Gastric cancer immunity and adoptive immunotherapy

Experiments have shown that patients with gastric cancer not only have defective cellular immune function, but also have decreased immune regulation ability, and the body's ability to kill gastric cancer cells is reduced. Therefore, improving the immune status of patients with gastric cancer is very necessary to improve the body's immune function and intrinsic anti-cancer ability.

(1) Non-specific immune enhancers ① Rubra actinomycete wall structure (N-CWS) can stimulate the activity of macrophages, NK cells, killer (TK) cells, etc. It has been reported that N-CWS combined with IL-2 monoclonal antibodies has considerable efficacy in the treatment of gastric cancer and lung cancer; ② PiciKanil (OK-432) is used to treat gastric cancer, which is prevalent in Japan. OK-432 can increase the activity of NK cells, the activity of its own tumor killer cells, granulocytes, etc., and promote the secretion of lymphokines: ③ Sizofilan (SPG) is a macromolecular glucan in the culture medium of basidiomycetes. The effective rate of SPG treatment is significantly higher than that of the control group: ④ Other immune activators, such as highly agglutinating staphylococcus aureus and anti-tumor ribonucleic acid (IRNA) combined with chemotherapy adjuvant treatment, have a certain effect on exacerbated gastric cancer.

(2) Application of lymphokines and lymphokine-activated killer cells ① Interferon (IFN) has definite antiviral and antitumor effects. In addition to enhancing the function of immune active cells, it can also activate proteases, phosphodiesterases, etc., and directly inhibit tumor cells; ② Interleukin-2 (IL-2) can increase the activity of NK cells and TK cells. After human spleen cells or peripheral blood lymphocytes are cultured with IL-2, they can induce killer cells that directly kill their own tumor cells, called LAK cells. Rosenberg compared LAK and IL-2 with IL-2 alone in 119 patients with advanced gastric cancer. The results showed that the former group was better than the latter group, with a total effective rate of 31% (33/106) and the longest complete remission period of 22 months. The total effective rate of the IL-2 alone group was 16% (7/46); ② TNF can promote lymphokine secretion, tissue decomposition and metabolism, and release inflammatory mediators, which can increase the activity of NK cells and cause bleeding and necrosis of tumor lesions. It may be one of the promising therapeutic weapons; ④ Monoclonal antibody-guided treatment of gastric cancer. Monoclonal antibodies combined with radioactive nuclides, plant toxins, and chemical drugs (5-FU, MTX, MMC, ADM) are made into "missiles" and fixed on tumor cells. High concentrations of radioactive nuclides, toxins, and chemical drugs serve as "warheads" to directly kill tumor target cells, which may have development prospects.

(3) Adoptive immunotherapy for gastric cancer Adoptive immunotherapy for tumors is a passive immunotherapy, which is to transfer or return immune effector cells with killing activity, such as LAK, TIL, CDsAK, to tumor patients after monocyte macrophage immune mediation and TNF, IL, Gm-CSG, etc., to improve the body's anti-tumor ability, thereby directly or indirectly leading to tumor regression. Among them, LAK and IL are commonly used methods for adoptive immunotherapy of gastric cancer, and the efficacy is relatively definite. Gu Qinlong used tumor-infiltrating lymphocytes in the tumor area blood supply artery perfusion combined with low-dose IL-2 to treat advanced gastric cancer, with a total effective rate of 66.7%. After treatment, the activity of peripheral blood lymphocyte subsets and NK cells was significantly improved, the tumor was reduced, and clinical symptoms improved. Therefore, the combination of transcatheter gastric artery perfusion of LAK and IL-2 and chemoembolization can play a synergistic role and enhance the efficacy.