Primordially conserved principles governing mucosal immune responses to pathogens and microbiota

控制对病原体和微生物群的粘膜免疫反应的基本保守原则

• 批准号: 8818513
• 负责人: J. ORIOL SUNYER
• 金额: $ 32.21万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2018-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8818513
• 关键词: Area; B-Lymphocyte Subsets; B-Lymphocytes; Birds; CD4 Positive T Lymphocytes; Cell Communication; Complement Activation; Crohn' s disease; Dependency; Dimensions; Disease; Distant; Fishes; Funding; Generations; Gills; Goals; Health; Homeostasis; Human; Imagery; Immune system; Immunoglobulin A; Immunoglobulin G; Immunoglobulin Isotypes; Immunoglobulin M; Immunoglobulins; In Vitro; Infection; Infection Control; Inflammatory Bowel Diseases; Interleukin-10; Knowledge; Lead; Lymphoid Tissue; Mammals; Measures; Microbe; Modeling; Mucosal Immune Responses; Mucosal Immunity; Mucous Membrane; Mucous body substance; Mus; Oral cavity; Pathway interactions; Phylogenetic Analysis; Plasma; Production; Reagent; Role; Serum; Site; Skin; Spleen; Surface; T cell response; T-Cell Depletion; T-Lymphocyte; Technology; Testing; Tetrapoda; Time; Tissues; Vertebrates; base; chemokine; chemokine receptor; human disease; in vivo; innovation; insight; interdisciplinary approach; microbiome; mortality; mucosal site; mucosal vaccine; novel; pathogen; response

DESCRIPTION (provided by applicant): The mucosal surfaces (i.e., gut, mouth) of vertebrates are continuously exposed to endogenous and exogenous microbes. Throughout evolutionary time, specific immunoglobulin (Ig) isotypes have become specialized to protect such mucosal sites. In mammals and birds, IgA predominates at mucosal surfaces, whereas IgG and IgM provide systemic protection. Although mucosal Igs were thought to evolve in four legged (tetrapod) species, during the previous funding period, we discovered that fish contain an Ig isotype, IgT, that is specialized for gut mucosal immunity. Thereafter we discovered extraordinarily similar IgT responses occurred in other mucosal sites, including the skin and gills. Based on these results, we hypothesize that IgT responses in all fish mucosal areas (gut, gills and skin) operate under the guidance of primordially conserved principles. Thus, the overarching goal of this renewal is to test the hypothesis that pathogen-specific IgT responses are locally induced (Aim 1) in a T cell-dependent fashion (Aim 2), and lead to the generation of effector IgT+ B cells that generate protective IgT responses and maintain tissue homeostasis through the production of IL-10 (Aim 3). In addition, as we have found bacterial microbiota from gill, gut and skin prevalently coated by IgT, we hypothesize that commensal microbiota induce local T-cell independent IgT responses (Aim 2) and, that this IgT homeostatically regulates the microbiome at mucosal sites (Aim 3). Delineating strategies of immunoglobulin-based mucosal immunity in our model will not only illuminate unresolved paradigms of mucosal immune responses in non-tetrapods, but will also provide insights into responses. More specifically, our proposed studies are expected to: a) provide novel insights into the extrafollicular pathways by which IgA production is regulated in response to pathogens and microbiota; b) contribute towards the understanding of the roles of CD4+ T cells in generating IgA responses to pathogens and microbiota; c) provide ground-breaking knowledge on the mechanisms by which mucosal Igs control microbiota and its composition (microbiome) at multiple mucosal sites. Thus, the aims of this renewal are: AIM 1. To investigate the inductive and effector sites involved in the generation of IgT responses and, to analyze the existence of a common mucosal immune system (CMIS) in fish. To uncover the IgT inductive and effector sites, in vivo pathogen-induced B and T cell proliferative responses along with the visualization of B-Tcell interactions will be assessed in all MALTs and the spleen, using normal fish and a novel splenectomized fish model. Here we will also assess the existence of a common mucosal immune system (CMIS) by determining whether B/T cell responses induced at one mucosal site lead to effector responses at other distant mucosal areas. AIM 2. To investigate the T-cell dependency of IgT responses to pathogens and microbiota. Using an innovative CD4-T cell depletion fish model, we will assess fish mortality rate, pathogen load, B cell proliferative and pathogen-specific Ig responses. We will also evaluate the effect of CD4-T cell depletion on the composition of all gut, gill and skin microbiomes and the percentage of bacterial microbiota coated with IgT and IgM. To gain insight into the mechanisms by which IgT responses are modulated in the absence of CD4+ T cells, we will also investigate the effect of CD4+ T cell depletion on the IgT sequence repertoire of all mucosal sites of na�ve and infected fish. AIM 3. To investigate the requirement of IgT+ B cells for the control of pathogens and bacterial microbiota. The goals of this aim will be accomplished using a powerful and novel IgT+ B cell depletion fish model. Fish mortality rates, tissue damage, pathogen load, complement activation and pathogen-specific systemic and mucosal Ig responses will be assessed in IgT+ B cell depleted fish upon pathogen challenge. Using the same fish models we will also evaluate changes in the microbiome composition of all mucosal sites and the percentage of bacterial microbiota coated with IgT and IgM.

