Anti-CD28 humanized antibodies
The invention relates to humanized antibodies directed against the human lymphocyte receptor CD28. When used in a monovalent form these antibodies are antagonists, i.e. capable of blocking of the CD28/B7 interaction, without activating CD28. These antibodies can be used in particular as therapeutic agents for blocking T cell activation through the CD28 receptor.
1. A method of treating a T-lymphocyte-mediated chronic inflammatory disease in a subject in need thereof comprising administering an anti-CD28 monovalent antibody to the subject, wherein the anti-CD28 monovalent antibody is selected from the group consisting of:
(a) an antibody having a CD28-binding site consisting of:
a heavy chain variable domain of SEQ ID NO: 1; and
a light chain variable domain of SEQ ID NO: 2, and
(b) an antibody having a CD28-binding site consisting of:
a heavy chain variable domain having all three complementarity determining regions (CDRs) of the variable domain of SEQ ID NO: 1; and
a light chain variable domain having all three CDRs of the variable domain of SEQ ID NO: 2.
2. The method of claim 1 , wherein the monovalent antibody is a heterodimer of:
a first protein chain having the sequence of amino-acids 21-251 of SEQ ID NO: 4; and
a second protein chain having the sequence of amino-acids 21-234 of SEQ ID NO: 6.
3. The method of claim 1 , wherein the monovalent antibody is a heterodimer of:
(I) a first protein chain consisting essentially of, from its N-terminus to its C-terminus:
i: a region A which is a heavy chain variable domain of SEQ ID NO: 1; and
ii: a region B consisting of a peptide linker followed by the CH2 and CH3 domains of an IgG immunoglobulin, and
(II) a second protein chain consisting essentially of, from its N-terminus to its C-terminus:
i: a region A′ which is a light chain variable domain of SEQ ID NO: 2; and
ii: a region B identical to the region B of the first protein chain.
4. The method of claim 3 , wherein the peptide linker is selected from the group consisting of:
a peptide of SEQ ID NO: 7; and
a peptide of SEQ ID NO: 8.
5. The method of claim 3 , wherein the CH2 and CH3 domains are those of an immunoglobulin of the IgG4 subclass.
6. The method of claim 5 , wherein the monovalent antibody is selected from the group consisting of:
a monovalent antibody wherein the polypeptide sequence of the first protein chain is the sequence of amino-acids 21-368 of SEQ ID NO: 10, and the polypeptide sequence of the second protein chain is the sequence of amino-acids 21-355 of SEQ ID NO: 12; and
a monovalent antibody wherein the polypeptide sequence of the first protein chain is the sequence of amino-acids 21-373 of SEQ ID NO: 14, and the polypeptide sequence of the second protein chain is the sequence of amino-acids 21-360 of SEQ ID NO: 16.
7. The method of claim 2 , wherein the second protein chain comprises a variable domain of SEQ ID NO: 2.
8. The method of claim 1 , wherein the monovalent antibody is administered in a composition and the composition further comprises a pharmaceutically acceptable excipient.
9. The method of claim 2 , wherein the second protein chain comprises a variable domain of SEQ ID NO: 2 where X represents an alanine or an asparagine residue.
10. The method of claim 2 , wherein the monovalent antibody is pegylated.
11. The method of claim 1 , wherein the heavy chain variable domain further comprises a Q residue at the N-terminal end.
12. The method of claim 1 , wherein the T-lymphocyte-mediated chronic inflammatory disease is hypertension.
13. The method of claim 1 , wherein the T-lymphocyte-mediated chronic inflammatory disease is allergic phenomena.
14. The method of claim 1 , wherein the T-lymphocyte-mediated chronic inflammatory disease is a disease following infection with a pathogenic agent.