Mechanistic studies of gut microbiota-mediated immune activation against hepatocellular cancer

肠道微生物介导的肝细胞癌免疫激活机制研究

基本信息

批准号：
10493129
负责人：
Guangfu Li
金额：
$ 45.9万
依托单位：
UNIVERSITY OF MISSOURI-COLUMBIA
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-23 至 2026-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10493129
关键词：
Antibiotics Area BAY 54-9085 Bacteria Bacteroides Bacteroides thetaiotaomicron Biological Assay CD8-Positive T-Lymphocytes Cancer Patient Canis familiaris Cell physiology DNA Dendritic Cells FDA approved Gastroenterology Genomic DNA Goals Grant Growth Hepatocarcinogenesis Hepatology Hepatotoxicity Human Human Cancer Pathology Imipenem Immune Immune Tolerance Immune response Immune system Immunologics Immunotherapy Journals Legal patent Link Liver Liver diseases Liver neoplasms Malignant - descriptor Malignant Neoplasms Malignant neoplasm of liver Mediating Mediator of activation protein Metagenomics Microbe Modeling Molecular Mus N-caproylsphingosine Neomycin Pathology Pathway interactions Patients Pattern recognition receptor Phagocytosis Phase I Clinical Trials Phase II Clinical Trials Play Positioning Attribute Prevalence Primary carcinoma of the liver cells Publishing Research Resistance Role SV40 T Antigens Sentinel Sterilization Supplementation T-Cell Activation T-Lymphocyte Testing Therapeutic Therapeutic Effect Treatment Efficacy Tumor Antigens Tumor Immunity Vancomycin anti-PD-1 anti-PD1 antibodies anti-tumor immune response base cancer care cancer immunotherapy cancer initiation cancer therapy chemotherapy clinical application genetic approach gut microbiota human disease human microbiota immune activation immune function improved in vivo insight knock-down macrophage member microbiota mouse model nanoliposome novel overexpression patient response response single-cell RNA sequencing transcription factor treatment response tumor tumor growth tumor immunology tumor progression

项目摘要

ABSTRACT Anti-PD-1 antibody has been approved to treat distinct cancers including hepatocellular cancer (HCC); however, the objective therapeutic response in human HCC patients is only about 14%. Microbes are now widely accepted to play critical roles in cancer pathology, and targeting them to improve cancer treatment is an active research area. To investigate the role of gut microbiota in HCC, a novel murine model was created which reflects the typical features in human disease and expresses SV40 T antigen (TAg) as a trackable tumor specific antigen (TSA). This model was used to study the influence of gut microbiota on HCC initiation and progression by treating pre- or post-malignant mice with an antibiotic cocktail (ABX) that contains three types of antibiotics. ABX treatment restored TSA CD8+ T-cell function, retarded hepatocarcinogenesis, and therapeutically slowed HCC growth. Metagenomic assay demonstrated ABX treatment mediated an enrichment of Bacteroides. Supplementation of Bacteroides thetaiotaomicron (B.th), one member of genus Bacteroides, acted similarly to ABX in suppressing tumor growth and activating anti-tumor immune response, associating with the intratumoral accumulation of CpG-rich genomic DNAs and increased expression of TLR9 in intratumoral dendritic cells (DCs) and macrophages (MΦs). In particular, complete gut sterilization of HCC-bearing mice with five types of antibiotics followed by B.th repopulation markedly improved the therapeutic efficacy of αPD1 Abs. Single cell RNA sequencing (scRNA-seq) revealed that B.th repopulation was associated with significant suppression of Kruppel-like factor 2 (KLF2) and significant increase of TLR9. Previous studies have demonstrated that KLF2 is a transcription factor which negatively controls expression of TLR9, phagocytosis in MФs and DCs, and function of T cells. Together, these results imply that B.th suppresses KLF2 expression, which abrogates its suppressive effect on TLR9, a pattern recognition receptor (PRR). The resultant increased TLR9 on sentinel MФs and DCs recognizes B.th-derived CpG-rich DNAs in tumors to activate TSA effector CD8+ T cells against HCC. Thus, this study will test the hypothesis that gut Bacteroides activate anti-HCC immune responses and improve anti-HCC immunotherapy by modulating immunological function of DCs and MФs via KLF2/TLR9/CpG molecular pathways. Aim 1 will dissect the molecular mechanisms by which B.th modulates DCs and MΦs to improve anti- HCC immunity and therapeutic effect through KLF2 and TLR9 pathways; aim 2 will dissect the cellular mechanisms by which B.th modulates DCs and MΦs to improve anti-HCC immunity and therapeutic effect; and aim 3 will investigate therapeutic and immune regulatory effect of gut microbiota in human HCC patient response to αPD-1 Ab treatment. Successful completion of the proposed studies will provide insight into the cellular and molecular mechanisms underlying B.th-activated anti-HCC immune response and advance gut microbiota- integrated immunotherapy to clinical application.

