.
3. The antibody or the functional fragment thereof according to claim 2 , wherein the human CD127 positive cells are human T cells expressing CD127.
4. The antibody or the functional fragment thereof according to claim 1 , which further has antagonist properties toward interleukin 7 (IL-7) thereby antagonizing access of IL-7 to CD127 on human CD127 positive cells.
5. The antibody according to claim 1 , wherein the antibody is a humanized monoclonal antibody or a chimeric monoclonal antibody.
6. The antibody or the functional fragment thereof according to claim 5 , wherein the antibody is a humanized antibody, wherein amino acid residue(s) present in constant region(s) of the antibody are substituted by amino acid residue(s) having corresponding location(s) in human antibodies according to standard definition and numbering, and wherein the substitution level is from 1% to 20% of the residues in said constant regions.
7. An antibody or a functional fragment thereof selected from the group consisting of:
(a) an antibody produced by hybridoma MD707-13 deposited at the CNCM under No I-4533 or a functional fragment thereof; and
(b) an antibody expressed by recombinant eukaryotic cells, which are recombined with nucleic acid molecule(s) identical to cDNA corresponding to RNA expressed in hybridoma MD707-13 deposited at the CNCM under No I-4533 that encodes the antibody of (a), or a functional fragment thereof.
8. A chimeric molecule comprising an antibody or a functional fragment thereof whose antigen-binding site comprises a Variable Heavy chain and a Variable Light chain, wherein the Variable Heavy chain comprises the following polypeptides:
(a) (i) VHCDR 1 having the amino acid sequence of SEQ ID No 38;
(ii) VHCDR 2 having the amino acid sequence of SEQ ID No 40; and
(iii) VHCDR 3 having the amino acid sequence of SEQ ID No 42; or
(b) VH having amino acid sequence from position 22 to position 135 of SEQ ID No 34; and
wherein the Variable Light chain comprises the following polypeptides:
(c) (i) VLCDR 1 having the amino acid sequence of SEQ ID No 44;
(ii) VLCDR 2 having the amino acid sequence of SEQ ID No 46; and
(iii) VLCDR 3 having the amino acid sequence of SEQ ID No 48; or
(d) VL having amino acid sequence from position 22 to position 129 of SEQ ID No 36;
wherein said antibody or functional fragment is associated with a functionally different molecule, and wherein said chimeric molecule is either a fusion chimeric protein or a conjugate resulting from covalent attachment of a chemical group or molecule.
9. The chimeric molecule according to claim 8 wherein said chimeric molecule is a conjugate resulting from covalent attachment of a PEG polymer or of a labeled antibody.
10. A pharmaceutical composition comprising a pharmaceutical vehicle and an antibody or a functional fragment thereof whose antigen-binding site comprises a Variable Heavy chain and a Variable Light chain, wherein the Variable Heavy chain comprises the following polypeptides:
(a) (i) VHCDR 1 having the amino acid sequence of SEQ ID No 38;
(ii) VHCDR 2 having the amino acid sequence of SEQ ID No 40; and
(iii) VHCDR 3 having the amino acid sequence of SEQ ID No 42; or
(b) VH having amino acid sequence from position 22 to position 135 of SEQ ID No 34; and
wherein the Variable Light chain comprises the following polypeptides:
(c) (i) VLCDR 1 having the amino acid sequence of SEQ ID No 44,
(ii) VLCDR 2 having the amino acid sequence of SEQ ID No 46, and
(iii) VLCDR 3 having the amino acid sequence of SEQ ID No 48; or
(d) VL having amino acid sequence from position 22 to position 129 of SEQ ID No 36.
11. The pharmaceutical composition of claim 10 , wherein the pharmaceutical composition is formulated for controlling CD127+ cells survival or expansion when administered to a human patient.
12. The pharmaceutical composition of claim 11 , wherein the pharmaceutical composition is formulated for controlling CD4+ and CD8+ memory T cells survival or expansion when administered to a human patient.
13. The pharmaceutical composition according to claim 10 further comprising a compound having a therapeutic immunomodulator effect on cells involved in allergy or autoimmunity.