Cancer immunotherapy has become a new generation of anti-tumor treatment, but its indications still focus on several types of tumors that are sensitive to the immune system. Therefore, effective strategies that can expand its indications and enhance its efficiency become the key element for the further development of cancer immunotherapy. Natural products are reported to have this effect on cancer immunotherapy, including cancer vaccines, immune-check points inhibitors, and adoptive immune-cells therapy. And the mechanism of that is mainly attributed to the remodeling of the tumor-immunosuppressive microenvironment, which is the key factor that assists tumor to avoid the recognition and attack from immune system and cancer immunotherapy. Therefore, this review summarizes and concludes the natural products that reportedly improve cancer immunotherapy and investigates the mechanism. And we found that saponins, polysaccharides, and flavonoids are mainly three categories of natural products, which reflected significant effects combined with cancer immunotherapy through reversing the tumor-immunosuppressive microenvironment. Besides, this review also collected the studies about nano-technology used to improve the disadvantages of natural products. All of these studies showed the great potential of natural products in cancer immunotherapy.

癌症免疫治疗已成为新一代的抗肿瘤治疗方法，但其适应症仍集中在对免疫系统敏感的几类肿瘤上。因此，扩大其适应症并提高其效率的有效策略成为癌症免疫治疗进一步发展的关键因素。据报道，天然产物对癌症免疫疗法有这种作用，包括癌症疫苗、免疫检查点抑制剂和过继免疫细胞疗法。而其机制主要归因于肿瘤免疫抑制微环境的重塑，这是帮助肿瘤避开免疫系统和癌症免疫治疗的识别和攻击的关键因素。所以，这篇综述总结并总结了据报道改善癌症免疫治疗的天然产物并研究了其机制。并且我们发现皂苷、多糖和黄酮类化合物主要是三大类天然产物，通过逆转肿瘤免疫抑制微环境，与肿瘤免疫治疗相结合，体现出显着的效果。此外，本综述还收集了有关纳米技术用于改善天然产物缺点的研究。所有这些研究都显示了天然产物在癌症免疫治疗中的巨大潜力。这反映了通过逆转肿瘤免疫抑制微环境与癌症免疫治疗相结合的显着效果。此外，本综述还收集了有关纳米技术用于改善天然产物缺点的研究。所有这些研究都显示了天然产物在癌症免疫治疗中的巨大潜力。这反映了通过逆转肿瘤免疫抑制微环境与癌症免疫治疗相结合的显着效果。此外，本综述还收集了有关纳米技术用于改善天然产物缺点的研究。所有这些研究都显示了天然产物在癌症免疫治疗中的巨大潜力。