Anti-PD-L1 antibodies
The present disclosure provides monoclonal antibodies against protein programmed cell death 1 ligand (PD-L1), which can block the binding of PD-L1 to PD-1, and therefore block the inhibitory function of PD-L1 on PD-1 expressing T cells. The antibodies of disclosure provide very potent agents for the treatment of multiple cancers via modulating human immune function.
1. An isolated monoclonal antibody or an antigen binding fragment thereof, comprising a heavy chain variable region comprising: SEQ ID NOs: 1, 2, and 3, and a light chain variable region comprising: SEQ ID NOs: 4, 5 and 6, wherein the monoclonal antibody or an antigen binding fragment thereof specifically binds to human or monkey PD-L1.
2. The antibody or an antigen binding fragment thereof of claim 1 , comprising:
a) a heavy chain variable region comprising SEQ ID NO: 7; and a light chain variable region comprising SEQ ID NO: 9;
b) a heavy chain variable region comprising SEQ ID NO: 11; and a light chain variable region comprising SEQ ID NO: 13;
c) a heavy chain variable region comprising SEQ ID NO: 11; and a light chain variable region comprising SEQ ID NO: 16;
d) a heavy chain variable region comprising SEQ ID NO: 18; and a light chain variable region comprising SEQ ID NO: 13; or
e) a heavy chain variable region comprising SEQ ID NO: 18; and a light chain variable region comprising SEQ ID NO:22.
3. The antibody or antigen-binding fragment thereof of claim 1 , which is a diabody, a scFv, an scFv dimer, a BsFv, a dsFv, a (dsFv) 2 , a dsFv-dsFv′, an Fv fragment, a Fab, a Fab′, a F(ab′) 2 , or a ds diabody.
4. The antibody or antigen-binding fragment thereof of claim 1 , further comprising a conjugate.
5. An isolated polynucleotide encoding the antibody or an antigen binding fragment thereof of claim 1 .
6. A vector comprising the isolated polynucleotide of claim 5 .
7. A host cell comprising the vector of claim 6 .
8. A method of expressing the antibody or antigen-binding fragment thereof of claim 1 , comprising culturing the host cell comprising a vector comprising an isolated polynucleotide encoding the antibody or an antigen binding fragment thereof of claim 1 , under the condition at which the polynucleotide is expressed.
9. A kit comprising the antibody or antigen-binding fragment thereof of claim 1 .
10. A method of detecting presence or level of human or monkey PD-L1 in a biological sample, comprising exposing the biological sample to the antibody or antigen-binding fragment thereof of claim 1 , and determining the presence or level of human or monkey PD-L1 in the sample.
11. A pharmaceutical composition comprising the antibody or antigen-binding fragment thereof of claim 1 and one or more pharmaceutically acceptable carriers.