Comparison of children and adults' lung tissues by scRNA-seq

The present study for the first time described the features of children's lung by scRNA-seq and compared the results to the data acquired from healthy adults (GSE122960). We analyzed the expression levels of viral-entry associated genes in both children and adults' lung tissues by single cell RNA sequencing (scRNA-seq) to explore whether the expression levels of these genes might contribute to the milder symptoms in SARS-CoV-2 infected children. The results of scRNA-seq showed comparable expression of the key genes for SARS-CoV-2 entry in children and adults, including ACE2, TMPRSS2 and FURIN, suggesting that instead of lower virus intrusion rate, other factors are more likely to be the key reasons for the milder symptoms of SARS-CoV-2 infected children. Overall design: Normal lung tissues from 10 children undergoing biopsy or surgery for various reasons were collected for sc-RNA seq. The study was approved by the Institutional Review Board and the Ethics Committee of Shanghai Children's Medical Center (SCMCIRB-K2020034), and written informed consent was obtained from the parents of each patient. The public data of 8 healthy adults were downloaded from Gene Expression Omnibus (GSE122960). We used Canonical Correlation Analysis (CCA) implemented in Seurat V3 (https://github.com/satijalab/seurat) to integrate the two datasets for the feature comparison of children and adults' lung tissues.