Antifungal immunity in Hirschsprung-Associated Enterocolitis

先天性巨结肠相关小肠结肠炎的抗真菌免疫

• 批准号: 9883716
• 负责人: Philip Kent Frykman
• 金额: $ 25.5万
• 依托单位: CEDARS-SINAI MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-03-01 至 2022-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9883716
• 关键词: Animals; Antibodies; Antibody titer measurement; Antifungal Agents; Automobile Driving; C Type Lectin Receptors; Candida; Candida albicans; Candida utilis; Cessation of life; Child; Colitis; Complication; Congenital Megacolon; Data; Development; Diagnosis; Disease; Early identification; Enterocolitis; Feces; Future; Genes; Genetic Polymorphism; Genetic Predisposition to Disease; Hospitalization; Immune response; Immunity; Immunologic Receptors; Inflammatory Bowel Diseases; Intestines; Investigation; Knockout Mice; Lead; Link; Methods; Modeling; Mus; Mutant Strains Mice; Operative Surgical Procedures; Patients; Population; Predisposition; Prevention; Receptor Signaling; Reporting; Rhodotorula; Risk; Risk Factors; Role; SNP genotyping; Saccharomyces cerevisiae; Severities; Severity of illness; Signaling Molecule; Single Nucleotide Polymorphism; cohort; dectin 1; dysbiosis; fungus; gut colonization; gut microbiota; high risk; inflammatory disease of the intestine; interest; loss of function; microbiome research; mouse model; mutant; novel; novel strategies; pathogenic fungus; personalized approach

PROJECT SUMMARY Hirschsprung associated enterocolitis (HAEC) is the most frequent complication in children with Hirschsprung disease (HSCR), resulting in frequent hospitalizations and half of deaths in this population. The mechanisms underlying HAEC are poorly understood. We reported in a microbiome study that Candida spp. are specifically enriched in stool of HAEC patients, and we report here that HAEC patients have elevated anti-Saccharomyces cerevisiae antibody (ASCA) titers. Since ASCA levels are known to be associated with inflammatory bowel disease (IBD), we hypothesized that other risk factors for IBD might be associated with HAEC. We genotyped single nucleotide polymorphisms (SNPs) in a small cohort of HSCR patients and found preliminary evidence that 37 SNPs previously found to associate with IBD may also be linked to the risk of developing HAEC. One of these genes, CARD9, particularly caught our interest because CARD9 is involved in host immune responses to intestinal microbes, especially fungi, as a signaling molecule involved in anti-fungal C-type lectin receptor signaling. We have established a mouse model of HAEC (Ednrb-null mouse model) and found that creating Ednrb-Clec7a double mutant mice (Clec7a gene encodes for the antifungal C-type lectin receptor Dectin-1) causes a 5-fold increase in fecal C. albicans and 4-fold increased enterocolitis severity compared with controls. We further observed in the Ednrb-null model that natural intestinal colonization with Candida utilis and Rhodotorula mucilaginosa is associated with the risk of developing HAEC. Finally, HAEC severity was reduced 65% when animals were treated with the antifungal drug isavuconazole. Together, these discoveries suggest new mechanisms for HAEC implicating intestinal fungi and antifungal immunity. Our overall hypothesis is that HSCR patients with genetic susceptibility to developing HAEC respond inappropriately to changes in the intestinal microbiota, (with a particular interest in fungi) leading to a difficult-to-treat colitis. This hypothesis will be investigated in the following two aims: 1) investigate the role of antifungal immunity gene Card9 in a mouse model of HAEC; 2) define the role of Candida utilis and Rhodotorula mucilaginosa in the same mouse model of HAEC. The line of investigation outlined here may lead to greater rationale for treating HAEC patients using personalized approaches and may lead to methods for early identification of patients at high risk of developing HAEC.

项目总结 先天性巨结肠炎(HAEC)是先天性巨结肠患儿最常见的并发症 疾病(HSCR)，导致该人群频繁住院和一半的死亡。其作用机制 人们对潜在的HAEC知之甚少。我们在微生物组研究中报道了假丝酵母菌。都是特别的 在HAEC患者的粪便中富含，我们在这里报告HAEC患者的抗酵母菌升高。 酿酒酵母抗体(ASCA)效价。由于已知ASCA水平与肠炎有关 疾病(IBD)，我们假设IBD的其他危险因素可能与HAEC相关。我们进行了基因分型 一小部分HSCR患者的单核苷酸多态(SNPs)研究及初步证据 先前发现的与IBD相关的37个SNP也可能与发生HAEC的风险有关。其中之一 这些基因，CARD9，尤其引起了我们的兴趣，因为CARD9参与了宿主对 肠道微生物，特别是真菌，作为信号分子参与抗真菌C型凝集素受体 发信号。我们已经建立了HAEC的小鼠模型(EDNRB-Null小鼠模型)，发现创建 EDNRB-Clec7a双突变小鼠(Clec7a基因编码抗真菌C型凝集素受体Dectin-1) 导致与对照组相比，粪便中白色念珠菌的数量增加了5倍，小肠结肠炎的严重性增加了4倍。 我们进一步在EDNRB零模型中观察到，念珠菌和白念珠菌的自然肠道定植 粘红酵母与HAEC的发病风险相关。最后，HAEC的严重程度降低了 当动物接受抗真菌药物异伍康唑治疗时，65%的人感染。总而言之，这些发现表明 HAEC参与肠道真菌和抗真菌免疫的新机制。我们的总体假设是 对发生HAEC有遗传易感性的HSCR患者对 肠道微生物区系(对真菌特别感兴趣)，导致难以治疗的结肠炎。这一假说将 1)研究抗真菌免疫基因CARD9在小鼠体内的作用 2)确定念珠菌和粘性红酵母在同一小鼠HAEC模型中的作用 HAEC。这里概述的调查路线可能会导致更多的理由来治疗HAEC患者使用 个性化的方法，并可能导致早期识别高危患者的方法 HAEC。