Fig. 4.

Reactivity of CD4⁺ regulatory T cells to peptides derived from IL-2R α chain. The reactivity of CD4⁺ regulatory T cells to three selected peptides derived from IL-2 receptor α chain was measured by ELISPOT. An irrelevant T cell antigen receptor peptide was used as a control. CD4⁺ regulatory T cell lines were cultured at 200,000 cells per well in triplicate in the presence of irradiated antigen-presenting cells and the indicated synthetic peptides at a concentration of 20 μg/ml in precoated ELISPOT plates. The results were presented as IL-10 secreting T cells per 200,000 CD4⁺ regulatory T cells. Among the T cell lines examined, E11, G4, F4, D4, F9, F5, F8, G5, G6, and B6 are considered as CD4⁺CD25⁺Foxp3⁻ T cell lines.