Major histocompatibility complex (MHC) class-I H-2kd-restricted cognate antigenic peptides islet-specific glucose-6-phosphatase
catalytic subunit-related protein (IGRP206–214) (VYLKTNVFL) and its mimotopes NRP (KYNKANWFL; agonist), NRP-V7 (KYNKANVFL; super agonist) and TUM (KYQAVTTTL; non-agonist) Selleckchem JNK inhibitor were custom synthesized by Genscript (Piscataway, NJ, USA). Expression of cell surface markers was evaluated by flow cytometry using fluorescence activated cell sorter (FACS)Canto flow cytometer (Becton Dickinson Flow Cytometry Systems, San Jose, CA, USA) and the data were analysed using FlowJo software (Tree Star Inc., Ashland, OR, USA). Total lymph node cells (2 × 105 cells) or purified CD8+ T cells (2·5 × 104 cells) were cultured in 96-well culture plates with the indicated peptides using irradiated splenocytes as antigen-presenting cells (APCs)
(1 × 105 cells) or with anti-CD3/CD28-coated beads for 72 h. Cell proliferation was measured by [3H]-thymidine incorporation [34]. To measure antigen-induced proliferation in vivo, 8.3 CD8+ T cells were labelled with Ibrutinib in vivo carboxyfluorescein diacetate succinimidyl ester (CFSE), as described previously [35], and injected intravenously. Bone marrow-derived dendritic cells (BMDCs) cultured with granulocyte–macrophage colony-stimulating factor (GM-CSF) and IL-4 were pulsed with IGRP206–214 or the control peptide TUM for 1 h at 37°C, washed, resuspended in phosphate-buffered saline (PBS) and injected
subcutaneously in hind footpads. Donor cells recovered from the draining inguinal lymph node were evaluated to measure proliferation. CTL activity was measured using RMA-S-Kd target cells loaded with the cognate peptide, as described previously [1, 32]. The amount of IL-2 in the culture supernatants was determined by sandwich ELISA using antibody pairs purchased from BD Pharmingen Biosciences (Palo Alto, CA, USA). Onset of T1D was monitored by measuring urine glucose levels using Keto-Diastix (Bayer, Canada). Idelalisib Animals with two consecutive readings of >3 were considered diabetic. At the time of euthanasia, pancreatic tissues were processed for histopathology analysis. At least three non-overlapping (200 μm apart) 5-μm sections were evaluated for insulitis [32]. Cumulative incidence of T1D was analysed using Prism software (GraphPad Software Inc., La Jolla, CA, USA). For diabetes incidence, significance was calculated using log-rank (Mantel–Cox) test. For all other parameters, statistical significance was calculated by Student’s t-test. The 8.3-NOD mouse expresses a highly pathogenic, MHC class I-restricted, transgenic 8.3 TCR specific to a peptide derived from the IGRP206–214 [33, 36]. In these mice, the 8.3 TCR transgenic CD8+ T cells (8.3 T cells) infiltrate pancreatic islets from 3 weeks of age [33]. Female 8.