Multinational study on rural environmental protection for childhood asthma – a central role for dendritic and regulatory B-cells during immune maturation

这项跨国研究旨在确定欧洲和中国儿童哮喘环境保护的核心机制。通过评估免疫成熟过程中的树突状细胞（DC）和调节性b细胞（Breg），该项目旨在通过两种强大的哮喘保护环境，找出有助于哮喘保护的新型中央调节枢纽。欧洲出生队列中来自最强哮喘保护环境（即农业）的几个年龄段儿童的连续血液样本的独特机会，以及同时从6岁时哮喘患病率高的香港（和广州）城市儿童和低患病率的从化农村儿童中招募儿童，可以比较欧洲和中国的哮喘保护机制。来自两个强“哮喘保护”地区的不同粉尘将通过16srRNA和宏基因组学分析微生物组成分，以确定未来研究的主要成分。两个中心细胞群，即DC和Bregs将被检查，以解开他们的功能贡献，这种环境保护。为了评估DC和Bregs的功能，将在儿童外周血中进行粉尘刺激后的动力学和剂量依赖性实验，并辅以农场粉尘引发的DC及其与B/ t细胞相互作用的共培养模型。与此同时，小鼠模型旨在利用转基因小鼠识别新的调节因子。最后，通过评估保护性环境暴露的年龄依赖性差异，将在出生队列中检查维持健康免疫平衡的潜在特定窗口。出生、6岁和10岁儿童的免疫调节将通过RNA-seq筛选，dc /Bregs的年龄依赖性细胞调节将通过流式细胞术检测。作为一项原理验证实验，将在发病的喘息儿童、明显哮喘儿童和健康对照中进行breg耗尽PBMCs的功能刺激，以确定疾病早期发病和明显哮喘期间的调节。该项目不仅将解开dc和Bregs的核心作用，而且还代表了一个独特的机会来剖析环境介导的儿童哮喘保护机制，如何在未来的预防研究中实施。此外，这些实验有可能确定人类和小鼠中最关键的时间窗口，在那里健康的免疫调节可以通过环境暴露来维持甚至恢复。这对于未来针对儿童哮喘的保护策略至关重要。

This multinational study aims to identify central mechanisms of environmental protection for childhood asthma in both Europe and China. By assessing dendritic cells (DC) and regulatory B-cells (Breg) during immune maturation, this project aims to disentangle novel central regulatory hubs which contribute to asthma protection via two strong asthma-protective environments. The unique chance of having consecutive blood samples of children at several ages of an European birth cohort from the strongest asthma-protective environment, namely farming, available and in parallel recruiting Chinese children from urban HongKong (and Guangzhou) with high asthma prevalence and rural Conghua with low prevalence at age 6 years allows the comparison of asthma-protective mechanisms across Europe and China. Different dusts from both strong “asthma-protective” areas will be analysed for microbiome components by 16srRNA and metagenomics to identify lead components for future studies. Two central cell populations, namely DC and Bregs will be examined to disentangle their functional contribution for this environmental protection. For functional assessment of DC and Bregs, kinetic and dose-dependent experiments following dust stimulation will be performed in peripheral blood of children, complemented by co-culture models of farm-dust primed DCs and their interaction with B/T-cells. In parallel, murine models aim to identify novel regulators using genetically modified mice. Finally, a potential specific window of maintaining healthy immune balance will be examined in the birth cohort by asssessing age-dependent differences for protective environmental exposure. Immune regulation of children at birth, age 6 and 10 yrs will be screened by RNA-seq and age-dependent cellular regulation of DCs/Bregs will be examined by flow cytometry. As a proof-of-principle experiment functional stimulation of Breg-depleted PBMCs will be performed in children with onset of wheeze, children with manifest asthma and healthy controls in order to identify regulation during early onset of disease and during manifest asthma.This project will not only disentangle a central role of DCs and Bregs, but also represents a unique opportunity to dissect mechanisms how environment-mediated protection against childhood asthma may be implemented in future prevention studies. Furthermore, these experiments have the potential to identify the most critical time windows in humans and mice, where healthy immune regulation can be maintained or even restored by environmental exposure. This is crucial for future protective strategies against childhood asthma.