Response to immunogenic peptides in the presence of Tregitope 167. Responses to antigen restimulation following initial stimulation with a pool of immunogenic peptides derived from C3d protein (■); C3d peptides plus Tregitope 134 (); and C3d peptides plus Tregitope 167 (). Responses are shown as fold increase over background, which was no stimulus (control) in the secondary incubation. The respective baseline (background) values in pg/ml are indicated within the x-axis labels. There was no difference in levels of IL-4, TNFα, or TGFβ1 (data not shown).