Regulation of C. difficile infection by the cytokine interleukin-22 (IL-22)

细胞因子白细胞介素 22 (IL-22) 对艰难梭菌感染的调节

基本信息

批准号：
10554370
负责人：
Lauren A Zenewicz
金额：
$ 25.82万
依托单位：
UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-03-01 至 2023-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10554370
关键词：
16S ribosomal RNA sequencing 3-Dimensional Adult Antibiotic Therapy Apoptosis Apoptotic Bacteria Bacterial Infections Biological Products Biology Cell Death Cells Chronic Clostridium difficile Colitis Colon Communicable Diseases Communities Complement Data Disease Epithelial Cells Epithelium Etiology Future Gastrointestinal tract structure Genes Genetic Goals Goblet Cells Guanosine Triphosphate Phosphohydrolases Health Hospitals Immune Immune response Immunity Immunobiology In Vitro Individual Infection Inflammation Inflammatory Bowel Diseases Inflammatory Response Intestines Life Link Lymphocyte Lymphocyte Activation MAP Kinase Gene Maintenance Mediating Modeling Monomeric GTP-Binding Proteins Mucous Membrane Mus Oklahoma Organ Organoids Paneth Cells Pathogenesis Pathology Patients Play Population Process Production Productivity Proteins Pseudomembranous Colitis Recurrent disease Regulation Relapse Reporter Role STAT3 gene Severities Signal Pathway Signal Transduction Small Interfering RNA Source Therapeutic Tissues Toxic effect Toxin Up-Regulation Villus Virulence Factors Work antimicrobial cell type chronic inflammatory disease commensal bacteria cytokine dysbiosis experimental study gastrointestinal gastrointestinal epithelium gastrointestinal infection high risk in vivo infectious disease treatment inflammatory milieu inflammatory modulation interest interleukin-22 intestinal epithelium intestinal homeostasis microbial microbiome microbiota mouse model neutralizing antibody pathogen pathogenic bacteria patient subsets pharmacologic prevent programs response stem cells therapeutic target

项目摘要

PROJECT SUMMARY Clostridioides difficile is a mucosal-associated pathogen that can cause life-threatening illness. The bacterium is a leading source of hospital-acquired GI infections, but is emerging in the healthy population. Asymptomatic colonization is common and only leads to productive infection in some individuals, and a subset of these patients will have a relapsing, more severe disease. C. difficile secretes toxin B (TcdB), an inactivator of small GTPases that induces epithelial cell death. This toxin helps C. difficile establish the niche it needs for productive infection. C. difficile requires perturbation in the microbiome to initiate disease. Although recent studies have revealed some means of how it overcomes commensals, we still do not fully understand how C. difficile establishes infection or initiates re-infection. Host immune responses likely play a role. Our long-term goal is to identify how cytokine biology may be therapeutically targeted to alleviate initial C. difficile infection or relapses in high-risk patients. Group 3 innate lymphocytes (ILC3s) are rare immune cells often found in mucosal tissues. They produce high levels of IL-22, a critical modulator of mucosal tissue responses. IL-22 is important for maintaining intestinal homeostasis in health and disease. Through maintenance of the epithelial barrier, the cytokine is protective in GI infections, although the role of IL-22 in C. difficile infection is not clear. In our studies investigating interactions between toxins and ILC3s, we examined the effects of TcdB on IL-22. Our preliminary data show that TcdB induces IL-22 in ILC3s in a GTPase-dependent manner. Pharmacological inhibition suggests that upregulation of IL-22 is through Cdc42. These data form the premise for our hypothesis that C. difficile modulates the host immune response. The overall objective for this application is to understand signaling pathway(s) through which TcdB may modulate ILC3 production of IL-22 and ascertain the benefits of elevated IL-22 to C. difficile during infection. In Aim 1 we will examine how the small GTPase Cdc42 may regulate IL-22 production in activated ILC3s. Through genetic or siRNA-mediated deletion of Cdc42 in ILC3s, we will examine if this small GTPase is a negative regulator of ILC3 activation as well as examine if there are links between Cdc42 and other signaling pathways, including STAT3 and MAPKs. In Aim 2, we will examine the interactions between C. difficile and TcdB, and IL-22 and the GI tissues. We will examine the function of IL- 22 signaling in C. difficile infection using a reductionist approach with colonic organoids. Studies will examine if IL-22 protects against TcdB-mediated apoptosis and identify which IL-22-inducible factors contribute to altering the niche. An in vivo C. difficile infection model will complement in vitro experiments. This study may identify new signaling pathways involved in regulation of IL-22, which is of interest to both the infectious disease and chronic inflammation fields. We will also have a more complete understanding of how increased IL-22 levels modulate the inflammatory environment to favor C. difficile over other bacteria in the GI tract. This has implications on how IL-22 biology may be manipulated in preventing primary or relapsing C. difficile infection.

