Identification of Distinct Immune Cells Associated with Various Clinical Presentations of COVID-19

The cell-mediated protective and pathogenic immune responses to SARS-CoV-2 infection remain largely unknown. Here, we identified 76 distinct cell subsets in the PBMC samples that were associated with various clinical presentations of COVID-19 using scRNA-seq technology coupled with a deep and comprehensive analysis of unique cell surface markers and differentially expressed genes. Notable cell subsets include (NCAM1hiCD160+)NK and (TRAV1-2+CD8+)MAIT cells increased in the asymptomatic subjects, (LAG3+CD160+CD8+)NKT cells increased in the symptomatic patients, (CD68-CSF1R-IL1BhiCD14+)classical monocytes associated with age and disease severity, (CD33-HLA-DMA-CD14+)classical monocytes and (CLEC10A-S100A9lo)pDC associated with the viral persistence, neutrophils and (CD68-CSF1R-IL1BhiCD14+ )classical monocytes dramatically increased in a fatal patient, whereas (LAG3+CD160+CD8+)NKT and (FOXP3+IL2RA+IL7R+CD4+)Treg cells markedly increased in a patient with humoral immunodeficiency. The GO and KEGG analyses identified enriched pathways related to immune responses, inflammation, apoptosis and other processes. These findings may enhance our understanding of the immunopathogenesis of COVID-19 and help develop novel strategies against SARS-CoV-2 infection.Funding Information: This study is supported in part by the Department of Science and Technology of Shaanxi Province (Grant No. 2020ZDXM2-SF-02) (CZ and BS) and the operational funds from The First Affiliated Hospital of Xi’an Jiaotong University (CZ and BS).Declaration of Interests: The authors declare that they have no competing financial interests.