Figure 1.

NOD mice immunized with CCGAD65 peptide in SPF animal facilities. (A) Four-week-old female NOD mice received four subcutaneous injections of 50 μg of peptide in alum with a 7-day interval. Mice were randomly divided in five cohorts of five groups each treated with the same immunization protocol. The first group was immunized with the CCGAD65 peptide in alum, the second with the loss-of-function AAGAD65 peptide in alum, the third group with the non-relevant CCHEL peptide in alum, the fourth group received alum alone, and the fifth group remained untreated. Results represent diabetes-free survival rates at, from top to bottom at 40 weeks, 43% for CCGAD65-immunized mice (n = 47), 38% for AAGAD65-immunized mice (n = 50), 35% for CCHEL-immunized mice (n = 23), 21% for alum-treated mice (n = 24), 17% for untreated control group (n = 23), *P < 0.05 and P > 0.1 reported as NS (Mantel–Cox log-rank test). (B,C) Pancreatic sections of mice sacrificed after two consecutive weekly glycemia above 300 mg/dl or after remaining normoglycemic during 40 weeks were stained with H&E and insulitis was scored by examining a minimum of 40 islets per mouse. (B) Individual II are represented for each group with line representing mean index; from left to right, CCGAD65 peptide in alum (n = 46, mean II = 0.51), AAGAD65 peptide in alum (n = 47, mean II = 0.63), CCHEL peptide in alum (n = 21, mean II = 0.63), alum alone (n = 23, mean II = 0.67), and untreated (n = 19, mean II = 0.70). Statistical significance was calculated with Kruskal–Wallis ANOVA test, P < 0.0001 followed by Dunn’s multiple comparison test as noted, *P < 0.05. (C) Grading of insulitis of the various groups as indicated. Statistical significance was calculated based on insulitis-free islets with Kruskal–Wallis ANOVA test, P < 0.0001 and Dunn’s multiple comparison test as indicated, *P < 0.05.