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1.
Int J Biol Sci ; 18(12): 4714-4730, 2022.
Article in English | MEDLINE | ID: covidwho-1954691

ABSTRACT

The Coronavirus Disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the biggest public health challenge the world has witnessed in the past decades. SARS-CoV-2 undergoes constant mutations and new variants of concerns (VOCs) with altered transmissibility, virulence, and/or susceptibility to vaccines and therapeutics continue to emerge. Detailed analysis of host factors involved in virus replication may help to identify novel treatment targets. In this study, we dissected the metabolome derived from COVID-19 patients to identify key host factors that are required for efficient SARS-CoV-2 replication. Through a series of metabolomic analyses, in vitro, and in vivo investigations, we identified ATP citrate lyase (ACLY) as a novel host factor required for efficient replication of SARS-CoV-2 wild-type and variants, including Omicron. ACLY should be further explored as a novel intervention target for COVID-19.


Subject(s)
COVID-19 , SARS-CoV-2 , ATP Citrate (pro-S)-Lyase , Humans , Pandemics , Virus Replication/genetics
2.
JCI Insight ; 7(11)2022 06 08.
Article in English | MEDLINE | ID: covidwho-1892019

ABSTRACT

SARS-CoV-2 has been confirmed in over 450 million confirmed cases since 2019. Although several vaccines have been certified by the WHO and people are being vaccinated on a global scale, it has been reported that multiple SARS-CoV-2 variants can escape neutralization by antibodies, resulting in vaccine breakthrough infections. Bacillus Calmette-Guérin (BCG) is known to induce heterologous protection based on trained immune responses. Here, we investigated whether BCG-induced trained immunity protected against SARS-CoV-2 in the K18-hACE2 mouse model. Our data demonstrate that i.v. BCG (BCG-i.v.) vaccination induces robust trained innate immune responses and provides protection against WT SARS-CoV-2, as well as the B.1.617.1 and B.1.617.2 variants. Further studies suggest that myeloid cell differentiation and activation of the glycolysis pathway are associated with BCG-induced training immunity in K18-hACE2 mice. Overall, our study provides the experimental evidence that establishes a causal relationship between BCG-i.v. vaccination and protection against SARS-CoV-2 challenge.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , BCG Vaccine , COVID-19/prevention & control , Humans , Melphalan , Mice , gamma-Globulins
3.
Nat Microbiol ; 7(5): 716-725, 2022 05.
Article in English | MEDLINE | ID: covidwho-1852420

ABSTRACT

Emerging SARS-CoV-2 variants continue to cause waves of new infections globally. Developing effective antivirals against SARS-CoV-2 and its variants is an urgent task. The main protease (Mpro) of SARS-CoV-2 is an attractive drug target because of its central role in viral replication and its conservation among variants. We herein report a series of potent α-ketoamide-containing Mpro inhibitors obtained using the Ugi four-component reaction. The prioritized compound, Y180, showed an IC50 of 8.1 nM against SARS-CoV-2 Mpro and had oral bioavailability of 92.9%, 31.9% and 85.7% in mice, rats and dogs, respectively. Y180 protected against wild-type SARS-CoV-2, B.1.1.7 (Alpha), B.1.617.1 (Kappa) and P.3 (Theta), with EC50 of 11.4, 20.3, 34.4 and 23.7 nM, respectively. Oral treatment with Y180 displayed a remarkable antiviral potency and substantially ameliorated the virus-induced tissue damage in both nasal turbinate and lung of B.1.1.7-infected K18-human ACE2 (K18-hACE2) transgenic mice. Therapeutic treatment with Y180 improved the survival of mice from 0 to 44.4% (P = 0.0086) upon B.1.617.1 infection in the lethal infection model. Importantly, Y180 was also highly effective against the B.1.1.529 (Omicron) variant both in vitro and in vivo. Overall, our study provides a promising lead compound for oral drug development against SARS-CoV-2.


