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2.
Cell Discov ; 7(1): 38, 2021 May 25.
Article in English | MEDLINE | ID: covidwho-1243287

ABSTRACT

The newly emerging coronavirus SARS-CoV-2 causes severe lung disease and substantial mortality. How the virus evades host defense for efficient replication is not fully understood. In this report, we found that the SARS-CoV-2 nucleocapsid protein (NP) impaired stress granule (SG) formation induced by viral RNA. SARS-CoV-2 NP associated with the protein kinase PKR after dsRNA stimulation. SARS-CoV-2 NP did not affect dsRNA-induced PKR oligomerization, but impaired dsRNA-induced PKR phosphorylation (a hallmark of its activation) as well as SG formation. SARS-CoV-2 NP also targeted the SG-nucleating protein G3BP1 and impaired G3BP1-mediated SG formation. Deficiency of PKR or G3BP1 impaired dsRNA-triggered SG formation and increased SARS-CoV-2 replication. The NP of SARS-CoV also targeted both PKR and G3BP1 to impair dsRNA-induced SG formation, whereas the NP of MERS-CoV targeted PKR, but not G3BP1 for the impairment. Our findings suggest that SARS-CoV-2 NP promotes viral replication by impairing formation of antiviral SGs, and reveal a conserved mechanism on evasion of host antiviral responses by highly pathogenic human betacoronaviruses.

4.
Cell Mol Immunol ; 18(3): 613-620, 2021 03.
Article in English | MEDLINE | ID: covidwho-894385

ABSTRACT

A novel SARS-related coronavirus (SARS-CoV-2) has recently emerged as a serious pathogen that causes high morbidity and substantial mortality. However, the mechanisms by which SARS-CoV-2 evades host immunity remain poorly understood. Here, we identified SARS-CoV-2 membrane glycoprotein M as a negative regulator of the innate immune response. We found that the M protein interacted with the central adaptor protein MAVS in the innate immune response pathways. This interaction impaired MAVS aggregation and its recruitment of downstream TRAF3, TBK1, and IRF3, leading to attenuation of the innate antiviral response. Our findings reveal a mechanism by which SARS-CoV-2 evades the innate immune response and suggest that the M protein of SARS-CoV-2 is a potential target for the development of SARS-CoV-2 interventions.


Subject(s)
Adaptor Proteins, Signal Transducing/immunology , COVID-19/immunology , Immunity, Innate , SARS-CoV-2/immunology , Signal Transduction/immunology , Viral Matrix Proteins/immunology , HEK293 Cells , HeLa Cells , Humans
5.
Cell Res ; 30(8): 670-677, 2020 08.
Article in English | MEDLINE | ID: covidwho-637104

ABSTRACT

The 2019 novel coronavirus (SARS-CoV-2) outbreak is a major challenge for public health. SARS-CoV-2 infection in human has a broad clinical spectrum ranging from mild to severe cases, with a mortality rate of ~6.4% worldwide (based on World Health Organization daily situation report). However, the dynamics of viral infection, replication and shedding are poorly understood. Here, we show that Rhesus macaques are susceptible to the infection by SARS-CoV-2. After intratracheal inoculation, the first peak of viral RNA was observed in oropharyngeal swabs one day post infection (1 d.p.i.), mainly from the input of the inoculation, while the second peak occurred at 5 d.p.i., which reflected on-site replication in the respiratory tract. Histopathological observation shows that SARS-CoV-2 infection can cause interstitial pneumonia in animals, characterized by hyperemia and edema, and infiltration of monocytes and lymphocytes in alveoli. We also identified SARS-CoV-2 RNA in respiratory tract tissues, including trachea, bronchus and lung; and viruses were also re-isolated from oropharyngeal swabs, bronchus and lung, respectively. Furthermore, we demonstrated that neutralizing antibodies generated from the primary infection could protect the Rhesus macaques from a second-round challenge by SARS-CoV-2. The non-human primate model that we established here provides a valuable platform to study SARS-CoV-2 pathogenesis and to evaluate candidate vaccines and therapeutics.


