Heightened innate immune responses in the respiratory tract of COVID-19 patients
Zhuo Zhou1,2,14, Lili Ren2,3,14, Li Zhang4,14, Jiaxin Zhong4,5,14, Yan Xiao2,14, Zhilong Jia6
The outbreaks of 2019 novel coronavirus disease (COVID-19) caused by SARS-CoV44 2 infection has posed a severe threat to global public health. It is unclear how the humanimmune 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 causeshypercytokinemia. Compared to SARS-CoV, which is thought to induce inadequateinterferon (IFN) responses, SARS-CoV-2 robustly triggered expression of numerousIFN-inducible genes (ISGs). These ISGs exhibit immunopathogenic potential, with overrepresentation of genes involved in inflammation. The transcriptome data was alsoused to estimate immune cell populations, revealing increases in activated dendritic cells and neutrophils. Collectively, these host responses to SARS-CoV-2 infectioncould further our understanding of disease pathogenesis and point towards antiviral
strategies.
