Authors: Lars Krogvold Anna Wiberg Bjørn Edwin Trond Buanes Frode Lars Jahnsen Kristian F Hanssen Erik Larsson Olle Korsgren Oskar Skog Knut DahlJørgensen
Publish Date: 2015/11/24
Volume: 59, Issue: 3, Pages: 492-501
Abstract
It is thought that T cells play a major role in the immunemediated destruction of beta cells in type 1 diabetes causing inflammation of the islets of Langerhans insulitis The significance of insulitis at the onset of type 1 diabetes is debated and the role of the T cells poorly understoodIn the Diabetes Virus Detection DiViD study pancreatic tissue from six living patients with recentonset type 1 diabetes was collected The insulitis was characterised quantitatively by counting CD3+ T cells and qualitatively by transcriptome analysis targeting 84 T and B lymphocyte genes of lasercaptured microdissected islets The findings were compared with gene expression in T cells collected from kidney biopsies from allografts with ongoing cellular rejection Cytokine and chemokine release from isolated islets was characterised and compared with that from islets from nondiabetic organ donorsAll six patients fulfilled the criteria for insulitis 5–58 of the insulincontaining islets in the six patients had ≥ 15 T cells/islet Of all the islets 36 contained insulin with several resembling completely normal islets The majority 61–83 of T cells were found as periinsulitis rather than within the islet parenchyma The expression pattern of T cell genes was found to be markedly different in islets compared with the rejected kidneys The isletinfiltrating T cells showed only background levels of cytokine/chemokine release in vitroInsulitis and a significant reserve reservoir for insulin production were present in all six cases of recentonset type 1 diabetes Furthermore the expression patterns and levels of cytokines argue for a different role of the T cells in type 1 diabetes when compared with allograft rejection
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