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1.
Cell Host Microbe ; 30(3): 373-387.e7, 2022 03 09.
Article in English | MEDLINE | ID: covidwho-1767977

ABSTRACT

SARS-CoV-2 lineages have diverged into highly prevalent variants termed "variants of concern" (VOCs). Here, we characterized emerging SARS-CoV-2 spike polymorphisms in vitro and in vivo to understand their impact on transmissibility and virus pathogenicity and fitness. We demonstrate that the substitution S:655Y, represented in the gamma and omicron VOCs, enhances viral replication and spike protein cleavage. The S:655Y substitution was transmitted more efficiently than its ancestor S:655H in the hamster infection model and was able to outcompete S:655H in the hamster model and in a human primary airway system. Finally, we analyzed a set of emerging SARS-CoV-2 variants to investigate how different sets of mutations may impact spike processing. All VOCs tested exhibited increased spike cleavage and fusogenic capacity. Taken together, our study demonstrates that the spike mutations present in VOCs that become epidemiologically prevalent in humans are linked to an increase in spike processing and virus transmission.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Mutation , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics
2.
Cell Rep ; 38(11): 110508, 2022 03 15.
Article in English | MEDLINE | ID: covidwho-1700144

ABSTRACT

Concerns that infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of coronavirus disease 2019 (COVID-19), may cause new-onset diabetes persist in an evolving research landscape, and precise risk assessment is hampered by, at times, conflicting evidence. Here, leveraging comprehensive single-cell analyses of in vitro SARS-CoV-2-infected human pancreatic islets, we demonstrate that productive infection is strictly dependent on the SARS-CoV-2 entry receptor ACE2 and targets practically all pancreatic cell types. Importantly, the infection remains highly circumscribed and largely non-cytopathic and, despite a high viral burden in infected subsets, promotes only modest cellular perturbations and inflammatory responses. Similar experimental outcomes are also observed after islet infection with endemic coronaviruses. Thus, the limits of pancreatic SARS-CoV-2 infection, even under in vitro conditions of enhanced virus exposure, challenge the proposition that in vivo targeting of ß cells by SARS-CoV-2 precipitates new-onset diabetes. Whether restricted pancreatic damage and immunological alterations accrued by COVID-19 increase cumulative diabetes risk, however, remains to be evaluated.


Subject(s)
COVID-19 , Diabetes Mellitus , Insulin-Secreting Cells , Humans , Pancreas , SARS-CoV-2
3.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-327539

ABSTRACT

A well-tolerated and cost-effective oral drug that blocks SARS-CoV-2 growth and dissemination would be a major advance in the global effort to reduce COVID-19 morbidity and mortality. Here, we show that the oral FDA-approved drug nitazoxanide (NTZ) significantly inhibits SARS-CoV-2 viral replication and infection in different primate and human cell models including stem cell-derived human alveolar epithelial type 2 cells. Furthermore, NTZ synergizes with remdesivir, and it broadly inhibits growth of SARS-CoV-2 variants B.1.351 (beta), P.1 (gamma), and B.1617.2 (delta) and viral syncytia formation driven by their spike proteins. Strikingly, oral NTZ treatment of Syrian hamsters significantly inhibits SARS-CoV-2-driven weight loss, inflammation, and viral dissemination and syncytia formation in the lungs. These studies show that NTZ is a novel host-directed therapeutic that broadly inhibits SARS-CoV-2 dissemination and pathogenesis in human and hamster physiological models, which supports further testing and optimization of NTZ-based therapy for SARS-CoV-2 infection alone and in combination with antiviral drugs.

