Chimeric antigen receptor T lymphocyte and application thereof to preparation of product for treating solid tumors

Abstract

The invention discloses a chimeric antigen receptor T lymphocyte and an application thereof to preparation of a product for treating solid tumors. A chimeric antigen receptor in the chimeric antigen receptor T lymphocyte sequentially comprises a human CD8 lead peptide, an anti-Siglec-15 single-chain antibody, a human CD8 hinge transmembrane region, a human 4-1BB intracellular region, a human CD3 zeta intracellular region, a self-cleavage peptide, a CSF2Ra signal peptide, an EGFRt protein, a self-cleavage peptide and a human CD27. Experiments prove that the chimeric antigen receptor T lymphocyte provided by the invention highly expresses IFN gamma and CD107a, has a strong killing function on Siglec-15 positive tumor cells, and has killing efficiency of more than 80% under the condition thatthe effect-target ratio is 1: 1. A tumor transplantation model experiment shows that the chimeric antigen receptor T lymphocyte also has a strong killing function on Siglec-15 positive tumor cells inan animal body.

Description

Technical field [0001] The present invention relates to the field of biotechnology medicine, in particular to a chimeric T cell antigen receptor and its application in preparing medicine for treating solid tumors in a product, particularly to a Siglec-15-CAR-CD27 chimeric antigen receptor gene modified T lymphocytes and its application in preparing medicine for treating solid tumors in a product. Background technique [0002] With the study of mechanisms of immune responses of T lymphocytes tumor growing emphasis on chimeric antigen receptor T (CAR-T) cell therapy is emerging as a new immunotherapeutic strategies in the field of cancer immunotherapy. Since the T cells recognize the target cell-specific receptor is dependent on T lymphocytes (T Cell Receptor, TCR), and therefore the single chain antibody fragment against tumor cell-associated antigen (scFv) CD3ζ or T cell receptor with FcεRIγ intracellular signaling like the activation motif fused to the chimeric receptor antigen ...

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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