Journal of Allergy and Clinical Immunology ( IF 14.2 ) Pub Date : 2020-10-08 , DOI: 10.1016/j.jaci.2020.09.032 Hui Li 1 , Huaqi Wang 1 , Leon Sokulsky 2 , Shaoxia Liu 1 , Rui Yang 1 , Xiaojie Liu 3 , Lujia Zhou 3 , Juan Li 1 , Chun Huang 1 , Fangfang Li 1 , Xu Lei 1 , Hongxia Jia 1 , Jiuling Cheng 1 , Fuguang Li 3 , Ming Yang 4 , Guojun Zhang 1
Background
Asthma exacerbations are associated with heightened asthma symptoms, which can result in hospitalization in severe cases. However, the molecular immunologic processes that determine the course of an exacerbation remain poorly understood, impeding the progression of development of effective therapies.
Objective
Our aim was to identify candidate genes that are strongly associated with asthma exacerbation at a cellular level.
Methods
Subjects with asthma exacerbation and healthy control subjects were recruited, and bronchoalveolar lavage fluid was isolated from these subjects via bronchoscopy. Cells were isolated through fluorescence-activated cell sorting, and single-cell RNA sequencing was performed on enriched cell populations.
Results
We showed that the levels of monocytes, CD8+ T cells, and macrophages are significantly elevated in the bronchoalveolar lavage fluid of patients. A set of cytokines and intracellular transduction regulators are associated with asthma exacerbations and are shared across multiple cell clusters, forming a complicated molecular framework. An additional group of core exacerbation-associated modules is activated, including eukaryotic initiation factor 2 signaling, ephrin receptor signaling, and C-X-C chemokine receptor type 4 signaling in the subpopulations of CD8+ T cells (C1-a) and monocyte clusters (C7 clusters), which are associated with infection.
Conclusion
Our study identified a significant number of severe asthma–associated genes that are differentially expressed by multiple cell clusters.