7), CD11b (M1/70), CD11c (HL3), CD19 (1D3), CD25 (PC61), CD62L (MEL-14), Ter119 (TER119), and streptavidin (SA)- allophycyanin, SA-allophycyanin Cy7, SA-FITC. Qdot605 anti-CD4 (RM4–5) and SA-Qd605 GDC-0068 cell line were

obtained from Invitrogen. Alexa Fluor 488 anti-LAG-3 (C9B7W) was obtained from AbD Serotec. PE anti-Egr-2 (erongr2) was obtained from e-Bioscience. Streptavidin-conjugated microbeads were purchased from Miltenyi Biotec. Recombinant murine IL-2, IL-10, IL-12, IL-21, and IL-27 were obtained from R&D Systems. Recombinant human TGF-β1 was purchased from R&D Systems. Recombinant murine IL-23 was obtained from Biolegend. Zymosan was obtained from Sigma. Eα52−68 peptide was purchased from Takara (Otsu, Japan). T cells were cultured in RPMI 1640 medium supplemented with 10% FBS, 100 μg/mL L-glutamine, 100 U/mL penicillin, 100 μg/mL streptomycin, and 50 μM 2-mercaptoethanol (all purchased from Sigma). Naïve CD4+ T cells (CD4+CD45RBhiCD62LhiCD25−) from C57BL/6 WT, Egr-2 CKO, or Blimp-1 CKO mice, WSX-1 KO mice, and STAT1 KO, or STAT3 CKO mice were isolated from their splenocytes. Briefly, single find protocol cell suspensions

were first purified by negative selection with MACS (Miltenyi Biotec) using anti-CD8α mAb, anti-CD11b mAb, anti-CD11c mAb, anti-CD19 mAb, anti-CD25mAb, and anti-Ter119 mAb, and were then purified by positive selection with anti-CD62L microbeads. The purity of MACS sorted cells was >90%. Purified cells Oxymatrine were cultured in flat-bottomed 24-well plates coated with anti-CD3ε (2 μg/mL) and anti-CD28 (2 μg/mL). Mouse IL-27 (25 ng/mL) was added at the start of culturing. To assess T-cell proliferation, purified naïve CD4+ T cells were labeled with 1 μM carboxyfluorescein diacetate succinimidyl diester (Invitrogen) by incubation

for 5 min at 37°C in the dark at a density of 2 × 106 cells/mL in RPMI medium. Other cytokines used were as follows: IL-2; 20 ng/mL, IL-6; 10 ng/mL, IL-12; 20 ng/mL, IL-23; 20 ng/mL and IFN-γ; 10 ng/mL. A total of 1 × 106 cells of CD4+ T cells from Eα52−68/I-Ab-specific transgenic mice were purified by positive selection with anti-CD4 microbeads and cultured with 5 × 105 cells of B cells from C57BL/6 WT mice in the presence of Eα52−68 peptide (3 μM) in flat-bottomed 24-well plates. IL-27 (20 ng/mL), TGF-β1 (20 ng/mL), IL-21 (50 ng/mL), IL-10 (50 ng/mL), and zymosan (25 μg/mL) were added, respectively. CD4+ T-cell RNA was prepared using an RNeasy Micro Kit (Qiagen). RNA was reverse-transcribed to cDNA with random primers (Invitrogen) and Superscript III (Invitrogen) in accordance with the manufacturer’s protocol (Invitrogen). The cellular expression level of each gene was determined by quantitative real-time PCR analysis using an iCycler (Bio-Rad).