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1.
Glycobiology ; 34(2)2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38048640

RESUMO

The emergence of SARS-CoV-2 variants alters the efficacy of existing immunity towards the viral spike protein, whether acquired from infection or vaccination. Mutations that impact N-glycosylation of spike may be particularly important in influencing antigenicity, but their consequences are difficult to predict. Here, we compare the glycosylation profiles and antigenicity of recombinant viral spike of ancestral Wu-1 and the Gamma strain, which has two additional N-glycosylation sites due to amino acid substitutions in the N-terminal domain (NTD). We found that a mutation at residue 20 from threonine to asparagine within the NTD caused the loss of NTD-specific antibody COVA2-17 binding. Glycan site-occupancy analyses revealed that the mutation resulted in N-glycosylation switching to the new sequon at N20 from the native N17 site. Site-specific glycosylation profiles demonstrated distinct glycoform differences between Wu-1, Gamma, and selected NTD variant spike proteins, but these did not affect antibody binding. Finally, we evaluated the specificity of spike proteins against convalescent COVID-19 sera and found reduced cross-reactivity against some mutants, but not Gamma spike compared to Wuhan spike. Our results illustrate the impact of viral divergence on spike glycosylation and SARS-CoV-2 antibody binding profiles.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Glicosilação , Glicoproteína da Espícula de Coronavírus , Anticorpos Antivirais
2.
J Gen Virol ; 105(1)2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38271027

RESUMO

The COVID-19 pandemic has highlighted the need for vaccines capable of providing rapid and robust protection. One way to improve vaccine efficacy is delivery via microarray patches, such as the Vaxxas high-density microarray patch (HD-MAP). We have previously demonstrated that delivery of a SARS-CoV-2 protein vaccine candidate, HexaPro, via the HD-MAP induces potent humoral immune responses. Here, we investigate the cellular responses induced by HexaPro HD-MAP vaccination. We found that delivery via the HD-MAP induces a type one biassed cellular response of much greater magnitude as compared to standard intramuscular immunization.


Assuntos
COVID-19 , Glicoproteína da Espícula de Coronavírus , Animais , Camundongos , Humanos , Glicoproteína da Espícula de Coronavírus/genética , Pandemias , COVID-19/prevenção & controle , SARS-CoV-2 , Vacinação , Imunidade Celular , Vacinas contra COVID-19 , Anticorpos Antivirais , Imunidade Humoral , Anticorpos Neutralizantes
3.
J Virol ; 97(11): e0125123, 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-37850747

RESUMO

IMPORTANCE: Dengue virus, an arbovirus, causes an estimated 100 million symptomatic infections annually and is an increasing threat as the mosquito range expands with climate change. Dengue epidemics are a substantial strain on local economies and health infrastructure, and an understanding of what drives severe disease may enable treatments to help reduce hospitalizations. Factors exacerbating dengue disease are debated, but gut-related symptoms are much more frequent in severe than mild cases. Using mouse models of dengue infection, we have shown that inflammation and damage are earlier and more severe in the gut than in other tissues. Additionally, we observed impairment of the gut mucus layer and propose that breakdown of the barrier function exacerbates inflammation and promotes severe dengue disease. This idea is supported by recent data from human patients showing elevated bacteria-derived molecules in dengue patient serum. Therapies aiming to maintain gut integrity may help to abrogate severe dengue disease.


Assuntos
Vírus da Dengue , Dengue Grave , Animais , Humanos , Camundongos , Culicidae , Vírus da Dengue/fisiologia , Inflamação/virologia , Dengue Grave/patologia , Cinética
4.
Mol Psychiatry ; 28(7): 2878-2893, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36316366

