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1.
Cell Discov ; 7(1): 82, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34493710

RESUMO

The pandemic of COVID-19 caused by SARS-CoV-2 has raised a new challenges to the scientific and industrious fields after over 1-year spread across different countries. The ultimate approach to end the pandemic is the timely application of vaccines to achieve herd immunity. Here, a novel SARS-CoV-2 receptor-binding domain (RBD) homodimer was developed as a SARS-CoV-2 vaccine candidate. Formulated with aluminum adjuvant, RBD dimer elicited strong immune response in both rodents and non-human primates, and protected mice from SARS-CoV-2 challenge with significantly reducing viral load and alleviating pathological injury in the lung. In the non-human primates, the vaccine could prevent majority of the animals from SARS-CoV-2 infection in the respiratory tract and reduce lung damage. In addition, antibodies elicited by this vaccine candidate showed cross-neutralization activities to SARS-CoV-2 variants. Furthermore, with our expression system, we provided a high-yield RBD homodimer vaccine without additional biosafety or special transport device supports. Thus, it may serve as a safe, effective, and low-cost SARS-CoV-2 vaccine candidate.

3.
Signal Transduct Target Ther ; 6(1): 300, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34381015

RESUMO

Elderly people and patients with comorbidities are at higher risk of COVID-19 infection, resulting in severe complications and high mortality. However, the underlying mechanisms are unclear. In this study, we investigate whether miRNAs in serum exosomes can exert antiviral functions and affect the response to COVID-19 in the elderly and people with diabetes. First, we identified four miRNAs (miR-7-5p, miR-24-3p, miR-145-5p and miR-223-3p) through high-throughput sequencing and quantitative real-time PCR analysis, that are remarkably decreased in the elderly and diabetic groups. We further demonstrated that these miRNAs, either in the exosome or in the free form, can directly inhibit S protein expression and SARS-CoV-2 replication. Serum exosomes from young people can inhibit SARS-CoV-2 replication and S protein expression, while the inhibitory effect is markedly decreased in the elderly and diabetic patients. Moreover, three out of the four circulating miRNAs are significantly increased in the serum of healthy volunteers after 8-weeks' continuous physical exercise. Serum exosomes isolated from these volunteers also showed stronger inhibitory effects on S protein expression and SARS-CoV-2 replication. Our study demonstrates for the first time that circulating exosomal miRNAs can directly inhibit SARS-CoV-2 replication and may provide a possible explanation for the difference in response to COVID-19 between young people and the elderly or people with comorbidities.


Assuntos
COVID-19/genética , Diabetes Mellitus/genética , MicroRNAs/genética , Glicoproteína da Espícula de Coronavírus/genética , Adulto , Fatores Etários , Idoso , COVID-19/sangue , COVID-19/patologia , COVID-19/virologia , China , MicroRNA Circulante/sangue , MicroRNA Circulante/genética , Estudos de Coortes , Diabetes Mellitus/sangue , Diabetes Mellitus/patologia , Diabetes Mellitus/virologia , Exercício Físico , Exossomos/genética , Exossomos/metabolismo , Exossomos/virologia , Feminino , Regulação da Expressão Gênica , Células HEK293 , Interações Hospedeiro-Patógeno/genética , Humanos , Masculino , MicroRNAs/sangue , Pessoa de Meia-Idade , SARS-CoV-2/genética , SARS-CoV-2/crescimento & desenvolvimento , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/sangue , Replicação Viral
4.
Viruses ; 13(6)2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34070281

RESUMO

Arenaviruses cause chronic and asymptomatic infections in their natural host, rodents, and several arenaviruses cause severe hemorrhagic fever that has a high mortality in infected humans, seriously threatening public health. There are currently no FDA-licensed drugs available against arenaviruses; therefore, it is important to develop novel antiviral strategies to combat them, which would be facilitated by a detailed understanding of the interactions between the viruses and their hosts. To this end, we performed a transcriptomic analysis on cells infected with arenavirus lymphocytic choriomeningitis virus (LCMV), a neglected human pathogen with clinical significance, and found that the signal transducer and activator of transcription 3 (STAT3) signaling pathway was activated. A further investigation indicated that STAT3 could be activated by the RNA-dependent RNA polymerase L protein (Lp) of LCMV. Our functional analysis found that STAT3 cannot affect LCMV multiplication in A549 cells. We also found that STAT3 was activated by the Lp of Mopeia virus and Junin virus, suggesting that this activation may be conserved across certain arenaviruses. Our study explored the interactions between arenaviruses and STAT3, which may help us to better understand the molecular and cell biology of arenaviruses.

5.
Nat Commun ; 12(1): 3623, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34131140

RESUMO

The ongoing pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) urgently needs an effective cure. 3CL protease (3CLpro) is a highly conserved cysteine proteinase that is indispensable for coronavirus replication, providing an attractive target for developing broad-spectrum antiviral drugs. Here we describe the discovery of myricetin, a flavonoid found in many food sources, as a non-peptidomimetic and covalent inhibitor of the SARS-CoV-2 3CLpro. Crystal structures of the protease bound with myricetin and its derivatives unexpectedly revealed that the pyrogallol group worked as an electrophile to covalently modify the catalytic cysteine. Kinetic and selectivity characterization together with theoretical calculations comprehensively illustrated the covalent binding mechanism of myricetin with the protease and demonstrated that the pyrogallol can serve as an electrophile warhead. Structure-based optimization of myricetin led to the discovery of derivatives with good antiviral activity and the potential of oral administration. These results provide detailed mechanistic insights into the covalent mode of action by pyrogallol-containing natural products and a template for design of non-peptidomimetic covalent inhibitors against 3CLpros, highlighting the potential of pyrogallol as an alternative warhead in design of targeted covalent ligands.


Assuntos
Proteases 3C de Coronavírus/efeitos dos fármacos , Pirogalol/química , Pirogalol/isolamento & purificação , Pirogalol/farmacologia , SARS-CoV-2/efeitos dos fármacos , Antivirais/química , Antivirais/farmacologia , COVID-19/tratamento farmacológico , Proteases Semelhantes à Papaína de Coronavírus , Desenho de Fármacos , Flavonoides , Células HEK293 , Humanos , Cinética , Ligantes , Simulação de Dinâmica Molecular , Inibidores de Proteases/química , Inibidores de Proteases/farmacologia , Proteínas não Estruturais Virais/química
6.
Cell Res ; 31(8): 847-860, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34112954

RESUMO

Cytokine storm and multi-organ failure are the main causes of SARS-CoV-2-related death. However, the origin of excessive damages caused by SARS-CoV-2 remains largely unknown. Here we show that the SARS-CoV-2 envelope (2-E) protein alone is able to cause acute respiratory distress syndrome (ARDS)-like damages in vitro and in vivo. 2-E proteins were found to form a type of pH-sensitive cation channels in bilayer lipid membranes. As observed in SARS-CoV-2-infected cells, heterologous expression of 2-E channels induced rapid cell death in various susceptible cell types and robust secretion of cytokines and chemokines in macrophages. Intravenous administration of purified 2-E protein into mice caused ARDS-like pathological damages in lung and spleen. A dominant negative mutation lowering 2-E channel activity attenuated cell death and SARS-CoV-2 production. Newly identified channel inhibitors exhibited potent anti-SARS-CoV-2 activity and excellent cell protective activity in vitro and these activities were positively correlated with inhibition of 2-E channel. Importantly, prophylactic and therapeutic administration of the channel inhibitor effectively reduced both the viral load and secretion of inflammation cytokines in lungs of SARS-CoV-2-infected transgenic mice expressing human angiotensin-converting enzyme 2 (hACE-2). Our study supports that 2-E is a promising drug target against SARS-CoV-2.


