title: Regulation of IL-10 gene expression in Th2 cells by Jun proteins.
abstract: IL-10 is a key regulatory cytokine produced by T lymphocytes. Although Th2 cells are a major source of IL-10, little is known about IL-10 gene regulation in Th2 cells. High levels of IL-10 mRNA transcription are induced in the Th2 clone D10 after PMA plus ionomycin (P/I) stimulation; however we found that the IL-10 promoter was not inducible by P/I in D10 cells. We therefore sought regulatory regions in the IL-10 gene that could promote P/I-activated transcription in Th2 cells. Two strong DNase I-hypersensitive sites (DHSSs) were identified in the IL-10 gene in mouse T cells, and conserved noncoding sequences (CNSs) between the mouse and human IL-10 genes were also identified. One IL-10 DHSS maps within or next to a highly conserved CNS region, CNS-3. The CNS-3 region contains an AP-1 site that binds JunB and c-Jun proteins specifically in Th2 cells and not in Th1 cells. The CNS-3 element activates transcription from the IL-10 promoter after P/I stimulation and is responsive to c-Jun and JunB. Retroviral mediated-expression of either c-Jun or JunB in primary T cells led to a large increase in IL-10 expression, and inhibition of AP-1 activity by a dominant negative form of c-Jun in primary T cells strongly repressed IL-10 expression. IFN-gamma was relatively unaffected by modulations in AP-1 activity. These data indicate that we have identified a novel regulatory element that can specifically activate transcription of the IL-10 gene in Th2 cells via the AP-1/Jun pathway.
authors.affiliation: Department of Microbiology and Immunology and Walther Oncology Center, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
authors.forename: Zheng-Yu
authors.initials: ZY
authors.lastname: Wang
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sato
authors.forename: Saritha
authors.initials: S
authors.lastname: Kusam
authors.forename: Sarita
authors.initials: S
authors.lastname: Sehra
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Toney
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Dent
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D002843:Chromatin / Q000235:genetics / Q000378:metabolism; D002999:Clone Cells; D017124:Conserved Sequence; D003850:Deoxyribonuclease I / Q000235:genetics; D005786:Gene Expression Regulation / Q000276:immunology*; D006801:Humans; D016753:Interleukin-10 / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D041681:NIH 3T3 Cells; D011485:Protein Binding; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism / Q000502:physiology*; D012045:Regulatory Sequences, Nucleic Acid; D018418:Th2 Cells / Q000276:immunology* / Q000378:metabolism*; D018808:Transcription Factor AP-1 / Q000378:metabolism / Q000502:physiology
chemical_list: D002843:Chromatin; D016755:Proto-Oncogene Proteins c-jun; D018808:Transcription Factor AP-1; D016753:Interleukin-10; D003850:Deoxyribonuclease I