Figure 6.

Anti-CD3 treatment of diabetic NOD (n = 11) and NOD^Irs2 mice (n = 11). Recent-onset diabetic mice (glucose >200 mg/dl) were injected daily with anti-CD3 antibody (10 μg/d) for 5 d. Remission of diabetes was defined as an average blood glucose concentration less than 200 mg/dl for 16 d after the last anti-CD3 antibody injection. A, The predicted fraction of NOD and NOD^Irs2 mice without diabetes was determined by binary logistic regression using the initial diagnostic glucose quartile and the presence or absence of transgenic Irs2 as covariates. The likelihood ratio test confirmed that the diagnostic glucose quartile and transgenic Irs2 expression were significant determinants for the recurrence of diabetes 16 d after the last injection of anti-CD3 antibody (glucose quartile, P < 0.0003; Irs2, P = 0.014). The estimated marginal means ± se were determined using SPSS (version 16.0). B, Representative images of pancreas sections from NOD^Irs2 and NOD mice that remained nondiabetic 16 d after the last anti-CD3 injection. The pancreas sections (5 μm) were formaldehyde fixed, paraffin embedded, and immunostained for insulin (green) and BrdU incorporation (red); nuclei were labeled with DAPI (blue). A higher-magnification image demonstrating BrdU staining in the nuclei of insulin-positive β-cells is shown for NOD^Irs2. C, Pancreas sections from NOD and NOD^Irs2 mice after anti-CD3 treatment were scored for the presence of replicating β-cells (double labeled insulin positive/BrdU positive cells). Results are expressed as the percentage of the total islets containing replicating β-cells. *, P < 0.01. D, Average percentage islet area in NOD^Irs2 and NOD mice. Type 1 diabetes-onset (T1D onset) mice are mice with recent onset of hyperglycemia. Posttreatment mice are animals with glucose less than 250 mg/dl 16 d after the last injection of anti-CD3 antibody. *, P < 0.01. E, The number of islets per square millimeter of pancreas area. F, Mean islet size. G, Islets from the same sections were also scored for the relative degree of leukocyte infiltration: 0, no insulitis; 1, periinsulitis (Peri), in which leukocytes remained largely in the periphery of the islet; 2, invasive insulitis, corresponding to 25–50% coverage of the islet; and 3, severe insulitis, in which greater than 50% of the islet was covered with infiltrate. Results are expressed as the percentage of the total islets in each group.