Identifying the active factor of an anti-inflammatory chemopreventive bacterium

鉴定抗炎化学预防细菌的活性因子

• 批准号: 10184104
• 负责人: Jimmy W Crott
• 金额: $ 15.72万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-01 至 2022-02-05
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10184104
• 关键词: Ablation; Address; Affect; Anti-Inflammatory Agents; Antiinflammatory Effect; Apoptosis; Aspirin; Bacteria; Bacteroides; Cancer Burden; Cell Culture Techniques; Cell Line; Cells; Cessation of life; Chemoprevention; Chemopreventive Agent; Cloning; Co-Immunoprecipitations; Colitis associated colorectal cancer; Colon; Colonic Neoplasms; Colorectal; Colorectal Cancer; Cytokine Activation; Cytotoxic T-Lymphocytes; Data; Development; Disease; Escherichia coli; Evolution; Foundations; Freeze Drying; Genes; Goals; Heating; Immune; Immune Evasion; In Vitro; Incidence; Inflammation; Inflammatory; Interleukin-10; Intestinal Neoplasms; Knowledge; Link; Malignant Neoplasms; Mediating; Membrane; Membrane Proteins; Mission; Molecular Target; Mucous Membrane; Mus; Mutate; Mutation; Outcome; Pathway interactions; Persons; Pharmaceutical Preparations; Population; Prevention strategy; Process; Production; Property; Proteins; Public Health; RNA Interference; Recombinants; Regulatory T-Lymphocyte; Risk Factors; Role; Signal Pathway; Signal Transduction; TLR4 gene; Testing; Time; Tumor Burden; United States; Vascularization; Work; antitumor effect; base; cancer chemoprevention; cancer prevention; colon tumorigenesis; colorectal cancer prevention; colorectal cancer risk; commensal bacteria; comparative genomics; cytokine; feeding; genetic manipulation; gut bacteria; gut microbes; gut microbiome; gut microbiota; innovation; knowledge base; microbial; microbiota; mouse model; mutant; novel; preclinical study; recruit; response; sensor; success; tumor; tumorigenesis; tumorigenic

Project Abstract/Summary Colorectal cancer (CRC) remains a major public health issue, with approximately 145,000 new cases and 51,000 deaths from this disease per year in the US alone. Alterations in the composition of the gut microbiota and elevated inflammation are established risk factors for CRC. We made the novel observation that the normal gut bacterium Parabacteroides distasonis (Pd) suppresses colorectal inflammation and tumor formation in mice. Importantly, we show that Pd suppresses the activation of the pro-inflammatory, pro-tumorigenic TLR4 signaling pathway. The objectives of this application are to determine whether blocking TLR4 is required for the anti-tumor effects of Pd, to identify the active factor of Pd and its host target and finally to define how Pd influences immune cell populations in the colon. Based on our robust data, we hypothesize that the chemopreventive effect of Pd is achieved by the suppression of pro-inflammatory TLR4 signaling and the recruitment of inflammation quelling T regulatory (Treg) cells to the colon. The specific aims of the study are to: 1) To identify anti-inflammatory factor of Pd; 1A) To test whether the anti-TLR4 function of Pd is required for its chemopreventive effect; 1B) To identify the molecular target of the Pd anti-inflammatory molecule and 2) To define how Pd influences immune cell populations in the colonic mucosa. The aims of this study will be addressed by comparing the ability of various closely-related bacterial species to inhibit TLR4 signaling in vitro followed by comparative genomics to identify genes common to inhibitory species but without homologs in non-inhibitory species. The function of candidates will be evaluated by expressing them in E.coli Nissle 1917 (EcN) and mutating them in Pd. To evaluate whether TLR4 inhibition is required for chemoprevention by Pd we will compare the ability of Pd and Pd lacking anti-TLR4 function to suppress colon tumorigenesis with EcN and EcN expressing Pd anti-TLR4 genes. Host target proteins will be identified by co-immunoprecipitation with the recombinant tagged Pd protein. Finally, the influence of Pd on colonic immune cells will be evaluated by comparing specific cancer and microbiota relevant immune cell populations between Pd fed and control mice over time. Understanding Pd’s mechanism of action and identifying its active and target molecules will pave the way for this bacterium, or its active component, to be utilized in the prevention of CRC. Our long-term goal is to identify bacteria with chemopreventive properties and to understand their mechanisms of action. Importantly, Pd appears to be compatible with other microbial therapies and does not disrupt the resident microbiota. These studies are highly worthwhile because although a few agents show promise as chemopreventive agents in pre-clinical studies, aspirin (a drug developed over 100 years ago) remains the only agent for which we have compelling evidence of efficacy and its detrimental effects may outweigh those benefits. These studies directly address the mission of the NCI to develop the knowledge base that will lessen the burden of cancer in the United States and around the world.

项目摘要/摘要 结直肠癌（CRC）仍然是一个主要的公共卫生问题，大约有145,000例新病例和51,000例 仅在美国，这种疾病每年死亡。肠道菌群组成的改变和 炎症升高是CRC的确定危险因素。我们对正常的肠道进行了新的观察 副细菌滴虫（PD）抑制小鼠结肠直肠感染和肿瘤形成。 重要的是，我们表明PD抑制了促炎性，促肿瘤的TLR4信号传导的激活 路径。该应用程序的目标是确定抗肿瘤是否需要阻止TLR4 PD的效果，确定PD及其宿主目标的活性因子，最后定义PD如何影响免疫 结肠中的细胞群体。根据我们的强大数据，我们假设PD的化学预防效应为 通过抑制促炎性TLR4信号传导和炎症平压T的募集来实现 调节性（Treg）细胞到结肠。该研究的具体目的是：1）确定抗炎因子的 PD; 1A）测试PD的抗TLR4功能是否需要其化学预防作用； 1b）识别 PD抗炎分子的分子靶标和2）定义PD如何影响免疫细胞 结肠粘膜中的种群。这项研究的目的将通过比较各种能力来解决 密切相关的细菌在体外抑制TLR4信号传导，然后进行比较基因组学鉴定 抑制性物种共同但在非抑制性物种中没有同源物的基因。候选人的功能 将通过在E.Coli Nissle 1917（ECN）中表达它们并在PD中进行评估。评估是否 TLR4抑制是通过PD进行化学预防需要的，我们将比较缺乏抗TLR4的PD和PD的能力 用ECN和ECN表达PD抗TLR4基因的ECN和ECN抑制结肠肿瘤的功能。宿主靶蛋白 将通过与重组标记的PD蛋白共免疫沉淀来识别。最后，PD的影响 在结肠免疫细胞上，将通过比较特定的癌症和菌群相关的免疫细胞来评估 随着时间的推移，PD喂养和控制小鼠之间的种群。了解PD的行动机制和识别 其活性和靶分子将为该细菌或其活性成分铺平道路 预防CRC。我们的长期目标是鉴定具有化学预防特性的细菌并了解 他们的作用机制。重要的是，PD似乎与其他微生物疗法兼容，并且 不要破坏居民微生物群。这些研究非常值得，因为尽管有一些代理商表明 作为临床前研究的化学预防剂的希望，阿司匹林（一种多年前开发的一种药物） 仍然是我们唯一具有令人信服的效率证据及其有害影响的药物 超过这些好处。这些研究直接解决了NCI发展知识库的使命 这将减少美国和世界各地的癌症伯恩。