FIG. 3.

Primary anti–PI-1(47–64) T-cell lines are reactive with β-cells. A: Three primary anti–PI-1(47–64) T-cell lines were generated by immunization of young NOD mice. One such line, ACP no. 2, recognized the PI-1(47–64) peptide in addition to the PI-1(49–61) segment and full-length C-peptide-1. The ACP no. 2 T-cell line recognized peptides from the PI-2 sequence, although not as well as PI-1. B: The ACP no. 2 T-cell line responded to freshly isolated β-cells from 4- to 6-week-old NOD mice. In both peptide and β-cell assays, irradiated NOD splenocytes were used as APCs and cultures were pulsed with labeled thymidine on day 2 and harvested on day 3. C: ACP no. 1 reacted to dispersed islets from 5-month-old NOD mice in the absence of exogenous APCs.