Subject(s)
Betacoronavirus/genetics , Betacoronavirus/immunology , Coronavirus Infections/pathology , Disease Models, Animal , Macaca mulatta/virology , Pneumonia, Viral/pathology , Animals , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , Betacoronavirus/isolation & purification , COVID-19 , Coronavirus Infections/blood , Coronavirus Infections/diagnostic imaging , Coronavirus Infections/virology , Female , Immunohistochemistry , Male , Pandemics , Pneumonia, Viral/blood , Pneumonia, Viral/diagnostic imaging , Pneumonia, Viral/virology , RNA, Viral/genetics , Radiography, Thoracic , Real-Time Polymerase Chain Reaction , SARS-CoV-2 , Viral Load , Virus Replication
6.
Signal Transduct Target Ther ; 5(1): 100, 2020 06 19.
Article in English | MEDLINE | ID: covidwho-606785
7.
Emerg Microbes Infect ; 9(1): 386-389, 2020.
Article in English | MEDLINE | ID: covidwho-1080

ABSTRACT

In December 2019, a novel coronavirus (2019-nCoV) caused an outbreak in Wuhan, China, and soon spread to other parts of the world. It was believed that 2019-nCoV was transmitted through respiratory tract and then induced pneumonia, thus molecular diagnosis based on oral swabs was used for confirmation of this disease. Likewise, patient will be released upon two times of negative detection from oral swabs. However, many coronaviruses can also be transmitted through oral-fecal route by infecting intestines. Whether 2019-nCoV infected patients also carry virus in other organs like intestine need to be tested. We conducted investigation on patients in a local hospital who were infected with this virus. We found the presence of 2019-nCoV in anal swabs and blood as well, and more anal swab positives than oral swab positives in a later stage of infection, suggesting shedding and thereby transmitted through oral-fecal route. We also showed serology test can improve detection positive rate thus should be used in future epidemiology. Our report provides a cautionary warning that 2019-nCoV may be shed through multiple routes.


Subject(s)
Betacoronavirus/isolation & purification , Coronavirus Infections/transmission , Feces/virology , Pneumonia, Viral/transmission , Virus Shedding , COVID-19 , China , Coronavirus Infections/blood , Humans , Pneumonia, Viral/blood , SARS-CoV-2
8.
Nature ; 579(7798): 270-273, 2020 03.
Article in English | MEDLINE | ID: covidwho-246

ABSTRACT

Since the outbreak of severe acute respiratory syndrome (SARS) 18 years ago, a large number of SARS-related coronaviruses (SARSr-CoVs) have been discovered in their natural reservoir host, bats1-4. Previous studies have shown that some bat SARSr-CoVs have the potential to infect humans5-7. Here we report the identification and characterization of a new coronavirus (2019-nCoV), which caused an epidemic of acute respiratory syndrome in humans in Wuhan, China. The epidemic, which started on 12 December 2019, had caused 2,794 laboratory-confirmed infections including 80 deaths by 26 January 2020. Full-length genome sequences were obtained from five patients at an early stage of the outbreak. The sequences are almost identical and share 79.6% sequence identity to SARS-CoV. Furthermore, we show that 2019-nCoV is 96% identical at the whole-genome level to a bat coronavirus. Pairwise protein sequence analysis of seven conserved non-structural proteins domains show that this virus belongs to the species of SARSr-CoV. In addition, 2019-nCoV virus isolated from the bronchoalveolar lavage fluid of a critically ill patient could be neutralized by sera from several patients. Notably, we confirmed that 2019-nCoV uses the same cell entry receptor-angiotensin converting enzyme II (ACE2)-as SARS-CoV.


Subject(s)
Betacoronavirus/classification , Betacoronavirus/genetics , Chiroptera/virology , Coronavirus Infections/epidemiology , Coronavirus Infections/virology , Disease Outbreaks , Pneumonia, Viral/epidemiology , Pneumonia, Viral/virology , Angiotensin-Converting Enzyme 2 , Animals , Antibodies, Viral/blood , Betacoronavirus/metabolism , Betacoronavirus/ultrastructure , COVID-19 , Cell Line , China/epidemiology , Chlorocebus aethiops , Female , Genome, Viral/genetics , Humans , Male , Peptidyl-Dipeptidase A/metabolism , Phylogeny , SARS Virus/classification , SARS Virus/genetics , SARS-CoV-2 , Sequence Homology, Nucleic Acid , Severe Acute Respiratory Syndrome , Vero Cells
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