Role of the complement C3a receptor on immune and non immune intestinal barrier functions and microbiota in colorectal cancer development

补体 C3a 受体对结直肠癌发展中免疫和非免疫肠道屏障功能和微生物群的作用

• 批准号: 10522693
• 负责人: Silvia Guglietta
• 金额: $ 36.17万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2027-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10522693
• 关键词: APC gene; Acute; Affect; Anaphylatoxins; Anti-Bacterial Agents; Anti-Inflammatory Agents; ApcMin/+ mice; Automobile Driving; Bioinformatics; Biological Assay; Biology; Bone Marrow; C3AR1 gene; Cells; Characteristics; Chimera organism; Coculture Techniques; Colon; Colon Carcinoma; Colonic Neoplasms; Colonic inflammation; Colorectal Cancer; Communication; Complement; Complement 3a; Complex; Cytometry; Data; Data Set; Development; Down-Regulation; Environment; Epidemiology; Epithelial; Equilibrium; Event; Functional disorder; Gastrointestinal tract structure; Gatekeeping; Health; Human; Image; Immune; Immune response; Immune system; Inflammation; Inflammatory; Inherited; Intestines; Investigation; Lesion; Link; Measures; Methylation; Microbiology; Mining; Minority; Modeling; Molecular; Mucosal Immune Responses; Mucous Membrane; Mus; Mutation; Natural Immunity; Organoids; Pathology; Pathway interactions; Patients; Pharmaceutical Preparations; Phenotype; Process; Production; Property; Research Personnel; Role; Seminal; Small Intestines; Specimen; Testing; Tumor-infiltrating immune cells; Work; cancer initiation; cancer survival; cell type; cohort; colorectal cancer prevention; complement C3a receptor; complement system; cytokine; dimensional analysis; dysbiosis; experimental study; fecal transplantation; follow-up; high dimensionality; immune function; intestinal barrier; intestinal epithelium; intestinal homeostasis; intestinal tumorigenesis; mesenteric lymph node; microbial; microbiota; monolayer; mouse model; multidisciplinary; novel; prevent; receptor; tumor; tumor microenvironment; tumorigenesis; tumorigenic

While it was initially believed that only a minority of CRC are driven by inflammation, studies showing that treatment with anti-inflammatory medications may prevent or delay the development of CRC in hereditary and sporadic cases, clearly identify inflammation as a key driver in the development and progression of all types of CRC. Yet, it is still unclear what are the mechanisms that in the complex intestinal environment contribute to the activation of the inflammatory pathways that initiate CRC. The intestine holds a delicate balance between host protection and control of excessive inflammation, and we posit that a dysregulated communication between the epithelial and the immune component of the intestinal barrier may link a sub-acute state of inflammation and CRC initiation. The complement system is emerging as an important player in the gastrointestinal tract. Specifically, the complement anaphylatoxin C3a and its receptor, C3aR, regulate the immune and epithelial compartments in the intestine and exert antibacterial properties. By mining publicly available datasets, we found that C3aR is down-regulated in patients with CRC and the fact that this down-regulation occurs already in stage 1 tumors, suggests that it may be an early event during CRC development. By crossing C3aR-/- mice with the APCMin/+ mice, that carry a mutation in the apc gene, similarly to the majority of human CRC, we showed that C3aR is protective in CRC. Indeed, while in APCMin/+ mice tumors mostly developed in the small intestine, in APCMin/+/C3aR-/- mice tumorigenesis dramatically shifted almost exclusively to the colon. We also found intestinal barrier dysfunction and microbial dysbiosis in mice lacking C3aR, suggesting that C3aR may be a novel gatekeeper in intestinal homeostasis. However, it is currently unknown how C3aR contributes to CRC development. We hypothesize that loss of C3aR causes intestinal barrier dysfunction by affecting the communication between epithelial and immune cells. This then leads to development of microbiota-driven inflammatory immune responses that promote the development of CRC. To test this hypothesis we propose: 1) to investigate how loss of C3aR affects the epithelial component of the intestinal barrier and the communication with the immune cells; 2) To investigate the contribution of C3aR on immune, non immune cell types, and microbiota to CRC development; 3) To investigate the C3aR status in human pre-invasive lesions and CRC. Bone marrow chimera in combination with single cell high dimensional analysis of immune infiltrates using mass cytometry and REAPseq will determine the contribution of C3aR on immune and non immune cells to colon inflammation and CRC development and progression. We will assess how C3aR down-regulation affects human CRC and survival by using human specimens from our well characterized patient cohorts. As loss of C3aR represents an early event during CRC, identifying the mechanisms linking loss of C3aR to the development of CRC will not only further our understanding of CRC but is highly significant for the prevention of CRC.

虽然最初认为只有少数结直肠癌是由炎症引起的，但研究表明 抗炎药物治疗可以预防或延缓遗传性和结直肠癌的发展 散发病例，清楚地确定炎症是所有类型的发展和进展的关键驱动因素 CRC。然而，目前尚不清楚复杂的肠道环境中导致这一现象的机制是什么。 激活引发 CRC 的炎症通路。 肠道在宿主保护和过度炎症控制之间保持着微妙的平衡，我们 认为肠道上皮细胞和免疫成分之间的通讯失调 屏障可能将亚急性炎症状态与结直肠癌的发生联系起来。补体系统正在出现 胃肠道中的重要角色。具体来说，补体过敏毒素 C3a 及其受体， C3aR，调节肠道内的免疫和上皮区室并发挥抗菌特性。经过 挖掘公开可用的数据集，我们发现 C3aR 在 CRC 患者中表达下调，并且以下事实 这种下调已经发生在 1 期肿瘤中，表明这可能是 CRC 期间的早期事件 发展。通过将 C3aR-/- 小鼠与携带 apc 基因突变的 APCMin/+ 小鼠杂交，类似地 对于大多数人类 CRC，我们表明 C3aR 对 CRC 具有保护作用。事实上，在 APCMin/+ 小鼠肿瘤中 主要在小肠中发育，在 APCMin/+/C3aR-/- 小鼠中，肿瘤发生几乎发生了急剧变化 专门针对结肠。我们还发现缺乏肠道屏障的小鼠存在肠道屏障功能障碍和微生物失调。 C3aR，表明 C3aR 可能是肠道稳态的新型看门人。然而，目前 尚不清楚 C3aR 如何促进 CRC 的发展。 我们假设 C3aR 的缺失通过影响肠道屏障之间的沟通而导致肠道屏障功能障碍。 上皮细胞和免疫细胞。这随后导致微生物群驱动的炎症免疫的发展 促进CRC发展的回应。为了检验这个假设，我们建议： 1) 研究C3aR的缺失如何影响肠屏障的上皮成分和 与免疫细胞的通讯； 2) 研究C3aR对免疫、非免疫细胞的贡献 类型和微生物群对 CRC 发展的影响； 3) 研究人类浸润前病变中的C3aR状态 和CRC。骨髓嵌合体与免疫浸润的单细胞高维分析相结合 使用质谱流式细胞术和 REAPseq 将确定 C3aR 对免疫和非免疫细胞的贡献 结肠炎症和结直肠癌的发生和进展。我们将评估 C3aR 下调如何影响 人类结直肠癌和生存率，通过使用来自我们明确特征的患者队列的人类样本。作为损失 C3aR 代表 CRC 期间的早期事件，确定了将 C3aR 丢失与发育联系起来的机制 结直肠癌的研究不仅有助于加深我们对结直肠癌的认识，而且对于结直肠癌的预防也具有重要意义。