Tai Ningwen, Wong F Susan, Wen Li
Section of Endocrinology, Department of Internal Medicine, Yale School of Medicine, New Haven, USA.
Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff, UK.
J Autoimmun. 2016 Jul;71:26-34. doi: 10.1016/j.jaut.2016.03.006. Epub 2016 Mar 24.
Type 1 diabetes (T1D) is an organ-specific autoimmune disease characterized by T cell-mediated destruction of the insulin-producing pancreatic β cells. A combination of genetic and environmental factors eventually leads to the loss of functional β cell mass and hyperglycemia. Both innate and adaptive immunity are involved in the development of T1D. In this review, we have highlighted the most recent findings on the role of innate immunity, especially the pattern recognition receptors (PRRs), in disease development. In murine models and human studies, different PRRs, such as toll-like receptors (TLRs) and nucleotide-binding domain, leucine-rich repeat-containing (or Nod-like) receptors (NLRs), have different roles in the pathogenesis of T1D. These PRRs play a critical role in defending against infection by sensing specific ligands derived from exogenous microorganisms to induce innate immune responses and shape adaptive immunity. Animal studies have shown that TLR7, TLR9, MyD88 and NLPR3 play a disease-predisposing role in T1D, while controversial results have been found with other PRRs, such as TLR2, TLR3, TLR4, TLR5 and others. Human studies also shown that TLR2, TLR3 and TLR4 are expressed in either islet β cells or infiltrated immune cells, indicating the innate immunity plays a role in β cell autoimmunity. Furthermore, some human genetic studies showed a possible association of TLR3, TLR7, TLR8 or NLRP3 genes, at single nucleotide polymorphism (SNP) level, with human T1D. Increasing evidence suggest that the innate immunity modulates β cell autoimmunity. Thus, targeting pathways of innate immunity may provide novel therapeutic strategies to fight this disease.
1型糖尿病(T1D)是一种器官特异性自身免疫性疾病,其特征在于T细胞介导的胰岛素生成胰腺β细胞的破坏。遗传和环境因素的共同作用最终导致功能性β细胞数量减少和高血糖。先天性免疫和适应性免疫均参与T1D的发病过程。在本综述中,我们重点介绍了先天性免疫,尤其是模式识别受体(PRR)在疾病发展中的最新研究结果。在小鼠模型和人体研究中,不同的PRR,如Toll样受体(TLR)和含核苷酸结合域、富含亮氨酸重复序列的(或Nod样)受体(NLR),在T1D发病机制中具有不同作用。这些PRR通过感知源自外源微生物的特定配体来诱导先天性免疫反应并塑造适应性免疫,从而在抵御感染中发挥关键作用。动物研究表明,TLR7、TLR9、MyD88和NLPR3在T1D中起疾病易感性作用,而对于其他PRR,如TLR2、TLR3、TLR4、TLR5等,研究结果存在争议。人体研究还表明,TLR2、TLR3和TLR4在胰岛β细胞或浸润的免疫细胞中表达,表明先天性免疫在β细胞自身免疫中发挥作用。此外,一些人类遗传学研究表明,在单核苷酸多态性(SNP)水平上,TLR3、TLR7、TLR8或NLRP3基因与人类T1D可能存在关联。越来越多的证据表明,先天性免疫调节β细胞自身免疫。因此,针对先天性免疫途径可能提供对抗这种疾病的新治疗策略。