Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 84
Filtrar
1.
EClinicalMedicine ; 67: 102372, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38169790

RESUMO

Background: The mRNA vaccine has demonstrated significant effectiveness in protecting against SARS-CoV-2 during the pandemic, including against severe forms of the disease caused by emerging variants. In this study, we examined safety, immunogenicity, and relative efficacy of a heterologous booster of the lipopolyplex (LPP)-based mRNA vaccine (SW-BIC-213) versus a homologous booster of an inactivated vaccine (BBIBP) in Laos. Methods: In this phase 3 clinical trial, which was randomized, parallel controlled and double-blinded, healthy adults aged 18 years and above were recruited from the Southern Savannakhet Provincial Hospital and Champhone District Hospital. The primary outcomes were safety and immunogenicity, with efficacy as an exploratory endpoint. Participants who were fully immunized with a two-dose inactivated vaccine for more than 6 months were assigned equally to either the SW-BIC-213 group (25 µg) or BBIBP group. The primary safety endpoint was to describe the safety profile of all participants in each group up to 6 months post-booster immunization. The primary immunogenic outcome was to demonstrate the superiority of the neutralizing antibody response, in terms of geometric mean titers (GMTs) of SW-BIC-213, compared with BBIBP 28 days after the booster dose. The exploratory efficacy endpoint aimed to assess the relative efficacy of SW-BIC-213 compared to BBIBP against virologically confirmed symptomatic COVID-19 over a 6-month period. The trial was registered with ClinicalTrials.gov (NCT05580159). Findings: Between October 10, 2022, and January 13, 2023, 1200 participants were assigned to SW-BIC-213 group and 1203 participants in the BBIBP group. All adverse reactions observed during the study were tolerable, transient, and resolved spontaneously. Solicited local reactions were the main adverse reactions in both the SW-BIC-213 group (43.8%) and BBIBP group (14.8%) (p < 0.001). Heterologous boosting with SW-BIC-213 induced higher live virus neutralizing antibodies to SARS-CoV-2 wildtype and BA.5 strains with GMTs reaching 750.1 and 192.9 than homologous boosting with BBIBP with GMTs of 131.5 (p < 0.001) and 47.5 (p < 0.001) on day 29. The statistical findings revealed that, following a period of 14-day to 6-month after booster vaccination, the SW-BIC-213 group exhibited a relative vaccine efficacy (VE) of 70.1% (95% CI: 34.2-86.4) against symptomatic COVID-19 when compared to the BBIBP group. Interpretation: A heterologous booster with the COVID-19 mRNA vaccine SW-BIC-213 manifests a favorable safety profile and proves highly immunogenic and efficacious in preventing symptomatic COVID-19 in individuals who have previously received two doses of inactivated vaccine. Funding: Shanghai Strategic Emerging Industries Development Special Fund, Biomedical Technology Support Special Project of Shanghai "Science and Technology Innovation Action Plan", Shanghai Municipal Science and Technology Commission.

3.
Vaccine ; 41(48): 7297-7306, 2023 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-37925316

RESUMO

BACKGROUND: COVID-19 caused by SARS-CoV-2 is a great threat to public health. We present the safety and immunogenicity data from a phase I trial in China of an mRNA vaccine (LVRNA009). METHODS: In the single-centre, double-blind, placebo-controlled and dose-escalation study, 72 healthy unvaccinated adults aged 18-59 years were randomized (3:1) to receive LVRNA009 with one of three vaccine dosage (25, 50 and 100 µg) or placebo, to evaluate for the safety, tolerability and immunogenicity of LVRNA009. RESULTS: All these participants received two injections 28 days apart. No adverse events higher than grade 2 were reported during the study. A total of 30 participants (42 %) reported solicited adverse reactions during the first 14 days after vaccinations. Of the events reported, fever (n = 11, 15 %) was the most common systemic adverse reaction, and pain at the injection site (n = 17, 24 %) was the most frequent solicited local adverse reaction. Anti-S-protein IgG and neutralising antibodies were observed to have been induced 14 days after the first dose, significantly increased 7 days after the second dose, and remained at a high level 28 days after the second dose. Specific T-cell responses peaked 7 days and persisted 28 days after second vaccination. CONCLUSION: LVRNA009 has demonstrated promising results in safety and tolerability at all three dose levels among Chinese adults. LVRNA009 at three dose levels could rapidly induce strong humoral and cellular immune responses, including binding and neutralising antibody production and IFN- γ secretion, which showed good immunogenicity. CLINICAL TRIAL REGISTRATION NUMBER: Clinicaltrials.gov NCT05364047; Chictr.org.cn ChiCTR2100049349.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Adulto , Humanos , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Vacinas contra COVID-19/uso terapêutico , Método Duplo-Cego , População do Leste Asiático , Imunogenicidade da Vacina , SARS-CoV-2 , Vacinas de mRNA
5.
J Med Virol ; 95(7): e28969, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37485644