项目摘要梭状芽胞杆菌艰难梭菌是一种与粘膜相关的病原体，可能导致威胁生命的疾病。细菌是医院获得的胃肠道感染的主要来源，但在健康人群中出现。无症状殖民化是常见的，仅导致某些个体的生产性感染，其中一部分患者将患有复发，更严重的疾病。艰难梭菌分泌毒素B（TCDB），一个小的灭活剂诱导上皮细胞死亡的GTP酶。这种毒素有助于艰难梭菌确定其需要的利基市场生产感染。艰难梭菌需要在微生物组中扰动才能引发疾病。虽然最近研究揭示了一些如何克服统计的手段，我们仍然不完全了解C. 艰难梭菌建立感染或引发重新感染。宿主免疫反应可能起作用。我们的长期目标是确定如何将细胞因子生物学用于治疗靶向以减轻艰难梭菌感染或高危患者复发。第3组先天淋巴细胞（ILC3S）是经常发现的罕见免疫细胞粘膜组织。它们产生高水平的IL-22，这是粘膜组织反应的关键调节剂。 IL-22是保持健康和疾病中的肠道稳态至关重要。通过维护上皮屏障，细胞因子在胃肠道感染中具有保护性，尽管IL-22在艰难梭菌感染中的作用尚不清楚。在研究毒素与ILC3之间相互作用的研究中，我们检查了TCDB对IL-22的影响。我们的初步数据表明，TCDB以GTPase依赖性方式在ILC3中诱导IL-22。药理抑制作用表明IL-22的上调是通过CDC42。这些数据构成了我们假设的前提艰难梭菌会调节宿主免疫反应。该应用程序的总体目标是了解 TCDB可以通过该信号通路调节IL-22的ILC3的产生并确定的好处感染过程中IL-22升高到艰难梭菌。在AIM 1中，我们将研究小型GTPase CDC42如何5月调节活化ILC3中的IL-22产生。通过遗传或siRNA介导的cdc42在ILC3S中的缺失，我们将检查这个小的GTPase是否是ILC3激活的负调节剂，并检查是否存在 CDC42和其他信号通路之间的链接，包括STAT3和MAPK。在AIM 2中，我们将检查艰难梭菌和TCDB以及IL-22与GI组织之间的相互作用。我们将检查IL-的功能 22使用结肠器官的还原主义方法在艰难梭菌感染中的信号传导。研究将检查是否 IL-22预防TCDB介导的细胞凋亡，并确定哪些IL-22诱导因素有助于改变利基。体内艰难梭菌感染模型将补充体外实验。这项研究可能确定与IL-22调节有关的新信号通路，这是传染病和慢性炎症场。我们还将对IL-22级别提高的水平有更全面的了解调节炎症环境，有利于艰难梭菌，而不是胃肠道的其他细菌。这就是在预防原发性或复发性艰难梭菌感染中如何操纵IL-22生物学的含义。