Department of Immunology, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, China.
Clin Rev Allergy Immunol. 2014 Oct;47(2):119-27. doi: 10.1007/s12016-013-8400-0.
Natural killer (NK) cells represent an important subpopulation of lymphocytes that are distributed throughout the body. The development of NK cells primarily occurs in the bone marrow during adult life, involving several putative intermediate stages that finally result in functional maturation. At steady state, NK cell egress from the bone marrow to various peripheral areas is controlled by a network of adhesion molecules, including integrins, selectins, and chemokine receptors and their corresponding ligands. NK cells at different developmental stages express distinct repertoire of adhesion molecules and can therefore be recruited to different sites of the body, including lymphoid and non-lymphoid tissues, and NK cells undergo further differentiation driven by local microenvironmental signals, resulting in unique tissue-specific NK cells. Through their abilities of cytotoxicity and cytokine production, NK cells not only play key roles in the innate immune system, but also participate in shaping adaptive immune responses. On the basis of their heterogeneity in phenotype, function, and tissue distribution, NK cells can be further subdivided into distinct subsets. Under pathological conditions, such as in autoimmune, inflammatory, and infectious diseases, as local microenvironment changes, NK cell subsets would redistribute between tissues and organs and rapidly accumulate at the local pathological sites to exert their effector functions. Here, we describe the development and tissue distribution of NK cell subsets in mice and humans. We focus on the trafficking of NK cell subsets within the bone marrow and emigration into periphery at steady state, and molecular mechanisms involved in their trafficking in autoimmune diseases.
自然杀伤 (NK) 细胞是分布于全身的淋巴细胞的一个重要亚群。NK 细胞在成年期主要在骨髓中发育，涉及几个假定的中间阶段，最终导致功能成熟。在稳态下，NK 细胞从骨髓迁移到各种外周区域是由一系列黏附分子控制的，包括整合素、选择素、趋化因子受体及其相应的配体。处于不同发育阶段的 NK 细胞表达不同的黏附分子谱，因此可以募集到身体的不同部位，包括淋巴组织和非淋巴组织，NK 细胞在局部微环境信号的驱动下进一步分化，产生具有独特组织特异性的 NK 细胞。通过其细胞毒性和细胞因子产生能力，NK 细胞不仅在固有免疫系统中发挥关键作用，而且参与塑造适应性免疫反应。基于其表型、功能和组织分布的异质性，NK 细胞可进一步细分为不同的亚群。在病理条件下，如自身免疫、炎症和感染性疾病中，随着局部微环境的变化，NK 细胞亚群将在组织和器官之间重新分布，并迅速聚集在局部病理部位发挥其效应功能。在这里，我们描述了小鼠和人类 NK 细胞亚群的发育和组织分布。我们重点介绍 NK 细胞亚群在骨髓中的迁移和在稳态下向外周的迁出，以及自身免疫疾病中涉及它们迁移的分子机制。