RESUMO

Coronavirus disease-2019 (COVID-19) is primarily a respiratory disease, however, an increasing number of reports indicate that SARS-CoV-2 infection can also cause severe neurological manifestations, including precipitating cases of probable Parkinson's disease. As microglial NLRP3 inflammasome activation is a major driver of neurodegeneration, here we interrogated whether SARS-CoV-2 can promote microglial NLRP3 inflammasome activation. Using SARS-CoV-2 infection of transgenic mice expressing human angiotensin-converting enzyme 2 (hACE2) as a COVID-19 pre-clinical model, we established the presence of virus in the brain together with microglial activation and NLRP3 inflammasome upregulation in comparison to uninfected mice. Next, utilising a model of human monocyte-derived microglia, we identified that SARS-CoV-2 isolates can bind and enter human microglia in the absence of viral replication. This interaction of virus and microglia directly induced robust inflammasome activation, even in the absence of another priming signal. Mechanistically, we demonstrated that purified SARS-CoV-2 spike glycoprotein activated the NLRP3 inflammasome in LPS-primed microglia, in a ACE2-dependent manner. Spike protein also could prime the inflammasome in microglia through NF-κB signalling, allowing for activation through either ATP, nigericin or α-synuclein. Notably, SARS-CoV-2 and spike protein-mediated microglial inflammasome activation was significantly enhanced in the presence of α-synuclein fibrils and was entirely ablated by NLRP3-inhibition. Finally, we demonstrate SARS-CoV-2 infected hACE2 mice treated orally post-infection with the NLRP3 inhibitory drug MCC950, have significantly reduced microglial inflammasome activation, and increased survival in comparison with untreated SARS-CoV-2 infected mice. These results support a possible mechanism of microglial innate immune activation by SARS-CoV-2, which could explain the increased vulnerability to developing neurological symptoms akin to Parkinson's disease in COVID-19 infected individuals, and a potential therapeutic avenue for intervention.


Assuntos
COVID-19 , Doença de Parkinson , Humanos , Camundongos , Animais , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Microglia/metabolismo , alfa-Sinucleína/metabolismo , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/metabolismo , COVID-19/metabolismo , Camundongos Transgênicos
5.
PLoS Pathog ; 17(7): e1009723, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34214142

RESUMO

SARS-CoV-2 uses the human ACE2 (hACE2) receptor for cell attachment and entry, with mouse ACE2 (mACE2) unable to support infection. Herein we describe an ACE2-lentivirus system and illustrate its utility for in vitro and in vivo SARS-CoV-2 infection models. Transduction of non-permissive cell lines with hACE2 imparted replication competence, and transduction with mACE2 containing N30D, N31K, F83Y and H353K substitutions, to match hACE2, rescued SARS-CoV-2 replication. Intrapulmonary hACE2-lentivirus transduction of C57BL/6J mice permitted significant virus replication in lung epithelium. RNA-Seq and histological analyses illustrated that this model involved an acute inflammatory disease followed by resolution and tissue repair, with a transcriptomic profile similar to that seen in COVID-19 patients. hACE2-lentivirus transduction of IFNAR-/- and IL-28RA-/- mouse lungs was used to illustrate that loss of type I or III interferon responses have no significant effect on virus replication. However, their importance in driving inflammatory responses was illustrated by RNA-Seq analyses. We also demonstrate the utility of the hACE2-lentivirus transduction system for vaccine evaluation in C57BL/6J mice. The ACE2-lentivirus system thus has broad application in SARS-CoV-2 research, providing a tool for both mutagenesis studies and mouse model development.


Assuntos
Enzima de Conversão de Angiotensina 2 , COVID-19 , Perfilação da Expressão Gênica , Lentivirus , SARS-CoV-2 , Transdução Genética , Enzima de Conversão de Angiotensina 2/biossíntese , Enzima de Conversão de Angiotensina 2/genética , Animais , COVID-19/genética , COVID-19/metabolismo , Chlorocebus aethiops , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Knockout , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , Células Vero
6.
Transfusion ; 63(2): 288-293, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36573801