RESUMO

Despite the extensive use of effective vaccines and antiviral drugs, chronic hepatitis B virus (HBV) infection continues to pose a serious threat to global public health. Therapies with novel mechanisms of action against HBV are being explored for achieving a functional cure. In this study, five murine models of HBV replication were used to investigate the inhibitory effect of RNA binding motif protein 24 (RBM24) on HBV replication. The findings revealed that RBM24 serves as a host restriction factor and suppresses HBV replication in vivo. The transient overexpression of RBM24 in hydrodynamics-based mouse models of HBV replication driven by the CMV or HBV promoters suppressed HBV replication. Additionally, the ectopic expression of RBM24 decreased viral accumulation and the levels of HBV covalently closed circular DNA (cccDNA) in an rcccDNA mouse model. The liver-directed transduction of adeno-associated viruses (AAV)-RBM24 mediated the stable hepatic expression of RBM24 in pAAV-HBV1.2 and HBV/tg mouse models, and markedly reduced the levels of HBV cccDNA and other viral indicators. Altogether, these findings revealed that RBM24 inhibits the replication of HBV in vivo, and RBM24 may be a potential therapeutic target for combating HBV infections.


Assuntos
Hepatite B Crônica , Hepatite B , Camundongos , Animais , Vírus da Hepatite B , Replicação Viral , DNA Circular , Motivos de Ligação ao RNA , DNA Viral/genética , DNA Viral/metabolismo
6.
J Virol ; 97(5): e0058023, 2023 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-37166302

RESUMO

Hepatitis B virus (HBV) infection affects hepatic metabolism. Serum metabolomics studies have suggested that HBV possibly hijacks the glycerol-3-phosphate (G3P) shuttle. In this study, the two glycerol-3-phosphate dehydrogenases (GPD1 and GPD2) in the G3P shuttle were analyzed for determining their role in HBV replication and the findings revealed that GPD2 and not GPD1 inhibited HBV replication. The knockdown of GPD2 expression upregulated HBV replication, while GPD2 overexpression reduced HBV replication. Moreover, the overexpression of GPD2 significantly reduced HBV replication in hydrodynamic injection-based mouse models. Mechanistically, this inhibitory effect is related to the GPD2-mediated degradation of HBx protein by recruiting the E3 ubiquitin ligase TRIM28 and not to the alterations in G3P metabolism. In conclusion, this study revealed GPD2, a key enzyme in the G3P shuttle, as a host restriction factor in HBV replication. IMPORTANCE The glycerol-3-phosphate (G3P) shuttle is important for the delivery of cytosolic reducing equivalents into mitochondria for oxidative phosphorylation. The study analyzed two key components of the G3P shuttle and identified GPD2 as a restriction factor in HBV replication. The findings revealed a novel mechanism of GPD2-mediated inhibition of HBV replication via the recruitment of TRIM28 for degrading HBx, and the HBx-GPD2 interaction could be another potential therapeutic target for anti-HBV drug development.


