TOX, A Novel Regulator of Thymocyte Selection

TOX，胸腺细胞选择的新型调节剂

• 批准号: 8037783
• 负责人: JONATHAN G KAYE
• 金额: $ 40.84万
• 依托单位: CEDARS-SINAI MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-12-01 至 2015-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8037783
• 关键词: Address; Adult; Affect; Animals; Appearance; Binding; Binding Sites; Breast Cancer Treatment; CD4 Positive T Lymphocytes; CD8B1 gene; Cancer cell line; Cell Lineage; Cells; Complement; Complex; DNA-Binding Proteins; Data; Development; Disease; Disease susceptibility; Ectopic Expression; Epitopes; Event; Family; Future; Gene Expression; Gene Expression Profiling; Gene Expression Regulation; Gene Family; Gene Proteins; Gene Targeting; Genes; Genome; Genomics; HMG-Box; HMGB Proteins; Health; Helper-Inducer T-Lymphocyte; Human; Immune system; Immunoprecipitation; In Vitro; Intraepithelial T-Lymphocyte; Knowledge; Laboratories; Lymphoid Tissue; MHC Class II Genes; Maps; Mass Spectrum Analysis; Molecular; Mus; Natural Killer Cells; Nuclear; Nuclear Proteins; Nucleic Acid Regulatory Sequences; Organ; Organogenesis; Pattern; Play; Population; Predisposition; Process; Property; Protein Binding; Protein Family; Proteins; Regulation; Regulatory Element; Regulatory T-Lymphocyte; Reporter; Reporting; Research; Rodent; Role; Site; Source; Staging; System; T-Cell Development; T-Lymphocyte; Testing; Thymocyte Selection; Thymus Gland; Transgenes; Transgenic Mice; Up-Regulation; Work; arm; cell type; cofactor; in vivo; insight; killer T cell; lymph nodes; malignant breast neoplasm; member; method development; mutant; novel; novel strategies; precursor cell; programs; public health relevance; reconstitution; thymocyte; tool; tumor

DESCRIPTION (provided by applicant): It has become increasingly clear that the workings of the thymus include greater complexity than first appreciated. Not only is this organ a generator of CD4 and CD8 T cells, but it is also a site for development of highly specialized lineages of natural killer T (NKT) cells, intraepithelial T lymphocytes, regulatory T (Treg) cells, and innate-like CD8 T cells. The detailed molecular mechanisms that control the differentiation of these distinct T cell sublineages from common precursors remain to be determined. Here we focus on the role of TOX (thymocyte selection-associated HMG box protein) in this context, a nuclear DNA-binding protein first identified in our laboratory as a regulator of thymic selection events. We produced TOX-deficient mice, demonstrating that TOX is required for development of the canonical CD4 T cell lineage as well as NKT and Treg cell development. Inhibition of the specific stage of T cell development that is affected in these mutant animals has not been reported previously, allowing novel insights into the process. In addition, we have found that TOX plays roles outside the thymus, including an obligatory role in NK cell development and lymph node organogenesis. We propose here three specific aims to delineate the role and mechanism of action of TOX in development of the immune system. First, we will investigate the relationship between TOX and regulation of CD4 and ThPOK expression in the thymus, the latter a dominant CD4 lineage commitment factor. In addition, we propose a novel approach to identify TOX-dependent genes involved in establishment of the CD4 lineage gene program, and will compare the role of TOX in development of different T cell lineages. Second, we will analyze the role of TOX in development of lymph node organogenesis, focusing on the potential for TOX to regulate lymphoid tissue inducer cell development. We also have replicated the inhibition of NK cell development in the absence of TOX in a culture system. We propose detailed analysis of the role for TOX in this context, including whether TOX might function to regulate another nuclear factor that shares some functional properties with TOX. Third, we propose state-of-the-art approaches to identify direct gene targets and protein binding partners of TOX, in an in vivo context of CD4 T cell development. TOX is highly conserved between rodents and humans, as is its expression pattern. Thus, these studies should provide insight into workings of the human immune system as well. TOX defines a small protein subfamily that includes three other members, one of which has been implicated as a breast cancer susceptibility locus, while TOX itself is highly expressed in some cancer cell lines and tumors. Understanding the mechanism of action of TOX is therefore likely to impact both human health and disease. PUBLIC HEALTH RELEVANCE: Development of T lymphocytes in the thymus is a complex process, but one that is key to creating a protective cellular arm of the immune system. This research program is directed at understanding the function of a small family of nuclear proteins, highly conserved in rodents and humans, in regulating this process. This knowledge will aid in future development of methods to reconstitute the immune system where necessary due to disease, and also may have future impact in treatment for breast cancer, since a gene encoding one member of this protein family has been mapped as a disease susceptibility locus.

描述（由申请人提供）：越来越清楚的是，胸腺的起作用比最初欣赏的更复杂。该器官不仅是CD4和CD8 T细胞的生成器，而且还是开发自然杀手T（NKT）细胞，上皮内T淋巴细胞，调节性T（Treg）细胞和先天CD8 T细胞的高度专业谱系的场所。控制这些独特的T细胞分散sublinea的详细分子机制与公共前体的分化尚待确定。在这里，我们关注TOX（胸腺细胞选择相关的HMG盒蛋白）的作用，在这种情况下，在我们的实验室中首先将核DNA结合蛋白视为胸腺选择事件的调节剂。 我们产生了缺陷型毒素的小鼠，表明托克斯是符合规范CD4 T细胞谱系以及NKT和Treg细胞发育所必需的。以前尚未报道对这些突变动物中T细胞发育的特定阶段的抑制作用，从而可以对该过程进行新的见解。此外，我们发现托克斯在胸腺外发挥作用，包括在NK细胞发育和淋巴结器官发生中的强制性作用。我们在这里提出了三个特定旨在描述托克斯在免疫系统发展中的作用和机制的特定旨在。首先，我们将研究托克斯与胸腺中CD4和ThPOK表达的调节之间的关系，后者是主要的CD4谱系承诺因子。此外，我们提出了一种新的方法来鉴定与CD4谱系基因程序建立有关的TOX依赖性基因，并将比较TOX在不同T细胞谱系发展中的作用。其次，我们将分析托克斯在淋巴结器官发生发展中的作用，重点是托克斯调节淋巴组织诱导者细胞发育的潜力。在培养系统中，我们还复制了NK细胞发育的抑制作用。我们提出了在这种情况下对TOX的作用的详细分析，包括托克斯是否可以调节与TOX具有某些功能特性的另一个核因子。第三，我们提出了最先进的方法，以在CD4 T细胞发育的体内环境中识别TOX的直接基因靶标和蛋白质结合伴侣。 托克斯和人类之间的表达模式在啮齿动物和人类之间是高度保守的。因此，这些研究也应深入了解人类免疫系统的工作。 TOX定义了一个小蛋白质的亚科，其中包括其他三个成员，其中一个被视为乳腺癌易感性基因座，而Tox本身在某些癌细胞系和肿瘤中高度表达。因此，了解托克斯的作用机理可能会影响人类健康和疾病。 公共卫生相关性：胸腺中T淋巴细胞的发展是一个复杂的过程，但这是创建免疫系统保护性细胞组的关键。该研究计划旨在理解一小部分核蛋白的功能，该核蛋白在啮齿动物和人类中高度保守，在调节这一过程中。这些知识将有助于未来在由于疾病引起的必要时重建免疫系统的方法，并且可能对乳腺癌的治疗产生影响，因为编码该蛋白质家族的一个成员的基因已被映射为疾病易感性基因座。