4.
Toxicol Pathol ; : 1926233211072767, 2022 Feb 05.
Article in English | MEDLINE | ID: covidwho-1673709

ABSTRACT

Coronavirus disease 2019 (COVID-19) in humans has a wide range of presentations, ranging from asymptomatic or mild symptoms to severe illness. Suitable animal models mimicking varying degrees of clinical disease manifestations could expedite development of therapeutics and vaccines for COVID-19. Here we demonstrate that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection resulted in subclinical disease in rhesus macaques with mild pneumonia and clinical disease in Syrian hamsters with severe pneumonia. SARS-CoV-2 infection was confirmed by formalin-fixed, paraffin-embedded (FFPE) polymerase chain reaction (PCR), immunohistochemistry, or in situ hybridization. Replicating virus in the lungs was identified using in situ hybridization or virus plaque forming assays. Viral encephalitis, reported in some COVID-19 patients, was identified in one macaque and was confirmed with immunohistochemistry. There was no evidence of encephalitis in hamsters. Severity and distribution of lung inflammation were substantially more in hamsters compared with macaques and exhibited vascular changes and virus-induced cytopathic changes as seen in COVID-19 patients. Neither the hamster nor macaque models demonstrated evidence for multisystemic inflammatory syndrome (MIS). Data presented here demonstrate that macaques may be appropriate for mechanistic studies of mild asymptomatic COVID-19 pneumonia and COVID-19-associated encephalitis, whereas Syrian hamsters may be more suited to study severe COVID-19 pneumonia.

5.
2021.
Preprint in English | Other preprints | ID: ppcovidwho-295806

ABSTRACT

Germicidal potential of specific wavelengths within the electromagnetic spectrum is an area of growing interest. While ultra-violet (UV) based technologies have shown satisfactory virucidal potential, the photo-toxicity in humans coupled with UV associated polymer degradation limit its use in occupied spaces. Alternatively, longer wavelengths with less irradiation energy such as visible light (405 nm) have largely been explored in the context of bactericidal and fungicidal applications. Such studies indicated that 405 nm mediated inactivation is caused by the absorbance of porphyrins within the organism creating reactive oxygen species which result in free radical damage to its DNA and disruption of cellular functions. The virucidal potential of visible-light based technologies has been largely unexplored and speculated to be ineffective given the lack of porphyrins in viruses. The current study demonstrated increased susceptibility of lipid-enveloped respiratory pathogens of importance such as SARS-CoV-2 (causative agent of COVID-19) as well as the influenza A virus to 405nm, visible light in the absence of exogenous photosensitizers indicating a potential porphyrin-independent alternative mechanism of visible light mediated viral inactivation. These results were obtained using less than expected irradiance levels which are generally safe for humans and commercially achievable. Our results support further exploration of the use of visible light technology for the application of continuous decontamination in occupied areas within hospitals and/or infectious disease laboratories, specifically for the inactivation of respiratory pathogens such as SARS-CoV-2 and Influenza A.

6.
Sci Rep ; 11(1): 22164, 2021 11 12.
Article in English | MEDLINE | ID: covidwho-1514425

ABSTRACT

The influenza A non-structural protein 1 (NS1) is known for its ability to hinder the synthesis of type I interferon (IFN) during viral infection. Influenza viruses lacking NS1 (ΔNS1) are under clinical development as live attenuated human influenza virus vaccines and induce potent influenza virus-specific humoral and cellular adaptive immune responses. Attenuation of ΔNS1 influenza viruses is due to their high IFN inducing properties, that limit their replication in vivo. This study demonstrates that pre-treatment with a ΔNS1 virus results in an antiviral state which prevents subsequent replication of homologous and heterologous viruses, preventing disease from virus respiratory pathogens, including SARS-CoV-2. Our studies suggest that ΔNS1 influenza viruses could be used for the prophylaxis of influenza, SARS-CoV-2 and other human respiratory viral infections, and that an influenza virus vaccine based on ΔNS1 live attenuated viruses would confer broad protection against influenza virus infection from the moment of administration, first by non-specific innate immune induction, followed by specific adaptive immunity.


Subject(s)
Influenza A virus/immunology , Influenza Vaccines/therapeutic use , Interferon Type I/immunology , Orthomyxoviridae Infections/prevention & control , Vaccines, Attenuated/therapeutic use , Viral Nonstructural Proteins/immunology , Adaptive Immunity , Animals , COVID-19/immunology , COVID-19/prevention & control , Chickens , Gene Deletion , Humans , Influenza A virus/genetics , Influenza Vaccines/genetics , Influenza Vaccines/immunology , Influenza, Human/immunology , Influenza, Human/prevention & control , Mice , Mice, Inbred C57BL , Orthomyxoviridae Infections/immunology , Vaccines, Attenuated/genetics , Vaccines, Attenuated/immunology , Viral Nonstructural Proteins/genetics
7.
Non-conventional in English | [Unspecified Source], Grey literature | ID: grc-750493

