A distal cis-regulatory element, CNS-9, controls NFAT1 and IRF4-mediated IL-10 gene activation in T helper cells

• Published in: Molecular immunology 2009-02, Vol.46 (4), p.613-621
• Main Authors: Lee, Choong-Gu, Kang, Kyu-Ho, So, Jae-Seon, Kwon, Ho-Keun, Son, Jun-Seock, Song, Min-Kyung, Sahoo, Anupama, Yi, Hwa-Joong, Hwang, Ki-Chul, Matsuyama, Toshifumi, Yui, Katsuyuki, Im, Sin-Hyeog
• Format: Article
• Language: English
• Subjects: Animals; Cell Line, Tumor; Cyclosporine - pharmacology; Cytokines; Enhancer Elements, Genetic - genetics; Gene regulation; Humans; Interferon Regulatory Factors - genetics; Interferon Regulatory Factors - metabolism; Interleukin-10 - genetics; Interleukin-10 - metabolism; Mice; Mice, Inbred C57BL; Mice, Knockout; Molecular immunology; NFATC Transcription Factors - genetics; NFATC Transcription Factors - metabolism; Signal Transduction - genetics; Th1 Cells - metabolism; Th1/Th2 Cells; Th2 Cells - drug effects; Th2 Cells - immunology; Th2 Cells - metabolism; Transcription factors; Transcriptional Activation
• ISSN: 0161-5890; 1872-9142
• DOI: 10.1016/j.molimm.2008.07.037

IL-10 is a multifunctional cytokine that plays a critical role in maintaining the balance between immunity and tolerance. Previously, we identified proximal regulatory elements and alterations of chromatin structure in the IL-10 gene loci of Th1 and Th2 cells. We have now characterized a crucial cis-regulatory element, CNS-9, located 9kb upstream of the transcription start site in IL-10 gene loci. The CNS-9 region is highly conserved in vertebrate genomes, and contains clustered NFAT and IRF binding motifs. In vitro binding of NFAT1 and IRF4 to the CNS-9 region was observed by EMSA. Furthermore, Th2-preferential in vivo binding of NFAT1 and IRF4 to the CNS-9 region was observed by ChIP. Cyclosporine A treatment on wild type Th2 cells or Th2 cells derived from NFAT1 knockout (NFAT1−/−) mice showed significantly reduced trans-activity of CNS-9. The Th2 subset-specific enhancer activity of CNS-9 was upregulated synergistically by NFAT1 and its partner IRF4. Mutations in the binding sites for NFAT1 and IRF4 abrogated its enhancer activity of CNS-9. Collectively, our results establish crucial roles for enhancer element CNS-9, and NFAT1 and IRF4 that bind to it, for IL-10 expression in differential T helper subsets.