Tumor therapeutic agent improved through IL-12/CD62L fusion protein and preparation method and application thereof

Abstract

The invention provides an efficient and low-toxin tumor therapeutic agent and a preparation method and application thereof, and particularly provides IL-12 / CD62L fusion protein. Anti-tumor T cells are modified through slow viruses containing IL-12 / CD62L fusion genes, and by means of specific cleavage and release induced by activation of CD62L tumor antigen dependence, release of cell membrane surface IL-12 activated through tumor antigens is achieved. A is shown through experiments, fixed-point and timed release of IL-12 can be achieved locally on tumors attacked by the T cells, so that the immune microenvironment of T cell-tumor tissue is changed, and accordingly the anti-tumor immune effect is the maximum. Besides, the toxic and side effects are remarkably reduced.

Description

technical field [0001] The invention relates to the field of medicine, in particular to a tumor therapeutic agent transformed by IL-12 / CD62L fusion protein and its preparation method and application. The invention provides a kind of IL-12 / CD62L gene-modified T cells with enhanced anti-tumor effect. Background technique [0002] IL-12 is a very important immune stimulating factor. IL-12 is a covalently linked heterodimeric cytokine composed of p35 and p40 subunits that is secreted by activated immune cells in vivo. IL-12 is an important regulatory factor of cellular immunity, and plays a role through NK cells and CTL in anti-infection immunity and immunity of malignant tumors. [0003] Individuals who are congenitally deficient or nonresponsive to IL-12 have profoundly deficient immunity against infection. A series of preclinical experimental models have confirmed that the intervention of IL-12 can significantly prolong the survival of tumor-bearing animal models. [0004...

AI Technical Summary

Problems solved by technology

[0004] Although IL-12 has a significant antitumor effect, it is greatly limited due to the systemic toxicity caused by its systemic administration.

Before the present invention, the clinical application of IL-12 was greatly limited due to the systemic toxic side effects induced by it, and the accidental death of two patients caused by systemic administration in early clinical trials.

[0005] In order to avoid the toxic and side effects of systemic administration and achieve the purpose of clinical application, clinical researchers have used local tumor injection, transient expression and multi-point injection in tumor clinical trials, but because the therapeutic effect of IL-12 is the same as The dose of reinfused IL-12 is directly related, and the above-mentioned local clinical scheme has not achieved significant anti-tumor effect

[0006] In order to solve this problem, the inventors once tried to maximize the anti-tumor effect by genetically modifying anti-tumor T cells to continuously secrete IL-12, but due to unknown reasons (one possible reason is the toxic side effects of IL-12 ) T cells genetically modified by the continuous secretion of IL-12 can not be effectively expanded in vitro, and cause a large number of T cell apoptosis

[0007] In order to solve this problem, the present inventors have also achieved the problem of effective expansion of T cells in vitro through the gene modification scheme of specifically regulating the expression of IL-12 through TCR activation, and also achieved a certain tumor-suppressing effect, but at the same time there is IL-12 -12 Toxic and side effects caused by deregulation cannot be effectively applied to clinical applications

[0008] In summary, there is still a lack of IL-12-based antitumor drugs with high efficiency and no obvious side effects in this field.

Images