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1.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-307708

ABSTRACT

SARS-CoV-2 carries the largest single-stranded RNA genome and is the causal pathogen of the ongoing COVID-19 pandemic. How the SARS-CoV-2 RNA genome is folded in the virion remains unknown. To fill the knowledge gap and facilitate structure-based drug development, we developed a virion RNA in situ conformation sequencing technology, named vRIC-seq, for probing viral RNA genome structure unbiasedly. Using vRIC-seq data, we reconstructed the tertiary structure of the SARS-CoV-2 genome and revealed a surprisingly "unentangled globule" conformation. We uncovered many long-range duplexes and higher-order junctions, both of which were under purifying selections and contributed to the sequential package of the SARS-CoV-2 genome. Unexpectedly, the D614G and the other two accompanying mutations might remodel duplexes into more stable forms. Lastly, the structure-guided design of potent small interfering RNAs could obliterate the SARS-CoV-2 in Vero cells. Overall, our work provides a framework for studying the genome structure, function, and dynamics of emerging deadly RNA viruses.

2.
Cell Res ; 32(1): 9-23, 2022 01.
Article in English | MEDLINE | ID: covidwho-1505077

ABSTRACT

In contrast to the extensive research about viral protein-host protein interactions that has revealed major insights about how RNA viruses engage with host cells during infection, few studies have examined interactions between host factors and viral RNAs (vRNAs). Here, we profiled vRNA-host protein interactomes for three RNA virus pathogens (SARS-CoV-2, Zika, and Ebola viruses) using ChIRP-MS. Comparative interactome analyses discovered both common and virus-specific host responses and vRNA-associated proteins that variously promote or restrict viral infection. In particular, SARS-CoV-2 binds and hijacks the host factor IGF2BP1 to stabilize vRNA and augment viral translation. Our interactome-informed drug repurposing efforts identified several FDA-approved drugs (e.g., Cepharanthine) as broad-spectrum antivirals in cells and hACE2 transgenic mice. A co-treatment comprising Cepharanthine and Trifluoperazine was highly potent against the newly emerged SARS-CoV-2 B.1.351 variant. Thus, our study illustrates the scientific and medical discovery utility of adopting a comparative vRNA-host protein interactome perspective.


Subject(s)
COVID-19 , RNA Viruses , Zika Virus Infection , Zika Virus , Animals , Antiviral Agents , Humans , Mice , RNA, Viral , SARS-CoV-2 , Viral Proteins
3.
Signal Transduct Target Ther ; 6(1): 382, 2021 11 03.
Article in English | MEDLINE | ID: covidwho-1500449

ABSTRACT

The global coronavirus disease 2019 (COVID-19) pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a positive-sense RNA virus. How the host immune system senses and responds to SARS-CoV-2 infection remain largely unresolved. Here, we report that SARS-CoV-2 infection activates the innate immune response through the cytosolic DNA sensing cGAS-STING pathway. SARS-CoV-2 infection induces the cellular level of 2'3'-cGAMP associated with STING activation. cGAS recognizes chromatin DNA shuttled from the nucleus as a result of cell-to-cell fusion upon SARS-CoV-2 infection. We further demonstrate that the expression of spike protein from SARS-CoV-2 and ACE2 from host cells is sufficient to trigger cytoplasmic chromatin upon cell fusion. Furthermore, cytoplasmic chromatin-cGAS-STING pathway, but not MAVS-mediated viral RNA sensing pathway, contributes to interferon and pro-inflammatory gene expression upon cell fusion. Finally, we show that cGAS is required for host antiviral responses against SARS-CoV-2, and a STING-activating compound potently inhibits viral replication. Together, our study reported a previously unappreciated mechanism by which the host innate immune system responds to SARS-CoV-2 infection, mediated by cytoplasmic chromatin from the infected cells. Targeting the cytoplasmic chromatin-cGAS-STING pathway may offer novel therapeutic opportunities in treating COVID-19. In addition, these findings extend our knowledge in host defense against viral infection by showing that host cells' self-nucleic acids can be employed as a "danger signal" to alarm the immune system.