Assuntos
Antivirais/metabolismo , COVID-19/patologia , Proteínas do Envelope de Coronavírus/metabolismo , Síndrome do Desconforto Respiratório/etiologia , SARS-CoV-2/metabolismo , Enzima de Conversão de Angiotensina 2/genética , Animais , Antivirais/química , Antivirais/uso terapêutico , Apoptose , COVID-19/complicações , COVID-19/tratamento farmacológico , COVID-19/virologia , Proteínas do Envelope de Coronavírus/antagonistas & inibidores , Proteínas do Envelope de Coronavírus/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Meia-Vida , Humanos , Pulmão/metabolismo , Pulmão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mutagênese Sítio-Dirigida , SARS-CoV-2/isolamento & purificação , SARS-CoV-2/patogenicidade , Baço/metabolismo , Baço/patologia , Carga Viral , Virulência
7.
Biosaf Health ; 3(3): 156-163, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34027383

RESUMO

Swine acute diarrhea syndrome coronavirus (SADS-CoV) is a recently discovered coronavirus that causes severe and acute diarrhea and rapid weight loss in piglets. SADS-CoV was reported to be capable of infecting cell lines derived from diverse species, including bats, mice, hamsters, rats, chickens, pigs, nonhuman primates, and humans, implying its high risk of cross-species infection. However, its receptor is still unknown. In this study, the receptor-binding domain of the SADS-CoV spike (S) protein was purified and then subjected to affinity purification (AP)-coupled mass spectrometry (MS)-based proteomic analysis to identify the interactors of the SADS-CoV S protein. Forty-three host proteins were identified, and a Gene Ontology analysis indicated that these interactors can be grouped into categories such as "cell-cell adhesion", "translation" "viral transcription", suggesting that these processes may participate in the SADS-CoV life cycles. RNA interference-based screening of these interactors indicated that PPIB and vimentin can affect SADS-CoV replication. Our study provides an overarching view into the host interactome of the SADS-CoV S protein and highlights potential targets for the development of therapeutics against SADS-CoV.

8.
J Virol ; 95(15): e0056021, 2021 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-33980602

RESUMO

Currently, there are no approved drugs for the treatment of flavivirus infection. Accordingly, we tested the inhibitory effects of the novel θ-defensin retrocyclin-101 (RC-101) against flavivirus infection and investigated the mechanism underlying the potential inhibitory effects. First, RC-101 robustly inhibited both Japanese encephalitis virus (JEV) and Zika virus (ZIKV) infections. RC-101 exerted inhibitory effects on the entry and replication stages. Results also indicated that the nonstructural protein NS2B-NS3 serine protease might serve as a potential viral target. Furthermore, RC-101 inhibited protease activity at the micromolar level. We also demonstrated that with respect to the glycoprotein E protein of flavivirus, the DE loop of domain III (DIII), which is the receptor-binding domain of the E protein, might serve as another viral target of RC-101. Moreover, a JEV DE mutant exhibited resistance to RC-101, which was associated with deceased binding affinity of RC-101 to DIII. These findings provide a basis for the development of RC-101 as a potential candidate for the treatment of flavivirus infection. IMPORTANCE Retrocyclin is an artificially humanized circular θ-defensin peptide, containing 18 residues, previously reported to possess broad antimicrobial activity. In this study, we found that retrocyclin-101 inhibited flavivirus (ZIKV and JEV) infections. Retrocyclin-101 inhibited NS2B-NS3 serine protease activity, suggesting that the catalytic triad of the protease is the target. Moreover, retrocyclin-101 bound to the DE loop of the E protein of flavivirus, which prevented its entry.


