Innate enteric immunity during induced Paneth cell deficiency

诱导潘氏细胞缺陷期间的先天肠道免疫

• 批准号: 8493004
• 负责人: Andre J. Ouellette
• 金额: $ 19.27万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-15 至 2015-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8493004
• 关键词: Acute; Affect; Age; Autophagocytosis; Bacteria; Bacterial Translocation; Bacteroidetes; Binding; Cell Count; Cell Differentiation process; Cell Lineage; Cell Maintenance; Cell Proliferation; Chronic; Complex; Defensins; Development; E1A-associated p300 protein; EP300 gene; Embryo; Enteral; Enterobacteriaceae; Epithelial; Eubacterium; Functional disorder; Future; Genetic Transcription; Growth; Health; Homeostasis; Host Defense; Immunity; Immunology; Impairment; Infection; Infiltration; Inflammation; Intestines; Lactobacillus; Life; Lymphoid Cell; Maintenance; Mediating; Mining; Mole the mammal; Monitor; Mucosal Immunity; Mus; Mutation; Myeloid Cells; Oral; Organoids; Paneth Cells; Phenotype; Predisposition; Recovery; Research; Research Proposals; Role; Salmonella; Secretory Vesicles; Signal Pathway; Signal Transduction; Small Intestines; Stem cells; Stress; Testing; Time; Transcription Coactivator; base; dosage; drug withdrawal; in vivo; inflammatory marker; innovation; intestinal crypt; intestinal epithelium; oral infection; pathogenic bacteria; progenitor; programs; public health relevance; response; restoration; small molecule

DESCRIPTION (provided by applicant): The proposed studies will test the hypothesis that induced imbalance in Wnt/¿-catenin signaling results in Paneth cell depletion, dysbiosis of the resident microbiota, inflammation, enhanced susceptibility to infection by pathogenic bacteria, and that these effects can be reversed or ameliorated using a specific modulator of the Wnt/¿-catenin signaling pathway. Anatomically restricted to the small bowel, Paneth cells release ¿-defensins and host defense molecules, and maintenance of Paneth cell homeostasis is essential to small intestinal health and integrity. The Wnt signaling cascade has a critical role i gut ontogeny, and Wnt signaling mediated by ¿- catenin p300 coactivator complexes is critical for Paneth cell differentiation. ¿-catenin/CBP-mediated transcription maintains stem cell potency; in contrast, ¿-catenin/p300 transcription complexes initiate differentiation programs of more limited proliferative capacity. The primary ¿-catenin co-activators CBP and p300 share extensive similarity but interact with ¿-catenin via their distinctive N termini, which has enabled development of small molecule antagonists that specifically inhibit their association with ¿-catenin and participation in ¿-catenin-mediated transcription. For example, ICG-001 promotes Wnt-dependent differentiation by binding to CBP specifically, but not to p300, blocking CBP/¿-catenin transcription without 1) interfering with p300, 2) altering levels of ¿-catenin, but still ) allowing CBP to participate in other transcription complexes. Conversely, IQ-1 antagonizes the ¿-catenin-p300 interaction but not CBP associations, providing a means for inducing selective Paneth cell deficiency. Thus, we will test the hypothesis that antagonism of ¿- catenin/p300 signaling in mice with IQ-1 induces Paneth cell depletion and dysfunction. The impact of disrupting Paneth cell homeostasis will be determined by monitoring the time course of IQ-1 induced Paneth cell deficiency and coincident changes in expression of Paneth cell specific markers and induced inflammation evident as infiltration and translocation of myeloid and lymphoid cells. Effects of Paneth cell deficiency on the composition of the prokaryotic and eukaryotic microbiota and on barrier integrity inferred from translocation of gut bacteria in vivo will be characterized. After establishing Paneth cell deficiency, the effects of drug withdrawal and of ICG-001 administration to correct co-activator imbalance and restore Paneth cell differentiation and barrier integrity will be determined, and Paneth cell autonomous responses to IQ-1 and ICG- 001 will be determined on crypt organoids ex vivo. The effect of reestablishing Paneth cell lineage allocation and crypt homeostasis on reversing prokaryotic and eukaryotic dysbiosis also will be determined. We anticipate that IQ-1-induced Paneth cell depletion will evoke proinflammatory responses, induce dysbiosis, and enhance susceptibility to bacterial translocation and that ICG-001 will selectively enable p300/¿-catenin driven transcription to promote Wnt-dependent Paneth cell differentiation and accelerate recovery of small bowel homeostasis.

描述（由申请人提供）：拟议的研究将验证以下假设：诱导Wnt/¿-catenin信号不平衡导致Paneth细胞衰竭、常驻微生物群失调、炎症、对致病菌感染的易感性增强，并且这些影响可以使用Wnt/¿-catenin信号通路的特定调节剂逆转或改善。Paneth细胞在解剖学上局限于小肠，释放防御素和宿主防御分子，维持Paneth细胞的稳态对小肠的健康和完整性至关重要。Wnt信号级联在肠道个体发生中起关键作用，由¿- catenin p300共激活物复合物介导的Wnt信号传导对Paneth细胞分化至关重要。-catenin/ cbp介导的转录维持干细胞效力；相比之下，¿-catenin/p300转录复合物启动的分化程序增殖能力更有限。主要的-catenin共激活剂CBP和p300具有广泛的相似性，但通过其独特的N端与-catenin相互作用，这使得