Bispecific antibody targeting TIM3 and use thereof
The present invention provides a bispecific antibody and a use thereof. The bispecific antibody comprises a first protein functional zone and a second protein functional zone. TIM-3 full-length antibody of targeting TIM-3 corresponding to the targeting TIM-3 in the first protein functional zone has a low binding activity with Macaca TIM-3, has strong binding activity with Marmoset and human TIM-3, and can activate the killing effect of a human NK cell on the tumor cell. The bispecific antibody reserves the activity of a single TIM-3 antibody of activating PBMC (NK) to kill the tumor cell while reserving the original activity of the other protein functional zone, and can achieve the same activity of being combined with two molecules or better activate the activity of a T lymphocyte.
1 . A bispecific antibody comprising
a first protein functional region and a second protein functional region,
wherein the first protein functional region is a protein functional region targeting TIM 3,
and the first protein functional region is one or more scFvs, wherein each scFv comprises a heavy chain variable region and a light chain variable region, and
the heavy chain variable region of each scFv comprises a CDR1 comprising SEQ ID NO: 1, a CDR2 comprising SEQ ID NO: 2 and a CDR3 comprising SEQ ID NO: 3; and
the light chain variable region of each scFv comprises a CDR1 comprising SEQ ID NO: 7, a CDR2 comprising SEQ ID NO: 8 and a CDR3 comprising SEQ ID NO: 9;
and the number of the scFvs is two or four or six or eight;
and the second protein functional region is an IgG, wherein the IgG comprises two light chains and two heavy chains;
and each heavy chain of the IgG has a human heavy chain constant region, and each light chain of the IgG has a human light chain constant region;
each scFv has a structure of light chain variable region-linker 1-heavy chain variable region from N-terminus to C-terminus, the N-terminus of the light chain variable region or the C-terminus of the heavy chain variable region of each scFv is respectively symmetrically connected to two C-termini or two N-termini of two light chains or two heavy chains of the IgG through linker 2; or
each scFv has a structure of heavy chain variable region-linker 1-light chain variable region from N-terminus to C-terminus, the N-terminus of the heavy chain variable region or the C-terminus of the light chain variable region of each scFv is respectively symmetrically connected to two C-termini or two N-termini of the light chains or heavy chains of the IgG through linker 2;
wherein the linker 1 and the linker 2 are both (G 4 S) 3 (SEQ ID NO: 36).
2 . The bispecific antibody of claim 1 , wherein in the first protein functional region, the amino acid sequence of the heavy chain variable region comprises SEQ ID NO: 13 and the amino acid sequence of the light chain variable region comprises SEQ ID NO: 14.
3 . The bispecific antibody of claim 1 , wherein the second protein functional region is a PD-1 antibody selected from the group consisting of Nivolumab or Pembrolizumab.
4 . The bispecific antibody of claim 1 , wherein the bispecific antibody has two light chains comprising SEQ ID NO: 17 and two heavy chains comprising SEQ ID NO: 18; or
the bispecific antibody has two light chains comprising SEQ ID NO: 23 and two heavy chains comprising SEQ ID NO: 24; or
the bispecific antibody has two light chains comprising SEQ ID NO: 32 and two heavy chains comprising SEQ ID NO: 33.
5 . An isolated host cell comprising an expression vector that contains a deoxyribonucleic acid (DNA) sequence encoding the bispecific antibody of claim 1 .
6 . A method for preparing the bispecific antibody of claim 1 , which comprises the following steps: culturing an isolated host cell and obtaining the bispecific antibody from the culture;
wherein the isolated host cell contains an expression vector, and the expression vector comprises a DNA sequence encoding the bispecific antibody.
7 . A pharmaceutical composition comprising the bispecific antibody of claim 1 ; wherein the pharmaceutical composition further comprises other anti-tumor drugs, and histidine buffer comprising 10-20 mM L-Histidine, 50-70 mg/mL sucrose, and 0.1-1.0% Polysorbate 80 or 0.01-0.05% Polysorbate 20.
8 . A product comprising a kit A and a kit B, wherein the kit A comprises the bispecific antibody of claim 1 , and the kit B comprises an anti-tumor drug.