Assuntos
Antivirais/farmacologia , Encefalite Japonesa/tratamento farmacológico , Peptídeos/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Infecção por Zika virus/tratamento farmacológico , Animais , Chlorocebus aethiops , Cricetinae , Defensinas/química , Vírus da Encefalite Japonesa (Espécie)/crescimento & desenvolvimento , Humanos , Domínios Proteicos/genética , Células Vero , Proteínas do Envelope Viral/metabolismo , Internalização do Vírus/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Zika virus/crescimento & desenvolvimento
10.
Protein Cell ; 12(11): 877-888, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-33864621

RESUMO

A new coronavirus (SARS-CoV-2) has been identified as the etiologic agent for the COVID-19 outbreak. Currently, effective treatment options remain very limited for this disease; therefore, there is an urgent need to identify new anti-COVID-19 agents. In this study, we screened over 6,000 compounds that included approved drugs, drug candidates in clinical trials, and pharmacologically active compounds to identify leads that target the SARS-CoV-2 papain-like protease (PLpro). Together with main protease (Mpro), PLpro is responsible for processing the viral replicase polyprotein into functional units. Therefore, it is an attractive target for antiviral drug development. Here we discovered four compounds, YM155, cryptotanshinone, tanshinone I and GRL0617 that inhibit SARS-CoV-2 PLpro with IC50 values ranging from 1.39 to 5.63 µmol/L. These compounds also exhibit strong antiviral activities in cell-based assays. YM155, an anticancer drug candidate in clinical trials, has the most potent antiviral activity with an EC50 value of 170 nmol/L. In addition, we have determined the crystal structures of this enzyme and its complex with YM155, revealing a unique binding mode. YM155 simultaneously targets three "hot" spots on PLpro, including the substrate-binding pocket, the interferon stimulating gene product 15 (ISG15) binding site and zinc finger motif. Our results demonstrate the efficacy of this screening and repurposing strategy, which has led to the discovery of new drug leads with clinical potential for COVID-19 treatments.


Assuntos
Proteases Semelhantes à Papaína de Coronavírus/química , Ensaios de Triagem em Larga Escala/métodos , Inibidores de Proteases/química , Antivirais/química , Antivirais/metabolismo , Antivirais/uso terapêutico , Sítios de Ligação , COVID-19/tratamento farmacológico , COVID-19/virologia , Proteases Semelhantes à Papaína de Coronavírus/genética , Proteases Semelhantes à Papaína de Coronavírus/metabolismo , Cristalografia por Raios X , Avaliação Pré-Clínica de Medicamentos , Reposicionamento de Medicamentos , Humanos , Imidazóis/química , Imidazóis/metabolismo , Imidazóis/uso terapêutico , Concentração Inibidora 50 , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , Naftoquinonas/química , Naftoquinonas/metabolismo , Naftoquinonas/uso terapêutico , Inibidores de Proteases/metabolismo , Inibidores de Proteases/uso terapêutico , Estrutura Terciária de Proteína , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , SARS-CoV-2/isolamento & purificação
11.
Signal Transduct Target Ther ; 6(1): 145, 2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33859168

RESUMO

Severe fever with thrombocytopenia syndrome (SFTS) virus (SFTSV) is an emerging tick-borne virus with high fatality and an expanding endemic. Currently, effective anti-SFTSV intervention remains unavailable. Favipiravir (T-705) was recently reported to show in vitro and in animal model antiviral efficacy against SFTSV. Here, we conducted a single-blind, randomized controlled trial to assess the efficacy and safety of T-705 in treating SFTS (Chinese Clinical Trial Registry website, number ChiCTR1900023350). From May to August 2018, laboratory-confirmed SFTS patients were recruited from a designated hospital and randomly assigned to receive oral T-705 in combination with supportive care or supportive care only. Fatal outcome occurred in 9.5% (7/74) of T-705 treated patients and 18.3% (13/71) of controls (odds ratio, 0.466, 95% CI, 0.174-1.247). Cox regression showed a significant reduction in case fatality rate (CFR) with an adjusted hazard ratio of 0.366 (95% CI, 0.142-0.944). Among the low-viral load subgroup (RT-PCR cycle threshold ≥26), T-705 treatment significantly reduced CFR from 11.5 to 1.6% (P = 0.029), while no between-arm difference was observed in the high-viral load subgroup (RT-PCR cycle threshold <26). The T-705-treated group showed shorter viral clearance, lower incidence of hemorrhagic signs, and faster recovery of laboratory abnormities compared with the controls. The in vitro and animal experiments demonstrated that the antiviral efficacies of T-705 were proportionally induced by SFTSV mutation rates, particularly from two transition mutation types. The mutation analyses on T-705-treated serum samples disclosed a partially consistent mutagenesis pattern as those of the in vitro or animal experiments in reducing the SFTSV viral loads, further supporting the anti-SFTSV effect of T-705, especially for the low-viral loads.