Subject(s)
COVID-19 , SARS-CoV-2 , Angiotensin-Converting Enzyme 2 , Animals , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , COVID-19/drug therapy , Disease Models, Animal , Dogs , Humans , Mice , Rats
4.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-321467

ABSTRACT

Mice are not susceptible to wildtype SARS-CoV-2 infection. Emerging SARS-CoV-2 variants including B.1.1.7, B.1.351, P.1, and P.3 contain mutations in spike, which have been suggested to associate with an increased recognition of mouse ACE2, raising the postulation that they may have evolved to expand species tropism to rodents. Here, we investigated the capacity of B.1.1.7 and other emerging SARS-CoV-2 variants in infecting mouse (Mus musculus) and rats (Rattus norvegicus) under in vitro and in vivo settings. Our results show that B.1.1.7 and P.3, but not B.1 or wildtype SARS-CoV-2, can utilize mouse and rat ACE2 for virus entry in vitro. High infectious virus titers, abundant viral antigen expression, and pathological changes are detected in the nasal turbinate and lung of B.1.1.7-inocluated mice and rats. Together, these results reveal that the current predominant circulating SARS-CoV-2 variant, B.1.1.7, has gained the capability to expand species tropism to rodents.

5.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-324830

ABSTRACT

Highly pathogenic coronaviruses including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 1,2 , Middle East respiratory syndrome coronavirus (MERS-CoV) 3,4 , and SARS-CoV-1 5 vary in their transmissibility and pathogenicity. However, infection by all three viruses result in substantial apoptosis in cell culture 6-8 and in patient samples 9-11 , suggesting a potential link between apoptosis and the pathogenesis of coronaviruses. To date, the underlying mechanism of how apoptosis modulates coronavirus pathogenesis is unknown. Here we show that a cysteine-aspartic protease of the apoptosis cascade, caspase-6, serves as an essential host factor for efficient coronavirus replication. We demonstrate that caspase-6 cleaves coronavirus nucleocapsid (N) proteins, generating N fragments that serve as interferon (IFN) antagonists, thus facilitating virus replication. Inhibition of caspase-6 substantially attenuates the lung pathology and body weight loss of SARS-CoV-2-infected golden Syrian hamsters and improves the survival of mouse-adapted MERS-CoV (MERS-CoV MA )-infected human DPP4 knock-in (hDPP4 KI) mice. Overall, our study reveals how coronaviruses exploit a component of the host apoptosis cascade to facilitate their replication. These results further suggest caspase-6 as a potential target of intervention for the treatment of highly pathogenic coronavirus infections including COVID-19 and MERS.

6.
Nature ; 603(7902): 693-699, 2022 03.
Article in English | MEDLINE | ID: covidwho-1641975

ABSTRACT

The Omicron (B.1.1.529) variant of SARS-CoV-2 emerged in November 2021 and is rapidly spreading among the human population1. Although recent reports reveal that the Omicron variant robustly escapes vaccine-associated and therapeutic neutralization antibodies2-10, the pathogenicity of the virus remains unknown. Here we show that the replication of Omicron is substantially attenuated in human Calu3 and Caco2 cells. Further mechanistic investigations reveal that Omicron is inefficient in its use of transmembrane serine protease 2 (TMPRSS2) compared with wild-type SARS-CoV-2 (HKU-001a) and previous variants, which may explain its reduced replication in Calu3 and Caco2 cells. The replication of Omicron is markedly attenuated in both the upper and lower respiratory tracts of infected K18-hACE2 mice compared with that of the wild-type strain and Delta (B.1.617.2) variant, resulting in its substantially ameliorated lung pathology. Compared with wild-type SARS-CoV-2 and the Alpha (B.1.1.7), Beta (1.351) and Delta variants, infection by Omicron causes the lowest reduction in body weight and the lowest mortality rate. Overall, our study demonstrates that the replication and pathogenicity of the Omicron variant of SARS-CoV-2 in mice is attenuated compared with the wild-type strain and other variants.


