Components of distinct rural environments confer asthma protection in childhood via A20-mediated immune effects in dendritic cells on regulatory T cells

本项目旨在解开A20介导的树突状细胞(DC)和调节性T细胞(Tregs)通过环境不同区域的化合物刺激血细胞而对儿童哮喘的不同保护性免疫调节机制。独一无二的自然暴露在两个强烈保护儿童哮喘的环境中，即欧洲的农场和中国的农村地区，为评估彼此不同的潜在免疫机制提供了绝佳的机会。由于A20(抗炎)和炎症体调节在不同的粉尘刺激下有不同的表达，我们将在不同的粉尘暴露于细胞系和分离的细胞后确定A20和炎症体调节的具体作用。我们将通过A20介导的树突状细胞对Tregs的作用，通过暴露于健康和哮喘儿童不同的农村环境粉尘，来揭示特定的哮喘保护免疫机制。我们将揭示来自不同环境地区(德国、芬兰、中国)的环境粉尘提取物对T调节功能、甲基化、乙酰化(FOXP3启动子)和mTOR信号转导的影响。我们的目标是确定树突状细胞中A20调节的信号和炎症体的激活。我们的目的是研究树突状细胞A20调节和炎性小体激活对Treg介导的抑制的影响。最后，在一项原理验证实验中，我们将与哮喘儿童相比，评估粉尘刺激对哮喘儿童DC中A20调节、炎症体和Treg调节的影响。微生物的不同代谢物，如短链脂肪酸(SCFA)，已被证明对Treg功能保护小鼠结肠炎至关重要，并可能对小鼠过敏性呼吸道炎症起到保护作用。因此，我们的目标是确定SCFA(以及不同环境地区粉尘的其他代谢物)对A20介导的DC-Treg轴和炎症小体调节的影响，以保护哮喘。为了确定相关成分，我们将检测不同粉尘中存在的SCFA和代谢物的含量。我们的目的是研究SCFA在体外对哮喘和哮喘儿童DC和Treg反应的影响。我们现在的独特地位是：i)有足够数量和质量的来自不同农村环境的粉尘可用，ii)对不同队列中有风险和受保护的哮喘儿童进行比较，以全面评估A20介导的DC-Treg机制，以用于后续儿童哮喘的一级/二级预防策略。该项目不仅将为哮喘保护的相关因素提供深入的途径分析，而且是一个无与伦比的机会，可以在环境非常不同的地区(欧洲/中国)理清不同或共同的途径，这对于将其转化为未来儿童哮喘预防战略至关重要。

This project aims to disentangle distinct protective immune regulatory mechanisms of A20-mediated effects of dendritic (DC) and regulatory T cells (Tregs) for childhood asthma by stimulation of blood cells with compounds of environmentally distinct areas. The unique natural exposure to two environments strongly protecting from childhood asthma, i.e. farms in Europe and rural areas in China offers the great opportunity to assess underlying immune mechanisms which are distinct from each other. As A20 (anti-inflammatory) and inflammasome regulation have been shown differentially expressed following different dust stimulation, we will identify the specific role of A20 and inflammasome regulation following environmental exposure with different dusts in cell lines, and isolated cells. We will disentangle specific asthma-protective immune mechanisms via A20-mediated effects of DCs on Tregs through exposure to distinct rural environmental dust in healthy and asthmatic children. We will unravel the effect of environmental dust extracts from different environmental areas (Germany, Finland, China) on T reg-function, methylation, acetylation (FOXP3 promoter), and mTOR signalling. We aim to identify signalling of A20 regulation in DCs and inflammasome activation. We aim to investigate the effect of A20-regulation in DCs and inflammasome activation on Treg-mediated suppression. Finally, in a proof-of-principle experiment, we will assess the effects of dust stimulation on A20-regulation in DCs, inflammasome and Treg regulation in children protected from asthma in comparison to asthmatic children. Different metabolites of microbial bacteria such as short-chain fatty acids (SCFA) have been shown critical for Treg-function protecting against murine colitis, and possibly murine allergic airway inflammation. Thus, we aim to identify the effect of SCFA (and other metabolites of dust of distinct environmental areas) on the regulation of the A20-mediated DC-Treg-axis and inflammasome regulation for asthma protection. To pin-point the relevant components, we will examine the content of SCFA and metabolites present in the different dusts. We aim to investigate the effects of SCFA on DC and Treg-responses in vitro in protected and asthmatic children. We are now in the unique position of i) having the dusts from distinct rural environments available in sufficient amount and quality, ii) having a comparison of children at risk and protected from asthma in different cohorts available to comprehensively assess A20-mediated DC-Treg mechanisms for subsequent strategies for primary/secondary prevention of childhood asthma. This project will not only provide in depth pathway analysis of relevant factors for asthma protection, but represents an unparalleled opportunity to disentangle different or common pathways in environmentally very distinct areas (Europe/China), which is critical for the translation into future prevention strategies for childhood asthma.