Clin Exp Immunol. 2013 Sep 10. doi: 10.1111/cei.12203. [Epub ahead of print] Elevated CD8 T cell responses in type 1 diabetes patients to a 13 amino acid celiac-active peptide from α-gliadin.
Barbeau WE, Hontecillas R, Horne W, Carbo A, Koch MH, Bassaganya-Riera J.
Department of Human Nutrition, Foods and Exercise, Virginia Tech, Blacksburg, VA, U.S.A. 24061-0430. Abstract
Some type 1 diabetes (T1D) patients have been reported to exhibit T cell reactivity to wheat gluten (WG). We tested the hypothesis that this T cell reactivity could be abolished by using prolyl-endopeptidase (PEP), an enzyme that cleaves peptide bonds after proline. Peripheral blood mononuclear cells (PBMCs) were isolated from T1D patients and healthy controls. PBMCs were stimulated with a peptic-tryptic digest of WG; a peptic-tryptic-PEP digest of WG; and a 13 amino acid peptide from WG. Fluorescent-labeled antibodies to CD3, CD4 and CD8 cell marker proteins were utilized to determine proliferative responses of CD3, CD4 and CD8 T cells. There were no significant differences in proliferative responses of CD3 or CD4 T cells to the WG antigens. A significantly higher proportion of CD8+ T cells from T1D patients proliferated in the presence of the 13 amino acid peptide than when challenged with the peptic-tryptic or the peptic-tryptic-PEP digests of WG. PEP treatment had no significant effect on CD8 T cell reactivity to the peptic-trytic digest of WG. Our results suggest that WG derived peptides, containing ≤ 13 amino acids, may evoke T cell responses in T1D patients.
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T cell responses, peptides, prolyl-endopeptidase, type 1 diabetes, wheat gluten
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