Indexed on: 29 May '18Published on: 29 May '18Published in: The American Journal of Pathology
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 qPCR 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 non-diabetic organ donors used as control. The demonstrated absence of MAIT cells in the insulitic lesions in humans questions a direct cytotoxic role of these cells in beta cell destruction. Copyright © 2018. Published by Elsevier Inc.