Assuntos
Glicerolfosfato Desidrogenase , Hepatite B , Proteína 28 com Motivo Tripartido , Proteínas Virais Reguladoras e Acessórias , Animais , Camundongos , Glicerol/metabolismo , Glicerolfosfato Desidrogenase/metabolismo , Hepatite B/metabolismo , Vírus da Hepatite B/fisiologia , Mitocôndrias/enzimologia , Fosfatos/metabolismo , Proteína 28 com Motivo Tripartido/metabolismo , Proteínas Virais Reguladoras e Acessórias/genética , Proteínas Virais Reguladoras e Acessórias/metabolismo , Replicação Viral
7.
J Med Virol ; 95(3): e28610, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36840407

RESUMO

Tick-borne encephalitis virus (TBEV) is the causative agent of a potentially fatal neurological infection in humans. Investigating virus-host interaction is important for understanding the pathogenesis of TBEV and developing effective antiviral drugs against this virus. Here, we report that mammalian ste20-like kinase 3 (MST3) is involved in the regulation of TBEV infection. The knockdown or knockout of MST3, but not other mammalian ste20-like kinase family members, inhibited TBEV replication. The knockdown of MST3 also significantly reduced TBEV replication in mouse primary astrocytes. Life cycle analysis indicated that MST3 remarkably impaired virion assembly efficiency and specific infectivity by respectively 59% and 95% in MST3-knockout cells. We further found that MST3 interacts with the viral proteins NS2A and prM; and MST3 enhances the interaction of NS2A-NS4A. Thus, MST3-NS2A complex plays a major role in recruiting prM-E heterodimers and NS4A and mediates the virion assembly. Additionally, we found that MST3 was biotinylated and combined with other proteins (e.g., ATG5, Sec24A, and SNX4) that are associated with the cellular membrane required for TBEV infection. Overall, our study revealed a novel function for MST3 in TBEV infection and identified as a novel host factor supporting TBEV assembly.


Assuntos
Vírus da Encefalite Transmitidos por Carrapatos , Encefalite Transmitida por Carrapatos , Animais , Camundongos , Humanos , Vírus da Encefalite Transmitidos por Carrapatos/genética , Proteínas Virais/metabolismo , Mamíferos/metabolismo , Proteínas de Transporte Vesicular
8.
Nat Commun ; 14(1): 1058, 2023 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-36828833

RESUMO

SARS-CoV-2 Omicron variants feature highly mutated spike proteins with extraordinary abilities in evading antibodies isolated earlier in the pandemic. Investigation of memory B cells from patients primarily with breakthrough infections with the Delta variant enables isolation of a number of neutralizing antibodies cross-reactive to heterologous variants of concern (VOCs) including Omicron variants (BA.1-BA.4). Structural studies identify altered complementarity determining region (CDR) amino acids and highly unusual heavy chain CDR2 insertions respectively in two representative cross-neutralizing antibodies-YB9-258 and YB13-292. These features are putatively introduced by somatic hypermutation and they are heavily involved in epitope recognition to broaden neutralization breadth. Previously, insertions/deletions were rarely reported for antiviral antibodies except for those induced by HIV-1 chronic infections. These data provide molecular mechanisms for cross-neutralization of heterologous SARS-CoV-2 variants by antibodies isolated from Delta variant infected patients with implications for future vaccination strategy.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Anticorpos Neutralizantes , Anticorpos Antivirais , Glicoproteína da Espícula de Coronavírus
9.
J Biosaf Biosecur ; 5(1): 1-7, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36624850

RESUMO

Orthopoxviruses (OPXVs) belong to a group of nucleo-cytoplasmic large DNA viruses. Human pathogenic OPXVs (hpOPXVs) include at least five viruses, among which smallpox virus and monkeypox virus are the most dangerous viral pathogens. Both viruses are classified as category-one human infectious pathogens in China. Although smallpox was globally eradicated in the 1980 s, it is still a top biosecurity threat owing to the possibility of either being leaked to the outside world from a laboratory or being weaponized by terrorists. Beginning in early May 2022, a sudden outbreak of monkeypox was concurrently reported in more than 100 disparate geographical areas, representing a public health emergency of international concern, as declared by the World Health Organization (WHO). In this review, we present the reasons for hpOPXVs such as monkeypox virus presenting a potential threat to public health. We then systematically review the historical and recent development of vaccines and drugs against smallpox and monkeypox. In the final section, we highlight the importance of viromics studies as an integral part of a forward defense strategy to eliminate the potential threat to public health from emerging or re-emerging hpOPXVs and their variants.

