Summary The outbreaks of 2019 novel coronavirus disease (COVID-19) caused by SARS-CoV-2 infection have posed a severe threat to global public health. It is unclear how the human immune system responds to this infection. Here, we used metatranscriptomic sequencing to profile immune signatures in the bronchoalveolar lavage fluid of eight COVID-19 cases. The expression of proinflammatory genes, especially chemokines, was markedly elevated in COVID-19 cases compared to community-acquired pneumonia patients and healthy controls, suggesting that SARS-CoV-2 infection causes hypercytokinemia. Compared to SARS-CoV, which is thought to induce inadequate interferon (IFN) responses, SARS-CoV-2 robustly triggered expression of numerous IFN-stimulated genes (ISGs). These ISGs exhibit immunopathogenic potential, with overrepresentation of genes involved in inflammation. The transcriptome data was also used to estimate immune cell populations, revealing increases in activated dendritic cells and neutrophils. Collectively, these host responses to SARS-CoV-2 infection could further our understanding of disease pathogenesis and point toward antiviral strategies. Graphical Abstract Highlights • BALF cell transcriptome indicates robust innate immune responses in COVID-19 patients • COVID-19 patients exhibit chemokine-dominant hypercytokinemia • ISGs are highly expressed in COVID-19 patients and exhibit pathogenic potential Zhou et al. use metatranscriptomic sequencing to profile immune signatures in the bronchoalveolar lavage fluid of COVID-19 patients. COVID-19 patients exhibit robust innate immune responses with notable hypercytokinemia and increased expression of IFN-stimulated genes. This analysis provides timely information for understanding SARS-CoV-2-host interactions and COVID-19 pathogenesis.
【저자키워드】 COVID-19, SARS-CoV-2, coronavirus, innate immune response, Metatranscriptomic sequencing, hypercytokinemia, chemokines, Bronchoalveolar lavage fluid, interferon response, interferon-stimulated genes,