12.
Virol Sin ; 36(4): 774-783, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33689141

RESUMO

Lassa virus (LASV) belongs to the Mammarenavirus genus (family Arenaviridae) and causes severe hemorrhagic fever in humans. The glycoprotein complex (GPC) contains eleven N-linked glycans that play essential roles in GPC functionalities such as cleavage, transport, receptor recognition, epitope shielding, and immune response. We used three mutagenesis strategies (asparagine to glutamine, asparagine to alanine, and serine/tyrosine to alanine mutants) to abolish individual glycan chain on GPC and found that all the three strategies led to cleavage inefficiency on the 2nd (N89), 5th (N119), or 8th (N365) glycosylation motif. To evaluate N to Q mutagenesis for further research, it was found that deletion of the 2nd (N89Q) or 8th (N365Q) glycan completely inhibited the transduction efficiency of pseudotyped particles. We further investigated the role of individual glycan on GPC-mediated immune response by DNA immunization of mice. Deletion of the individual 1st (N79Q), 3rd (N99Q), 5th (N119Q), or 6th (N167Q) glycan significantly enhanced the proportion of effector CD4+ cells, whereas deletion of the 1st (N79Q), 2nd (N89Q), 3rd (N99Q), 4th (N109Q), 5th (N119Q), 6th (N167Q), or 9th (N373Q) glycan enhanced the proportion of CD8+ effector T cells. Deletion of specific glycan improves the Th1-type immune response, and abolishment of glycan on GPC generally increases the antibody titer to the glycan-deficient GPC. However, the antibodies from either the mutant or WT GPC-immunized mice show little neutralization effect on wild-type LASV. The glycan residues on GPC provide an immune shield for the virus, and thus represent a target for the design and development of a vaccine.


Assuntos
Vírus Lassa , Envelope Viral , Animais , Imunidade , Vírus Lassa/genética , Camundongos , Polissacarídeos , Proteínas do Envelope Viral
13.
Nat Struct Mol Biol ; 28(3): 319-325, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33674802

RESUMO

The COVID-19 pandemic caused by nonstop infections of SARS-CoV-2 has continued to ravage many countries worldwide. Here we report that suramin, a 100-year-old drug, is a potent inhibitor of the SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) and acts by blocking the binding of RNA to the enzyme. In biochemical assays, suramin and its derivatives are at least 20-fold more potent than remdesivir, the currently approved nucleotide drug for treatment of COVID-19. The 2.6 Å cryo-electron microscopy structure of the viral RdRp bound to suramin reveals two binding sites. One site directly blocks the binding of the RNA template strand and the other site clashes with the RNA primer strand near the RdRp catalytic site, thus inhibiting RdRp activity. Suramin blocks viral replication in Vero E6 cells, although the reasons underlying this effect are likely various. Our results provide a structural mechanism for a nonnucleotide inhibitor of the SARS-CoV-2 RdRp.