10.
Antiviral Res ; 209: 105478, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36464077

RESUMO

SARS-CoV-2 is a betacoronavirus with single-stranded positive-sense RNA, which is a serious global threat to human health. Understanding the molecular mechanism of viral replication is crucial for the development of antiviral drugs. The synthesis of viral polyproteins is a crucial step in viral progression. The synthesis of viral polyproteins in coronaviruses is regulated by the 5'-untranslated region (UTR); however, the detailed regulatory mechanism needs further investigation. The present study demonstrated that the RNA binding protein, RBM24, interacts with the RNA genome of SARS-CoV-2 via its RNA recognition submotifs (RNPs). The findings revealed that RBM24 recognizes and binds to the GUGUG element at stem-loop 4 (SL4) in the 5'-UTR of SARS-CoV-2. The interaction between RBM24 and 5'-UTR prevents 80S ribosome assembly, which in turn inhibits polyproteins translation and the replication of SARS-CoV-2. Notably, other RNA viruses, including SARS-CoV, MERS-CoV, Ebolavirus, rhinovirus, West Nile virus, Zika virus, Japanese encephalitis virus, yellow fever virus, hepatitis C virus, and human immunodeficiency virus-1 also contain one or several G(U/C/A)GUG sequences in the 5'-UTR, which is also targeted by RBM24. In conclusion, the present study demonstrated that RBM24 functions by interacting with the 5'-UTR of SARS-CoV-2 RNA, and elucidated that RBM24 could be a host restriction factor for SARS-CoV-2 and other RNA viruses.


Assuntos
COVID-19 , Vírus de RNA , Infecção por Zika virus , Zika virus , Humanos , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , RNA Viral/metabolismo , Regiões 5' não Traduzidas , Replicação Viral/genética , Zika virus/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
12.
Nat Commun ; 13(1): 7629, 2022 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-36494373

RESUMO

The ongoing COVID-19 pandemic has demonstrated that viral diseases represent an enormous public health and economic threat to mankind and that individuals with compromised immune systems are at greater risk of complications and death from viral diseases. The development of broad-spectrum antivirals is an important part of pandemic preparedness. Here, we have engineer a series of designer cells which we term autonomous, intelligent, virus-inducible immune-like (ALICE) cells as sense-and-destroy antiviral system. After developing a destabilized STING-based sensor to detect viruses from seven different genera, we have used a synthetic signal transduction system to link viral detection to the expression of multiple antiviral effector molecules, including antiviral cytokines, a CRISPR-Cas9 module for viral degradation and the secretion of a neutralizing antibody. We perform a proof-of-concept study using multiple iterations of our ALICE system in vitro, followed by in vivo functionality testing in mice. We show that dual output ALICESaCas9+Ab system delivered by an AAV-vector inhibited viral infection in herpetic simplex keratitis (HSK) mouse model. Our work demonstrates that viral detection and antiviral countermeasures can be paired for intelligent sense-and-destroy applications as a flexible and innovative method against virus infection.


Assuntos
COVID-19 , Viroses , Vírus , Humanos , Camundongos , Animais , Antivirais/farmacologia , Antivirais/uso terapêutico , Replicação Viral , Pandemias
13.
Nat Microbiol ; 7(10): 1635-1649, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36151403

RESUMO

Population antibody response is thought to be important in selection of virus variants. We report that SARS-CoV-2 infection elicits a population immune response that is mediated by a lineage of VH1-69 germline antibodies. A representative antibody R1-32 from this lineage was isolated. By cryo-EM, we show that it targets a semi-cryptic epitope in the spike receptor-binding domain. Binding to this non-ACE2 competing epitope results in spike destruction, thereby inhibiting virus entry. On the basis of epitope location, neutralization mechanism and analysis of antibody binding to spike variants, we propose that recurrent substitutions at 452 and 490 are associated with immune evasion of the identified population antibody response. These substitutions, including L452R (present in the Delta variant), disrupt interactions mediated by the VH1-69-specific hydrophobic HCDR2 to impair antibody-antigen association, enabling variants to escape. The first Omicron variants were sensitive to antibody R1-32 but subvariants that harbour L452R quickly emerged and spread. Our results provide insights into how SARS-CoV-2 variants emerge and evade host immune responses.