ABSTRACT

Severe acute respiratory syndrome CoV-2 (SARS-CoV-2) is currently causing a worldwide pandemic with high morbidity and mortality. Development of animal models that recapitulate important aspects of coronavirus disease 2019 (COVID-19) is critical for the evaluation of vaccines and antivirals, and understanding disease pathogenesis. SARS-CoV-2 has been shown to use the same entry receptor as SARS-CoV-1, human angiotensin-converting enzyme 2 (hACE2)(1-3). Due to amino acid differences between murine and hACE2, inbred mouse strains fail to support high titer viral replication of SARS-CoV-2 virus. Therefore, a number of transgenic and knock-in mouse models, as well as viral vector-mediated hACE2 delivery systems have been developed. Here we compared the K18-hACE2 transgenic model to adenovirus-mediated delivery of hACE2 to the mouse lung. We show that K18-hACE2 mice replicate virus to high titers in both the lung and brain leading to lethality. In contrast, adenovirus-mediated delivery results in viral replication to lower titers limited to the lung, and no clinical signs of infection with a challenge dose of 10 (4) plaque forming units. The K18-hACE2 model provides a stringent model for testing the ability of vaccines and antivirals to protect against disease, whereas the adenovirus delivery system has the flexibility to be used across multiple genetic backgrounds and modified mouse strains.

8.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-292099

ABSTRACT

Concerns that infection with SARS-CoV-2, the etiological agent of COVID-19, may cause new-onset diabetes persist amidst an evolving research landscape, and precise risk assessment is hampered by at times conflicting evidence. Here, leveraging comprehensive single-cell analyses of in vitro SARS-CoV-2-infected human pancreatic islets, we demonstrate that productive infection is strictly dependent on the SARS-CoV-2 entry receptor ACE2 and targets all pancreatic cell types. Importantly, the infection remains highly circumscribed, largely non-cytopathic, and despite high viral burden in infected subsets, promotes only modest cellular perturbations and inflammatory responses. Similar experimental outcomes are also observed after islet infection with endemic coronaviruses. Thus, the limits of pancreatic SARS-CoV-2 infection, even under in vitro conditions of enhanced virus exposure, do not support the proposition that in vivo targeting of beta cells by SARS-CoV-2 precipitates new-onset diabetes. If restricted pancreatic damage accrued by COVID-19 increases cumulative diabetes risk, however, remains to be evaluated.Funding: These efforts were supported by JDRF 3-PDF-2018-575-A-N (V.v.d.H.);NIH/NIDDK R01DK12392, NIH/NIAID P01AI042288 and NIH/NIAID U54AI142766-S1 (M.A.A.);NIH/NIAID Center of Excellence for Influenza Research and Response/Center for Research for Influenza Pathogenesis and Transmission contract # 75N93019R00028, NIH/NIAID U19AI135972 (supplement), Defense Advanced Research Projects Agency HR0011-19-2-0020, JPB Foundation, and Open Philanthropy Project # 2020-215611 (5384), Anonymous (A.G.-S.);NIH/NIAID R01AI151029 and NIA/NIAID U01AI150748 (B.R.R.);NIH/NIDDK R01DK130425 (M.S.);and NIH/NIAID R01AI134971, NIH/NIDDK U01DK123716, NIH/NIDDK U01DK104162, NIH/NIDDK P30DK020541 and NIH/NIDDK R01DK130425 (D.H.).Funding: The AG-S laboratory has received research support from Pfizer, Senhwa Biosciences, Kenall Manufacturing, Avimex, Johnson & Johnson, Dynavax, 7Hills Pharma, Pharmamar, ImmunityBio, Accurius, Nanocomposix, Hexamer, N-fold LLC, Model Medicines and Merck, outside of the reported work. Declaration of Interests: AG-S has consulting agreements for the following companies involving cash and/or stock: Vivaldi Biosciences, Contrafect, 7Hills Pharma, Avimex, Vaxalto, Pagoda, Accurius, Esperovax, Farmak, Applied Biological Laboratories and Pfizer, outside of the reported work. AG-S is inventor on patents and patent applications on the use of antivirals and vaccines for the treatment and prevention of virus infections and cancer, owned by the Icahn School of Medicine at Mount Sinai, New York, outside of the reported work. All other authors declare no conflict of interest. Ethics Approval Statement: Our study is considered “not human subjects research” since all donor islet preparations were provided as de-identified tissue specimens by a commercial purveyor

