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

• 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
• 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

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癌（HCC）在内的不同癌症。然而， 人HCC患者的客观治疗反应仅为14％。微生物现在被广泛接受 一项积极的研究 区域。为了研究肠道菌群在HCC中的作用，创建了一种新型的鼠模型，反映了 人类疾病的典型特征，并表达SV40 t抗原（TAG）作为可追踪肿瘤的抗原 （TSA）。该模型用于研究肠道微生物群对HCC计划的影响和通过治疗 带有抗生素鸡尾酒（ABX）的恶性小鼠或后小鼠，其中包含三种类型的抗生素。 ABX 治疗恢复了TSA CD8+ T细胞功能，延迟的肝癌发生和热速度HCC 生长。宏基因组学测定表明ABX治疗介导了大量的菌囊。 补充杀菌剂菌（B.Th）的补充，菌属的一名成员与 ABX抑制肿瘤生长和激活抗肿瘤免疫响应，与肿瘤内相关 富含CpG的基因组DNA的积累和TLR9在肿瘤内树突状细胞（DCS）中的表达增加 和巨噬细胞（mφs）。特别是，具有五种类型的含HCC的小鼠的完全肠道灭菌 抗生素随后B. The Repotuals显着提高了αPD1ABS的治疗效率。单细胞 RNA测序（SCRNA-Seq）表明，B。重生与对的显着抑制有关 Kruppel样因子2（KLF2）和TLR9的显着增加。以前的研究表明KLF2是 负面控制TLR9表达的转录因子，MOS和DC中的吞噬作用以及功能 T细胞。总之，这些结果暗示B. TH抑制KLF2表达，从而消除了其抑制作用 对TLR9的影响，TLR9是模式识别受体（PRR）。最终增加的TLR9在Sentinel MOS和DC上增加了 识别肿瘤中富含CpG的富含CpG的DNA，以激活针对HCC的TSA效应CD8+ T细胞。那，这个 研究将检验肠道杀菌激活抗HCC免疫反应并改善抗HCC的假设 通过KLF2/TLR9/CPG分子调节DC和MOS的免疫功能通过免疫疗法 途径。 AIM 1将剖析B. TH调节DC和Mφ的分子机制，以改善抗抗 通过KLF2和TLR9途径的HCC免疫和治疗效果； AIM 2将剖析细胞 B. TH调节DC和Mφ以改善抗HCC免疫和治疗效果的机制；和 AIM 3将研究肠道菌群对人HCC患者反应的治疗和免疫调节作用 进行αPD-1 AB处理。拟议研究的成功完成将为细胞和 B.激活的抗HCC免疫反应并提高肠道微生物群的分子机制 将免疫疗法综合用于临床应用。