Mice observed in a moribund state were euthanized. Data presented are the mean clinical scores of five mice per group. Polyclonal Treg cells were isolated on the basis of CD25 expression using the Treg cell isolation kit (catalog number 130-091-041) from Miltenyi Biotec according to the manufacturer’s protocol. The purified Treg cells were activated for 3 days on plate-bound anti-CD3 (Becton Dickinson) in 24-well plates (Falcon) at JNK inhibitor manufacturer 2 μg/well in complete medium with IL-2 100 IU/mL. Foxp3 purity was consistently 85–95%. CD4+ cells were isolated using the CD4+ T-cell isolation kit (catalog number 130-090-860) from Miltenyi according to the manufacturer’s instructions.

CD4+CD25− were purified on the AutoMacs. iTreg cells were induced from CD4+CD25− precursors by a 3-day incubation on plate-bound anti-CD3 (2 μg/well) and

anti-CD28 (1 μg/well) in 24-well plates in complete medium containing TGF-β (5 ng/mL) and IL-2 (100 IU/mL). Where indicated, cells were labeled with CFSE by incubation in 1 μM CFSE in PBS for 8 min followed by a wash in complete MK-1775 in vivo medium, followed by an additional wash in PBS. DCs were obtained from collagenase (Liberase Blendzyme TH, Roche) digested spleens by incubation with CD11c beads (Miltenyi) followed by purification on the AutoMacs cell separator (Miltenyi) using the POSSELD2 program. For immunization in the flank, mice were injected with peptide (either PCC or MOG) emulsified in CFA. Cells from the draining inguinal LN were used for

analysis. For immunization with peptide-pulsed DCs, mice were injected i.v. with both the DCs and the T cells, and cells from the spleen were used for analysis. Single-cell suspensions, obtained by mechanical disruption of the organ, were incubated with a combination of fluorochrome-labeled antibodies appropriate for the particular experiment, washed and subjected to flow cytometry on the LSRII instrument (BD). Cells from the ear dermis were obtained as previously Liothyronine Sodium described 23. CD4-Pacific Blue (1:250), CD45.1-allophycocyanin (1:250), CD45.2-allophycocyanin-Alexa750 (1:250) and CD44-Alexa700 (1:250), IFN-γ-PECy7 (1:600), IL-17-PerCPCy5.5 (1:350), and FoxP3PE were all obtained from eBioscience. The cells were first stained for surface markers in PBS containing 5% BSA and 2 mM EDTA and washed. If intracellular staining was desired, the cells were then fixed and permeabilized with Fix/Perm buffer followed by staining in Perm buffer (FoxP3 staining buffer kit, eBioscience). Analysis was performed with the FlowJo software (Treestar). These studies were supported by the Division of Intramural Research, National Institute of Allergy and Infectious Diseases. Conflict of interest: The authors declare no financial or commercial conflict of interest. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors.