U.O.C. Immunologia, IRCCS Ospedale Policlinico San Martino, Genoa, Italy.
Department of Experimental Medicine, University of Genoa, Genoa, Italy.
Front Immunol. 2019 Jun 19;10:1415. doi: 10.3389/fimmu.2019.01415. eCollection 2019.
Natural killer (NK) cells were originally defined as effector lymphocytes of innate immunity characterized by the unique ability of killing tumor and virally infected cells without any prior priming and expansion of specific clones. The "missing-self" theory, proposed by Klas Karre, the seminal discovery of the first prototypic HLA class I-specific inhibitory receptors, and, later, of the Natural Cytotoxicity Receptors (NCRs) by Alessandro Moretta, provided the bases to understand the puzzling behavior of NK cells. Actually, those discoveries proved crucial also for many of the achievements that, along the years, have contributed to the modern view of these cells. Indeed, NK cells, besides killing susceptible targets, are now known to functionally interact with different immune cells, sense pathogens using TLR, adapt their responses to the local environment, and, even, mount a sort of immunological memory. In this review, we will specifically focus on the main activating NK receptors and on their crucial role in the ever-increasing number of functions assigned to NK cells and other innate lymphoid cells (ILCs).
自然杀伤 (NK) 细胞最初被定义为先天免疫的效应淋巴细胞，其特征是具有独特的能力，可以在没有任何预先致敏和特定克隆扩增的情况下杀死肿瘤和病毒感染的细胞。由 Klas Karre 提出的“缺失自我”理论，以及后来 Alessandro Moretta 发现的第一个原型 HLA 类 I 特异性抑制性受体，为理解 NK 细胞令人费解的行为提供了依据。实际上，这些发现对于多年来为现代细胞观做出贡献的许多成就也至关重要。事实上，NK 细胞除了杀死易感靶标外，现在已知还可以与不同的免疫细胞进行功能相互作用，使用 TLR 感知病原体，适应其对局部环境的反应，甚至产生某种免疫记忆。在这篇综述中，我们将特别关注主要的激活 NK 受体及其在 NK 细胞和其他固有淋巴细胞 (ILC) 被赋予的越来越多的功能中的关键作用。