RESUMO

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unlikely to be a major transfusion-transmitted pathogen; however, convalescent plasma is a treatment option used in some regions. The risk of transfusion-transmitted infections can be minimized by implementing Pathogen Inactivation (PI), such as THERAFLEX MB-plasma and THERAFLEX UV-Platelets systems. Here we examined the capability of these PI systems to inactivate SARS-CoV-2. STUDY DESIGN AND METHODS: SARS-CoV-2 spiked plasma units were treated using the THERAFLEX MB-Plasma system in the presence of methylene blue (~0.8 µmol/L; visible light doses: 20, 40, 60, and 120 [standard] J/cm2 ). SARS-CoV-2 spiked platelet concentrates (PCs) were treated using the THERAFLEX UV-platelets system (UVC doses: 0.05, 0.10, 0.15, and 0.20 [standard] J/cm2 ). Samples were taken prior to the first and after each illumination dose, and viral infectivity was assessed using an immunoplaque assay. RESULTS: Treatment of spiked plasma with the THERAFLEX MB-Plasma system resulted in an average ≥5.03 log10 reduction in SARS-CoV-2 infectivity at one third (40 J/cm2 ) of the standard visible light dose. For the platelet concentrates (PCs), treatment with the THERAFLEX UV-Platelets system resulted in an average ≥5.18 log10 reduction in SARS-CoV-2 infectivity at the standard UVC dose (0.2 J/cm2 ). CONCLUSIONS: SARS-CoV-2 infectivity was reduced in plasma and platelets following treatment with the THERAFLEX MB-Plasma and THERAFLEX UV-Platelets systems, to the limit of detection, respectively. These PI technologies could therefore be an effective option to reduce the risk of transfusion-transmitted emerging pathogens.


Assuntos
COVID-19 , Azul de Metileno , Humanos , Azul de Metileno/farmacologia , SARS-CoV-2 , COVID-19/terapia , Soroterapia para COVID-19 , Luz , Raios Ultravioleta , Plaquetas , Inativação de Vírus
7.
J Gen Virol ; 102(1)2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33054904

RESUMO

Although enveloped viruses canonically mediate particle entry through virus-cell fusion, certain viruses can spread by cell-cell fusion, brought about by receptor engagement and triggering of membrane-bound, viral-encoded fusion proteins on the surface of cells. The formation of pathogenic syncytia or multinucleated cells is seen in vivo, but their contribution to viral pathogenesis is poorly understood. For the negative-strand paramyxoviruses respiratory syncytial virus (RSV) and Nipah virus (NiV), cell-cell spread is highly efficient because their oligomeric fusion protein complexes are active at neutral pH. The recently emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has also been reported to induce syncytia formation in infected cells, with the spike protein initiating cell-cell fusion. Whilst it is well established that fusion protein-specific antibodies can block particle attachment and/or entry into the cell (canonical virus neutralization), their capacity to inhibit cell-cell fusion and the consequences of this neutralization for the control of infection are not well characterized, in part because of the lack of specific tools to assay and quantify this activity. Using an adapted bimolecular fluorescence complementation assay, based on a split GFP-Renilla luciferase reporter, we have established a micro-fusion inhibition test (mFIT) that allows the identification and quantification of these neutralizing antibodies. This assay has been optimized for high-throughput use and its applicability has been demonstrated by screening monoclonal antibody (mAb)-mediated inhibition of RSV and NiV fusion and, separately, the development of fusion-inhibitory antibodies following NiV vaccine immunization in pigs. In light of the recent emergence of coronavirus disease 2019 (COVID-19), a similar assay was developed for SARS-CoV-2 and used to screen mAbs and convalescent patient plasma for fusion-inhibitory antibodies. Using mFITs to assess antibody responses following natural infection or vaccination is favourable, as this assay can be performed entirely at low biocontainment, without the need for live virus. In addition, the repertoire of antibodies that inhibit cell-cell fusion may be different to those that inhibit particle entry, shedding light on the mechanisms underpinning antibody-mediated neutralization of viral spread.


Assuntos
Anticorpos Neutralizantes/farmacologia , Anticorpos Antivirais/farmacologia , COVID-19/diagnóstico , Infecções por Henipavirus/diagnóstico , Ensaios de Triagem em Larga Escala , Infecções por Vírus Respiratório Sincicial/diagnóstico , Proteínas Virais de Fusão/antagonistas & inibidores , Animais , Anticorpos Neutralizantes/isolamento & purificação , Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/isolamento & purificação , Anticorpos Antivirais/metabolismo , COVID-19/imunologia , COVID-19/virologia , Fusão Celular , Convalescença , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Infecções por Henipavirus/imunologia , Infecções por Henipavirus/virologia , Humanos , Soros Imunes/química , Luciferases/genética , Luciferases/metabolismo , Modelos Moleculares , Vírus Nipah/imunologia , Vírus Nipah/patogenicidade , Conformação Proteica , Infecções por Vírus Respiratório Sincicial/imunologia , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/imunologia , Vírus Sincicial Respiratório Humano/patogenicidade , SARS-CoV-2/imunologia , SARS-CoV-2/patogenicidade , Suínos , Inibidores de Proteínas Virais de Fusão/química , Inibidores de Proteínas Virais de Fusão/metabolismo , Inibidores de Proteínas Virais de Fusão/farmacologia , Proteínas Virais de Fusão/genética , Proteínas Virais de Fusão/imunologia
8.
Environ Res ; 196: 110944, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33647300

RESUMO

The COVID-19 pandemic has revealed gaps in our understanding of safe, effective and efficient means of disinfecting high use public spaces. Whilst this creates an opportunity for development and application of innovative approaches such as unmanned aerial vehicle (UAV) based disinfection, unregulated outdoor disinfection using chlorine has led to environmental and public health risks. This study has quantified the efficiency, safety and efficacy of UAV-based spraying of aqueous ozone. Optimised UAV flight characteristics of 4.7 km/h at 1.7 m elevation spraying 2.4 L/min were able to provide >97% and >92% coverage of a 1 m and 2 m wide swath respectively. During spraying operations using 1 mg/L aqueous ozone, atmospheric concentrations of ozone remained within background levels (<0.04 ppm). Highly efficient inactivation of two different isolates of SARS-CoV-2 virus was achieved at aqueous ozone concentrations of 0.75 mg/L after an incubation period of only 5 min, with 0.375 mg/L achieving 82-91.5% inactivation in this time. Exposure of diamondback moth larvae and parasitic wasps to 1 mg/L aqueous ozone did not significantly affect their survivorship. These results indicate for the first time that aqueous ozone may provide the required balance between human and environmental safety and viral inactivation efficacy for targeted application in high risk outdoor settings.


Assuntos
COVID-19 , Desinfetantes , Ozônio , Desinfecção , Humanos , Pandemias , SARS-CoV-2
9.
J Infect Dis ; 219(12): 2015-2025, 2019 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-30715407

RESUMO

Rocio virus (ROCV) is a highly neuropathogenic mosquito-transmitted flavivirus responsible for an unprecedented outbreak of human encephalitis during 1975-1976 in Sao Paulo State, Brazil. Previous studies have shown an increased number of inflammatory macrophages in the central nervous system (CNS) of ROCV-infected mice, implying a role for macrophages in the pathogenesis of ROCV. Here, we show that ROCV infection results in increased expression of CCL2 in the blood and in infiltration of macrophages into the brain. Moreover, we show, using CCR2 knockout mice, that CCR2 expression is essential for macrophage infiltration in the brain during ROCV infection and that the lack of CCR2 results in increased disease severity and mortality. Thus, our findings show the protective role of CCR2-mediated infiltration of macrophages in the brain during ROCV infection.


Assuntos
Encefalite/metabolismo , Infecções por Flavivirus/metabolismo , Flavivirus/patogenicidade , Macrófagos/metabolismo , Receptores CCR2/metabolismo , Animais , Encéfalo , Brasil , Encefalite/virologia , Feminino , Infecções por Flavivirus/virologia , Macrófagos/virologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
10.
Chemistry ; 25(22): 5664-5667, 2019 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-30924209

RESUMO

Stachyonic acid A, arising from the first in-depth phytochemical investigation of the herb Basilicum polystachyon, was found to display potent inhibitory activity against dengue virus, with limited cytotoxicity. Andrographolide, a known dengue virus inhibitor and closely related labdane-type diterpene, is structurally more complex but displayed poor antiviral activity in the PRNT assay, and increased cytotoxicity in comparison. Furthermore, a Diels-Alder reaction with PTAD identified the active pharmacophore of stachyonic acid to be the conjugated diene.