9.
Nat Commun ; 12(1): 6197, 2021 10 27.
Article in English | MEDLINE | ID: covidwho-1493100

ABSTRACT

Rapid development of COVID-19 vaccines has helped mitigating SARS-CoV-2 spread, but more equitable allocation of vaccines is necessary to limit the global impact of the COVID-19 pandemic and the emergence of additional variants of concern. We have developed a COVID-19 vaccine candidate based on Newcastle disease virus (NDV) that can be manufactured at high yields in embryonated eggs. Here, we show that the NDV vector expressing an optimized spike antigen (NDV-HXP-S) is a versatile vaccine inducing protective antibody responses. NDV-HXP-S can be administered intramuscularly as inactivated vaccine or intranasally as live vaccine. We show that NDV-HXP-S GMP-produced in Vietnam, Thailand and Brazil is effective in the hamster model. Furthermore, we show that intramuscular vaccination with NDV-HXP-S reduces replication of tested variants of concerns in mice. The immunity conferred by NDV-HXP-S effectively counteracts SARS-CoV-2 infection in mice and hamsters.


Subject(s)
Newcastle disease virus/immunology , SARS-CoV-2/immunology , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolism , Animals , Female , Mice , Mice, Inbred BALB C , Newcastle disease virus/metabolism , SARS-CoV-2/pathogenicity , Vaccines, Attenuated/therapeutic use
10.
Nat Commun ; 12(1): 6097, 2021 10 20.
Article in English | MEDLINE | ID: covidwho-1475295

ABSTRACT

Effective treatments against Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) are urgently needed. Monoclonal antibodies have shown promising results in patients. Here, we evaluate the in vivo prophylactic and therapeutic effect of COVA1-18, a neutralizing antibody highly potent against the B.1.1.7 isolate. In both prophylactic and therapeutic settings, SARS-CoV-2 remains undetectable in the lungs of treated hACE2 mice. Therapeutic treatment also causes a reduction in viral loads in the lungs of Syrian hamsters. When administered at 10 mg kg-1 one day prior to a high dose SARS-CoV-2 challenge in cynomolgus macaques, COVA1-18 shows very strong antiviral activity in the upper respiratory compartments. Using a mathematical model, we estimate that COVA1-18 reduces viral infectivity by more than 95% in these compartments, preventing lymphopenia and extensive lung lesions. Our findings demonstrate that COVA1-18 has a strong antiviral activity in three preclinical models and could be a valuable candidate for further clinical evaluation.


Subject(s)
Antibodies, Monoclonal/administration & dosage , Antibodies, Neutralizing/administration & dosage , Antiviral Agents/administration & dosage , COVID-19/drug therapy , SARS-CoV-2/immunology , Angiotensin-Converting Enzyme 2/genetics , Animals , Antibodies, Monoclonal/pharmacokinetics , Antiviral Agents/pharmacokinetics , COVID-19/blood , COVID-19/immunology , COVID-19/virology , Disease Models, Animal , Drug Evaluation, Preclinical , Female , Humans , Lung/metabolism , Lung/virology , Macaca fascicularis , Male , Mesocricetus , Mice , Mice, Transgenic , SARS-CoV-2/isolation & purification , Tissue Distribution , Viral Load
11.
Sci Rep ; 11(1): 19970, 2021 10 07.
Article in English | MEDLINE | ID: covidwho-1462030

