TRANSCRIPTIONAL CONTROL OF INTERFERON-GAMMA IN T AND NK CELLS

描述（由申请人提供）：IFN-？它是一种主要由NK细胞和Th1 CD4和CD8 T细胞产生的细胞因子，在细胞内病原体感染的免疫反应中起核心作用。相反，对细胞外后生动物的保护依赖于Th2 CD4 T细胞及其产生的细胞因子，包括IL-4、IL-13和IL-5。IFN-?的表达Th2细胞因子的表达主要在转录水平上受到调控。而控制IFN-？近年来，人们已经非常详细地阐明了它们的表达方式，但对于它们在哪里以及如何起作用却知之甚少。与IFN-？在哺乳动物中，Th2细胞因子IL-4、IL-13和IL-5聚集在一个约150kb的基因座中，现在人们对它们的调控已经有了相当详细的了解。在这个应用中，我们建议获得关于IFN-？通过全面识别控制IFN-？通过3个目的研究Ifng基因座的表达和功能边界：

DESCRIPTION (provided by applicant): IFN-?, a cytokine produced primarily by NK cells and by Th1 CD4 and CD8 T cells, plays a central role in the immune response to infection with intracellular pathogens. Conversely, protection against extracellular metazoans is dependent on Th2 CD4 T cells and the cytokines they produce, which include IL-4, IL-13 and IL-5. Expression of IFN-? and of Th2 cytokines is primarily regulated at the level of transcription. While transcription factors that govern IFN-? expression have in recent years been elucidated in considerable detail, very little is known regarding where and how they act. By contrast to IFN-?, regulation of the Th2 cytokines IL-4, IL-13 and IL-5, which are clustered into a single ~150 kb locus in mammals, is now understood in considerable molecular detail. In this application, we propose to gain a similar level of knowledge regarding IFN-? by comprehensively identifying the regulatory elements governing IFN-? expression and the functional boundaries of the Ifng locus through 3 Aims: Aim 1: Identify regulatory elements governing the expression of IFN-? through comprehensive chromatin profiling of the murine Ifng locus. Hypothesis: DNase hypersensitive sites and regions enriched in transcriptionally favorable histone modifications extend ~50 kb upstream and downstream of the murine Ifng gene and identify regulatory elements governing IFN-? expression. Aim 2: Define the functional boundaries of the Ifng locus using BAG transgenes to complement the defect in IFN-? knockout (GKO) mice. Hypothesis: BAG transgenes containing the murine Ifng gene and extending >= 50 kb 5' and 3' will reconstitute proper IFN-? expression and thereby complement the immunological defect in GKO mice. Aim 3: Identify the mechanisms bv which the transcriptional regulatory elements within the Ifng locus influence IFN-? expression and the key transcription factors that act at these sites. Hypotheses: T-bet, STAT4, NFAT, NF-?B and AP-1 bind not only to the Ifng promoter but to additional upstream and downstream regulatory elements, thereby affecting IFN-? expression; Ifng5'CNS 2 and 3 and/or Ifng3'CNS3 help to insulate the Ifng locus from the influence of surrounding genes.