Great strides have been made in recent years towards understanding the roles of natural killer (NK) cells in immunity to tumours and viruses. NK cells are cytotoxic innate lymphoid cells that produce inflammatory cytokines and chemokines. By lysing transformed or infected cells, they limit tumour growth and viral infections. Whereas T cells recognize peptides presented by MHC molecules, NK cells display receptors that recognize stress-induced autologous proteins on cancer cells. At the same time, their functional activity is inhibited by MHC molecules displayed on such cells. The enormous potential of NK cells for immunotherapy for cancer is illustrated by their broad recognition of stressed cells regardless of neoantigen presentation, and enhanced activity against tumours that have lost expression of MHC class I owing to acquired resistance mechanisms. As a result, many efforts are under way to mobilize endogenous NK cells with therapeutics, or to provide populations of ex vivo-expanded NK cells as a cellular therapy, in some cases by equipping the NK cells with chimeric antigen receptors. Here we consider the key features that underlie why NK cells are emerging as important new additions to the cancer therapeutic arsenal.

近年来，在了解自然杀伤 (NK) 细胞在肿瘤和病毒免疫中的作用方面取得了长足的进步。NK 细胞是产生炎性细胞因子和趋化因子的细胞毒性先天性淋巴样细胞。通过裂解转化或感染的细胞，它们可以限制肿瘤生长和病毒感染。T 细胞识别由 MHC 分子呈递的肽，而 NK 细胞则展示识别癌细胞上应激诱导的自体蛋白的受体。同时，它们的功能活性受到此类细胞上展示的 MHC 分子的抑制。NK 细胞在癌症免疫治疗方面的巨大潜力体现在它们对应激细胞的广泛识别，无论新抗原呈递如何，由于获得性耐药机制，增强了对失去 MHC I 类表达的肿瘤的活性。因此，正在进行许多努力来动员内源性 NK 细胞进行治疗，或提供离体扩增的 NK 细胞群作为细胞疗法，在某些情况下通过为 NK 细胞配备嵌合抗原受体。在这里，我们考虑了一些关键特征，这些特征是 NK 细胞为何成为癌症治疗武器库的重要新成员的基础。