Subject(s)
COVID-19/immunology , Chromatin/immunology , Cytoplasm/immunology , Immunity, Innate , Nucleotidyltransferases/immunology , SARS-CoV-2/immunology , Animals , COVID-19/genetics , Chromatin/genetics , Cytoplasm/genetics , Disease Models, Animal , HEK293 Cells , HeLa Cells , Humans , Mice , Mice, Transgenic , Nucleotidyltransferases/genetics , SARS-CoV-2/genetics
4.
Am J Respir Crit Care Med ; 204(12): 1379-1390, 2021 12 15.
Article in English | MEDLINE | ID: covidwho-1430274

ABSTRACT

Rationale: Alteration of human respiratory microbiota had been observed in coronavirus disease (COVID-19). How the microbiota is associated with the prognosis in COVID-19 is unclear. Objectives: To characterize the feature and dynamics of the respiratory microbiota and its associations with clinical features in patients with COVID-19. Methods: We conducted metatranscriptome sequencing on 588 longitudinal oropharyngeal swab specimens collected from 192 patients with COVID-19 (including 39 deceased patients) and 95 healthy controls from the same geographic area. Meanwhile, the concentration of 27 cytokines and chemokines in plasma was measured for patients with COVID-19. Measurements and Main Results: The upper respiratory tract (URT) microbiota in patients with COVID-19 differed from that in healthy controls, whereas deceased patients possessed a more distinct microbiota, both on admission and before discharge/death. The alteration of URT microbiota showed a significant correlation with the concentration of proinflammatory cytokines and mortality. Specifically, Streptococcus-dominated microbiota was enriched in recovered patients, and showed high temporal stability and resistance against pathogens. In contrast, the microbiota in deceased patients was more susceptible to secondary infections and became more deviated from the norm after admission. Moreover, the abundance of S. parasanguinis on admission was significantly correlated with prognosis in nonsevere patients (lower vs. higher abundance, odds ratio, 7.80; 95% CI, 1.70-42.05). Conclusions: URT microbiota dysbiosis is a remarkable manifestation of COVID-19; its association with mortality suggests it may reflect the interplay between pathogens, symbionts, and the host immune status. Whether URT microbiota could be used as a biomarker for diagnosis and prognosis of respiratory diseases merits further investigation.


Subject(s)
COVID-19/microbiology , COVID-19/mortality , Microbiota , Respiratory Tract Infections/microbiology , Respiratory Tract Infections/mortality , Adult , Aged , COVID-19/epidemiology , Female , Humans , Male , Middle Aged , Prognosis , SARS-CoV-2
5.
Biosaf Health ; 3(5): 238-243, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1401267

ABSTRACT

Many factors have been identified as having the ability to affect the sensitivity of rapid antigen detection (RAD) tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study aimed to identify the impact of sample processing on the sensitivity of the RAD tests. We explored the effect of different inactivation methods, viral transport media (VTM) solutions, and sample preservation on the sensitivity of four RAD kits based on two SARS-CoV-2 strains. Compared with non-inactivation, heat inactivation significantly impacted the sensitivity of most RAD kits; however, ß-propiolactone inactivation only had a minor effect. Some of the VTM solutions (VTM2, MANTACC) had a significant influence on the sensitivity of the RAD kits, especially for low viral-loads samples. The detection value of RAD kits was slightly decreased, while most of them were still in the detection range with the extension of preservation time and the increase of freeze-thaw cycles. Our results showed that selecting the appropriate inactivation methods and VTM solutions is necessary during reagent development, performance evaluation, and clinical application.

6.
Nat Commun ; 12(1): 3917, 2021 06 24.
Article in English | MEDLINE | ID: covidwho-1281717

ABSTRACT

SARS-CoV-2 carries the largest single-stranded RNA genome and is the causal pathogen of the ongoing COVID-19 pandemic. How the SARS-CoV-2 RNA genome is folded in the virion remains unknown. To fill the knowledge gap and facilitate structure-based drug development, we develop a virion RNA in situ conformation sequencing technology, named vRIC-seq, for probing viral RNA genome structure unbiasedly. Using vRIC-seq data, we reconstruct the tertiary structure of the SARS-CoV-2 genome and reveal a surprisingly "unentangled globule" conformation. We uncover many long-range duplexes and higher-order junctions, both of which are under purifying selections and contribute to the sequential package of the SARS-CoV-2 genome. Unexpectedly, the D614G and the other two accompanying mutations may remodel duplexes into more stable forms. Lastly, the structure-guided design of potent small interfering RNAs can obliterate the SARS-CoV-2 in Vero cells. Overall, our work provides a framework for studying the genome structure, function, and dynamics of emerging deadly RNA viruses.