抽象的抗 PD-1 抗体已被批准用于治疗包括肝细胞癌 (HCC) 在内的不同癌症；目前，微生物对人类 HCC 患者的客观治疗反应仅为 14% 左右。在癌症病理学中发挥关键作用，并针对它们来改善癌症治疗是一项积极的研究为了研究肠道微生物群在 HCC 中的作用，创建了一种反映肠道微生物群的新型小鼠模型。人类疾病的典型特征，并将 SV40 T 抗原 (TAg) 表达为可追踪的肿瘤特异性抗原 (TSA)。该模型用于研究肠道微生物群通过治疗对 HCC 发生和进展的影响。恶性前或恶性后的小鼠使用含有三种抗生素的抗生素混合物（ABX）。治疗可恢复 TSA CD8+ T 细胞功能，延缓肝癌发生，并在治疗上减缓 HCC 宏基因组分析表明 ABX 处理介导了拟杆菌的富集。补充多形拟杆菌 (B.th)（拟杆菌属的一种成员），其作用与 ABX 抑制肿瘤生长并激活抗肿瘤免疫反应，与肿瘤内瘤内树突状细胞 (DC) 中富含 CpG 的基因组 DNA 积累和 TLR9 表达增加特别是，用五种类型的 HCC 小鼠完成肠道灭菌。抗生素治疗后进行 B.th 增殖显着提高了 αPD1 单细胞抗体的治疗效果。 RNA 测序 (scRNA-seq) 揭示 B.th 增殖与显着抑制 Kruppel 样因子 2 (KLF2) 和 TLR9 显着增加先前的研究表明 KLF2 是一种转录因子，负向控制 TLR9 的表达、MФ 和 DC 的吞噬作用以及功能总之，这些结果表明 B.th 抑制 KLF2 表达，从而消除其抑制作用。对 TLR9（一种模式识别受体 (PRR)）的影响由此产生的前哨 MФ 和 DC 上的 TLR9 增加。识别肿瘤中富含 B.th CpG 的 DNA，以激活 TSA 效应 CD8+ T 细胞对抗 HCC。研究将检验肠道拟杆菌激活抗 HCC 免疫反应并改善抗 HCC 的假设通过 KLF2/TLR9/CpG 分子调节 DC 和 MФ 的免疫功能进行免疫治疗目标 1 将剖析 B.th 调节 DC 和 MΦ 以提高抗- 的分子机制。通过 KLF2 和 TLR9 途径实现 HCC 免疫和治疗效果目标 2 将剖析细胞 B.th 调节 DC 和 MΦ 提高抗 HCC 免疫力和治疗效果的机制；目标 3 将研究肠道微生物群对人类 HCC 患者反应的治疗和免疫调节作用 αPD-1 Ab 治疗的成功完成将提供对细胞和抗体治疗的深入了解。 B.th 激活抗 HCC 免疫反应和促进肠道微生物群的分子机制整合免疫治疗临床应用。