Understanding Mechanisms Underlying Chronic Stress-Induced Asthma in Children by Population and Single-Cell Epigenomics Approaches

总结 哮喘是一种严重的长期肺部疾病，影响着美国数百万儿童。的感染 鼻病毒（RV）是哮喘发作的最常见触发因素，可能危及患有哮喘的儿童的生命。 预先存在的条件。在哮喘相关疾病中存在显著的种族和民族差异， 非洲裔美国人和西班牙裔儿童更有可能被诊断为哮喘， 与非西班牙裔白色儿童相比，哮喘相关的发病率。遗传因素单独或 与环境暴露或生活方式的差异相结合是重要的，但还不能完全 解释观察到的差异。社会环境，如种族和族裔的慢性压力源， 少数群体与感染和包括哮喘在内的慢性病的易感性增加有关。 我们假设，儿童时期的社会劣势导致了关键基因的长期表观遗传改变。 影响免疫细胞基因功能的调节区，其负面影响抗病毒防御， 从而增加哮喘的风险。我们的目标是将联合收割机基于群体的鼻粘膜表观基因组定位与鼻粘膜上皮细胞的表观基因组定位相结合， 非裔美国儿童哮喘大型队列的粘膜单免疫细胞分析 关于哮喘和病毒状态以及几个领域的慢性压力暴露的详细信息。在 目的1，我们将使用我们的甲基化捕获测序方法实现表观基因组富集测定 为了查询鼻粘膜中的完整功能性甲基化组（估计覆盖约3M动态CpG）， 成千上万的孩子。我们将在特征良好的儿科队列中部署该方法，以探索 鼻表观基因组特征对捕获慢性应激、病毒感染沿着哮喘的预测能力 表型在目标2中，我们将通过高通量转录组学和免疫细胞生物学分析来描绘免疫细胞景观。 在数百名哮喘儿童中进行单细胞分辨率的表观基因组测定。我们将把我们的单细胞 对来自暴露于高水平与低水平慢性病毒的RV感染儿童的血液进行分析的努力 强调表征免疫细胞信号传导和病毒反应机制的表观遗传学改变， 社会经验的结果。在目标3中，我们将在体外验证RV反应， 巨噬细胞从儿童的循环单核细胞中分化出来，与慢性应激不一致 exposure.我们将在体外实验前后进行详细的单细胞转录组和表观基因组作图 这将使我们能够量化社会劣势对免疫基因表达的影响 在基线时和对RV感染的反应。 总的来说，我们的计划将提供新的见解如何基因和社会环境联合收割机结合起来，以影响 对环境压力源的反应的异质性，并导致儿童的健康差异 哮喘

SUMMARY Asthma is a severe long-term disease of the lungs affecting millions of children in the US. An infection by Rhinovirus (RV) is the most common trigger of an asthma attack which can be life threating for children with a pre-existing condition. There are significant racial and ethnic disparities in asthma-related conditions where African American and Hispanic children are more likely to have a diagnosis of asthma and significantly higher asthma-related morbidity in comparisons with non-Hispanic white children. Genetic factors alone or in combination with differences in environment exposures or lifestyle are important but have not been able to fully explain observed disparities. Social environment such as chronic stressors experienced by racial and ethnic minority groups have been linked to increased susceptibility to infection and chronic illness including asthma. We hypothesize that social disadvantages during childhood result in long-lasting epigenetic alterations in key regulatory regions impacting immune cell gene function that negatively impacts antiviral defense and subsequently increase the risk of asthma. Our goal is to combine population-based epigenome mapping in nasal mucosa with single immune cell analysis in large pediatric asthma cohorts of African American children with detailed information about asthma and viral status as well as chronic stress exposures of several domains. In Aim 1, we will implement an epigenome enrichment assay using our Methylation Capture Sequencing approach to query the complete functional methylome in nasal mucosa (estimated to cover ~3M dynamic CpGs) derived from thousands of children. We will deploy the approach in well-characterized pediatric cohorts to explore predictive power of nasal epigenome signatures to capture chronic stress, viral infection along with asthma phenotypes. In Aim 2, we will profile the immune cell landscape by high-throughput transcriptomic and epigenome assays at single-cell resolution in hundreds of children with asthma. We will focus our single-cell profiling efforts in blood derived from RV infected children that are exposed to high vs. low levels of chronic stress to characterize immune cell signaling and viral response mechanisms epigenetically altered as a consequence of social experiences. In Aim 3, we will perform in vitro validations of RV response in primary macrophages differentiated from circulating monocytes from children that are discordant for chronic stress exposure. We will perform detailed single-cell transcriptome and epigenome mapping before and after in vitro infection with RV which will allow us to quantify the effects of social disadvantages on immune gene expression at baseline and in response to RV infection. Overall, our program will provide new insight into how genes and the social environment combine to influence heterogeneity in the response to environmental stressors and contribute to the health disparity seen in children with asthma.