{"title":"多梳蛋白在分化的小鼠T辅助细胞(CD4+)中的双重功能。","authors":"Eyal Jacob, Reut Hod-Dvorai, Or Lea Ben-Mordechai, Yulia Boyko, Orly Avni","doi":"10.1186/1750-2187-6-5","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Following antigen recognition, naive T helper (Th; CD4+) cells can differentiate toward one of several effector lineages such as Th1 and Th2; each expressing distinctive transcriptional profiles of cytokine genes. These cytokines eventually instruct the strategy of the immune response. In our search for factors that propagate the transcriptional programs of differentiated Th cells, we previously found that Polycomb group (PcG) proteins, which are known as epigenetic regulators that maintain repressive chromatin states, bind differentially the signature cytokine genes. Unexpectedly, their binding to the Ifng (Interferon-g) in Th1 cells and Il4 (Interleukin-4) in Th2 cells, was correlated with transcriptional activation. Therefore, in this study we aimed to determine the functional role of PcG proteins in the regulation of the expression of the signature cytokine genes.</p><p><strong>Methods: </strong>PcG proteins were knocked down in primary and established murine Th cells using transduction of lentiviruses encoding short hairpin RNAs (shRNAs) directed to Mel-18, Ezh2, Eed and Ring1A, representative of two different PcG complexes. The chromatin structure and the binding activity of PcG proteins and transcription factors at the Ifng promoter were assessed by chromatin immunoprecipitation (ChIP) assays.</p><p><strong>Results: </strong>Downregulation of PcG proteins was consistent with their function as positive regulators of the signature cytokine genes in primary and established Th1 and Th2 cells. Moreover, the PcG protein Mel-18 was necessary to recruit the Th1-lineage specifying transcription factor T-bet, and the T cell receptor (TCR)-inducible transcription factor NFAT1 to the Ifng promoter in Th1 cells. Nevertheless, our results suggest that PcG proteins can function also as conventional transcriptional repressors in Th cells of their known target the Hoxa7 gene.</p><p><strong>Conclusions: </strong>Our data support a model whereby the non-differentially expressed PcG proteins are recruited in a Th-lineage specific manner to their target genes to enforce the maintenance of specific transcriptional programs as transcriptional repressors or activators. Although our results suggest a direct effect of PcG proteins in the regulation of cytokine gene expression, indirect functions cannot be excluded.</p>","PeriodicalId":35051,"journal":{"name":"Journal of Molecular Signaling","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2011-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1750-2187-6-5","citationCount":"38","resultStr":"{\"title\":\"Dual function of polycomb group proteins in differentiated murine T helper (CD4+) cells.\",\"authors\":\"Eyal Jacob, Reut Hod-Dvorai, Or Lea Ben-Mordechai, Yulia Boyko, Orly Avni\",\"doi\":\"10.1186/1750-2187-6-5\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><strong>Background: </strong>Following antigen recognition, naive T helper (Th; CD4+) cells can differentiate toward one of several effector lineages such as Th1 and Th2; each expressing distinctive transcriptional profiles of cytokine genes. These cytokines eventually instruct the strategy of the immune response. In our search for factors that propagate the transcriptional programs of differentiated Th cells, we previously found that Polycomb group (PcG) proteins, which are known as epigenetic regulators that maintain repressive chromatin states, bind differentially the signature cytokine genes. Unexpectedly, their binding to the Ifng (Interferon-g) in Th1 cells and Il4 (Interleukin-4) in Th2 cells, was correlated with transcriptional activation. Therefore, in this study we aimed to determine the functional role of PcG proteins in the regulation of the expression of the signature cytokine genes.</p><p><strong>Methods: </strong>PcG proteins were knocked down in primary and established murine Th cells using transduction of lentiviruses encoding short hairpin RNAs (shRNAs) directed to Mel-18, Ezh2, Eed and Ring1A, representative of two different PcG complexes. The chromatin structure and the binding activity of PcG proteins and transcription factors at the Ifng promoter were assessed by chromatin immunoprecipitation (ChIP) assays.</p><p><strong>Results: </strong>Downregulation of PcG proteins was consistent with their function as positive regulators of the signature cytokine genes in primary and established Th1 and Th2 cells. Moreover, the PcG protein Mel-18 was necessary to recruit the Th1-lineage specifying transcription factor T-bet, and the T cell receptor (TCR)-inducible transcription factor NFAT1 to the Ifng promoter in Th1 cells. Nevertheless, our results suggest that PcG proteins can function also as conventional transcriptional repressors in Th cells of their known target the Hoxa7 gene.