A chimeric antigen receptor T-lymphocyte and its application in the preparation of products for treating solid tumors

Abstract

The invention discloses a chimeric antigen receptor T lymphocyte and its application in preparing products for treating solid tumors. The chimeric antigen receptors in the chimeric antigen receptor T lymphocytes sequentially include human CD8 leader peptide, anti-Siglec-15 single-chain antibody, human CD8 hinge transmembrane region, human 4-1BB intracellular region, human CD3ζ cell Inner region, self-cleaving peptide, CSF2Ra signal peptide, EGFRt protein, self-cleaving peptide and human CD27. It is proved by experiments that the chimeric antigen receptor T lymphocytes of the present invention highly express IFNγ and CD107a, have a strong killing function on Siglec-15 positive tumor cells, and the killing efficiency exceeds 1 when the effect-target ratio is 1:1. 80%. Tumor transplantation model experiments show that the chimeric antigen receptor T lymphocytes of the present invention also have a strong killing function against Siglec‑15 positive tumor cells in animals.

Description

technical field [0001] The invention relates to the technical field of biomedicine, in particular to a chimeric antigen receptor T lymphocyte and its application in the preparation of products for treating solid tumors, in particular to a Siglec-15-CAR-CD27 chimeric antigen receptor gene Modified T lymphocytes and their application in the preparation of products for treating solid tumors. Background technique [0002] As the research on the mechanism of T lymphocyte tumor immune response has been paid more and more attention, chimeric antigen receptor T (CAR-T) cell therapy is becoming a new immunotherapy strategy in the field of tumor immunotherapy. Since the recognition of target cells by T cells depends specifically on the T cell receptor (TCR), the single-chain antibody fragment (scFv) targeting tumor cell-associated antigens and CD3ζ or FcεRIγ of the T cell receptor Intracellular signal activation motifs are fused into a chimeric antigen receptor (Chimeric antigen rece...

AI Technical Summary

Problems solved by technology

The existing targets at this stage, such as Glypican 3 (GPC-3), Claudin18.2, EpCAM, Mesothelin (MSLN), etc., have achieved certain results in preclinical research, but they have not made further progress in clinical efficacy

Although some abnormally high-expressed proteins on the surface of tumor cells can be screened only through omics detection and big data analysis, when immunotherapy products (such as antibody therapy, CAR-T therapy) targeting these protein antigens are released in human When working in vivo, it is often isolated by the immune microenvironment of tumor cells, and cannot really exert its anti-tumor effect

One of the reasons is that in the process of interaction between tumor cells and immune effector cells (such as T cells, macrophages, etc.), the immune checkpoint pathway (such as B7 family protein) of immune cells is often activated, resulting in a decrease in the viability of effector cells. , resulting in immune escape

In addition, the continuous proliferation and insufficient residence time of CAR-T cells in the body also limits the response rate of CAR-T therapy and increases the recurrence rate of CAR-T therapy

More importantly, some solid tumor targets such as HER2, VEGFR, etc. are prone to off-target toxicity due to non-specific expression, and the safety in the actual clinical application process is questionable

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