Subject(s)
COVID-19/pathology , COVID-19/virology , SARS-CoV-2/pathogenicity , Virus Replication , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Animals , COVID-19/immunology , Caco-2 Cells , Female , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , SARS-CoV-2/immunology , SARS-CoV-2/metabolism , Serine Endopeptidases/metabolism , Virulence
7.
Nature ; 602(7898): 676-681, 2022 02.
Article in English | MEDLINE | ID: covidwho-1616993

ABSTRACT

The B.1.1.529/Omicron variant of SARS-CoV-2 was only recently detected in southern Africa, but its subsequent spread has been extensive, both regionally and globally1. It is expected to become dominant in the coming weeks2, probably due to enhanced transmissibility. A striking feature of this variant is the large number of spike mutations3 that pose a threat to the efficacy of current COVID-19 vaccines and antibody therapies4. This concern is amplified by the findings of our study. Here we found that B.1.1.529 is markedly resistant to neutralization by serum not only from patients who recovered from COVID-19, but also from individuals who were vaccinated with one of the four widely used COVID-19 vaccines. Even serum from individuals who were vaccinated and received a booster dose of mRNA-based vaccines exhibited substantially diminished neutralizing activity against B.1.1.529. By evaluating a panel of monoclonal antibodies against all known epitope clusters on the spike protein, we noted that the activity of 17 out of the 19 antibodies tested were either abolished or impaired, including ones that are currently authorized or approved for use in patients. Moreover, we also identified four new spike mutations (S371L, N440K, G446S and Q493R) that confer greater antibody resistance on B.1.1.529. The Omicron variant presents a serious threat to many existing COVID-19 vaccines and therapies, compelling the development of new interventions that anticipate the evolutionary trajectory of SARS-CoV-2.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/virology , Immune Evasion/immunology , SARS-CoV-2/immunology , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19/blood , COVID-19/immunology , COVID-19 Vaccines/administration & dosage , COVID-19 Vaccines/immunology , Cell Line , Convalescence , Evolution, Molecular , Humans , Immune Sera/immunology , Inhibitory Concentration 50 , Models, Molecular , Mutation , Neutralization Tests , SARS-CoV-2/chemistry , SARS-CoV-2/classification , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology
8.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-296805

ABSTRACT

The Omicron (B.1.1.529) variant of SARS-CoV-2 was only recently detected in southern Africa, but its subsequent spread has been extensive, both regionally and globally1. It is expected to become dominant in the coming weeks2, probably due to enhanced transmissibility. A striking feature of this variant is the large number of spike mutations3 that pose a threat to the efficacy of current COVID-19 vaccines and antibody therapies4. This concern is amplified by the findings from our study. We found B.1.1.529 to be markedly resistant to neutralization by serum not only from convalescent patients, but also from individuals vaccinated with one of the four widely used COVID-19 vaccines. Even serum from persons vaccinated and boosted with mRNA-based vaccines exhibited substantially diminished neutralizing activity against B.1.1.529. By evaluating a panel of monoclonal antibodies to all known epitope clusters on the spike protein, we noted that the activity of 18 of the 19 antibodies tested were either abolished or impaired, including ones currently authorized or approved for use in patients. In addition, we also identified four new spike mutations (S371L, N440K, G446S, and Q493R) that confer greater antibody resistance to B.1.1.529. The Omicron variant presents a serious threat to many existing COVID-19 vaccines and therapies, compelling the development of new interventions that anticipate the evolutionary trajectory of SARS-CoV-2.