</p><p><strong>Conclusions: </strong>Our data support a model whereby the non-differentially expressed PcG proteins are recruited in a Th-lineage specific manner to their target genes to enforce the maintenance of specific transcriptional programs as transcriptional repressors or activators. Although our results suggest a direct effect of PcG proteins in the regulation of cytokine gene expression, indirect functions cannot be excluded.</p>\",\"PeriodicalId\":35051,\"journal\":{\"name\":\"Journal of Molecular Signaling\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2011-05-30\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1186/1750-2187-6-5\",\"citationCount\":\"38\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Molecular Signaling\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1186/1750-2187-6-5\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"Biochemistry, Genetics and Molecular Biology\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Molecular Signaling","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1186/1750-2187-6-5","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"Biochemistry, Genetics and Molecular Biology","Score":null,"Total":0}
引用次数: 38
摘要
背景:抗原识别后,naive T helper (Th;CD4+)细胞可以分化为几种效应谱系中的一种,如Th1和Th2;每个表达不同的细胞因子基因转录谱。这些细胞因子最终指导免疫反应的策略。在我们寻找增殖分化Th细胞转录程序的因子的过程中,我们之前发现Polycomb group (PcG)蛋白,被称为维持抑制染色质状态的表观遗传调节因子,与特征细胞因子基因的结合差异。出乎意料的是,它们与Th1细胞中的Ifng(干扰素-g)和Th2细胞中的Il4(白细胞介素-4)的结合与转录激活有关。因此,在本研究中,我们旨在确定PcG蛋白在调节特征细胞因子基因表达中的功能作用。方法:利用慢病毒编码短发夹rna (short hairpin RNAs, shRNAs),将两种不同PcG复合物的代表Mel-18、Ezh2、Eed和Ring1A进行转导,在原代和已建立的小鼠Th细胞中敲除PcG蛋白。采用染色质免疫沉淀法(ChIP)检测Ifng启动子的染色质结构和PcG蛋白与转录因子的结合活性。结果:PcG蛋白的下调与其在原代和培养的Th1和Th2细胞中作为特征细胞因子基因的正调节因子的功能一致。此外,PcG蛋白Mel-18对于募集Th1谱系指定的转录因子T-bet和T细胞受体(TCR)诱导的转录因子NFAT1到Th1细胞中的Ifng启动子是必需的。然而,我们的研究结果表明,PcG蛋白在其已知靶基因Hoxa7的Th细胞中也可以作为传统的转录抑制因子发挥作用。结论:我们的数据支持一个模型,即非差异表达的PcG蛋白以th谱系特异性的方式被招募到它们的靶基因,以强制维持特定的转录程序,作为转录抑制因子或激活因子。虽然我们的研究结果表明PcG蛋白在调节细胞因子基因表达方面有直接作用,但不能排除其间接作用。
Dual function of polycomb group proteins in differentiated murine T helper (CD4+) cells.
Background: Following antigen recognition, naive T helper (Th; CD4+) cells can differentiate toward one of several effector lineages such as Th1 and Th2; each expressing distinctive transcriptional profiles of cytokine genes. These cytokines eventually instruct the strategy of the immune response. In our search for factors that propagate the transcriptional programs of differentiated Th cells, we previously found that Polycomb group (PcG) proteins, which are known as epigenetic regulators that maintain repressive chromatin states, bind differentially the signature cytokine genes. Unexpectedly, their binding to the Ifng (Interferon-g) in Th1 cells and Il4 (Interleukin-4) in Th2 cells, was correlated with transcriptional activation. Therefore, in this study we aimed to determine the functional role of PcG proteins in the regulation of the expression of the signature cytokine genes.
Methods: PcG proteins were knocked down in primary and established murine Th cells using transduction of lentiviruses encoding short hairpin RNAs (shRNAs) directed to Mel-18, Ezh2, Eed and Ring1A, representative of two different PcG complexes. The chromatin structure and the binding activity of PcG proteins and transcription factors at the Ifng promoter were assessed by chromatin immunoprecipitation (ChIP) assays.
Results: Downregulation of PcG proteins was consistent with their function as positive regulators of the signature cytokine genes in primary and established Th1 and Th2 cells. Moreover, the PcG protein Mel-18 was necessary to recruit the Th1-lineage specifying transcription factor T-bet, and the T cell receptor (TCR)-inducible transcription factor NFAT1 to the Ifng promoter in Th1 cells. Nevertheless, our results suggest that PcG proteins can function also as conventional transcriptional repressors in Th cells of their known target the Hoxa7 gene.
Conclusions: Our data support a model whereby the non-differentially expressed PcG proteins are recruited in a Th-lineage specific manner to their target genes to enforce the maintenance of specific transcriptional programs as transcriptional repressors or activators. Although our results suggest a direct effect of PcG proteins in the regulation of cytokine gene expression, indirect functions cannot be excluded.
期刊介绍:
Journal of Molecular Signaling is an open access, peer-reviewed online journal that encompasses all aspects of molecular signaling. Molecular signaling is an exponentially growing field that encompasses different molecular aspects of cell signaling underlying normal and pathological conditions. Specifically, the research area of the journal is on the normal or aberrant molecular mechanisms involving receptors, G-proteins, kinases, phosphatases, and transcription factors in regulating cell proliferation, differentiation, apoptosis, and oncogenesis in mammalian cells. This area also covers the genetic and epigenetic changes that modulate the signaling properties of cells and the resultant physiological conditions.