Experimental Zooprophylactic Institute of Sicily, Via Marinuzzi 3, 90100 Palermo, Italy.
Biomedical Department of Internal and Specialized Medicine, Rheumatology Section, University of Palermo, Piazza delle Cliniche 2, 90100 Palermo, Italy.
Int J Mol Sci. 2018 Feb 1;19(2):440. doi: 10.3390/ijms19020440.
Natural killer T cells (NKT) are a subset of T lymphocytes bridging innate and adaptive immunity. These cells recognize self and microbial glycolipids bound to non-polymorphic and highly conserved CD1d molecules. Three NKT cell subsets, type I, II, and NKT-like expressing different antigen receptors (TCR) were described and TCR activation promotes intracellular events leading to specific functional activities. NKT can exhibit different functions depending on the secretion of soluble molecules and the interaction with other cell types. NKT cells act as regulatory cells in the defense against infections but, on the other hand, their effector functions can be involved in the pathogenesis of several inflammatory disorders due to their exposure to different microbial or self-antigens, respectively. A deep understanding of the biology and functions of type I, II, and NKT-like cells as well as their interplay with cell types acting in innate (neuthrophils, innate lymphoid cells, machrophages, and dendritic cells) and adaptive immunity (CD4⁺,CD8⁺, and double negative T cells) should be important to design potential immunotherapies for infectious and autoimmune diseases.
自然杀伤 T 细胞（NKT）是连接先天免疫和适应性免疫的 T 淋巴细胞亚群。这些细胞识别与非多态性和高度保守的 CD1d 分子结合的自身和微生物糖脂。描述了三种 NKT 细胞亚群，即表达不同抗原受体（TCR）的 I 型、II 型和 NKT 样细胞，TCR 的激活促进了导致特定功能活性的细胞内事件。NKT 可以根据可溶性分子的分泌和与其他细胞类型的相互作用表现出不同的功能。NKT 细胞在防御感染中作为调节细胞发挥作用，但另一方面，由于它们分别暴露于不同的微生物或自身抗原，其效应功能可能参与几种炎症性疾病的发病机制。深入了解 I 型、II 型和 NKT 样细胞的生物学和功能以及它们与先天免疫（中性粒细胞、固有淋巴细胞、巨噬细胞和树突状细胞）和适应性免疫（CD4⁺、CD8⁺和双阴性 T 细胞）中发挥作用的细胞类型的相互作用对于设计针对感染和自身免疫性疾病的潜在免疫疗法应该是重要的。
