Balato Anna, Unutmaz Derya, Gaspari Anthony A
Department of Dermatology, University of Naples Federico II, Naples, Italy.
J Invest Dermatol. 2009 Jul;129(7):1628-42. doi: 10.1038/jid.2009.30. Epub 2009 Mar 5.
Natural killer T (NKT) cells are a unique subset of lymphocytes that express NK cell markers such as CD161 and CD94, as well as a T-cell receptor (TCR) alpha/beta, with a restricted repertoire, which distinguishes them from NK cells, which lack a TCR. In contrast to conventional T-lymphocytes, the TCR of NKT cells does not interact with that of peptide antigens presented by classical major histocompatibility complex-encoded class I or II molecules. Instead, this TCR recognizes glycolipids presented by CD1d, a non-classical antigen-presenting molecule. The rapid response of NKT cells to their cognate antigens is characteristic of an innate immune response, and allows the polarizing cytokines (IFN-gamma and/or IL-4) to regulate adaptive immunity. NKT cells have been found to be critical in the immune response against viral infections and malaria, as well as in tumor immunity, and certain autoimmune diseases. NKT cells have been assessed to represent the "trait d'union" between innate and adaptive immunity. They play an active role in skin diseases, such as contact sensitivity, which have been implicated in UV-induced immunosuppression and psoriasis. Thus, NKT-cells are emerging as an important subset of lymphocytes, with a protective role in host defense and a pathogenic role in certain immune-mediated disease states.
自然杀伤T（NKT）细胞是淋巴细胞的一个独特亚群，它们表达NK细胞标志物如CD161和CD94，以及具有有限库的T细胞受体（TCR）α/β，这使它们与缺乏TCR的NK细胞区分开来。与传统T淋巴细胞不同，NKT细胞的TCR不与经典主要组织相容性复合体编码的I类或II类分子呈递的肽抗原的TCR相互作用。相反，这种TCR识别由非经典抗原呈递分子CD1d呈递的糖脂。NKT细胞对其同源抗原的快速反应是先天免疫反应的特征，并允许极化细胞因子（IFN-γ和/或IL-4）调节适应性免疫。已发现NKT细胞在针对病毒感染和疟疾的免疫反应以及肿瘤免疫和某些自身免疫性疾病中起关键作用。NKT细胞被评估为代表先天免疫和适应性免疫之间的“联系纽带”。它们在皮肤疾病如接触性敏感中发挥积极作用，接触性敏感与紫外线诱导的免疫抑制和银屑病有关。因此，NKT细胞正成为淋巴细胞的一个重要亚群，在宿主防御中起保护作用，在某些免疫介导的疾病状态中起致病作用。
