Regulatory T Cell Control of Intestinal Tumorigenesis

肠道肿瘤发生的调节性 T 细胞控制

• 批准号: 9024465
• 负责人: Alfred LM Bothwell
• 金额: $ 34.55万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-03-01 至 2019-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9024465
• 关键词: Acids; Address; Adenomatous Polyposis Coli; Affect; ApcMin/+ mice; Biopsy; Biopsy Specimen; CD4 Positive T Lymphocytes; Cell Proliferation; Cells; Clinic; Colon; Colorectal Cancer; Development; Disease; Disease model; Down-Regulation; Emulsions; Flow Cytometry; Gene Family; Gene Mutation; Genes; Health; Human; Immune; Immune system; Immunologic Surveillance; In Vitro; Inflammatory; Inflammatory Bowel Diseases; Inflammatory disease of the intestine; Inherited; Interleukin-10; Interleukin-17; Intestinal Neoplasms; Intestinal Polyps; Intestines; Knock-in Mouse; Lead; Malignant Neoplasms; Measures; Mediating; Modeling; Monitor; Mus; Mutation; Pathway interactions; Patients; Polyps; Process; Regulatory T-Lymphocyte; Role; Serum; Signal Pathway; Signal Transduction; Source; Stem cells; Study models; T-Lymphocyte; Techniques; Testing; Therapeutic; Translations; Tumor Expansion; Work; base; cell type; colon cancer patients; cytokine; defined contribution; deoxycholate; in vitro Assay; in vivo; insight; intestinal homeostasis; mutant; nanoparticle; prevent; receptor; research study; response; therapeutic development; tumor; tumor microenvironment; tumorigenesis

DESCRIPTION (provided by applicant): Mutations in the Apc gene occur in many cancers but are especially frequent in colorectal cancer (CRC). The ApcMin/+ mouse is a highly studied model of intestinal tumorigenesis since the Apc gene mutation results in dysregulation of the Wnt signaling pathway. Our recent work using IL-17A deficient (KO) ApcMin/+ mice has identified IL-17A as a proinflammatory cytokine affecting tumorigenesis. Introduction of wildtype (WT) Tregs into ApcMin/+ mice regressed tumors markedly while Tregs from ApcMin/+ mice could not, suggesting an important factor from Tregs for tumor regression lacking in ApcMin/+ Tregs. In ApcMin/+ mice, the expression of Gata-3 was decreased in Tregs as well as effector T cells. Our analysis of Tregs and other immune cell types has identified the Wnt antagonist Dikkopf-1(Dkk1) as the most abundant Wnt family gene produced by Tregs. Importantly, IL-17A effectively inhibited Dkk1 expression in ApcMin/+ Tregs but not in WT Tregs. Dkk1 could induce Gata-3 and also IL-10, which was downregulated in ApcMin/+ mice. Dkk1 also stimulated Treg proliferation but did not impair Treg function. The lack of Treg-derived Dkk1 blocked the ability of Treg to suppress inflammatory bowel disease (IBD) in a standard murine IBD model. Based on these results, first we hypothesize that Treg-derived Dkk1 suppresses intestinal inflammation that is fueled by IL-17A under homeostatic conditions. Second, we argue that the loss of Dkk1 expression in ApcMin/+ Treg leads to the loss of IL-10, and also fails to regulate the Wnt pathway controlling ApcMin/+ intestinal stem cell proliferation. Third, we hypothesize that Treg-derived Dkk1 and IL-17A from Th17 cells are crucial regulators of the tumor microenvironment, directly targeting ISCs carrying the ApcMin/+ mutation. Four aims will focus on testing these three hypotheses. First, Dkk-1 deficient Treg will be used in in vivo tumor regression experiments and in in vitro biologic studies to define the contribution of Dkk1 to Treg function. The mechanism that Dkk1 induces Treg proliferation will be studied in three different signaling pathways. Second, the role of IL-17A to downregulate Dkk1 in ApcMin/+ Tregs will be studied by utilizing IL-17 receptor-deficient Foxp3+ ApcMin/+ Tregs in vivo and in vitro. The mechanism which IL-17A and Dkk1 regulates IL-10 will be studied as well. Third, the effects of IL-17A and Dkk1 on intestinal stem cells (ISC) carrying the mutation in the Apc gene will be characterized. Conditional deletion of the IL-17 receptor in ISCs in the ApcMin/+ background will be studied in vivo. We will deliver Dkk1 into the intestine in ApcMin/+ mice, testing the potential for Dkk1 as a therapeutic. Finally, we will extend our findings to human FAP Treg utilizing a Treg/T cell expansion technique from colon biopsies, and compare them with cells from sporadic colon cancer patients and healthy donors. These studies should give important mechanistic insight into the specific inflammatory molecules that can compromise cells of the immune system. This mechanistic insight should provide a rational approach to translation of these results to the clinic.

