CN-122029205-A - Fusion protein and application thereof

Abstract

A fusion protein and its application are disclosed, which are antigen-binding protein or antibody-binding protein. Immune cells expressing the antigen binding protein or antibody binding protein may exhibit enhanced cytotoxicity. Also provided are uses of the antigen binding proteins or antibody binding proteins.

Inventors

• LIU YARONG
• CUI JUN
• YUAN HUI

Assignees

• 北京沙砾生物医药股份有限公司
• 上海沙砾生物科技有限公司

Dates

Publication Date

20260512

Application Date

20240918

Priority Date

20230919

Claims (20)

1. An antigen binding protein, wherein the antigen binding protein comprises an intracellular domain comprising an intracellular domain of a mutated DNAM-1, the intracellular domain of the mutated DNAM-1 lacks one or more basic amino acids, truncates a sequence containing one or more basic amino acids, and/or one or more basic amino acids are replaced with non-basic amino acids relative to the intracellular domain of a wild-type DNAM-1.
2. The antigen binding protein of claim 1, wherein the intracellular domain of wild-type DNAM-1 comprises the sequence of NRRRRRERRDLFTESWDTQKAPNNYRSPISTGQPTNQSMDDTREDIYVNYPTFSRRPKTRV (SEQ ID NO: 9).
3. The antigen binding protein of any one of claims 1-2, wherein the intracellular domain of the mutant DNAM-1 lacks 1 to 5 basic amino acids at the C-terminus, truncates a sequence containing 1 to 5 basic amino acids and/or 1 to 5 basic amino acids are replaced with non-basic amino acids relative to the intracellular domain of the wild-type DNAM-1.
4. The antigen binding protein of any one of claims 1-3, wherein the intracellular domain of the mutant DNAM-1 is truncated at amino acids 1 to 4 of the C-terminus relative to the intracellular domain of the wild-type DNAM-1.
5. The antigen binding protein of any one of claims 1-4, wherein the intracellular domain of the mutant DNAM-1 lacks 1 to 5 basic amino acids at the N-terminus, truncates a sequence containing 1 to 5 basic amino acids and/or 1 to 5 basic amino acids are replaced with non-basic amino acids relative to the intracellular domain of the wild-type DNAM-1.
6. The antigen binding protein of any one of claims 1-5, wherein the intracellular domain of the mutant DNAM-1 is truncated at amino acids 2 to 4 of the N-terminus relative to the intracellular domain of the wild-type DNAM-1.
7. The antigen binding protein of any one of claims 1-6, wherein the intracellular domain of the mutated DNAM-1 is truncated at amino acids 1 to 40 of the N-terminus relative to the intracellular domain of the wild-type DNAM-1.
8. The antigen binding protein of any one of claims 1-7, wherein the intracellular domain of the mutated DNAM-1 comprises the sequence of any one of SEQ ID NOs 10-13.
9. The antigen binding protein of any one of claims 1-8, wherein the antigen binding protein further comprises an additional intracellular domain other than the intracellular domain of the mutated DNAM-1, which additional intracellular domain is directly or indirectly linked to the intracellular domain of the mutated DNAM-1.
10. The antigen binding protein of claim 9, wherein the additional intracellular domain is located N-terminal to the intracellular domain of the mutated DNAM-1.
11. The antigen binding protein of any one of claims 9-10, wherein the additional intracellular domain comprises an intracellular domain of a protein selected from the group consisting of 2B4, and DAP10, or a functional fragment thereof.
12. The antigen binding protein of any one of claims 9-11, wherein said additional intracellular domain comprises the sequence set forth in SEQ ID No. 8.
13. The antigen binding protein of any one of claims 1-12, wherein the antigen binding protein further comprises a transmembrane domain directly or indirectly linked to the intracellular domain.
14. The antigen binding protein of claim 13, wherein said transmembrane domain is located N-terminal to said other intracellular domain.
15. The antigen binding protein of any one of claims 13-14, wherein the transmembrane domain comprises a transmembrane domain of a protein selected from the group consisting of an IL-7 receptor, and CD8a, or a functional fragment thereof.
16. The antigen binding protein of any one of claims 13-15, wherein the transmembrane domain comprises a mutated IL-7 receptor transmembrane sequence set forth in SEQ ID No. 7.
17. The antigen binding protein of any one of claims 13-15, wherein the transmembrane domain comprises the CD8a transmembrane sequence shown in SEQ ID No. 6.
18. The antigen binding protein of any one of claims 1-17, wherein the antigen binding protein further comprises a hinge domain directly or indirectly linked to the intracellular domain.
19. The antigen binding protein of claim 18, wherein the hinge domain is located N-terminal to the transmembrane domain.
20. The antigen binding protein of any one of claims 18-19, wherein the hinge domain comprises a hinge domain of CD8a or a functional fragment thereof.