Assuntos
COVID-19 , SARS-CoV-2 , Anticorpos Antivirais , Formação de Anticorpos , Epitopos/genética , Humanos , Mutação , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/metabolismo
14.
Virol Sin ; 37(5): 695-703, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35781091

RESUMO

Several variants of concern (VOCs) have emerged since the WIV04 strain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first isolated in January 2020. Due to mutations in the spike (S) protein, these VOCs have evolved to enhance viral infectivity and immune evasion. However, whether mutations of the other viral proteins lead to altered viral propagation and drug resistance remains obscure. The replicon is a noninfectious viral surrogate capable of recapitulating certain steps of the viral life cycle. Although several SARS-CoV-2 replicons have been developed, none of them were derived from emerging VOCs and could only recapitulate viral genome replication and subgenomic RNA (sgRNA) transcription. In this study, SARS-CoV-2 replicons derived from the WIV04 strain and two VOCs (the Beta and Delta variants) were prepared by removing the S gene from their genomes, while other structural genes remained untouched. These replicons not only recapitulate viral genome replication and sgRNA transcription but also support the assembly and release of viral-like particles, as manifested by electron microscopic assays. Thus, the S-deletion replicon could recapitulate virtually all the post-entry steps of the viral life cycle and provides a versatile tool for measuring viral intracellular propagation and screening novel antiviral drugs, including inhibitors of virion assembly and release. Through the quantification of replicon RNA released into the supernatant, we demonstrate that viral intracellular propagation and drug response to remdesivir have not yet substantially changed during the evolution of SARS-CoV-2 from the WIV04 strain to the Beta and Delta VOCs.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Antivirais/farmacologia , Replicon , RNA , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus , Proteínas Virais , Vírion/genética
15.
J Virol ; 96(13): e0058522, 2022 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-35862693

RESUMO

The biogenesis of covalently closed circular DNA (cccDNA) from relaxed circular DNA (rcDNA) is essential for chronic hepatitis B virus (HBV) infection. Different host DNA repair proteins are involved in the conversion of rcDNA to cccDNA. Here, we reported that the DNA repair factor poly(ADP-ribose) polymerase 1 (PARP1) is engaged in HBV cccDNA formation. PARP1 depletion remarkably impaired HBV replication and cccDNA synthesis. Inhibition of PARP1 poly (ADP-ribosylation) activity by olaparib suppressed cccDNA synthesis both in vitro and in vivo. Specifically, the early stage of cccDNA reservoir establishment was more sensitive to olaparib, suggesting that PARP1 participated in de novo cccDNA formation. Furthermore, PARP1 was activated by recognizing the rcDNA-like lesions directly and combined with other DNA repair proteins. The results presented proposed that the DNA damage-sensing protein PARP1 and poly(ADP-ribosylation) modification play a key role in cccDNA formation, which might be the target for developing the anti-HBV drug. IMPORTANCE The biogenesis and eradication of HBV cccDNA have been a research priority in recent years. In this study, we identified the DNA repair factor PARP1 as a host factor required for the HBV de novo cccDNA formation. HBV infection caused PARylation through PARP1 in Huh7-NTCP cells, primary human hepatocytes, and human-liver chimeric mice. We found that PARP1 could directly bind to the rcDNA lesions and was activated, PARylating other DNA repair proteins. We address the importance of PARP1-mediated PARylation in HBV cccDNA formation, which is a potential therapeutic target for chronic hepatitis B.


Assuntos
DNA Circular , Hepatite B , Poli(ADP-Ribose) Polimerase-1 , Animais , Reparo do DNA , DNA Circular/genética , DNA Circular/metabolismo , DNA Viral/genética , DNA Viral/metabolismo , Hepatite B/virologia , Vírus da Hepatite B/genética , Humanos , Camundongos , Poli(ADP-Ribose) Polimerase-1/genética , Poli(ADP-Ribose) Polimerase-1/metabolismo , Provírus/genética
16.
Emerg Microbes Infect ; 11(1): 1910-1919, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35686572

RESUMO

Waning of neutralizing titres along with decline of protection efficacy after the second dose of COVID-19 vaccines was observed, including China-made inactivated vaccines. Efficacy of a heterologous boosting using one dose of a recombinant SARS-CoV-2 fusion protein vaccine (V-01) in inactivated vaccine-primed population was studied, aimed to restore the immunity. A randomized, double-blind and placebo-controlled phase III trial was conducted in healthy people aged 18 years or older in Pakistan and Malaysia. Each eligible participant received one dose of the V-01 vaccine developed by Livzon Mabpharm Inc. or placebo within the 3-6 months after the two-dose primary regimen, and was monitored for safety and efficacy. The primary endpoint was protection against confirmed symptomatic SARS-CoV-2 infection. A total of 10,218 participants were randomly assigned to receive a vaccine or placebo. Virus-neutralizing antibodies were assessed in 419 participants. A dramatic increase (11.3-fold; 128.3-1452.8) of neutralizing titres was measured in the V-01 group at 14 days after the booster. Over two months of surveillance, vaccine efficacy was 47.8% (95%CI: 22.6-64.7) according to the intention-to-treat principle. The most common adverse events were transient, mild-to-moderate pain at the injection site, fever, headache, and fatigue. Serious adverse events occurred almost equally in V-01 (0.12%) and placebo (0.16%) groups. The heterologous boosting with the V-01 vaccine was safe and efficacious, which could elicit robust humoral immunity under the epidemic of the Omicron variant.Trial registration: ClinicalTrials.gov identifier: NCT05096832.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Imunização Secundária , SARS-CoV-2 , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Vacinas contra COVID-19/imunologia , Humanos , Imunogenicidade da Vacina , Interferons , Proteínas Recombinantes de Fusão/genética , Vacinas de Produtos Inativados
17.
Eur J Med Chem ; 238: 114458, 2022 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-35635946

RESUMO

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), as the pathogen of coronavirus disease 2019 (COVID-19), has infected millions of people and took hundreds of thousands of lives. Unfortunately, there is deficiency of effective medicines to prevent or treat COVID-19. 3C like protease (3CLPro) of SARS-CoV-2 is essential to the viral replication and transcription, and is an attractive target to develop anti-SARS-CoV-2 agents. Targeting on the 3CLPro, we screened our protease inhibitor library and obtained compound 10a as hit to weakly inhibit the SARS-CoV-2 3CLPro, and determined the co-crystal structure of 10a and the protease. Based on the deep understanding on the protein-ligand complexes between the hit and SARS-CoV-2 3CLPro, we designed a series of peptidomimetic inhibitors, with outstanding inhibitory activity against SARS-CoV-2 3CLPro and excellent anti-viral potency against SARS-CoV-2. The protein-ligand complexes of the other key inhibitors with SARS-CoV-2 3CLPro were explicitly described by the X-ray co-crystal study. All such results suggest these peptidomimetic inhibitors could be further applied as encouraging drug candidates.


Assuntos
Tratamento Farmacológico da COVID-19 , Peptidomiméticos , Antivirais/química , Cisteína Endopeptidases/química , Humanos , Ligantes , Peptídeo Hidrolases , Peptidomiméticos/química , Peptidomiméticos/farmacologia , Inibidores de Proteases/química , SARS-CoV-2
18.
Virol Sin ; 37(2): 238-247, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35527227

RESUMO

Multiple new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have constantly emerged, as the delta and omicron variants, which have developed resistance to currently gained neutralizing antibodies. This highlights a critical need to discover new therapeutic agents to overcome the variants mutations. Despite the availability of vaccines against coronavirus disease 2019 (COVID-19), the use of broadly neutralizing antibodies has been considered as an alternative way for the prevention or treatment of SARS-CoV-2 variants infection. Here, we show that the nasal delivery of two previously characterized broadly neutralizing antibodies (F61 and H121) protected K18-hACE2 mice against lethal challenge with SARS-CoV-2 variants. The broadly protective efficacy of the F61 or F61/F121 cocktail antibodies was evaluated by lethal challenge with the wild strain (WIV04) and multiple variants, including beta (B.1.351), delta (B.1.617.2), and omicron (B.1.1.529) at 200 or 1000 TCID50, and the minimum antibody administration doses (5-1.25 â€‹mg/kg body weight) were also evaluated with delta and omicron challenge. Fully prophylactic protections were found in all challenged groups with both F61 and F61/H121 combination at the administration dose of 20 â€‹mg/kg body weight, and corresponding mice lung viral RNA showed negative, with almost all alveolar septa and cavities remaining normal. Furthermore, low-dose antibody treatment induced significant prophylactic protection against lethal challenge with delta and omicron variants, whereas the F61/H121 combination showed excellent results against omicron infection. Our findings indicated the potential use of broadly neutralizing monoclonal antibodies as prophylactic and therapeutic agent for protection of current emerged SARS-CoV-2 variants infection.


Assuntos
COVID-19 , SARS-CoV-2 , Animais , Anticorpos Neutralizantes , Anticorpos Antivirais , Peso Corporal , Anticorpos Amplamente Neutralizantes , COVID-19/prevenção & controle , Humanos , Camundongos , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/genética
19.
Virol Sin ; 37(3): 408-417, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35523417

RESUMO

Hepatitis B virus (HBV)/Hepatitis C virus (HCV) coinfection is frequently observed because of the common infection routine. Despite the reciprocal inhibition exerted by HBV and HCV genomes, the coinfection of HBV and HCV is associated with more severe forms of liver diseases. However, the complexity of viral interference and underlying pathological mechanism is still unclarified. With the demonstration of absence of direct viral interplay, some in vitro studies suggest the indirect effects of viral-host interaction on viral dominance outcome. Here, we comprehensively investigated the viral replication and host immune responses which might mediate the interference between viruses in HBV/HCV coinfected Huh7-NTCP cells and immunocompetent HCV human receptors transgenic ICR mice. We found that presence of HCV significantly inhibited HBV replication in vitro and in vivo irrespective of the coinfection order, while HBV did not affect HCV replication. Pathological alteration was coincidently reproduced in coinfected mice. In addition to the participation of innate immune response, an involvement of HCV in up-regulating HBV-specific immune responses was described to facilitate HBV clearance. Our systems partially recapitulate HBV/HCV coinfection and unveil the uncharacterized adaptive anti-viral immune responses during coinfection, which renews the knowledge on the nature of indirect viral interaction during HBV/HCV coinfection.


Assuntos
Coinfecção , Hepatite B , Hepatite C , Animais , Hepacivirus/fisiologia , Vírus da Hepatite B/fisiologia , Hepatite C/complicações , Imunidade , Camundongos , Camundongos Endogâmicos ICR
20.
Virol Sin ; 37(3): 341-347, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35393265

RESUMO

Transformation-associated recombination (TAR) has been widely used to assemble large DNA constructs. One of the significant obstacles hindering assembly efficiency is the presence of error-prone DNA repair pathways in yeast, which results in vector backbone recircularization or illegitimate recombination products. To increase TAR assembly efficiency, we prepared a dual-selective TAR vector, pGFCS, by adding a PADH1-URA3 cassette to a previously described yeast-bacteria shuttle vector, pGF, harboring a PHIS3-HIS3 cassette as a positive selection marker. This new cassette works as a negative selection marker to ensure that yeast harboring a recircularized vector cannot propagate in the presence of 5-fluoroorotic acid. To prevent pGFCS bearing ura3 from recombining with endogenous ura3-52 in the yeast genome, a highly transformable Saccharomyces cerevisiae strain, VL6-48B, was prepared by chromosomal substitution of ura3-52 with a transgene conferring resistance to blasticidin. A 55-kb genomic fragment of monkeypox virus encompassing primary detection targets for quantitative PCR was assembled by TAR using pGFCS in VL6-48B. The pGFCS-mediated TAR assembly showed a zero rate of vector recircularization and an average correct assembly yield of 79% indicating that the dual-selection strategy provides an efficient approach to optimizing TAR assembly.


Assuntos
Monkeypox virus , Saccharomyces cerevisiae , Clonagem Molecular , Vetores Genéticos , Monkeypox virus/genética , Recombinação Genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Transformação Genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA