FIGURE 9.

DM susceptibility of DR1 complexes with selected DC-eluted and lymph peptides. DM susceptibility was measured using a kinetic inhibition assay (113) and reported as ΔIC₅₀, i.e. IC₅₀ in the presence of DM minus IC₅₀ in the absence of DM, measured after a 24-h incubation. DR1 binding inhibition was measured at 24 h in the presence (+) and absence (−) of DM for: a, C3 peptides, b, MHC IIa peptides, and c, classic DM-resistant (HA) and DM-sensitive (CLIP) peptides. Peptide sequences with core epitopes underlined are shown above the plots, with values for equilibrium binding affinity (IC₅₀ at 72 h) and DM susceptibility (ΔIC₅₀ at 24 h). d, summary of binding affinity (IC₅₀) and DM susceptibility (ΔIC₅₀) values for 13 peptides eluted from DCs, for nine peptides identified in lymph, and for replicate measurements of HA and CLIP. Statistical analysis was done using the Mann-Whitney test.