In vivo persistence and immuno-pathogenesis of Mycobacterium abscessus in a new Xenopus tadpole model

脓肿分枝杆菌在新爪蟾蝌蚪模型中的体内持久性和免疫发病机制

基本信息

批准号：
10608077
负责人：
Martin S. Pavelka
金额：
$ 19.25万
依托单位：
UNIVERSITY OF ROCHESTER
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-04-11 至 2024-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10608077
关键词：
Acids Address Alleles Amphibia Animal Model Antibiotic Resistance Antibiotic Therapy B-Lymphocytes Bacteria Biological Assay Breathing Bronchiectasis Burkholderia cepacia Chronic Chronic lung disease Comparative Biology Cystic Fibrosis Development Disease Embryo Embryo Research Exhibits Fertilization Flow Cytometry Gene Mutation Genes Genetic Determinism Genus Mycobacterium Histology Homologous Gene Human Immune Immune response Immune system Immunity Immunocompetent Immunocompromised Host Infection Interferons Investigation Knock-out Knockout Mice Label Laboratory Organism Leukocytes Liver Lower respiratory tract structure Lung Lung diseases Lung infections Macrophage Mammals Microbial Biofilms Microscopy Modeling Morphology Multi-Drug Resistance Mus Mycobacterium abscessus Mycobacterium marinum Myeloid Cells Pathogenesis Pathogenicity Pathology Patients Phenotype Positioning Attribute Prevalence Production Proliferating Pseudomonas aeruginosa Refractory Research Proposals Resistance Role Skin Soil System T-Lymphocyte Tadpoles Tissues Transgenic Organisms Virulence Factors Visualization Water Xenopus Xenopus laevis Zebrafish adaptive immunity arm cell envelope chronic infection emerging pathogen genome annotation host colonization human disease human tissue immunopathology in vivo insight intravital microscopy lung pathogen mutant non-tuberculosis mycobacteria novel pathogen prevent promoter respiratory pathogen response transcriptomics

项目摘要

Owing to its increasing prevalence, persistence, multidrug resistance, pathogenicity and treatment challenges, the non-tuberculosis mycobacterium (NTM) Mycobacterium abscessus (Mab) has become a serious threat to humans with chronic lung diseases such as bronchiectasis and cystic fibrosis, as well as immunocompromised patients. However, Mab is still understudied compared to other pathogenic mycobacteria. In addition, there is a limitation in current animal models that poses a real challenge for investigating the respective roles of two Mab morphotypes, smooth (S) and rough (R), in lung immunopathology, persistence and host immune response. The clearance of Mab in immunocompetent and even immunocompromised mice prevent the study of chronic infection, and while for zebrafish embryos are instrumental for investigating Mab infection, they cannot be used to model a pulmonary infection and T cell involvement. Thus, there is a need for complementary animal models. Since like zebrafish embryos, X. laevis tadpoles are transparent, allowing visualization of pathogen dissemination, but that in addition they do have functional lungs and exhibit an immune system including T cells remarkably similar to humans, we propose to develop a X. laevis tadpole model of Mab infection that mimics human pulmonary disease. Relying on an established comparative biology approach to study immunity to mycobacteria in tadpoles and our recent demonstration that both S and R Mab morphotypes readily infect tadpoles, disseminate in tadpole lungs and persist up to 50 days, the objective of the exploratory research proposal is to investigate in vivo for over 40 days Mab persistence, and immuno-pathogenesis. Specifically, to address the hypothesis that persistent R Mab is more actively proliferating and immunopathogenic than S Mab in X. laevis tadpoles we propose: , by comparing the host immune response and persistence of R and S Mab in the lung and other tissues using intravital (1) Characterize immune-pathogenesis in tadpole lungs during persisting Mab infection microscopy flow cytometry and transcriptomics as well as fluorescently labeled Mab and transgenic tadpoles with fluorescent macrophages. (2) Investigate the relevance of S to R morphotype switch in vivo for pathogenesis and persistence , by using a promoter system to control the S to R switch following infection and examining effect of switches on persistence, pathogenicity and host immune response. (3) Investigate genetic determinants of Mab immune-pathogenesis , using selected Mab deletion mutants generated by allelic exchange of Mab-specific genes as well as gene homologs shared by Gram- negative lung pathogens. We anticipate that novel insights relevant to human will be gathered. Our collaborative team is uniquely positioned to carry these studies due to our background and complementary expertise.

由于其患病率增加，持久性，多药抵抗力，致病性和治疗挑战，非结核分枝杆菌（NTM）分枝杆菌（MAB）已成为严重威胁人类患有慢性肺部疾病，例如支气管扩张和囊性纤维化，以及免疫功能低下的患者。但是，与其他致病性相比，MAB仍被研究不足分枝杆菌。此外，当前动物模型有一个限制，这对在肺中调查了两个mab形态的光滑（S）和粗糙（R）的各自的作用免疫病理学，持久性和宿主免疫反应。 MAB在免疫能力和即使是免疫功能低下的小鼠也阻止了慢性感染的研究，而对于斑马鱼胚胎是用于研究mAb感染的工具，它们不能用于建模肺部感染和T细胞参与。因此，需要互补的动物模型。因为像斑马鱼胚胎一样 t是透明的，允许病原体传播可视化，但此外，它们确实具有功能性肺并表现出一种免疫系统，包括与人类非常相似的T细胞，我们建议开发一种模仿人类肺部疾病的mAb感染的X. laevis t t t模型。依靠一个建立的比较生物学方法是研究对t的促成分枝杆菌的免疫力和我们最近的 S和R mAb形态型都易于感染t，在t肺中传播，并长达50天，探索性研究建议的目的是在体内调查40多个 Days mab的持久性和免疫性致病发生。具体而言，要解决持续r的假设与我们提出的X. laevis t相比，MAB比S MAB更为积极地增殖和免疫致病性：，通过比较宿主的免疫反应和R和S MAB在肺和其他组织中使用插入术的持久性（1）在持续的mAb感染过程中表征t的t肺中的免疫性致病发生显微镜流式细胞术和转录组学以及荧光标记的mAb和转基因t 与荧光巨噬细胞。（2）研究S与体内形态型开关的相关性对于发病机理和持久性，经过使用启动子系统控制感染后的S到R开关，并检查开关的效果持久性，致病性和宿主免疫反应。（3）研究MAB免疫可病发生的遗传决定因素，使用选定的MAB删除等位基因交换mAb特异性基因以及革兰氏共享的基因同源物产生的突变体阴性肺病原体。我们预计将收集与人类相关的新颖见解。我们的协作团队是独特的由于我们的背景和补充专业知识，可以进行这些研究。