Ubiquitin-Modified Proteome of SARS-CoV-2-Infected Host Cells Reveals Insights into Virus-Host Interaction and Pathogenesis.

The outbreak of coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has posed a serious threat to global public health. The mechanism of pathogenesis and the host immune response to SARS-CoV-2 infection are largely unknown. In the present study, we applied a quantitative proteomic technology to identify and quantify the ubiquitination changes that occur in both the virus and the Vero E6 cells during SARS-CoV-2 infection. By applying label-free, quantitative liquid chromatography with tandem mass spectrometry proteomics, 8943 lysine ubiquitination sites on 3086 proteins were identified, of which 138 sites on 104 proteins were quantified as significantly upregulated, while 828 sites on 447 proteins were downregulated at 72 h post-infection. Bioinformatics analysis suggested that SARS-CoV-2 infection might modulate host immune responses through the ubiquitination of important proteins, including USP5, IQGAP1, TRIM28, and Hsp90. Ubiquitination modification was also observed on 11 SAR-CoV-2 proteins, including proteins involved in virus replication and inhibition of the host innate immune response. Our study provides new insights into the interaction between SARS-CoV-2 and the host as well as potential targets for the prevention and treatment of COVID-19.

Kindergartens Reopening in the Period of Regular Epidemic Prevention and Control, Benefitial or Harmful?

In the period of regular epidemic prevention and control of Coronavirus disease 2019 (COVID-19) in our country, work resumption has been fully advanced. But there are still new sporadic local cases and imported cases across the country. In this situation, whether kindergartens reopening will increase the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread still remains uncertain. We reviewed two pediatric patients with moderate COVID-19, collected the epidemiologic information and monitored the cycle threshold value of rectal specimen and the viral loads, and discussed the transmission of SARS-CoV-2 in pediatric patients and the virulence of feces in children with moderate COVID-19, in order to analyze the risk of kindergartens reopening.