Paneth cell heterogeneity in infection and inflammation

项目摘要 克罗恩病（CD）是IBD的一种形式，其通常涉及小肠，其中大部分潘氏细胞（Paneth cell）在小肠中表达。 居住。由于大量CD患者对标准治疗无反应或难治， 对基于新作用机制的新治疗选择的未满足需求。最近的研究表明， 有缺陷的潘氏细胞可能在引发回肠炎症中起关键作用，并且可能在回盲部CD中起关键作用。潘氏 CD患者或小鼠IBD模型中的细胞通常表现出颗粒表型， 其中几种富含抗菌因子的潘氏细胞， 颗粒分散到细胞质中。与缺陷性ER应激、自噬和分泌相关的假设 已经发展到解释这些CD潘氏细胞缺陷，然而，因果关系 仍然模糊。迄今为止，现有的研究一直将潘氏细胞作为同质群体处理。基于 在新开发的时间控制的Paneth细胞报告小鼠模型上，我们建立了单细胞 在稳态、生态失调、感染和炎症条件下回肠潘氏细胞的转录组图谱。我们 发现潘氏细胞异质性响应于微生物群改变，感染， 和潜在的遗传风险因素。分析不同条件下的潘氏细胞群， 免疫活化潘氏细胞亚群具有不同的抗微生物肽谱、富集的细胞因子 受体，并提高先天免疫和脱粒活动。潘氏细胞携带的信号 在回肠CD和UC化生性病变中发现标记物。我们将检验一个动态潘氏细胞 由遗传、肠道微生物群和环境因素（如病原体）相互作用调节的异质性 感染对于激活潘氏细胞介导的先天性保护对抗炎症诱导是关键的， 恶化目的1将通过检测这些潘氏细胞的功能和疾病相关性， 先天性免疫功能，脱粒能力，染色质和表观遗传特征，特异性 分泌的粘膜五聚素，以及与CD潘氏细胞缺陷和临床结果的相关性。目标2将测试如何 两种潘氏细胞内在途径和CD生态失调微生物群影响潘氏细胞异质性， 潘氏细胞特异性基因消融和过表达，以及粪便微生物组移植， 开发了无菌Paneth细胞报告小鼠。这一提议提出了一个重要的创新假设 与潘氏细胞异质性有关，可能有助于潘氏细胞驱动的 CD发病机制。一旦一个新的机制调节适当的潘氏细胞活化和炎症保护 如果确定，则可以利用它进行IBD干预。

PROJECT SUMMARY Crohn’s disease (CD) is a form of IBD that commonly involves small intestine, where the majority of Paneth cells reside. As a great number of CD patients show no response or refractory to standard treatment, there is an unmet need for new therapeutic options based on new mechanisms of action. Recent studies suggested that defective Paneth cells may play the key role in initiating inflammation in ileal, and maybe ileocecal CD. Paneth cells in CD patients or mouse IBD models often exhibit granule phenotypes characterized initially by Dr. Ta- Chiang Liu, where several Paneth cell-enriched antimicrobial factors, instead of being packed into secretory granules, are dispersed to the cytoplasm. Hypotheses relating to defective ER stress, autophagy, and secretion have been developed to interpret these CD Paneth cell defects, however the cause-and-effect relationship remains obscure. To date, existing studies has been treating Paneth cells as a homogeneous population. Based on a newly developed temporally controlled Paneth cell reporter mouse model, we establish single cell transcriptomic maps for ileal Paneth cells in homeostasis, dysbiosis, infection and inflammation conditions. We found that there is a profound change in Paneth cell heterogeneity in response to microbiota alteration, infection, and potentially genetic risk factors. Analyzing Paneth cell populations across different conditions revealed an immunologically activated Paneth cell subset that has distinct antimicrobial peptide profile, enriched cytokine receptor, and heightened innate immune and degranulation activities. Paneth cells carrying the signature markers are found in ileal CD and UC metaplastic lesions. We will test the hypothesis that a dynamic Paneth cell heterogeneity regulated by interactions of genetic, gut microbiota, and environmental factors such as pathogen infection is critical for activation of Paneth cell-mediated innate protection against inflammatory induction and aggravation. Aim 1 will determine the function and disease relevance of these Paneth cells by examine their innate immune function, degranulation capacity, chromatin and epigenetic profile, in vivo role of specifically secreted mucosal pentraxins, and relevance to CD Paneth cell defects and clinical outcomes. Aim 2 will test how two Paneth cell intrinsic pathways and CD dysbiotic microbiota affect Paneth cell heterogeneity, by performing Paneth cell specific genetic ablation and overexpression, as well as fecal microbiome transplantation in newly developed germ-free Paneth cell reporter mice. This proposal addresses a significant and innovative hypothesis relating to Paneth cell heterogeneity that may contribute to the causality and mechanism of Paneth cell-driven CD pathogenesis. Once a new mechanism regulating proper Paneth cell activation and inflammatory protection is identified, it may be leveraged for IBD intervention.