Assuntos
Antivirais/farmacologia , RNA-Polimerase RNA-Dependente de Coronavírus/antagonistas & inibidores , RNA-Polimerase RNA-Dependente de Coronavírus/química , Inibidores Enzimáticos/farmacologia , Suramina/farmacologia , Animais , Antivirais/química , Antivirais/metabolismo , Sítios de Ligação , Domínio Catalítico , Chlorocebus aethiops , RNA-Polimerase RNA-Dependente de Coronavírus/metabolismo , Microscopia Crioeletrônica , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Conformação Proteica , RNA Viral/química , RNA Viral/metabolismo , SARS-CoV-2/efeitos dos fármacos , Suramina/química , Suramina/metabolismo , Células Vero , Replicação Viral/efeitos dos fármacos
14.
Artigo em Inglês | MEDLINE | ID: mdl-33753340

RESUMO

Mosquito-borne Japanese encephalitis virus (JEV) causes serious illness worldwide and is associated with high morbidity and mortality. To identify potential host therapeutic targets, a high-throughput receptor tyrosine kinase small interfering RNA library screening was performed with recombinant JEV particles. Platelet-derived growth factor receptor beta (PDGFRß) was identified as a hit after two rounds of screening. Knockdown of PDGFRß blocked JEV infection and transcomplementation of PDGFRß could partly restore its infectivity. The PDGFRß inhibitor imatinib, which has been approved for the treatment of malignant metastatic cancer, protected mice against JEV-induced lethality by decreasing the viral load in the brain while abrogating the histopathological changes associated with JEV infection. These findings demonstrated that PDGFRß is important in viral infection and provided evidence for the potential to develop imatinib as a therapeutic intervention against JEV infection.


Assuntos
Vírus da Encefalite Japonesa (Espécie) , Encefalite Japonesa , Animais , Encéfalo , Vírus da Encefalite Japonesa (Espécie)/genética , Encefalite Japonesa/tratamento farmacológico , Camundongos , Interferência de RNA , Receptor beta de Fator de Crescimento Derivado de Plaquetas , Receptores do Fator de Crescimento Derivado de Plaquetas , Replicação Viral
15.
Adv Ther (Weinh) ; : 2000224, 2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33786369

RESUMO

SARS-CoV-2 caused the emerging epidemic of coronavirus disease in 2019 (COVID-19). To date, there are more than 82.9 million confirmed cases worldwide, there is no clinically effective drug against SARS-CoV-2 infection. The conserved properties of the membrane fusion domain of the spike (S) protein across SARS-CoV-2 make it a promising target to develop pan-CoV therapeutics. Herein, two clinically approved drugs, Itraconazole (ITZ) and Estradiol benzoate (EB), are found to inhibit viral entry by targeting the six-helix (6-HB) fusion core of SARS-CoV-2 S protein. Further studies shed light on the mechanism that ITZ and EB can interact with the heptad repeat 1 (HR1) region of the spike protein, to present anti-SARS-CoV-2 infections in vitro, indicating they are novel potential therapeutic remedies for COVID-19 treatment. Furthermore, ITZ shows broad-spectrum activity targeting 6-HB in the S2 subunit of SARS-CoV and MERS-CoV S protein, inspiring that ITZ have the potential for development as a pan-coronavirus fusion inhibitor.

16.
J Virol ; 2021 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-33536168

RESUMO

Lassa virus (LASV) belongs to the Old World Mammarenavirus genus (family Arenaviridae). At present, there are no approved drugs or vaccines specific for LASV. In this study, high-throughput screening of a botanical drug library was performed against LASV entry using a pseudotype virus bearing the LASV envelope glycoprotein complex (GPC). Two hit compounds, bergamottin and casticin, were identified as micromolar range inhibitors of LASV entry. A mechanistic study revealed that casticin inhibited LASV entry by blocking low pH-induced membrane fusion. Analysis of adaptive mutants demonstrated that the F446L mutation, located in the transmembrane domain of GP2, conferred resistance to casticin. Furthermore, casticin antiviral activity extends to the New World (NW) pathogenic mammarenaviruses, and mutation of the conserved F446 also conferred resistance to casticin in these viruses. Unlike casticin, bergamottin showed little effect on LASV GPC-mediated membrane fusion, instead inhibiting LASV entry by blocking endocytic trafficking. Notably, both compounds showed inhibitory effects on authentic lymphocytic choriomeningitis virus. Our study shows that both casticin and bergamottin are candidates for LASV therapy and that the conserved F446 in LASV GPC is important in drug resistance in mammarenaviruses.IMPORTANCE: Currently, there is no approved therapy to treat Lassa fever (LASF). Our goal was to identify potential candidate molecules for LASF therapy. Herein, we screened a botanical drug library and identified two compounds, casticin and bergamottin, that inhibited LASV entry via different mechanisms.