ABSTRACT

Particulate respirators such as N95s are an essential component of personal protective equipment (PPE) for front-line workers. This study describes a rapid and effective UVC irradiation system that would facilitate the safe re-use of N95 respirators and provides supporting information for deploying UVC for decontamination of SARS-CoV-2 during the COVID-19 pandemic. To assess the inactivation potential of the proposed UVC germicidal device as a function of time by using 3 M 8211-N95 particulate respirators inoculated with SARS-CoV-2. A germicidal UVC device to deliver tailored UVC dose was developed and test coupons (2.5 cm2) of the 3 M-N95 respirator were inoculated with 106 plaque-forming units (PFU) of SARS-CoV-2 and were UV irradiated. Different exposure times were tested (0-164 s) by fixing the distance between the lamp and the test coupon to 15.2 cm while providing an exposure of at least 5.43 mWcm-2. Primary measure of outcome was titration of infectious virus recovered from virus-inoculated respirator test coupons after UVC exposure. Other measures included the method validation of the irradiation protocol, using lentiviruses (biosafety level-2 agent) and establishment of the germicidal UVC exposure protocol. An average of 4.38 × 103 PFU ml-1 (SD 772.68) was recovered from untreated test coupons while 4.44 × 102 PFU ml-1 (SD 203.67), 4.00 × 102 PFU ml-1 (SD 115.47), 1.56 × 102 PFU ml-1 (SD 76.98) and 4.44 × 101 PFU ml-1 (SD 76.98) was recovered in exposures 2, 6, 18 and 54 s per side respectively. The germicidal device output and positioning was monitored and a minimum output of 5.43 mW cm-2 was maintained. Infectious SARS-CoV-2 was not detected by plaque assays (minimal level of detection is 67 PFU ml-1) on N95 respirator test coupons when irradiated for 120 s per side or longer suggesting 3.5 log reduction in 240 s of irradiation, 1.3 J cm-2. A scalable germicidal UVC device to deliver tailored UVC dose for rapid decontamination of SARS-CoV-2 was developed. UVC germicidal irradiation of N95 test coupons inoculated with SARS-CoV-2 for 120 s per side resulted in 3.5 log reduction of virus. These data support the reuse of N95 particle-filtrate apparatus upon irradiation with UVC and supports use of UVC-based decontamination of SARS-CoV-2 during the COVID-19 pandemic.


Subject(s)
COVID-19/prevention & control , Decontamination/instrumentation , N95 Respirators/virology , SARS-CoV-2/radiation effects , Ultraviolet Rays , Animals , COVID-19/virology , Chlorocebus aethiops , Decontamination/economics , Equipment Design , Equipment Reuse , HEK293 Cells , Humans , SARS-CoV-2/isolation & purification , Time Factors , Vero Cells
12.
Front Immunol ; 12: 729189, 2021.
Article in English | MEDLINE | ID: covidwho-1450809

ABSTRACT

Several SARS-CoV-2 vaccines have received EUAs, but many issues remain unresolved, including duration of conferred immunity and breadth of cross-protection. Adjuvants that enhance and shape adaptive immune responses that confer broad protection against SARS-CoV-2 variants will be pivotal for long-term protection as drift variants continue to emerge. We developed an intranasal, rationally designed adjuvant integrating a nanoemulsion (NE) that activates TLRs and NLRP3 with an RNA agonist of RIG-I (IVT DI). The combination adjuvant with spike protein antigen elicited robust responses to SARS-CoV-2 in mice, with markedly enhanced TH1-biased cellular responses and high virus-neutralizing antibody titers towards both homologous SARS-CoV-2 and a variant harboring the N501Y mutation shared by B1.1.7, B.1.351 and P.1 variants. Furthermore, passive transfer of vaccination-induced antibodies protected naive mice against heterologous viral challenge. NE/IVT DI enables mucosal vaccination, and has the potential to improve the immune profile of a variety of SARS-CoV-2 vaccine candidates to provide effective cross-protection against future drift variants.


Subject(s)
Adjuvants, Immunologic/pharmacology , Antibodies, Viral/immunology , COVID-19 Vaccines/immunology , COVID-19/prevention & control , SARS-CoV-2/immunology , Vaccines, Synthetic/immunology , Adaptive Immunity/immunology , Animals , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Chlorocebus aethiops , Cross Protection/immunology , DEAD Box Protein 58 , HEK293 Cells , Humans , Immunity, Humoral/immunology , Immunization, Passive , Mice , Mice, Inbred C57BL , Receptors, Immunologic/agonists , Recombinant Proteins/immunology , Spike Glycoprotein, Coronavirus/immunology , Vaccination , Vero Cells
13.
Sci Rep ; 11(1): 19470, 2021 09 30.
Article in English | MEDLINE | ID: covidwho-1447318