Subject(s)
COVID-19/pathology , RNA, Viral/chemistry , SARS-CoV-2/genetics , Sequence Analysis, RNA/methods , Virion/genetics , Animals , COVID-19/genetics , COVID-19/virology , Cells, Cultured , Chlorocebus aethiops , Genome, Viral , Humans , Nucleic Acid Conformation , RNA, Viral/genetics , SARS-CoV-2/isolation & purification , SARS-CoV-2/pathogenicity , Virion/chemistry , Virion/metabolism
7.
Cell ; 184(7): 1865-1883.e20, 2021 04 01.
Article in English | MEDLINE | ID: covidwho-1071139

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of the ongoing coronavirus disease 2019 (COVID-19) pandemic. Understanding of the RNA virus and its interactions with host proteins could improve therapeutic interventions for COVID-19. By using icSHAPE, we determined the structural landscape of SARS-CoV-2 RNA in infected human cells and from refolded RNAs, as well as the regulatory untranslated regions of SARS-CoV-2 and six other coronaviruses. We validated several structural elements predicted in silico and discovered structural features that affect the translation and abundance of subgenomic viral RNAs in cells. The structural data informed a deep-learning tool to predict 42 host proteins that bind to SARS-CoV-2 RNA. Strikingly, antisense oligonucleotides targeting the structural elements and FDA-approved drugs inhibiting the SARS-CoV-2 RNA binding proteins dramatically reduced SARS-CoV-2 infection in cells derived from human liver and lung tumors. Our findings thus shed light on coronavirus and reveal multiple candidate therapeutics for COVID-19 treatment.


Subject(s)
COVID-19/drug therapy , Drug Repositioning , RNA, Viral , RNA-Binding Proteins/antagonists & inhibitors , SARS-CoV-2 , Animals , Cell Line , Chlorocebus aethiops , Deep Learning , Humans , Nucleic Acid Conformation , RNA, Viral/chemistry , RNA-Binding Proteins/metabolism , SARS-CoV-2/drug effects , SARS-CoV-2/genetics
8.
Emerg Microbes Infect ; 9(1): 2707-2714, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-953975

ABSTRACT

To identify the association between the kinetics of viral load and clinical outcome in severe coronavirus disease 2019 (COVID-19) patients, a retrospective study was performed by involved 188 hospitalized severe COVID-19 patients in the LOTUS China trial. Among the collected 578 paired throat swab (TS) and anal swab (AS) samples, viral RNA was detected in 193 (33.4%) TS and 121 (20.9%) AS. A higher viral RNA load was found in TS than that of AS, with means of 1.0 × 106 and 2.3 × 105 copies/ml, respectively. In non-survivors, the viral RNA in AS was detected earlier than that in survivors (median of 14 days vs 19 days, P = 0.007). The positivity and viral load in AS were higher in non-survivors than that of survivors at week 2 post symptom onset (P = 0.006). A high initial viral load in AS was associated with death (OR 1.368, 95% CI 1.076-1.741, P = 0.011), admission to the intensive care unit (OR 1.237, 95% CI 1.001-1.528, P = 0.049) and need for invasive mechanical ventilation (OR 1.340, 95% CI 1.076-1.669, P = 0.009). Our findings indicated viral replication in extrapulmonary sites should be monitored intensively during antiviral therapy.


Subject(s)
Anal Canal/virology , COVID-19/virology , SARS-CoV-2/isolation & purification , Viral Load , Adolescent , Adult , Aged , Aged, 80 and over , COVID-19/mortality , Female , Humans , Male , Middle Aged , Pharynx/virology , RNA, Viral/analysis , Retrospective Studies , Time Factors , Virus Replication , Young Adult
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