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: 9206553
• 负责人: Alfred LM Bothwell
• 金额: $ 12.62万
• 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/9206553
• 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基因突变发生在许多癌症中，但在结直肠癌（CRC）中尤为常见。ApcMin/+小鼠是一种高度研究的肠道肿瘤发生模型，因为Apc基因突变导致Wnt信号通路失调。我们最近使用IL-17 A缺陷（KO）ApcMin/+小鼠的工作已经将IL-17 A鉴定为影响肿瘤发生的促炎细胞因子。将野生型（WT）TcR引入ApcMin/+小鼠中显著地使肿瘤消退，而来自ApcMin/+小鼠的TcR不能，这表明TcR是ApcMin/+ TcR中缺乏的肿瘤消退的重要因素。在ApcMin/+小鼠中，加塔-3的表达在T细胞以及效应T细胞中降低。我们的分析TcB和其他免疫细胞类型已经确定Wnt拮抗剂Dikkopf-1（Dkk 1）是TcB产生的最丰富的Wnt家族基因。重要的是，IL-17 A有效地抑制ApcMin/+ TcM中的Dkk 1表达，但在WT TcM中不抑制。Dkk 1可诱导加塔-3和IL-10，其在ApcMin/+小鼠中下调。Dkk 1也刺激Treg增殖，但不损害Treg功能。Treg衍生的Dkk 1的缺乏阻断了Treg在标准鼠IBD模型中抑制炎性肠病（IBD）的能力。基于这些结果，我们首先假设Treg衍生的Dkk 1抑制了在稳态条件下由IL-17 A激发的肠道炎症。其次，我们认为ApcMin/+ Treg中Dkk 1表达的丧失导致IL-10的丧失，并且也未能调节控制ApcMin/+肠干细胞增殖的Wnt通路。第三，我们假设来自Th 17细胞的Treg衍生的Dkk 1和IL-17 A是肿瘤微环境的关键调节剂，直接靶向携带ApcMin/+突变的ISCs。四个目标将集中在测试这三个假设。首先，Dkk-1缺陷型Treg将用于体内肿瘤消退实验和体外生物学研究，以确定Dkk 1对Treg功能的贡献。Dkk 1诱导Treg增殖的机制将在三种不同的信号通路中进行研究。第二，将通过利用IL-17受体缺陷型Foxp 3 + ApcMin/+ Tcl 2在体内和体外研究IL-17 A下调Dkk 1在ApcMin/+ Tcl 2中的作用。IL-17 A和Dkk 1对IL-10的调节机制也将进一步探讨。第三，将表征IL-17 A和Dkk 1对携带Apc基因突变的肠干细胞（ISC）的作用。将在体内研究在ApcMin/+背景下ISC中IL-17受体的条件性缺失。我们将在ApcMin/+小鼠中将Dkk 1递送到肠道中，测试Dkk 1作为一种免疫调节剂的潜力。 有治疗作用的最后，我们将利用来自结肠活检的Treg/T细胞扩增技术将我们的发现扩展到人类FAP Treg，并将其与来自散发性结肠癌患者和健康供体的细胞进行比较。这些研究应该提供重要的机制洞察特定的炎症分子，可以损害免疫系统的细胞。这种机制的见解应该提供一个合理的方法来翻译这些结果的临床。