ABSTRACT

The germicidal potential of specific wavelengths within the electromagnetic spectrum is an area of growing interest. While ultra-violet (UV) based technologies have shown satisfactory virucidal potential, the photo-toxicity in humans coupled with UV associated polymer degradation limit their use in occupied spaces. Alternatively, longer wavelengths with less irradiation energy such as visible light (405 nm) have largely been explored in the context of bactericidal and fungicidal applications. Such studies indicated that 405 nm mediated inactivation is caused by the absorbance of porphyrins within the organism creating reactive oxygen species which result in free radical damage to its DNA and disruption of cellular functions. The virucidal potential of visible-light based technologies has been largely unexplored and speculated to be ineffective given the lack of porphyrins in viruses. The current study demonstrated increased susceptibility of lipid-enveloped respiratory pathogens of importance such as SARS-CoV-2 (causative agent of COVID-19) and influenza A virus to 405 nm, visible light in the absence of exogenous photosensitizers thereby indicating a potential alternative porphyrin-independent mechanism of visible light mediated viral inactivation. These results were obtained using less than expected irradiance levels which are considered safe for humans and commercially achievable. Our results support further exploration of the use of visible light technology for the application of continuous decontamination in occupied areas within hospitals and/or infectious disease laboratories, specifically for the inactivation of respiratory pathogens such as SARS-CoV-2 and Influenza A.


Subject(s)
Disinfection/methods , Influenza A Virus, H1N1 Subtype/radiation effects , SARS-CoV-2/radiation effects , Disinfection/instrumentation , Dose-Response Relationship, Radiation , Encephalomyocarditis virus/radiation effects , Light , Time Factors , Virus Inactivation/radiation effects
15.
Science ; 373(6554): 541-547, 2021 07 30.
Article in English | MEDLINE | ID: covidwho-1334531

ABSTRACT

Repurposing drugs as treatments for COVID-19, the disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has drawn much attention. Beginning with sigma receptor ligands and expanding to other drugs from screening in the field, we became concerned that phospholipidosis was a shared mechanism underlying the antiviral activity of many repurposed drugs. For all of the 23 cationic amphiphilic drugs we tested, including hydroxychloroquine, azithromycin, amiodarone, and four others already in clinical trials, phospholipidosis was monotonically correlated with antiviral efficacy. Conversely, drugs active against the same targets that did not induce phospholipidosis were not antiviral. Phospholipidosis depends on the physicochemical properties of drugs and does not reflect specific target-based activities-rather, it may be considered a toxic confound in early drug discovery. Early detection of phospholipidosis could eliminate these artifacts, enabling a focus on molecules with therapeutic potential.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Drug Repositioning , Lipidoses/chemically induced , Phospholipids/metabolism , SARS-CoV-2/drug effects , A549 Cells , Animals , Antiviral Agents/chemistry , Antiviral Agents/therapeutic use , Antiviral Agents/toxicity , COVID-19/virology , Cations , Chlorocebus aethiops , Dose-Response Relationship, Drug , Female , Humans , Mice , Microbial Sensitivity Tests , SARS-CoV-2/physiology , Surface-Active Agents/chemistry , Surface-Active Agents/pharmacology , Surface-Active Agents/toxicity , Vero Cells , Virus Replication/drug effects
18.
Cell ; 184(10): 2618-2632.e17, 2021 05 13.
Article in English | MEDLINE | ID: covidwho-1157174

ABSTRACT

The ongoing pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently affecting millions of lives worldwide. Large retrospective studies indicate that an elevated level of inflammatory cytokines and pro-inflammatory factors are associated with both increased disease severity and mortality. Here, using multidimensional epigenetic, transcriptional, in vitro, and in vivo analyses, we report that topoisomerase 1 (TOP1) inhibition suppresses lethal inflammation induced by SARS-CoV-2. Therapeutic treatment with two doses of topotecan (TPT), an FDA-approved TOP1 inhibitor, suppresses infection-induced inflammation in hamsters. TPT treatment as late as 4 days post-infection reduces morbidity and rescues mortality in a transgenic mouse model. These results support the potential of TOP1 inhibition as an effective host-directed therapy against severe SARS-CoV-2 infection. TPT and its derivatives are inexpensive clinical-grade inhibitors available in most countries. Clinical trials are needed to evaluate the efficacy of repurposing TOP1 inhibitors for severe coronavirus disease 2019 (COVID-19) in humans.


