Single-Cell Transcriptomics of Eosinophil in Allergic Asthma

<bold>Introduction</bold>. Eosinophils distinguish phenotypic plasticity related to the tissue environment. Single-cell transcriptomics of eosinophils in asthma could reveal the eosinophils heterogeneity, identify new cell-surface markers, and disclose acute allergic asthma episode-related differences of gene expression profiles of eosinophils subtypes leading to the possibility of identifying eosinophil subtype-orientated therapeutic targets. <bold>Aim</bold>. To characterize gene expression profiles of the blood eosinophil in allergic asthma at single-cell level. <bold>Methods</bold>. We included 4 steroid-naive allergic asthma (AA) and 4 healthy control subjects (HS). AA patients underwent bronchial provocation with D. Pteronyssinus allergen. Blood eosinophils were isolated using high-density Ficoll centrifugation and magnetic separation. Single-cell transcriptomic libraries preparation was completed by using the HIVE scRNAseq Solution kit. Sequencing performed by Illumina NovaSeq™ X Series (400M reads, 100 cycles)—analysis performed by BeeNetPlus on Terra automated analysis. <bold>Results</bold>. Analysis revealed a total of 16 distinct blood eosinophil subpopulations among AA patients with 12 of them with clear gene markers. A total of 223 genes were classified as potential markers for blood eosinophil subpopulation identification. 1 cluster was identified as unique for AA patients before and 8 clusters after bronchial provocation imitating acute episodes. 3 clusters were identified as unique for the AA group compared to HS. <bold>Conclusions</bold>. With eosinophil plasticity-related distinct eosinophil subpopulations with unique gene expression profiles might be a target for eosinophil subtype-orientated therapeutic strategies.