Fig. 4.

Preproinsulin epitopes inducing CD8 T cell reactivity. Positions of epitopes within preproinsulin targeted by 25 TCR clonotypes are indicated with donor ID (A) and HLA restriction (B). Amino acid sequences in the signal peptide, B-chain, C-peptide, and A-chain regions are shown in red, blue, green, and yellow, respectively. (C) Intensity of responses by individual TCRs was evaluated by EC₅₀ values. EC₅₀ values of TCR transductants responding to peptides within insulin-DRiP, signal peptide, B-chain, C-peptide, and A-chain regions are shown in black, red, blue, green, and yellow. TCR clonotypes reactive to peptides in the first half (positions 1 to 13) and the latter half (positions 15 to 26) of signal peptide region are indicated by circles and inverse triangles, respectively. The TCR clonotype derived from a nondiabetic control donor (ND-2) is shown in blue open circle.