Project description:Allergic diseases are common and affect a large proportion of the population. IL-13-expressing follicular T (Tfh13) cells are a newly identified population of Tfh cells that have been associated with high affinity IgE responses. However, the origins, developmental signals, transcriptional programming and precise functions of Tfh13 cells are unknown. Here, we examined the developmental signals for Tfh13 cells and found a direct and progressive differentiation pathway marked by the production of IL-21. These two pathways differed in kinetics and extrinsic requirements. However, both pathways converged, forming transcriptionally similar Tfh13 cells that express the transcription factor JunB as a critical stabilizing factor. Using an intersectional genetics-based Tfh13-DTR model to perturb these cells, we found that Tfh13 cells were essential to drive broad germinal center responses and allergen-specific IgG and IgE. Moreover, we found that IL-21 is a broad positive regulator of allergen germinal center B cells and synergizes with IL-13 produced by Tfh13 cells to amplify allergic responses. Thus, Tfh13 cells orchestrate multiple features of allergic inflammation.
Project description:This study is designed to determine the direct target genes of JunB transcription factor in human keratinocytes Mice with epidermal deletion of JunB transcription factor displayed a psoriasis-like inflammation. The relevance of these findings to humans and the mechanisms mediating JunB function are not fully understood. Here, we demonstrate that impaired JunB function via gene silencing or overexpression of a dominant negative mutant increased human keratinocyte cell proliferation but decreased cell barrier function. RNA-seq revealed over 500 genes affected by JunB loss-of-function which included an upregulation of an array of proinflammatory molecules relevant to psoriasis. Among these were TNFa, CCL2, CXCL10, IL6R and SQSTM1, an adaptor protein involved in NF-kB activation. ChIP-Seq and gene reporter analyses showed that JunB directly suppressed SQSTM1 through binding to a consensus AP-1 cis-element located around 2 Kb upstream of SQSTM1-trasncription start site. Similar to JunB loss-of-function, SQSTM1-overexpression induced TNFa, CCL2 and CXCL10. Conversely, NF-kB-inhibition genetically with a mutant IkBa or pharmacologically with PDTC prevented cytokine, but not IL6R, induction by JunB-deficiency. Taken together, our findings indicate that JunB controls epidermal growth, barrier formation and proinflammatory responses through direct and indirect mechanisms, pinpointing SQSTM1 as a key mediator of JunB-suppression of NF-kB-dependent inflammation.
Project description:To determne JunB target gene in human keratincoytes Mice with epidermal deletion of JunB transcription factor displayed a psoriasis-like inflammation. The relevance of these findings to humans and the mechanisms mediating JunB function are not fully understood. Here, we demonstrate that impaired JunB function via gene silencing or overexpression of a dominant negative mutant increased human keratinocyte cell proliferation but decreased cell barrier function. RNA-seq revealed over 500 genes affected by JunB loss-of-function which included an upregulation of an array of proinflammatory molecules relevant to psoriasis. Among these were TNFa, CCL2, CXCL10, IL6R and SQSTM1, an adaptor protein involved in NF-kB activation. ChIP-Seq and gene reporter analyses showed that JunB directly suppressed SQSTM1 through binding to a consensus AP-1 cis-element located around 2 Kb upstream of SQSTM1-trasncription start site. Similar to JunB loss-of-function, SQSTM1-overexpression induced TNFa, CCL2 and CXCL10. Conversely, NF-kB-inhibition genetically with a mutant IkBa or pharmacologically with PDTC prevented cytokine, but not IL6R, induction by JunB-deficiency. Taken together, our findings indicate that JunB controls epidermal growth, barrier formation and proinflammatory responses through direct and indirect mechanisms, pinpointing SQSTM1 as a key mediator of JunB-suppression of NF-kB-dependent inflammation.
Project description:The AP-1 transcription factor subunit Junb acts as a context-dependent transcriptional regulator. While positive regulatory functions of Junb are widely studied, the mechanism by which Junb exerts negative regulatory functions remains unclear. miRNAs could translate repressor functions of Junb. Therefore, the aim of this study was to identify Junb-dependent miRNAs in immortalized fibroblasts (MEFs) derived from murine Junb knock-out and wildtype embryos. Cells were published previously in Licht et al. (2010) J Clin Invest. 120(7):2307-18.
Project description:Analysis of gene expression in immortalized human microvascular endothelial cells (TIME cells) following forced expression of the JunB. Results provide insight into a role for the JunB signaling pathway in endothelial cell.
Project description:Purpose: The purpose of this study is to identify the genome-wide binding sites for IRF4 interaction partners PU.1, BATF, and JunB in dendritic cells. These ChIP-seq data were integrated with gene expression analysis in IRF4-sufficient and -deficient BMDCs in order to assemble an IRF4 gene regulatory network. Hematopoietic bone marrow progenitors from C57BL/6 mice were differentiated with GM-CSF and IL-4 for 5 days. On day 6, BMDCs were stimulated for 6 hours with 100ng/ml LPS. Fixed chromatin was immunoprecipitated with anti-PU.1, BATF, and JunB antibodies and subjected to high-throughput sequencing. The sequencing data for the input DNA was previously submitted as GSM999807.
Project description:To understand the mechanisms through which JunB regulates Tregs-mediated immune regulation, we examined the global gene expression profiles in the JunB WT and KO Tregs by performing RNA sequencing (RNA-seq) analysis.