The noncoding and coding transcriptional landscape of the peripheral immune response in patients with COVID‐19

Background COVID‐19 is currently a global pandemic, but the response of human immune system to severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection remains unclear. Noncoding RNAs serve as immune regulators and thus may play a critical role in disease progression. Methods We performed multi‐transcriptome sequencing of both noncoding RNAs and mRNAs isolated from the red blood cell depleted whole blood of moderate and severe COVID‐19 patients. The functions of noncoding RNAs were validated by analyses of the expression of downstream mRNAs. We further utilized the single‐cell RNA‐seq data of COVID‐19 patients from Wilk et al. and Chua et al. to characterize noncoding RNA functions in different cell types. Results We defined four types of microRNAs with different expression tendencies that could serve as biomarkers for COVID‐19 progress. We also identified miR‐146a‐5p, miR‐21‐5p, miR‐142‐3p, and miR‐15b‐5p as potential contributors to the disease pathogenesis, possibly serving as biomarkers of severe COVID‐19 and as candidate therapeutic targets. In addition, the transcriptome profiles consistently suggested hyperactivation of the immune response, loss of T‐cell function, and immune dysregulation in severe patients. Conclusions Collectively, these findings provide a comprehensive view of the noncoding and coding transcriptional landscape of peripheral immune cells during COVID‐19, furthering our understanding and offering novel insights into COVID‐19 pathogenesis. Highlight 1. miR‐146a‐5p, miR‐21‐5p, and miR‐142‐3p are potential biomarkers of, and therapeutic targets for COVID‐19. 2. Several miRNAs, such as miR‐15b‐5p, are specific for severe COVID‐19 and may serve as potential biomarkers and therapeutic targets. 3. The blood transcriptome profiles suggest hyperactivation of the immune response, loss of T‐cell function, and immune dysregulation in patients with severe COVID‐19.