Figure 3. Identification of the main M3R peptide responsible for IL-17 secretion.
In this study, 2.5 × 105 to 5 × 105 cells/well of PBMCs from pSS patients positive for peripheral M3R-reactive IL-17 secreting cells were incubated separately with each of a mixture of M3R peptides (12–20 amino acids components each) predicted to bind to each HLA-DRB1. We compared the number of counted spots for each condition. All 5 such patients (pSS1, -3, -5, -8, and -9) reacted to M3R AA83-95. Patient pSS8 also reacted to M3R AA76-87. *P < 0.05, Kruskal-Wallis test. AA, amino acid; mix, mixture of selected top 10 M3R peptides highly ranked as HLA binding epitope for each case; PHA, Phytohemagglutinin stimulation (positive control).