17.
ACS Infect Dis ; 7(6): 1409-1422, 2021 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-33183004

RESUMO

Arenaviruses are a large family of enveloped negative-strand RNA viruses that include several causative agents of severe hemorrhagic fevers. Currently, there are no FDA-licensed drugs to treat arenavirus infection except for the off-labeled use of ribavirin. Here, we performed antiviral drug screening against the Old World arenavirus lymphocytic choriomeningitis virus (LCMV) using an FDA-approved drug library. Five drug candidates were identified, including mycophenolic acid, benidipine hydrochloride, clofazimine, dabrafenib, and apatinib, for having strong anti-LCMV effects. Further analysis indicated that benidipine hydrochloride inhibited LCMV membrane fusion, and an adaptive mutation on the LCMV glycoprotein D414 site was found to antagonize the anti-LCMV activity of benidipine hydrochloride. Mycophenolic acid inhibited LCMV replication by depleting GTP production. We also found mycophenolic acid, clofazimine, dabrafenib, and apatinib can inhibit the newly emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Owing to their FDA-approved status, these drug candidates can potentially be used rapidly in the clinical treatment of arenavirus and SARS-CoV-2 infection.


Assuntos
COVID-19 , Preparações Farmacêuticas , Ensaios de Triagem em Larga Escala , Humanos , SARS-CoV-2 , Replicação Viral
18.
Virol Sin ; 36(2): 273-280, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32897505

RESUMO

The membrane-proximal external region (MPER) of Lassa virus (LASV) glycoprotein complex (GPC) is critical in modulating its functionality. Till now, the high-resolution structure of the intact GPC, including MPER is not available. In this study, we used alanine substitution to scan all 16 residues located in LASV MPER. Western blotting and quantification fusion assay showed that the residues located at the C terminus of the HR2 (M414 and L415) and N terminus of the MPER (K417 and Y419) are critical for GPC-mediated membrane fusion function. Furthermore, cell surface biotinylation experiments revealed that M414A, K417A and Y419A expressed similar levels as WT, whereas L415A mutant led to a reduction of mature GPC on the cell surface. Moreover, substitution of these residues with the similar residue such as M414L, L415I, K417R and Y419F would partly compensate the loss of the fusion activity caused by the alanine mutant in these sites. Results from this study showed that several key residues in the MPER region are indispensable to promote the conformational changes that drive fusion events and shed light on the structure analysis of LASV GPC and anti-LASV therapeutics.


Assuntos
Vírus Lassa , Envelope Viral , Membrana Celular , Vírus Lassa/genética , Fusão de Membrana , Proteínas do Envelope Viral/genética , Internalização do Vírus
20.
Cell Discov ; 6(1): 96, 2020 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-33349633

RESUMO

The coronavirus disease (COVID-19) caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has now spread to >200 countries posing a global public health concern. Patients with comorbidity, such as hypertension suffer more severe infection with elevated mortality. The development of effective antiviral drugs is in urgent need to treat COVID-19 patients. Here, we report that calcium channel blockers (CCBs), a type of antihypertensive drug that is widely used in clinics, inhibited the post-entry replication events of SARS-CoV-2 in vitro, while no in vitro anti-SARS-CoV-2 effect was observed for the two other major types of antihypertensive drugs, namely, angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers. CCB combined with chloroquine showed a significantly enhanced anti-SARS-CoV-2 efficacy. A retrospective clinical investigation on hospitalized COVID-19 patients with hypertension as the only comorbidity revealed that the CCB amlodipine besylate therapy was associated with a decreased case fatality rate. The results from this study suggest that CCB administration to COVID-19 patients with hypertension as the comorbidity might improve the disease outcome.

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