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。对这些微生物的不适当反应，无论是通过遗传 易感性，改变免疫或上皮反应，或尚未确定的环境影响，是 假定导致炎症性肠病（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等）、II型IFN（IFN β）和III型IFN或IFNλ。迄今为止， 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报道，IFNλ在结肠炎小鼠模型中降低氧化应激和肠道损伤， 外源性IFNλ能抑制肠道炎症。重要的是，我们发现了两名不相关的患者， 伴IFNλ2和IFNλ3罕见和功能性有害突变的突发性IBD。值得注意的是，每个病人的 疾病随着年龄的增长而显著改善。我们有初步的数据表明IFNλ2和IFNλ3可能更重要 在出生后的前几个月，IFNλ3-/-小鼠的结肠炎比FNλ1更严重， 野生型小鼠。综上所述，我们假设INFλs是粘膜炎症的重要调节剂， 体内平衡，预防IBD发展，并保持治疗潜力。现有治疗方法 用于IBD的管理不能治疗大量患者。这项工作将提供一个更好的理解 IFNλ在粘膜稳态中的作用，并可能为实施新的策略提供基础， 通过操纵IFNλ信号转导治疗IBD。阐明IFNλ在维持粘膜稳态中的作用， 通过以下目标实现：（1）建立IFNλs的发育表达， 使用批量和单细胞RNA测序技术在不同年龄的人类中检测细胞因子和受体（2） 使用多种小鼠在体内确定IFNλ信号传导在结肠炎发展的易感性中的作用 结肠炎模型;（3）使用IFN-λ基因在体外表征患者编码的IFN-λ变体的功能后果。 T84细胞以及人对照和患者来源的肠类器官。K 08奖项有助于 使瓦希德博士能够获得必要的结构化培训，以精通关键技能： RNAseq分析、结肠炎的鼠模型和免疫分析以及肠免疫的产生/操作。 类器官和上皮分析，辅以教学课程，帮助她走向独立 作为一个成功的物理学家和科学家 该补助金的目的是为一名全职研究助理提供12个月的资金。这 额外的支持对于确保瓦希德博士在工作期间和立即继续工作至关重要 在她即将到来的产假之后。

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 (IFN) 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 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. The K08 award is instrumental in enabling Dr. Ouahed’s acquisition of the 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. The purpose of this supplement is to provide 12 months of funding for a full-time research assistant. This additional support is critical to assure continued productivity of Dr. Ouahed’s work during and immediately following her upcoming maternity leave.