背景:肠系膜脂肪组织(MAT)增生,被称为爬行脂肪,是克罗恩病(CD)的病理特征。在我们之前报道的队列中,我们观察到肺白杆菌是由爬行脂肪培养的最丰富和最普遍的细菌。
方法:使用mAT衍生的肺曲霉的T3SS直向同源物的全基因组测序和鉴定。功能性III型分泌系统(T3SS)在体外和小鼠结肠炎模型中介导了肺曲霉的致病潜力。此外,引入了T3SSFinder管道来评估CD患者粪便中的肠道细菌T3SS直向同源物,溃疡性结肠炎和结直肠癌患者。
结果:这里,我们发现MAT衍生的肺曲霉具有功能性T3SS,通过T3SS加重小鼠结肠炎,并在巨噬细胞和上皮细胞中通过不依赖caspase的机制表现出T3SS依赖性细胞毒性,这证明了携带T3SS的肺曲霉的致病潜力。宏基因组分析显示,与健康对照相比,克罗恩病患者粪便中嗜酸性杆菌的丰度增加。各种肠道疾病中总微生物vT3SS丰度的综合比较表明,在CD的粪便样品中显示出vT3SS基因的特异性富集,溃疡性结肠炎和结直肠癌患者,在新招募的CD队列中发现并验证了10种基于T3SS基因的CD生物标志物。此外,独家肠内营养(EEN)治疗,改善CD患者症状的干预措施,发现与粪便样品中T3SS基因的患病率显着降低有关。
结论:这些发现强调了T3SS在CD中的致病意义,并鉴定了特定的T3SS基因,这些基因可能作为诊断和监测CD患者临床状态的生物标志物。
背景:这项工作得到了国家重点研究发展计划(2020YFA0907800)的支持,中国博士后科学基金(2023M744089),国家自然科学基金(32000096),深圳市科技计划(KQTD20200820145822023、RCIC20231211085944057和ZDSYS20220606100803007),国家重点临床学科,广东省消化疾病临床研究中心(2020B1111170004),中国克罗恩病基金会庆丰科研基金(CCCF)(CCCF-QF-2022B71-1),第六附属医院,中山大学临床研究1010项目1010CG(2023)-08。这些资助为这项研究工作提供了很好的支持,涉及数据收集,分析,解释,患者招募等。
BACKGROUND: Mesenteric adipose tissue (mAT) hyperplasia, known as creeping fat, is a pathologic characteristic of Crohn\'s disease (CD). In our previously reported cohort, we observed that Achromobacter pulmonis was the most abundant and prevalent bacteria cultivated from creeping fat.
METHODS: A whole genomic sequencing and identification of T3SS orthologs of mAT-derived A. pulmonis were used. A functional type III secretion system (T3SS) mediated the pathogenic potential of A. pulmonis in vitro and in mouse colitis model. Furthermore, a T3SS Finder pipeline was introduced to evaluate gut bacterial T3SS orthologs in the feces of CD patients, ulcerative colitis and colorectal cancer patients.
RESULTS: Here, we reveal that mAT-derived A. pulmonis possesses a functional T3SS, aggravates colitis in mice via T3SS, and exhibits T3SS-dependent cytotoxicity via a caspase-independent mechanism in macrophages and epithelial cells, which demonstrated the pathogenic potential of the T3SS-harboring A. pulmonis. Metagenomic analyses demonstrate an increased abundance of Achromobacter in the fecal of Crohn\'s disease patients compared to healthy controls. A comprehensive comparison of total microbial vT3SS abundance in various intestine diseases demonstrated that the specific enrichment of vT3SS genes was shown in fecal samples of CD, neither ulcerative colitis nor colorectal cancer patients, and ten T3SS gene-based biomarkers for CD were discovered and validated in a newly recruited CD cohort. Furthermore, treatment with exclusive enteral nutrition (EEN), an intervention that improves CD patient symptomatology, was found associated with a significant reduction in the prevalence of T3SS genes in fecal samples.
CONCLUSIONS: These findings highlight the pathogenic significance of T3SSs in the context of CD and identify specific T3SS genes that could potentially function as biomarkers for diagnosing and monitoring the clinical status of CD patients.
BACKGROUND: This work is supported by the National Key Research and Development Program of China (2020YFA0907800), the China Postdoctoral Science Foundation (2023M744089), the National Natural Science Foundation of China (32000096), the Shenzhen Science and Technology Programs (KQTD20200820145822023, RCIC20231211085944057, and ZDSYS20220606100803007), National Key Clinical Discipline, Guangdong Provincial Clinical Research Center for Digestive Diseases (2020B1111170004), Qingfeng Scientific Research Fund of the China Crohn\'s & Colitis Foundation (CCCF) (CCCF-QF-2022B71-1), and the Sixth Affiliated Hospital, Sun Yat-sen University Clinical Research 1010 Program 1010CG(2023)-08. These funding provided well support for this research work, which involved data collection, analysis, interpretation, patient recruitment and so on.