Probiotic Lactobacillus-Mediated Suppression of TNF in Pediatric Crohn's Disease

描述（由申请人提供）：益生菌或有益菌是预防和治疗小儿炎症性肠病（IBD）的有前途的药物。几种乳杆菌被认为是具有吸引人的免疫调节功能的益生菌，并被用作营养补充剂或替代药物。这些研究旨在了解益生菌免疫调节的基本机制，以便为未来的医学治疗合理设计天然或工程益生菌。总体假设是益生菌罗伊氏乳杆菌菌株释放通过转录调节抑制人肿瘤坏死因子-α（TNF-α）的寡糖。罗伊氏乳杆菌代表了一种模式益生菌生物，因为该物种具有无可挑剔的安全记录，并已在人类个体和小鼠IBD模型中显示出有益效果。L.罗伊氏乳杆菌是一种已确立的益生菌物种，其代表了人类肠道中选择的少数土著乳杆菌物种之一。该提案的具体目标如下。1)研究来源于罗伊氏乳杆菌的寡糖通过原代人巨噬细胞中的转录调节抑制人TNF-α的相对能力。将使用来自患有活动性克罗恩病的儿童的原代细胞检测来自益生菌菌株的富含益生菌寡糖的HPLC级分的TNF抑制活性。2)探索益生菌寡糖对AP-1介导的人TNF-α转录调节的抑制和对巨噬细胞中MAP激酶信号通路的调节。依赖于Toll样受体2（TLR 2）或Toll样受体4（TLR 4）信号传导的人巨噬细胞模型（两种细胞系）将用于检查益生菌寡糖如何调节MAP激酶信号传导途径。益生菌调节的人类信号通路的鉴定将促进新抗炎化合物的靶点的具体化，并可能使益生菌从“替代”医学转变为“主流”医学。

DESCRIPTION (provided by applicant): Probiotics, or beneficial bacteria, are promising agents for the prevention and treatment of pediatric inflammatory bowel disease (IBD). Several Lactobacillus species are considered to be probiotic organisms with attractive immunoregulatory features and are being consumed as nutritional supplements or alternative medicines. The proposed studies aim to comprehend basic mechanisms of immunoregulation by probiotics so that natural or engineered probiotics can be rationally devised for future medical therapies. The overall hypothesis is that probiotic Lactobacillus reuteri strains release oligosaccharides that suppress human tumor necrosis factor-alpha (TNF-a) by transcriptional regulation. Lactobacillus reuteri represents a model probiotic organism because this species has an impeccable safety record and has demonstrated beneficial effects in human individuals and mouse IBD models. L. reuteri is an established probiotic species that represents one of a select few indigenous Lactobacillus species of the human intestine. The specific aims of the proposal are as follows. 1) Investigate the relative abilities of Lactobacillus reuteri-derived oligosaccharides to inhibit human TNF-a by transcriptional regulation in primary human macrophages. Probiotic-derived oligosaccharide-enriched HPLC fractions from probiotic strains will be tested for TNF-inhibitory activity using primary cells derived from children with active Crohn's disease. 2) Explore suppression of AP-1-mediated transcriptional regulation of human TNF-a and modulation of MAP kinase signaling pathways in macrophages by probiotic oligosaccharides. Human macrophage models (two cell lines) that depend on either Toll-like receptor 2 (TLR2) or Toll-like receptor 4 (TLR4) signaling will be used to examine how probiotic oligosaccharides modulate MAP kinase signaling pathways. The identification of human signaling pathways regulated by probiotics will facilitate specification of targets for new anti-inflammatory compounds and may move probiotics from "alternative" to "mainstream" medicine.