Fig. 2.

C-peptide specific TCR responses to deamidated C-peptide variants (A) Each peptide is referred to by the position, within C-peptide of the glutamine (Q), in bold, to glutamic acid (E), in red text, substitutions. The native sequence is referred to as wildtype (WT) C-peptide. The five variants are named according to the position within C-peptide of the substitution (i.e Q6E, Q9E etc), except for the peptide with all Qs substituted for E (QallE). (B) An example of a titration experiment using a Jurkat line (ACD4_38) expressing a C-peptide specific TCR. Each point represents the mean of triplicate measures and vertical bars, the standard deviation. (C) The EC₅₀ for each peptide was calculated the and the EC₅₀ from two independent experiments are shown. The bars represent the mean of the two experiments. (D) The fold change in EC₅₀, relative to WT C-peptide for this TCR. The dotted line indicates a fold change of 1 relative to WT C-peptide. (E) A summary of the fold change, relative to WT C-peptide for all 18 clones tested. (F). Fold change for clones where the Q to E substitution falls within (F), or outside (G) the mapped epitope. (H) A comparison of the responses to a peptide when the modification falls within (overlapping) or outside (non-overlapping) the mapped epitope. Statistical significance was determined using the Mann-Whitney test (ns, not significant, 8, p < 0.05, **p < 0.01, ***p < 0.001).