描述（由申请人提供）：APC基因中的突变发生在许多癌症中，但在结直肠癌（CRC）中尤为频繁。 APCMIN/+小鼠是肠道肿瘤发生的高度研究模型，因为APC基因突变导致Wnt信号通路的失调。我们最近使用IL-17A缺乏（KO）APCMIN/+小鼠的工作确定IL-17A是影响肿瘤发生的促炎细胞因子。将野生型（WT）Treg引入APCMIN/+小鼠中，显着回归肿瘤，而来自APCMIN/+小鼠的Tregs则不能，这表明Tregs的重要因素是APCMIN/+ Treg缺乏的肿瘤回归。在APCMIN/+小鼠中，Treg和效应T细胞中GATA-3的表达降低。我们对Treg和其他免疫细胞类型的分析已确定Wnt拮抗剂Dikkopf-1（DKK1）是Treg产生的最丰富的Wnt家族基因。重要的是，IL-17A有效地抑制了APCMIN/+ Treg中的DKK1表达，但在WT Treg中不抑制DKK1。 DKK1可以诱导GATA-3和IL-10，它在APCMIN/+小鼠中被下调。 DKK1还刺激了Treg的增殖，但并未损害Treg功能。缺乏Treg衍生的DKK1阻止了Treg在标准鼠IBD模型中抑制炎症性肠病（IBD）的能力。基于这些结果，首先我们假设Treg衍生的DKK1抑制了在稳态条件下IL-17A助长的肠道炎症。其次，我们认为APCMIN/+ Treg中DKK1表达的损失导致IL-10的损失，并且也无法调节控制APCMIN/+肠干细胞增殖的WNT途径。第三，我们假设来自Th17细胞的Treg衍生的DKK1和IL-17A是肿瘤微环境的关键调节剂，直接针对带有APCMIN/+突变的ISC。四个目标将集中于测试这三个假设。首先，DKK-1缺乏Treg将用于体内肿瘤回归实验和体外生物学研究中，以定义DKK1对Treg功能的贡献。 DKK1诱导Treg增殖的机制将在三种不同的信号通路中进行研究。其次，将研究IL-17a在APCMIN/+ Treg中下调DKK1在体内和体外利用IL-17受体缺陷的FOXP3+ APCMIN/+ Tregs的作用。还将研究IL-17A和DKK1调节IL-10的机制。第三，将表征IL-17A和DKK1对携带APC基因突变的肠道干细胞（ISC）的影响。将在体内研究APCMIN/+背景中IL-17受体的条件缺失。我们将将DKK1传递到Apcmin/+小鼠中的肠中，以测试DKK1的潜力 治疗性。最后，我们将利用结肠活检的Treg/T细胞扩张技术将发现扩展到人类FAP Treg，并将它们与零星结肠癌患者和健康供体的细胞进行比较。这些研究应对可能损害免疫系统细胞的特定炎症分子进行重要的机械洞察力。这种机械洞察力应为这些结果翻译给诊所提供合理的方法。