9.
EBioMedicine ; 73: 103643, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1482542

ABSTRACT

BACKGROUND: Wildtype mice are not susceptible to SARS-CoV-2 infection. Emerging SARS-CoV-2 variants, including B.1.1.7, B.1.351, P.1, and P.3, contain mutations in spike that has been suggested to associate with an increased recognition of mouse ACE2, raising the postulation that these SARS-CoV-2 variants may have evolved to expand species tropism to wildtype mouse and potentially other murines. Our study evaluated this possibility with substantial public health importance. METHODS: We investigated the capacity of wildtype (WT) SARS-CoV-2 and SARS-CoV-2 variants in infecting mice (Mus musculus) and rats (Rattus norvegicus) under in vitro and in vivo settings. Susceptibility to infection was evaluated with RT-qPCR, plaque assays, immunohistological stainings, and neutralization assays. FINDINGS: Our results reveal that B.1.1.7 and other N501Y-carrying variants but not WT SARS-CoV-2 can infect wildtype mice. High viral genome copies and high infectious virus particle titres are recovered from the nasal turbinate and lung of B.1.1.7-inocluated mice for 4-to-7 days post infection. In agreement with these observations, robust expression of viral nucleocapsid protein and histopathological changes are detected from the nasal turbinate and lung of B.1.1.7-inocluated mice but not that of the WT SARS-CoV-2-inoculated mice. Similarly, B.1.1.7 readily infects wildtype rats with production of infectious virus particles. INTERPRETATION: Our study provides direct evidence that the SARS-CoV-2 variant, B.1.1.7, as well as other N501Y-carrying variants including B.1.351 and P.3, has gained the capability to expand species tropism to murines and public health measures including stringent murine control should be implemented to facilitate the control of the ongoing pandemic. FUNDING: A full list of funding bodies that contributed to this study can be found in the Acknowledgements section.


Subject(s)
COVID-19/pathology , SARS-CoV-2/physiology , Viral Tropism , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Animals , Antibodies, Viral/blood , Antibodies, Viral/immunology , COVID-19/virology , Female , Humans , Lung/pathology , Lung/virology , Mice , Mice, Inbred C57BL , Mice, Transgenic , Neutralization Tests , Nucleocapsid Proteins/immunology , Nucleocapsid Proteins/metabolism , RNA, Viral/analysis , RNA, Viral/metabolism , Rats , Rats, Sprague-Dawley , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification , Turbinates/pathology , Turbinates/virology , Virus Internalization
10.
Sci Adv ; 7(25)2021 06.
Article in English | MEDLINE | ID: covidwho-1276873

ABSTRACT

Infection by highly pathogenic coronaviruses results in substantial apoptosis. However, the physiological relevance of apoptosis in the pathogenesis of coronavirus infections is unknown. Here, with a combination of in vitro, ex vivo, and in vivo models, we demonstrated that protein kinase R-like endoplasmic reticulum kinase (PERK) signaling mediated the proapoptotic signals in Middle East respiratory syndrome coronavirus (MERS-CoV) infection, which converged in the intrinsic apoptosis pathway. Inhibiting PERK signaling or intrinsic apoptosis both alleviated MERS pathogenesis in vivo. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and SARS-CoV induced apoptosis through distinct mechanisms but inhibition of intrinsic apoptosis similarly limited SARS-CoV-2- and SARS-CoV-induced apoptosis in vitro and markedly ameliorated the lung damage of SARS-CoV-2-inoculated human angiotensin-converting enzyme 2 (hACE2) mice. Collectively, our study provides the first evidence that virus-induced apoptosis is an important disease determinant of highly pathogenic coronaviruses and demonstrates that this process can be targeted to attenuate disease severity.


Subject(s)
Antiviral Agents/pharmacology , Apoptosis/drug effects , COVID-19/drug therapy , Coronavirus Infections/drug therapy , eIF-2 Kinase/metabolism , Adenine/analogs & derivatives , Adenine/pharmacology , Angiotensin-Converting Enzyme 2/genetics , Animals , Apoptosis/physiology , COVID-19/etiology , COVID-19/pathology , Cell Line , Coronavirus Infections/etiology , Coronavirus Infections/pathology , Dipeptidyl Peptidase 4/genetics , Epithelial Cells/virology , Female , Humans , Indoles/pharmacology , Lung/virology , Male , Mice, Transgenic , eIF-2 Kinase/antagonists & inhibitors , eIF-2 Kinase/genetics
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