A gluten free diet lowers NKG2D and ligand expression in BALB/c and NOD mice.

The interplay between diet and immune-parameters which could affect type 1 diabetes (T1D) pathogenesis is not sufficiently clarified. Intestinal upregulation of the activating receptor NKG2D(CD314) and its ligands is a hallmark of celiac disease (CD). However, the direct effect of gluten on NKG2D expression is not known. We studied, by FACS (lymphoid tissues) and RT-qPCR (intestine and pancreatic islets), if a gluten-free diet from 4 weeks (GF diet) or a gluten-free diet introduced in breeding pairs (SGF diet), induces changes in NKG2D expression on NK-cells DX5(+) (CD49b) and CD8(+) T-cells, as well as in intestinal and islet levels of NKG2D and ligands in BALB/c and NOD mice. Gluten-free NOD mice had lower insulitis (p<0.0001). Gluten-free NOD mice had reduced expression of NKG2D on DX5(+) NK-cells in spleen and auricular lymph nodes (p<0.05) and on CD8(+) T-cells in pancreas associated lymph nodes (p=0.04). Moreover, the level of CD71 on DX5(+) NK-cells and CD8(+) T-cells (p<0.005) was markedly reduced. GF and SGF mice had reduced expression of NKG2D and DX5 mRNA in intestine (p