Harvard Medical School, Department of Pathology, Boston, Massachusetts, USA.
Nat Immunol. 2011 Jun;12(6):500-8. doi: 10.1038/ni.2032.
Natural killer (NK) cells are bone marrow–derived granular lymphocytes that have a key role in immune defense against viral and bacterial infections and malignancies. NK cells are traditionally defined as cells of the innate immune response because they lack RAG recombinase–dependent clonal antigen receptors. However, evidence suggests that specific subsets of mouse NK cells can nevertheless develop long-lived and highly specific memory to a variety of antigens. Here we review published evidence of NK cell–mediated, RAG-independent adaptive immunity. We also compare and contrast candidate mechanisms for mammalian NK cell memory and antigen recognition with other examples of RAG-independent pathways that generate antigen receptor diversity in non-mammalian species and discuss NK cell memory in the context of lymphocyte evolution.
自然杀伤 (NK) 细胞是骨髓衍生的颗粒淋巴细胞，在免疫防御病毒和细菌感染以及恶性肿瘤方面发挥着关键作用。NK 细胞传统上被定义为先天免疫反应的细胞，因为它们缺乏 RAG 重组酶依赖性克隆抗原受体。然而，有证据表明，特定的小鼠 NK 细胞亚群仍然可以对各种抗原产生长期的、高度特异性的记忆。在这里，我们回顾了已发表的关于 NK 细胞介导的、不依赖 RAG 的适应性免疫的证据。我们还比较和对比了哺乳动物 NK 细胞记忆和抗原识别的候选机制与其他非哺乳动物物种中产生抗原受体多样性的不依赖 RAG 途径的例子，并讨论了 NK 细胞记忆在淋巴细胞进化中的背景。