Assuntos
Antivirais/química , Antivirais/farmacologia , Vírus da Dengue/efeitos dos fármacos , Dengue/tratamento farmacológico , Diterpenos/química , Diterpenos/farmacologia , Descoberta de Drogas , Humanos , Lamiaceae/química , Modelos Moleculares , Replicação Viral/efeitos dos fármacos
11.
J Nat Prod ; 82(10): 2828-2834, 2019 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-31553187

RESUMO

The highly oxygenated pimarane diterpenoids basimarols A, B, and C (3-5) were isolated from the plant species Basilicum polystachyon, which was collected within the Australian arid zone. Structure elucidation was performed using a suite of spectroscopic techniques, including X-ray crystallography. Anticancer and anti-DENV activity of 3-5 was explored, but only limited activity was observed. More extensive antiviral evaluation of stachyonic acid A (1), which was also isolated from B. polystachyon, revealed broad spectrum antiviral activity against West Nile virus (Kunjin strain, WNVKun) and human influenza viruses H1N1 and H3N2.


Assuntos
Abietanos/isolamento & purificação , Antineoplásicos Fitogênicos/isolamento & purificação , Antivirais/isolamento & purificação , Lamiaceae/química , Abietanos/química , Abietanos/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Antivirais/química , Antivirais/farmacologia , Linhagem Celular Tumoral , Humanos
12.
Adv Exp Med Biol ; 1062: 89-106, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29845527

RESUMO

Recent structural and functional advances provide fresh insight into the biology of the dengue virus non-structural protein, NS1 and suggest new avenues of research. The work of our lab and others have shown that the secreted, hexameric form of NS1 has a systemic toxic effect, inducing inflammatory cytokines and acting directly on endothelial cells to produce the hallmark of dengue disease, vascular leak. We also demonstrated that NS1 exerts its toxic activity through recognition by the innate immune receptor TLR4, mimicking the bacterial endotoxin LPS. This monograph covers the background underpinning these new findings and discusses new avenues for antiviral and vaccine intervention.


Assuntos
Vírus da Dengue/imunologia , Dengue Grave/virologia , Proteínas não Estruturais Virais/imunologia , Animais , Citocinas/genética , Citocinas/imunologia , Vírus da Dengue/química , Vírus da Dengue/genética , Células Endoteliais/imunologia , Células Endoteliais/virologia , Humanos , Receptores Virais/genética , Receptores Virais/imunologia , Dengue Grave/imunologia , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologia , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/genética
13.
Immunol Cell Biol ; 95(5): 491-495, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28220810

RESUMO

The secreted hexameric form of the dengue virus (DENV) non-structural protein 1 (NS1) has recently been shown to elicit inflammatory cytokine release and disrupt endothelial cell monolayer integrity. This suggests that circulating NS1 contributes to the vascular leak that plays a major role in the pathology of dengue haemorrhagic fever and shock. Pathways activated by NS1 are thus of great interest as potential therapeutic targets. Recent works have separately implicated both toll-like receptor 4 (TLR4) and the TLR2/6 heterodimer in immune cell activation by NS1. Here we have used mouse gene knockout macrophages and antibodies blocking TLR function in human peripheral blood mononuclear cells to show that recombinant NS1, expressed and purified from eukaryotic cells, induces cytokine production via TLR4 but not TLR2/6. Furthermore, the commercial Escherichia coli-derived recombinant NS1 preparation used in other work to implicate TLR2/6 in the response is not correctly folded and appears to be contaminated by several microbial TLR ligands. Thus TLR4 remains a therapeutic target for DENV infections, with TLR4 antagonists holding promise for the treatment of dengue disease.


