Role of Interferon lambda signaling in mucosal homeostasis and infantile-onset inflammatory bowel disease

项目总结/摘要 胃肠道是由单层上皮细胞组成的，与免疫细胞处于平衡状态 和大量的微生物。对这些微生物的不当反应，无论是通过 遗传易感性，改变的免疫或上皮反应，或尚未确定的环境影响， 被认为会导致炎症性肠病（IBD）。免疫信号识别并响应 微生物组的细菌和病毒成分仍然不完全清楚。干扰素（IFN）发挥作用， 在肠上皮的抗病毒免疫防御中起主要作用，并且在调节 免疫和非免疫细胞的增殖、分化、存活和效应子功能。有三 IFN的种类：I型IFN（IFNα、IFN β和其他）、II型IFN（IFNγ）和III型IFN或IFNλ。迄今为止，大多数 研究IFN在IBD中的应用的研究集中在I型IFN上，并且没有发现其有效性。 博士Ivan Zanoni最近报道，IFNλ可降低小鼠的氧化应激和肠道损伤， 结论：外源性IFNλ对结肠炎模型有明显的抑制作用。重要的是，我们发现了两个 具有IFNλ2和IFNλ3中罕见和功能有害突变的无亲缘关系的突发性IBD患者。 值得注意的是，每个患者的疾病随着年龄的增长而显著改善。我们有初步数据表明IFNλ2和 IFNλ3在出生后的头几个月可能比FNλ1更重要，数据表明， 与野生型小鼠相比，Ifnλ3-/-小鼠中的结肠炎。综上所述，我们假设INFλ是 粘膜稳态的基本调节剂，预防IBD的发展，并保持治疗 潜力目前可用于IBD管理的治疗剂未能治疗大量患者。 这项工作将提供一个更好的理解的作用，干扰素λ在粘膜稳态，并可能提供 为实施通过操纵IFNλ信号转导治疗IBD的新策略奠定了基础。揭开的作用 IFNλ维持粘膜内环境稳定的作用将通过以下目标实现：（1）建立 使用散装制剂在不同年龄的人中IFNλs、相关细胞因子和受体的发育表达 和单细胞RNA测序技术（2）确定IFNλ信号转导在易感性中的作用 使用各种结肠炎的鼠模型在体内发展结肠炎;（3）表征功能性结肠炎的发生; 使用T84细胞以及人对照和患者对照的患者编码的IFNλ变体的体外结果 衍生的肠类器官该奖项将使瓦希德博士获得必要的结构化培训， 精通关键技能：RNAseq分析，结肠炎和免疫分析的小鼠模型， 肠类器官和上皮分析的生成/操作，辅以教学 课程，协助她独立的道路，作为一个成功的物理学家，科学家。

PROJECT SUMMARY/ABSTRACT The gastrointestinal tract is composed of a single layer of epithelial cells that is in equipoise with immune cells and a vast number of microorganisms. Inappropriate responses to these microorganisms, either through genetic predisposition, altered immune or epithelial responses, or yet to be defined environmental influences, are postulated to lead to inflammatory bowel diseases (IBD). The immune signals that recognize and respond to bacterial and viral components of the microbiome remain incompletely understood. Interferons (IFNs) play a major role in antiviral immune defense in the intestinal epithelium, and are also important in regulating proliferation, differentiation, survival and effector functions of immune and non-immune cells. There are three classes of IFNs: type I IFNs (IFNα, β, and others), type II IFN (IFNγ) and type III IFNs, or IFNλs. To date, most studies investigating the use of IFNs on IBD have focused on type I IFNs and were not found to be effective. Dr. Ivan Zanoni recently reported that IFNλ decreases oxidative stress and intestinal damage in a murine model of colitis and that exogenous IFNλ can suppress intestinal inflammation. Importantly, we identified two unrelated patients with infantile-onset IBD with rare and functionally deleterious mutations in IFNλ2 and IFNλ3. Of note, each patient's disease improved significantly with age. We have preliminary data that IFNλ2 and IFNλ3 may be more important in the first months of life than FNλ1, and data illustrating more severe murine colitis in Ifnλ3-/- mice as compared to wild type mice. Taken together, we hypothesize that INFλs are essential modulators of mucosal homeostasis, prevent development of IBD, and hold therapeutic potential. Current therapeutics available for the management of IBD fail to treat a large number of patients. This work will provide a better understanding of the role of IFNλ in mucosal homeostasis, and may provide the groundwork to implement novel strategies to treat IBD by manipulating IFNλ signaling. Unraveling the role of IFNλ in maintaining mucosal homeostasis will be achieved through the following aims: (1) Establishing the developmental expression of IFNλs, related cytokines and receptors in humans at different ages using bulk and single cell RNA sequencing technologies (2) Determining the role of IFNλ signaling in predisposition to development of colitis in vivo using various murine models of colitis; (3) Characterizing the functional consequences of patient-encoded IFNλ variants in vitro using T84 cells as well as human control and patient- derived intestinal organoids. This award will enable Dr. Ouahed to acquire necessary structured training to become proficient in critical skills: RNAseq analysis, murine models of colitis and immune analyses, and generation/manipulation of intestinal organoids and epithelial analyses, complimented with didactic coursework, assisting her path to independence as a successful physician-scientist.