Monoclonal antibody against human LAG-3, method for preparing the same, and use thereof
Provided are novel fully human monoclonal antibodies that bind to human LAG-3. It also provides the methods of hybridoma generation using humanized rats, the nucleic acid molecules encoding the anti-LAG-3 antibodies, expression vectors and host cells used for the expression of anti-LAG-3 antibodies. The invention further provides the methods for validating the function of antibodies in vitro. The antibodies of invention provide a potent agent for the treatment of multiple cancers via modulating human immune function.
1. An isolated antibody or the antigen-binding portion thereof that is capable of binding LAG-3, wherein the antibody or the antigen-binding portion thereof comprises:
(a) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 13; and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 14; or
(b) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 15; and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 16.
2. The isolated antibody or the antigen-binding portion thereof of claim 1 , wherein the antibody or the antigen-binding portion thereof comprises:
(a) a CDRH1, a CDRH2 and a CDRH3 of a VH sequence as set forth in SEQ ID NO: 13, and a CDRL1, a CDRL2 and a CDRL3 of a VL sequence as set forth in SEQ ID NO: 14; or
(b) a CDRH1, a CDRH2 and a CDRH3 of a VH sequence as set forth in SEQ ID NO: 15, and a CDRL1, a CDRL2 and a CDRL3 of a VL sequence as set forth in SEQ ID NO: 16.
3. The isolated antibody or the antigen-binding portion thereof of claim 1 , wherein the antibody or the antigen-binding portion thereof comprises:
(a) a CDRH1 comprising the amino acid sequence of SEQ ID NO: 1, a CDRH2 comprising the amino acid sequence of SEQ ID NO: 2, a CDRH3 comprising the amino acid sequence of SEQ ID NO: 3, a CDRL1 comprising the amino acid sequence of SEQ ID NO: 4, a CDRL2 comprising the amino acid sequence of SEQ ID NO: 5, and a CDRL3 comprising the amino acid sequence of SEQ ID NO: 6; or
(b) a CDRH1 comprising the amino acid sequence of SEQ ID NO: 7, a CDRH2 comprising the amino acid sequence of SEQ ID NO: 8, a CDRH3 comprising the amino acid sequence of SEQ ID NO: 9, a CDRL1 comprising the amino acid sequence of SEQ ID NO: 10, a CDRL2 comprising the amino acid sequence of SEQ ID NO: 11, and a CDRL3 comprising the amino acid sequence of SEQ ID NO: 12.
4. The isolated antibody or the antigen-binding portion thereof of claim 1 , wherein the isolated antibody or the antigen-binding portion thereof comprises:
(a) a CDRH1 consisting of SEQ ID NO: 1;
(b) a CDRH2 consisting of SEQ ID NO: 2;
(c) a CDRH3 consisting of SEQ ID NO: 3;
(d) a CDRL1 consisting of SEQ ID NO: 4;
(e) a CDRL2 consisting of SEQ ID NO: 5; and
(f) a CDRL3 consisting of SEQ ID NO: 6.
5. The isolated antibody or the antigen-binding portion thereof of claim 1 , wherein the isolated antibody or the antigen-binding portion thereof comprises:
(a) a CDRH1 consisting of SEQ ID NO: 7;
(b) a CDRH2 consisting of SEQ ID NO: 8;
(c) a CDRH3 consisting of SEQ ID NO: 9;
(d) a CDRL1 consisting of SEQ ID NO: 10;
(e) a CDRL2 consisting of SEQ ID NO: 11; and
(f) a CDRL3 consisting of SEQ ID NO: 12.
6. The isolated antibody or the antigen-binding portion thereof of claim 1 , having one or more of the following properties:
(a) inhibits binding of LAG-3 to major histocompatibility (MHC) class II molecules;
(b) inhibits binding of LAG-3 to fibrinogen-like protein 1 (FGL1) ligand molecules;
(c) inhibits binding of LAG-3 to LSECtin and/or Galectin-3;
(d) binds to human LAG-3 without cross-family reactions; or
(e) has no cross-reactivity to human CD4.
7. The isolated antibody or the antigen-binding portion thereof of claim 1 , wherein the antibody is a chimeric antibody, a humanized antibody or a fully human antibody.
8. The isolated antibody or the antigen-binding portion thereof of claim 7 , wherein the antibody is a fully human monoclonal antibody produced by a rat having recombinant immunoglobulin loci.
9. A pharmaceutical composition comprising at least one antibody or antigen-binding portion thereof as defined in claim 1 and a pharmaceutically acceptable carrier.
10. A kit comprising a container comprising the antibody or antigen-binding portion thereof as defined in claim 1 .
11. An isolated nucleic acid molecule, comprising a nucleic acid sequence encoding the heavy chain variable region and/or the light chain variable region of the isolated antibody as defined in claim 1 .
12. An expression vector comprising the nucleic acid molecule of claim 11 .
13. A host cell comprising the expression vector of claim 12 .
14. A method for preparing an antibody or antigen-binding fragment thereof that binds to LAG-3, the method comprising:
incubating the host cell of claim 13 in conditions suitable for expression the antibody or antigen-binding fragment thereof; and
isolating the antibody or antigen-binding fragment thereof.
15. A method for inhibiting or blocking the binding of LAG-3 to LSECtin and/or Galectin-3, comprising in the presence of LAG-3 contacting LSECtin and/or Galectin-3 with the antibody or antigen-binding portion thereof as defined in claim 1 .
16. A method for inhibiting growth of tumor cells in a subject, comprising administering to the subject the antibody or antigen-binding portion thereof as defined in claim 1 such that growth of the tumor is inhibited in the subject.
17. A method for treating cancers in a subject, comprising administering an effective amount of the antibody or antigen-binding portion thereof as defined in claim 1 to the subject.
18. A method for detecting LAG-3 in a sample, comprising contacting the sample with the antibody or antigen-binding portion thereof as defined in claim 1 , and detecting presence or absence, or level of association, of the antibody bound in the sample.