Assuntos
Vírus da Dengue/imunologia , Leucócitos/virologia , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Receptor 6 Toll-Like/metabolismo , Proteínas não Estruturais Virais/imunologia , Animais , Vírus da Dengue/efeitos dos fármacos , Escherichia coli/metabolismo , Humanos , Leucócitos/efeitos dos fármacos , Leucócitos/patologia , Lipopolissacarídeos , Camundongos Endogâmicos C57BL , Polimixina B/farmacologia , Multimerização Proteica/efeitos dos fármacos
14.
ACS Appl Bio Mater ; 7(5): 2862-2871, 2024 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-38699864

RESUMO

Mosquito-borne viruses are a major worldwide health problem associated with high morbidity and mortality rates and significant impacts on national healthcare budgets. The development of antiviral drugs for both the treatment and prophylaxis of these diseases is thus of considerable importance. To address the need for therapeutics with antiviral activity, a library of heparan sulfate mimetic polymers was screened against dengue virus (DENV), Yellow fever virus (YFV), Zika virus (ZIKV), and Ross River virus (RRV). The polymers were prepared by RAFT polymerization of various acidic monomers with a target MW of 20 kDa (average Mn ∼ 27 kDa by GPC). Among the polymers, poly(SS), a homopolymer of sodium styrenesulfonate, was identified as a broad spectrum antiviral with activity against all the tested viruses and particularly potent inhibition of YFV (IC50 = 310 pM). Our results further uncovered that poly(SS) exhibited a robust inhibition of ZIKV infection in both mosquito and human cell lines, which points out the potential functions of poly(SS) in preventing mosquito-borne viruses associated diseases by blocking viral transmission in their mosquito vectors and mitigating viral infection in patients.


Assuntos
Antivirais , Biomimética , Flavivirus , Heparitina Sulfato , Mosquitos Vetores , Poliestirenos , Ross River virus , Poliestirenos/farmacologia , Poliestirenos/uso terapêutico , Heparitina Sulfato/química , Antivirais/farmacologia , Antivirais/uso terapêutico , Ross River virus/efeitos dos fármacos , Flavivirus/efeitos dos fármacos , Relação Estrutura-Atividade , Células A549 , Humanos , Animais , Mosquitos Vetores/virologia
15.
NPJ Vaccines ; 9(1): 134, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39085247

RESUMO

In 2022, a genotype IV (GIV) strain of Japanese encephalitis virus (JEV) caused an unprecedented and widespread outbreak of disease in pigs and humans in Australia. As no veterinary vaccines against JEV are approved in Australia and all current approved human and veterinary vaccines are derived from genotype (G) III JEV strains, we used the recently described insect-specific Binjari virus (BinJV) chimeric flavivirus vaccine technology to produce a JEV GIV vaccine candidate. Herein we describe the production of a chimeric virus displaying the structural prM and E proteins of a JEV GIV isolate obtained from a stillborn piglet (JEVNSW/22) in the genomic backbone of BinJV (BinJ/JEVNSW/22-prME). BinJ/JEVNSW/22-prME was shown to be antigenically indistinguishable from the JEVNSW/22 parental virus by KD analysis and a panel of JEV-reactive monoclonal antibodies in ELISA. BinJ/JEVNSW/22-prME replicated efficiently in C6/36 cells, reaching titres of >107 infectious units/mL - an important attribute for vaccine manufacture. As expected, BinJ/JEVNSW/22-prME failed to replicate in a variety of vertebrate cells lines. When used to immunise mice, the vaccine induced a potent virus neutralising response against JEVNSW/22 and to GII and GIII JEV strains. The BinJ/JEVNSW/22-prME vaccine provided complete protection against lethal challenge with JEVNSW/22, whilst also providing partial protection against viraemia and disease for the related Murray Valley encephalitis virus. Our results demonstrate that BinJ/JEVNSW/22-prME is a promising vaccine candidate against JEV.

