Method for screening immune anti-cancer active cytokine and composition for preventing or treating cancer disease comprising IL-15 as active ingredient

Abstract

The present invention relates to a method for screening a cytokine having immune anti-cancer activity for inhibiting secretion of exosomes from cancer cells or inhibiting expression of programmed apoptosis ligands, in which a vector consisting of a gene encoding a cytokine, a linker domain encoding a linker and a transmembrane domain encoding a transmembrane protein is transformed into cancer cells, a cytokine exhibiting immune anti-cancer activity, which inhibits the expression level of a gene associated with exosome secretion or the expression level of PD-L1, can be selected, and the selected cytokine can be provided as a novel anti-cancer agent. Further, the present invention relates to a composition for preventing or treating cancer diseases, comprising IL-15 or an expression promoter or activator thereof selected using the above-mentioned screening technique as an active ingredient. In the present invention, it was found that treatment of cancer cells with IL-15 inhibits secretion of exosomes derived from cancer cells and expression of PD-L1 that induces immune escape of T cells, and it was also found that an anti-cancer effect is directly expressed on cancer cells. It was found that IL-15 activates cytotoxic T cells, reduces immune checkpoints PD-1 and CTLA-4, and promotes exosomes derived from immune cells, and thus exhibits immune anti-cancer activity. Therefore, IL-15 or an expression promoter or activator thereof can be effectively used as a composition for preventing or treating cancer diseases.