Chimeric antigen receptor nano-antibody exosome and purification method thereof

Abstract

The invention relates to the technical field of genetic engineering, in particular to a chimeric antigen receptor nano-antibody exosome. The exosome is CAR-NB-exo, and the surface of the exosome specifically comprises three antibodies, a first antibody is a CD3 antibody, a second antibody is a CD33 antibody, and a third antibody is a PD-L1 nano-antibody. The invention also discloses a purification method of the chimeric antigen receptor nano-antibody exosome. The purification method comprises the following steps: step 1, collecting a culture medium of Expi293 cells transfected by an expression construct on the third and sixth days after transfection; and step 2, separating the CAR-NB-exo through differential speed centrifugation and ultra-speed centrifugation. Compared with the prior art, the exosome has the beneficial effects that the generated dual targeting T cells CD3 and CD33 can be combined with the surfaces of the T cells and cancer cells, and besides, the PD-L1 nano antibody can block the combination of the cancer cells and PD-1 receptors on the surfaces of T lymphocytes, so that the effect of immunotherapy can be greatly improved.

Description

technical field [0001] The invention relates to the technical field of genetic engineering, in particular to a chimeric antigen receptor nanobody exosome and a purification method thereof. Background technique [0002] Exosomes are cell secretions, which refer to small membrane vesicles containing complex RNA and proteins. In 1983, exosomes were first discovered in sheep reticulocytes. Johnstone named them "exosome" in 1987. A variety of cells can secrete exosomes under normal and pathological conditions. It is mainly derived from the multivesicular body formed by the invagination of lysosomal particles in the cell, and is released into the extracellular matrix after the fusion of the outer membrane of the multivesicle and the cell membrane. [0003] With the continuous development of science and technology, exosome platform technology can be developed to form a treatment method for diseases, which can well treat diseases that cannot be treated by traditional drugs under cu...

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Problems solved by technology

[0003] With the continuous development of science and technology, exosome platform technology can be developed to form a treatment method for diseases, which can well treat diseases that cannot be treated by traditional drugs under current technology, such as cancer, and exosome technology is in practical application There are still many problems, and its effect is unstable. The combination of cancer cells and PD-1 receptors on the surface of T lymphocytes will allow cancer cells to escape the inspection of the body's immune system, resulting in a greatly reduced therapeutic effect.

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