16.
J Med Chem ; 67(14): 11885-11916, 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-38995734

RESUMO

Herein, we report the synthesis and biological evaluation of a novel series of heparinoid amphiphiles as inhibitors of heparanase and SARS-CoV-2. By employing a tailor-made synthetic strategy, a library of highly sulfated homo-oligosaccharides bearing d-glucose or a C5-epimer (i.e., l-idose or l-iduronic acid) conjugated with various lipophilic groups was synthesized and investigated for antiviral activity. Sulfated higher oligosaccharides of d-glucose or l-idose with lipophilic aglycones displayed potent anti-SARS-CoV-2 and antiheparanse activity, similar to or better than pixatimod (PG545), and were more potent than their isosteric l-iduronic acid congeners. Lipophilic groups such as cholestanol and C18-aliphatic substitution are more advantageous than functional group appended lipophilic moieties. These findings confirm that fine-tuning of higher oligosaccharides, degree of sulfation, and lipophilic groups can yield compounds with potent anti-SARS-CoV-2 activity.


Assuntos
Antivirais , SARS-CoV-2 , Antivirais/farmacologia , Antivirais/química , Antivirais/síntese química , SARS-CoV-2/efeitos dos fármacos , Humanos , Oligossacarídeos/farmacologia , Oligossacarídeos/síntese química , Oligossacarídeos/química , Tratamento Farmacológico da COVID-19 , Animais , Células Vero , Chlorocebus aethiops , Relação Estrutura-Atividade , COVID-19/virologia , Glucuronidase , Saponinas
17.
Vaccines (Basel) ; 12(7)2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39066430

RESUMO

Several technological approaches have been used to develop vaccines against COVID-19, including those based on inactivated viruses, viral vectors, and mRNA. This study aimed to monitor the maintenance of anti-SARS-CoV-2 antibodies in individuals from Brazil according to the primary vaccination regimen, as follows: BNT162b2 (group 1; 22) and ChAdOx1 (group 2; 18). Everyone received BNT162b2 in the first booster while in the second booster CoronaVac, Ad26.COV2.S, or BNT162b2. Blood samples were collected from 2021 to 2023 to analyze specific RBD (ELISA) and neutralizing antibodies (PRNT50). We observed a progressive increase in anti-RBD and neutralizing antibodies in each subsequent dose, remaining at high titers until the end of follow-up. Group 1 had higher anti-RBD antibody titers than group 2 after beginning the primary regimen, with significant differences after the 2nd and 3rd doses. Group 2 showed a more expressive increase after the first booster with BNT162B2 (heterologous booster). Group 2 also presented high levels of neutralizing antibodies against the Gamma and Delta variants until five months after the second booster. In conclusion, the circulating levels of anti-RBD and neutralizing antibodies against the two variants of SARS-CoV-2 were durable even five months after the 4th dose, suggesting that periodic booster vaccinations (homologous or heterologous) induced long-lasting immunity.

18.
Nat Commun ; 14(1): 3577, 2023 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-37328468

RESUMO

In August 2022, a novel henipavirus (HNV) named Langya virus (LayV) was isolated from patients with severe pneumonic disease in China. This virus is closely related to Mòjiang virus (MojV), and both are divergent from the bat-borne HNV members, Nipah (NiV) and Hendra (HeV) viruses. The spillover of LayV is the first instance of a HNV zoonosis to humans outside of NiV and HeV, highlighting the continuing threat this genus poses to human health. In this work, we determine the prefusion structures of MojV and LayV F proteins via cryogenic electron microscopy to 2.66 and 3.37 Å, respectively. We show that despite sequence divergence from NiV, the F proteins adopt an overall similar structure but are antigenically distinct as they do not react to known antibodies or sera. Glycoproteomic analysis revealed that while LayV F is less glycosylated than NiV F, it contains a glycan that shields a site of vulnerability previously identified for NiV. These findings explain the distinct antigenic profile of LayV and MojV F, despite the extent to which they are otherwise structurally similar to NiV. Our results carry implications for broad-spectrum HNV vaccines and therapeutics, and indicate an antigenic, yet not structural, divergence from prototypical HNVs.