Description

Fusion protein and application thereof Technical Field The invention belongs to the biomedical field, and in particular relates to a fusion protein and application thereof. Background Chimeric antigen receptors (CHIMERIC ANTIGEN receptors, CARs) direct CAR-expressing immune cells to clear tumors by specifically recognizing antigens expressed on the surface of tumor cells. For example, when antigen positive cells against which the CAR is directed are present, cells expressing the CAR can recognize and kill these antigen positive cells. However, the CARs existing in the art still have problems of low activity and weak killing ability of cells expressing the CARs. Thus, there is a need in the art for a CAR whose structure is further optimized to achieve the effect of increasing the killing ability of the cells expressing the CAR. Disclosure of Invention The present invention provides an antigen binding protein of improved structure, which may be in the form of a Chimeric Antigen Receptor (CAR). The antigen binding protein may have one or more effects selected from the group consisting of (1) excellent expression efficiency, (2) a cell expressing the antigen binding protein has a remarkable antitumor activity, (3) a cell expressing the antigen binding protein has a sustained antitumor activity, (4) a cell expressing the antigen binding protein has a remarkable cell activating ability, and (5) a cell expressing the antigen binding protein has a remarkable cytokine secreting ability. In one aspect, the invention provides an antigen binding protein comprising an intracellular domain comprising a mutated intracellular domain of DNAM-1, the mutated intracellular domain of DNAM-1 lacking one or more basic amino acids, truncating a sequence containing one or more basic amino acids, and/or replacing one or more basic amino acids with non-basic amino acids relative to the intracellular domain of wild-type DNAM-1. In another aspect, the invention provides the use of an intracellular domain comprising a mutated intracellular domain of DNAM-1, which mutated intracellular domain of DNAM-1 lacks one or more basic amino acids, truncates a sequence containing one or more basic amino acids and/or replaces one or more basic amino acids with non-basic amino acids relative to the intracellular domain of wild-type DNAM-1 in the preparation of an antigen binding protein. In another aspect, the invention provides an antibody binding protein comprising an extracellular antibody binding domain and an intracellular domain comprising an intracellular domain of a mutated DNAM-1, the intracellular domain of the mutated DNAM-1 lacking one or more basic amino acids, truncating a sequence comprising one or more basic amino acids, and/or replacing one or more basic amino acids with non-basic amino acids relative to the intracellular domain of the wild-type DNAM-1. In another aspect, the invention provides the use of an intracellular domain comprising a mutated intracellular domain of DNAM-1, which mutated intracellular domain of DNAM-1 lacks one or more basic amino acids, truncates a sequence containing one or more basic amino acids and/or replaces one or more basic amino acids with non-basic amino acids relative to the intracellular domain of wild-type DNAM-1 in the preparation of an antibody binding protein. In another aspect, the invention provides a polypeptide comprising an antigen binding protein of the invention, and/or an antibody binding protein of the invention. In another aspect, the invention provides a nucleic acid encoding an antigen binding protein of the invention, an antibody binding protein of the invention and/or a polypeptide of the invention. In another aspect, the invention provides a vector comprising a nucleic acid of the invention. In another aspect, the invention provides a cell comprising an antigen binding protein of the invention, an antibody binding protein of the invention, a polypeptide of the invention, a nucleic acid of the invention and/or a vector of the invention. In another aspect, the invention provides a method of producing an antigen binding protein of the invention, an antibody binding protein of the invention and/or a polypeptide of the invention, the method comprising culturing a cell of the invention under conditions such that the antigen binding protein, antibody binding protein of the invention and/or the polypeptide is expressed. In another aspect, the invention provides a composition comprising an antigen binding protein of the invention, an antibody binding protein of the invention, a polypeptide of the invention, a nucleic acid of the invention, a vector of the invention, and/or a cell of the invention, and optionally a pharmaceutically acceptable carrier. In another aspect, the invention provides a kit comprising an antigen binding protein of the invention, an antibody binding protein of the invention, a polypeptide of the invention, a nucleic acid of the invention, a vector of the invention,