Supplemental Figure 3Expression of MHC molecules in islets at 8 weeks of age. (A) Representative images of the immunohistochemical detection of insulin (brown) in pancreas from 8-week-old NOD and NOD-IGF1 mice (n = 6–7/group). Original magnification ×20 (scale bar: 500 μm), insets ×200 (scale bar: 50 μm). (B) Insulitis score in the same cohorts as in A, showing a low degree of infiltration at this age. (C) Relative expression of the molecules that participate in antigen presentation β₂-microglobulin (β₂-m) and histocompatibility 2, class II antigen A (H2-Aa) in islets isolated from 8-week-old NOD and NOD-IGF1 mice (n = 5–6 animals/group). (D) Relative gene expression of insulin (Ins1) and Cd45 in pancreatic islets isolated from 8-week-old NOD and NOD-IGF1 mice and cultured for 40 h to allow spontaneous extrusion of leucocytes as indicated in Material and Methods. Histograms depict the ratio of qPCR data obtained for each gene in islets over the value obtained in cells pelleted from the culture media, demonstrating efficient depletion of islet leukocytes. (E) Relative expression of β₂-m and H2-Aa in cultured, immune cell-depleted islets from NOD and NOD-IGF1 mice. Results are expressed as mean of 6 NOD and 10 NOD-IGF1 mice ± SEM. *P < 0.05 vs. NOD.