Ndfip2 limits Th17 pathogenicity to attenuate colitis-associated colon cancer

描述（由申请人提供）：在结肠炎中，TH 17细胞介导的炎症可破坏粘膜屏障表面并引起慢性炎症，从而产生肿瘤容许微环境。因此，结肠炎患者患结直肠癌的风险增加。因此，TH 17型免疫应答的负调节是预防和减轻结肠炎相关结肠直肠癌（CAC）的重要组成部分。Nedd 4家族E3泛素连接酶是已知的T细胞活化和细胞因子产生的调节剂。 这些连接酶可以通过与衔接蛋白如Nedd 4家族相互作用蛋白2（Ndfip 2）相互作用而被激活。 体外研究表明，Ndfip 2可以结合并激活几种Nedd 4家族E3连接酶的催化功能。虽然已经表明Ndfip 2表达在T细胞活化时增加，但Ndfip 2的生理作用尚未被证实。 被描述。 新产生的Ndfip 2-/-小鼠没有表现出明显的免疫病理学，但显示淋巴细胞在小肠和结肠中的积累。 在自身免疫性结肠炎的T细胞转移模型中，Ndfip 2-/-CD 4 + T细胞的转移在Rag 1-/-受体中引起比WT对照细胞更严重的结肠病理学。 有助于解释这种增加的病理学，与WT CD 4 + T细胞相比，更多的Ndfip 2-/-CD 4 + T细胞产生IL-17。 这些数据表明，Ndfip 2通过与Nedd 4家族E3连接酶的相互作用，是一种具有生物学活性的蛋白。 粘膜免疫应答和TH 17细胞致病性的负调节因子。 该提案将测试Ndfip 2激活特异性Nedd 4家族E3连接酶以限制致病性TH 17细胞的效应子功能和持久性，从而促进粘膜屏障完整性和减弱CAC进展的假设。 Ndfip 2可以通过限制细胞因子的产生或激活的T细胞的扩增/持续来调节粘膜TH 17细胞的致病性。在目的1中，使用体外培养物和通过体内诱导TH 17介导的炎症来检查Ndfip 2在调节TH 17细胞中的作用。该目的将确定Ndfip 2对细胞因子类型和数量的影响，并检查细胞活力和分裂以确定Ndfip 2是否影响活化的TH 17细胞的持久性和/或功能。将用两种相关Nedd 4家族E3连接酶缺陷的CD 4 + T细胞重复这些实验，以确定这些连接酶是否影响TH 17细胞的致病潜力。目的2将使用CAC的小鼠模型确定Ndfip 2在TH 17介导的粘膜炎症中的生理相关性。将通过定量疾病进展期间相对于WT动物的炎症和肿瘤负荷的程度来确定Ndfip 2缺陷对粘膜炎症的影响;将分析T细胞和先天性细胞对疾病的贡献。 总之，这些目标将描述一种新的泛素介导的途径，限制胃肠道炎症和结肠癌，并可能揭示以前未被认识到的致病途径，在炎症性癌症，可能是治疗的目标。此外，本文中详细介绍的研究 该提案将为未来的工作奠定基础，旨在确定底物泛素化的Ndfip 2依赖的方式。

DESCRIPTION (provided by applicant): In colitis, TH17 cell-mediated inflammation can damage mucosal barrier surfaces and cause chronic inflammation, creating a tumor-permissive microenvironment. Individuals with colitis are therefore at increased risk for developing colorectal cancers. Accordingly, negative regulation of TH17-type immune responses is an important component in prevention and attenuation of colitis-associated colorectal cancer (CAC). Nedd4-family E3 ubiquitin ligases are known regulators of T cell activation and cytokine production. These ligases can be activated by interaction with adaptor proteins like Nedd4-family interacting protein 2 (Ndfip2). In vitro data indicate that Ndfip2 can bindto and activate the catalytic function of several Nedd4-family E3 ligases. While it has been shown that Ndfip2 expression is increased upon T cell activation, a physiological role for Ndfip2 has not been described. Newly generated Ndfip2-/- mice do not exhibit overt immunopathology, but show an accumulation of lymphocytes in the small bowel and colon. In a T cell transfer model of autoimmune colitis, transfer of Ndfip2-/- CD4+ T cells caused more severe colon pathology in Rag1-/- recipients than WT control cells. Helping to explain this increase pathology, more Ndfip2-/- CD4+ T cells produced IL-17 compared to WT CD4+ T cells. These data suggest that Ndfip2, through interaction with Nedd4-family E3 ligases, is a negative regulator of mucosal immune responses and TH17 cell pathogenicity. This proposal will test the hypothesis that Ndfip2 activates specific Nedd4-family E3 ligases to limit the effector function and persistence of pathogenic TH17 cells, thereby promoting mucosal barrier integrity and attenuating CAC progression. Ndfip2 could regulate the pathogenicity of mucosal TH17 cells through limiting cytokine production or the expansion/persistence of activated T cells. In aim 1, the role of Ndfip2 in regulation of TH17 cell is examined using in vitro cultures and by in vivo induction of TH17-mediated inflammation. This aim will determine effects of Ndfip2 on cytokine type and quantity, and examine cell viability and division to determine if Ndfip2 affects the persistence and/or function of activated TH17 cells. These experiments will be repeated with CD4+ T cells deficient in two relevant Nedd4-family E3 ligases to determine if these ligases affect the pathogenic potential of TH17 cells. Aim 2 will determine the physiological relevance of Ndfip2 in TH17-mediated mucosal inflammation using a mouse model of CAC. The impact of Ndfip2 deficiency on mucosal inflammation will be determined by quantifying the magnitude of inflammation and tumor burden during progression of disease relative to WT animals; the contribution of T cels and innate cells to disease will be analyzed. Together, these aims will characterize a novel ubiquitin-mediated pathway that limits gastrointestinal inflammation and colon cancer, and is likely to reveal previously unappreciated pathogenic pathways in inflammatory cancers that might be targeted therapeutically. Additionally, studies detailed in this proposal will lay the foundation for future work aimed at identifying substrates ubiquitylated in a Ndfip2-dependent manner.