Viral Invasion and Type I Interferon Response Characterize the Immunophenotypes During Covid-19 Infection

The new coronavirus Covid-19 has spread globally and caused a pneumonia outbreak. Although the whole genome sequences of Covid-19 have been rapidly obtained, pathogenesis of Covid-19 caused severe disease remains elusive. Understanding the immune responses in patients with severe disease may significantly advance the development of effective therapies. Here, using scRNA-seq technology, we profiled the immunophenotypes of four patients’ PBMCs before, during, and after their ICU cares. Our data identified gene expression signatures of viral invasion and type I interferon (IFN-I) responses as the key manifestations characterizing the life-threatening stage of Covid-19 infection in human. The association between viral load/IFN-α levels and disease severity in Covid-19 infection marked the key difference in the pathogenesis of this new coronavirus from previous coronavirus such as SARS-CoV infections.Funding: This work was supported by Zhongshan Ophthalmic Center Annual Fund to L.W., and National Science and Technology Key Projects for Major Infectious Diseases (2017ZX10302301-002), National Natural Science This preprint research paper has not been peer reviewed. Foundation of China (31470877), Guangzhou Science and Technology Planning Project (201604020006) to X.H.Conflict of Interest: No potential conflict of interest relevant to this article was reported.Ethical Approval: This study adhered to the tenets of the Declaration of Helsinki and was approved by the Institutional Review Boards of the Fifth Affiliated Hospital, Sun Yat-sen University (protocol # K158-1). All subjects provided written informed consent before participation of our study.