Subject(s)
COVID-19/drug therapy , DNA Topoisomerases, Type I/metabolism , SARS-CoV-2/metabolism , Topoisomerase I Inhibitors/pharmacology , Topotecan/pharmacology , Animals , COVID-19/enzymology , COVID-19/pathology , Chlorocebus aethiops , Humans , Inflammation/drug therapy , Inflammation/enzymology , Inflammation/pathology , Inflammation/virology , Mesocricetus , Mice , Mice, Transgenic , THP-1 Cells , Vero Cells
19.
mBio ; 12(2)2021 03 02.
Article in English | MEDLINE | ID: covidwho-1115091

ABSTRACT

The spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been identified as the prime target for vaccine development. The spike protein mediates both binding to host cells and membrane fusion and is also so far the only known viral target of neutralizing antibodies. Coronavirus spike proteins are large trimers that are relatively unstable, a feature that might be enhanced by the presence of a polybasic cleavage site in SARS-CoV-2 spike. Exchange of K986 and V987 for prolines has been shown to stabilize the trimers of SARS-CoV-1 and the Middle East respiratory syndrome coronavirus spike proteins. Here, we test multiple versions of a soluble spike protein for their immunogenicity and protective effect against SARS-CoV-2 challenge in a mouse model that transiently expresses human angiotensin-converting enzyme 2 via adenovirus transduction. Variants tested include spike proteins with a deleted polybasic cleavage site, proline mutations, or a combination thereof, besides the wild-type protein. While all versions of the protein were able to induce neutralizing antibodies, only the antigen with both a deleted cleavage site and the K986P and V987P (PP) mutations completely protected from challenge in this mouse model.IMPORTANCE A vaccine for SARS-CoV-2 is urgently needed. A better understanding of antigen design and attributes that vaccine candidates need to have to induce protective immunity is of high importance. The data presented here validate the choice of antigens that contain the PP mutations and suggest that deletion of the polybasic cleavage site may lead to a further-optimized design.


Subject(s)
Proline/chemistry , SARS-CoV-2/immunology , Animals , COVID-19 Vaccines/chemistry , COVID-19 Vaccines/immunology , COVID-19 Vaccines/therapeutic use , Mice , Mutation , Spike Glycoprotein, Coronavirus/chemistry
20.
Science ; 371(6532): 926-931, 2021 02 26.
Article in English | MEDLINE | ID: covidwho-1048642

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral proteins interact with the eukaryotic translation machinery, and inhibitors of translation have potent antiviral effects. We found that the drug plitidepsin (aplidin), which has limited clinical approval, possesses antiviral activity (90% inhibitory concentration = 0.88 nM) that is more potent than remdesivir against SARS-CoV-2 in vitro by a factor of 27.5, with limited toxicity in cell culture. Through the use of a drug-resistant mutant, we show that the antiviral activity of plitidepsin against SARS-CoV-2 is mediated through inhibition of the known target eEF1A (eukaryotic translation elongation factor 1A). We demonstrate the in vivo efficacy of plitidepsin treatment in two mouse models of SARS-CoV-2 infection with a reduction of viral replication in the lungs by two orders of magnitude using prophylactic treatment. Our results indicate that plitidepsin is a promising therapeutic candidate for COVID-19.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Depsipeptides/pharmacology , Peptide Elongation Factor 1/antagonists & inhibitors , SARS-CoV-2/drug effects , Adenosine Monophosphate/analogs & derivatives , Adenosine Monophosphate/pharmacology , Adenosine Monophosphate/therapeutic use , Alanine/analogs & derivatives , Alanine/pharmacology , Alanine/therapeutic use , Animals , Antiviral Agents/therapeutic use , COVID-19/prevention & control , COVID-19/virology , Coronavirus Nucleocapsid Proteins/biosynthesis , Coronavirus Nucleocapsid Proteins/genetics , Depsipeptides/administration & dosage , Depsipeptides/therapeutic use , Drug Evaluation, Preclinical , Female , HEK293 Cells , Humans , Lung/virology , Mice, Inbred C57BL , Mutation , Peptides, Cyclic , Phosphoproteins/biosynthesis , Phosphoproteins/genetics , RNA, Viral/biosynthesis , RNA, Viral/genetics , SARS-CoV-2/genetics , SARS-CoV-2/physiology , Virus Replication/drug effects
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