Assuntos
Infecções por Henipavirus , Henipavirus , Vírus Nipah , Humanos , Glicoproteínas/metabolismo , Proteínas Virais/metabolismo , Vírus Nipah/metabolismo
19.
EBioMedicine ; 97: 104842, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37865043

RESUMO

BACKGROUND: We previously demonstrated the safety and immunogenicity of an MF59-adjuvanted COVID-19 vaccine based on the SARS-CoV-2 spike glycoprotein stabilised in a pre-fusion conformation by a molecular clamp using HIV-1 glycoprotein 41 sequences. Here, we describe 12-month results in adults aged 18-55 years and ≥56 years. METHODS: Phase 1, double-blind, placebo-controlled trial conducted in Australia (July 2020-December 2021; ClinicalTrials.govNCT04495933; active, not recruiting). Healthy adults (Part 1: 18-55 years; Part 2: ≥56 years) received two doses of placebo, 5 µg, 15 µg, or 45 µg vaccine, or one 45 µg dose of vaccine followed by placebo (Part 1 only), 28 days apart (n = 216; 24 per group). Safety, humoral immunogenicity (including against virus variants), and cellular immunogenicity were assessed to day 394 (12 months after second dose). Effects of subsequent COVID-19 vaccination on humoral responses were examined. FINDINGS: All two-dose vaccine regimens were well tolerated and elicited strong antigen-specific and neutralising humoral responses, and CD4+ T-cell responses, by day 43 in younger and older adults, although cellular responses were lower in older adults. Humoral responses waned by day 209 but were boosted in those receiving authorised vaccines. Neutralising activity against Delta and Omicron variants was present but lower than against the Wuhan strain. Cross-reactivity in HIV diagnostic tests declined over time but remained detectable in most participants. INTERPRETATION: The SARS-CoV-2 molecular clamp vaccine is well tolerated and evokes robust immune responses in adults of all ages. Although the HIV glycoprotein 41-based molecular clamp is not being progressed, the clamp concept represents a viable platform for vaccine development. FUNDING: This study was funded by the Coalition for Epidemic Preparedness Innovations, the National Health and Medical Research Council of Australia, and the Queensland Government.


Assuntos
COVID-19 , Infecções por HIV , Vacinas , Humanos , Idoso , SARS-CoV-2 , Vacinas contra COVID-19/efeitos adversos , COVID-19/prevenção & controle , Glicoproteína da Espícula de Coronavírus , Adjuvantes Imunológicos , Infecções por HIV/prevenção & controle , Glicoproteínas , Método Duplo-Cego , Anticorpos Antivirais , Anticorpos Neutralizantes
20.
Nat Aging ; 3(12): 1561-1575, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37957361

RESUMO

Aging is a major risk factor for neurodegenerative diseases, and coronavirus disease 2019 (COVID-19) is linked to severe neurological manifestations. Senescent cells contribute to brain aging, but the impact of virus-induced senescence on neuropathologies is unknown. Here we show that senescent cells accumulate in aged human brain organoids and that senolytics reduce age-related inflammation and rejuvenate transcriptomic aging clocks. In postmortem brains of patients with severe COVID-19 we observed increased senescent cell accumulation compared with age-matched controls. Exposure of human brain organoids to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induced cellular senescence, and transcriptomic analysis revealed a unique SARS-CoV-2 inflammatory signature. Senolytic treatment of infected brain organoids blocked viral replication and prevented senescence in distinct neuronal populations. In human-ACE2-overexpressing mice, senolytics improved COVID-19 clinical outcomes, promoted dopaminergic neuron survival and alleviated viral and proinflammatory gene expression. Collectively our results demonstrate an important role for cellular senescence in driving brain aging and SARS-CoV-2-induced neuropathology, and a therapeutic benefit of senolytic treatments.


Assuntos
COVID-19 , Humanos , Camundongos , Animais , Idoso , Senoterapia , SARS-CoV-2 , Envelhecimento , Encéfalo
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