Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.
Division of Paediatric and Adolescent Medicine, Oslo University Hospital, Oslo, Norway; Faculty of Odontology, University of Oslo, Oslo, Norway.
Am J Pathol. 2018 Aug;188(8):1744-1748. doi: 10.1016/j.ajpath.2018.04.009. Epub 2018 May 25.
Mucosal-associated invariant T (MAIT) cells are innate T cells that recognize bacteria-infected cells and are thought to play a role in autoimmune diseases. Translocation of duodenal bacteria and viruses to the pancreas through the pancreatic duct has been hypothesized to initiate an innate inflammatory response that could contribute to the development of type 1 diabetes, a process that could involve MAIT cells. In this study, we used immunohistochemistry and quantitative PCR to search for evidence of MAIT cells in the insulitic lesions in the pancreas of human patients recently diagnosed with type 1 diabetes. Only a few scattered MAIT cells were found within the exocrine parenchyma in all pancreatic samples, but no MAIT cells were found in association to the islets. Also, only low gene expression levels of the MAIT T-cell receptor Vα7.2-Jα33 were found in the pancreas of patients with type 1 diabetes, in similar levels as that in nondiabetic organ donors used as control. The absence of MAIT cells shown in insulitic lesions in humans questions the direct cytotoxic role of these cells in β-cell destruction.
黏膜相关不变 T（MAIT）细胞是先天 T 细胞，可识别受细菌感染的细胞，被认为在自身免疫性疾病中发挥作用。十二指肠细菌和病毒通过胰管向胰腺移位，被假设引发固有炎症反应，从而导致 1 型糖尿病的发生，这一过程可能涉及 MAIT 细胞。在这项研究中，我们使用免疫组织化学和定量 PCR 来检测最近被诊断患有 1 型糖尿病的人类患者胰腺胰岛炎病变中 MAIT 细胞的证据。在所有胰腺样本的外分泌实质中仅发现少数散在的 MAIT 细胞，但在胰岛周围未发现 MAIT 细胞。此外，1 型糖尿病患者胰腺中 MAIT T 细胞受体 Vα7.2-Jα33 的基因表达水平也较低，与用作对照的非糖尿病器官捐献者的水平相似。在人类胰岛炎病变中未发现 MAIT 细胞表明这些细胞在 β 细胞破坏中的直接细胞毒性作用值得怀疑。
