Screening and antitumor use of KRAS mutation specific T cell receptor
View Patent ↗The present disclosure provides two specific T cell receptors targeting a G12V or G12C mutant epitope of a KRAS gene, and an anti-tumor use thereof. Each of the two T cell receptors consists of an α peptide chain and a β peptide chain. Further provided are an antigen binding fragment of the T cell receptors, a nucleic acid encoding the T cell receptors or an antigen binding fragment thereof, a vector comprising the nucleic acid, and a host cell comprising the vector. Further provided is a method for preparing a specific T cell receptor for a KRAS G12V mutation or an antigen-binding fragment thereof. The specific T cell receptor and antigen-binding fragment thereof can be used as an immune activator to stimulate an immune response of an organism, thereby generating an effect against tumors and other diseases.
1 . A T cell receptor (TCR) or antigen-binding fragment thereof, capable of binding to a complex of KRAS-G12V 8-16 epitope of SEQ ID NO: 35 and HLA-A11, a complex of KRAS-G12C 8-16 epitope of SEQ ID NO: 37 and HLA-A11, or a complex of KRAS-G12V 8-16 epitope of SEQ ID NO: 35 and HLA-A03 and comprising an α-chain variable region and a β-chain variable region, wherein the TCR or antigen-binding fragment thereof comprises the following α-chain complementarity determining regions (CDRs) and β-chain complementarity determining regions (CDRs):
an α-chain complementarity determining region CDR1 comprising SEQ ID NO: 3;
an α-chain complementarity determining region CDR2 comprising SEQ ID NO: 4;
an α-chain complementarity determining region CDR3 comprising SEQ ID NO: 5;
a β-chain complementarity determining region CDR1 comprising SEQ ID NO: 8;
a β-chain complementarity determining region CDR2 comprising SEQ ID NO: 9; and
a β-chain complementarity determining region CDR3 comprising SEQ ID NO: 10;
or
an α-chain complementarity determining region CDR1 comprising SEQ ID NO: 13;
an α-chain complementarity determining region CDR2 comprising SEQ ID NO: 14;
an α-chain complementarity determining region CDR3 comprising SEQ ID NO: 15;
a β-chain complementarity determining region CDR1 comprising SEQ ID NO: 18;
a β-chain complementarity determining region CDR2 comprising SEQ ID NO: 19; and
a β-chain complementarity determining region CDR3 comprising SEQ ID NO: 20.
2 . The T cell receptor (TCR) or antigen-binding fragment thereof of claim 1 , which comprises:
an α-chain variable region comprising SEQ ID NO: 2, and
a β-chain variable region comprising SEQ ID NO: 7;
or
an α-chain variable region as set forth in SEQ ID NO: 12, and
a β-chain variable region comprising SEQ ID NO: 17.
3 . The TCR or antigen-binding fragment thereof according to claim 1 , wherein the TCR is a murine TCR, a human-mouse chimeric TCR or a humanized TCR.
4 . A polynucleotide encoding the TCR or antigen-binding fragment thereof of claim 1 , which is one or more sequences selected from the group consisting of SEQ ID NO: 1, SEQ ID NO:6, SEQ ID NO:11, and SEQ ID NO:16.
5 . An expression vector comprising the polynucleotide of claim 4 , wherein the expression vector is a lentivirus vector.
6 . A host cell comprising the expression vector of claim 5 .
7 . A method for preparing the TCR or antigen-binding fragment thereof of claim 1 , comprising:
i) culturing a host cell comprising an expression vector, wherein the expression vector comprises a polynucleotide, and the polynucleotide comprises one or more sequences selected from the group consisting of SEQ ID NO:1, SEQ ID NO:6, SEQ ID NO:11, and SEQ ID NO:16;
ii) recovering the TCR or antigen-binding fragment thereof of claim 1 from the host cell or a culture medium thereof.
8 . A pharmaceutical composition, which comprises the TCR or antigen-binding fragment thereof according to claim 1 , and a pharmaceutically acceptable carrier.
9 . A method for increasing interferon (IFN)-γ cytokine level secreted by a T cell, comprising contacting a T cell expressing the TCR or antigen-binding fragment thereof of claim 1 with a polypeptide comprising a KRAS-G12V 8-16 mutation of SEQ ID NO: 35 or a KRAS-G12C 8-16 mutation of SEQ ID NO: 37, thereby increasing IFN-γ cytokine level secreted by the T cell.
10 . A method for detecting a tumor cell expressing a KRAS-G12V 8-16 mutation of SEQ ID NO: 35 or a KRAS-G12C 8-16 mutation of SEQ ID NO: 37, comprising contacting a protein comprising the TCR or antigen-binding fragment thereof of claim 1 with the tumor cell to be detected, thereby detecting presence or absence of the tumor cell expressing the KRAS-G12V 8-16 mutation or the KRAS-G12C 8-16 mutation.
11 . A method for treating a tumor with a KRAS-G12V 8-16 mutation of SEQ ID NO: 35 and/or a KRAS-G12C8-16 mutation of SEQ ID NO: 37 of a KRAS gene in a patient, comprising administering to the patient a T cell expressing the TCR or antigen-binding fragment thereof of claim 1 , thereby treating the patient.
12 . The method of claim 11 , wherein the tumor is selected from pancreas cancer, colorectal cancer, or lung cancer.
13 . The method of claim 12 , wherein the tumor is non-small cell lung cancer.
14 . The method of claim 11 , wherein the TCR or antigen-binding fragment thereof comprises:
an α-chain variable region comprising SEQ ID NO: 2, and
a β-chain variable region comprising SEQ ID NO: 7;
or
an α-chain variable region comprising SEQ ID NO: 12, and
a β-chain variable region comprising SEQ ID NO: 17.
15 . The method of claim 11 , wherein the TCR is a murine TCR, a human-mouse chimeric TCR or a humanized TCR.