描述(申请人提供)：脊椎动物的粘膜表面(即肠道、口腔)持续暴露于内源和外源微生物。在整个进化过程中，特定的免疫球蛋白(Ig)亚型已经变得专门化，以保护这些粘膜部位。在哺乳动物和鸟类中，免疫球蛋白A主要存在于粘膜表面，而免疫球蛋白和免疫球蛋白M则提供全身保护。虽然粘膜免疫球蛋白被认为是在四条腿(四足类)物种中进化的，但在之前的资助期间，我们发现鱼含有一种免疫球蛋白同型IGT，它专门用于肠道粘膜免疫。此后，我们发现在包括皮肤和鳃在内的其他粘膜部位也出现了非常相似的IGT反应。基于这些结果，我们假设所有鱼类粘膜区域(肠道、鳃和皮肤)的IGT反应都是在原始保守原则的指导下进行的。因此，此次更新的首要目标是验证病原体特异性IGT反应是以T细胞依赖的方式局部诱导(目标1)的假设(目标2)，并导致产生效应性IGT+B细胞，产生保护性IGT反应并通过产生IL-10维持组织动态平衡(目标3)。此外，由于我们已经发现来自鳃、肠道和皮肤的细菌微生物群普遍被IGT覆盖，我们假设共生微生物群诱导局部T细胞非依赖性IGT反应(目标2)，并且这种IGT稳态调节粘膜部位的微生物群(目标3)。在我们的模型中描绘基于免疫球蛋白的黏膜免疫的策略不仅将阐明非四足动物黏膜免疫反应的未解决范例，而且还将提供对反应的洞察。更具体地说，我们拟议的研究有望：a)为卵泡外免疫球蛋白A的产生调控病原体和微生物区系的途径提供新的见解；b)有助于理解CD4+T细胞在产生对病原体和微生物区系的IgA反应中的作用；c)提供关于粘膜免疫球蛋白控制多个粘膜部位的微生物区系及其组成(微生物组)的机制的开创性知识。因此，这次更新的目的是：1.研究IGT反应的诱导和效应部位，并分析鱼类中是否存在共同的粘膜免疫系统(CMIS)。为了揭示IGT的诱导和效应部位，将使用正常FISH和一种新的脾切除FISH模型，在体内评估病原体诱导的B和T细胞增殖反应以及B-T细胞相互作用的可视化。在这里，我们还将通过确定在一个粘膜部位诱导的B/T细胞反应是否会导致其他远处粘膜区域的效应者反应来评估共同粘膜免疫系统(CMIS)的存在。目的2.研究T细胞对病原体和微生物区系对IGT反应的依赖性。使用创新的CD4-T细胞耗尽FISH模型，我们将评估鱼的死亡率、病原体负载、B细胞增殖和病原体特异性Ig反应。我们还将评估CD4-T细胞耗尽对所有肠道、鳃和皮肤微生物群组成的影响，以及覆盖IGT和IgM的细菌微生物群的百分比。为了深入了解在没有CD4+T细胞的情况下IGT反应的调节机制，我们还将 研究CD_4~+T细胞耗竭对NA、�、VE和感染鱼所有粘膜部位IGT序列的影响。目的3.探讨IGT+B细胞对病原菌和微生物区系控制的需求。这一目标的目标将使用一种强大而新颖的IGT+B细胞耗竭FISH模型来实现。将评估IGT+B细胞耗竭的鱼类在病原体攻击时的鱼死亡率、组织损伤、病原体载量、补体激活以及病原体特异性的全身和粘膜Ig反应。使用相同的FISH模型，我们还将评估所有粘膜部位的微生物群组成的变化，以及覆盖有IGT和IgM的细菌微生物群的百分比。