(A) BDC cells were cultured in the absence or presence of stimulatory peptide with or without CTL4Ig and anti-CD154. At 1, 2, and 3 days a sample of supernatant was removed and quantitated for IL-2. Shown are the mean IL2 Levels and standard deviation from 3 independent experiments. ANOVA then post hoc Student’s t-Test (p values displayed) was conducted to compare IL2 levels on day 1 vs. 2 and day 2 vs. 3 on the peptide only cultures. (B) Exogenous IL-2 was added to BDC cells cultured in the presence of stimulatory peptide and CTLA4Ig and anti-CD154, then 2.5 x 106 cells were intravenously transferred to nod.scid mice that were serially assessed for diabetes. For comparison shown are also the results of recipients of cells stimulated in the presence of combined costimulation blockade. Fishers Exact test was used to compare diabetes incidence at 7 weeks.
