The invention discloses a CAR-
T cell based on a
secretion enhancement strategy as well as a preparation method and medical application thereof. The constructed asCAR-
T cell contains a
secretion-enhanced
chimeric antigen receptor (asCAR for short) and small interfering
nucleic acid of DDR1
protein. The asCAR sequentially comprises a single-chain variable fragment scFv, a
hinge region, a
transmembrane domain, a costimulatory factor, a
signal transduction structural domain CD3 zeta and TNFRSF1B ICD from an
extracellular structure to an
intracellular structure, wherein the TNFRSF1B ICD is a TRAF2 binding structural domain in a TNFR2
cell; the small interfering
nucleic acid of the DDR1
protein comprises shRNA-DDR1 (short hairpin ribonucleic acid) or miRNA-DDR1 (micro ribonucleic acid). After the
antigen activates the asCAR-T cells, the ICD of the TNFRSF1B enhances the expression of the PD-1 through the NF-kappa B pathway and releases the
extracellular vesicles loaded with the shRNA-DDR1 or the miRNA-DDR1. The
extracellular vesicles released by the asCAR-T cells degrade PD-L1 on the surfaces of
tumor cells and inhibit DDR1 expression, and the immune infiltration and anti-tumor effects of the asCAR-T cells are enhanced based on the
positive feedback loop.