JunB promotes Th17 cell identity and restrains alternative CD4+ T-cell programs during inflammation

Abstract

T helper 17 (Th17) cell plasticity contributes to both immunity and autoimmunity; however, the factors that control lineage flexibility are mostly unknown. Here we show the activator protein-1 (AP-1) factor JunB is an essential regulator of Th17 cell identity. JunB activates expression of Th17 lineage-specifying genes and coordinately represses genes controlling Th1 and regulatory T-cell fate. JunB supports Th17 cell identity by regulating key AP-1 complex constituents. In particular, JunB limits the expression of the subset repressor IRF8, and impedes access of JunD to regulatory regions of alternative effector loci. Although dispensable for homeostatic Th17 cell development, JunB is required for induction and maintenance of Th17 effector responses in the inflammatory contexts of both acute infection and chronic autoimmunity in mice. Through regulatory network analysis, we show that JunB is a core regulator of global transcriptional programs that promote Th17 cell identity and restrict alternative CD4+ T-cell potential.

IL-23 and IL-1β Drive Human Th17 Cell Differentiation and Metabolic Reprogramming in Absence of CD28 Costimulation

“…This led us to query other known Th17 inhibitors induced under CD28 costimulation conditions, and indeed, Gfi1, oncostatin M, and SOCS3 were increased along with Foxp3, CTLA4, and LAG3 (Chang et al, 2009; Kurebayashi et al, 2012; Qin et al, 2009; Son et al, 2017; Zhu et al, 2009; Figures 2A and 2E–2H). Differential expression of AP-1 transcription family members has been found to modulate Th17 development (Bauquet et al, 2009; Carr et al, 2017; Ciofani et al, 2012; Schraml et al, 2009), and accordingly, JUN, JUND, FOS, and FOSL2 were increased following CD28 costimulation, whereas Th17 CD28null cells expressed relatively higher levels of Th17-promoting BATF and MAF (Figures 2A, 2I, and 2J), indicating that CD28 signaling altered the balance of expression of AP-1 family members to disfavor Th17 development. Taken together, these data support our conclusion that IL-23 and IL-1β drive the Th17 transcriptional program in human naive T cells and that this program is largely suppressed by CD28 signaling.…”

Cutting Edge: c-Maf Is Required for Regulatory T Cells To Adopt RORγt+ and Follicular Phenotypes

“…Cell isolation from the spleen, mesenteric lymph node (mLN), small intestine lamina propria (siLP), and colonic lamina propria (coLP) was performed as previously described (21), with the modification that HBSS used for washing and digestion was supplemented with 10% FBS and 10 mM HEPES. Peyer’s patches (PP) were minced and digested in HBSS (supplemented as above) containing collagenase D (1 mg/mL; Roche) and DNase-I (0.1 mg/mL; Sigma) for 30 minutes at 37°C with rotation.…”

“…T cell restimulation and staining were as described in (21). Abs for staining were purchased from eBioscience (TCRβ, CD4, FoxP3, CD44, CD62L, c-Maf, Helios, RORγt, CD69, ICOS, CTLA-4, IL-10, IL-17A, IFNγ, Streptavidin); BD (CXCR5, TCRβ); Biolegend (PD-1); or R&D Systems (CCR2).…”

“…Naïve CD4 + T cells were obtained from Maf Rorc mice as described (21). These were cultured in the presence of T cell-depleted, mitomycin C-treated CD45.1 + splenocytes (1:5 ratio) in RPMI media (Gibco) with 1 μg/mL anti-CD3ε, neutralizing IFNγ and IL-4 Abs, 5 ng/mL TGFβ1, and 100U/mL IL-2 with indicated amounts of IL-6 (all eBioscience) with or without all- trans retinoic acid (Sigma) for 72 h.…”

“…Libraries were prepared from purified RNA using the Clontech Ultra-Low Input RNA-seq kit, and were sequenced on an Illumina HiSeq 4000 by the Duke GCB Sequencing Facility. Read alignment, counting, and DE analysis were as described (21), except that HTseq-count was used in “stranded” mode. Genes were considered DE if having an FDR-adjusted p-value < 0.05.…”