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1.
Nat Commun ; 15(1): 2202, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38485927

RESUMO

Viral fusion proteins facilitate cellular infection by fusing viral and cellular membranes, which involves dramatic transitions from their pre- to postfusion conformations. These proteins are among the most protective viral immunogens, but they are metastable which often makes them intractable as subunit vaccine targets. Adapting a natural enzymatic reaction, we harness the structural rigidity that targeted dityrosine crosslinks impart to covalently stabilize fusion proteins in their native conformations. We show that the prefusion conformation of respiratory syncytial virus fusion protein can be stabilized with two engineered dityrosine crosslinks (DT-preF), markedly improving its stability and shelf-life. Furthermore, it has 11X greater potency as compared with the DS-Cav1 stabilized prefusion F protein in immunogenicity studies and overcomes immunosenescence in mice with simply a high-dose formulation on alum.


Assuntos
Infecções por Vírus Respiratório Sincicial , Vacinas contra Vírus Sincicial Respiratório , Vírus Sincicial Respiratório Humano , Tirosina/análogos & derivados , Animais , Camundongos , Anticorpos Neutralizantes , Anticorpos Antivirais , Tirosina/metabolismo , Proteínas Virais de Fusão , Infecções por Vírus Respiratório Sincicial/prevenção & controle
2.
Hum Vaccin Immunother ; 20(1): 2327142, 2024 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38508690

RESUMO

Respiratory syncytial virus (RSV) is a highly contagious virus that affects the lungs and respiratory passages of many vulnerable people. It is a leading cause of lower respiratory tract infections and clinical complications, particularly among infants and elderly. It can develop into serious complications such as pneumonia and bronchiolitis. The development of RSV vaccine or immunoprophylaxis remains highly active and a global health priority. Currently, GSK's Arexvy™ vaccine is approved for the prevention of lower respiratory tract disease in older adults (>60 years). Palivizumab and currently nirsevimab are the approved monoclonal antibodies (mAbs) for RSV prevention in high-risk patients. Many studies are ongoing to develop additional therapeutic antibodies for preventing RSV infections among newborns and other susceptible groups. Recently, additional antibodies have been discovered and shown greater potential for development as therapeutic alternatives to palivizumab and nirsevimab. Plant expression platforms have proven successful in producing recombinant proteins, including antibodies, offering a potential cost-effective alternative to mammalian expression platforms. Hence in this study, an attempt was made to use a plant expression platform to produce two anti-RSV fusion (F) mAbs 5C4 and CR9501. The heavy-chain and light-chain sequences of both these antibodies were transiently expressed in Nicotiana benthamiana plants using a geminiviral vector and then purified using single-step protein A affinity column chromatography. Both these plant-produced mAbs showed specific binding to the RSV fusion protein and demonstrate effective viral neutralization activity in vitro. These preliminary findings suggest that plant-produced anti-RSV mAbs are able to neutralize RSV in vitro.


Assuntos
Infecções por Vírus Respiratório Sincicial , Vacinas contra Vírus Sincicial Respiratório , Vírus Sincicial Respiratório Humano , Lactente , Animais , Humanos , Recém-Nascido , Idoso , Palivizumab/uso terapêutico , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Anticorpos Monoclonais/uso terapêutico , Anticorpos Antivirais , Anticorpos Neutralizantes , Proteínas Virais de Fusão/genética , Mamíferos/metabolismo
3.
Influenza Other Respir Viruses ; 18(2): e13236, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38314063

RESUMO

Background: Respiratory syncytial virus (RSV) is a contagious pathogen causing acute respiratory infections (ARIs). Symptoms range from mild upper respiratory tract infections to potentially life-threatening lower respiratory tract disease (LRTD). In adults ≥60 years old, vaccine efficacy of a candidate vaccine for older adults (RSVPreF3 OA) was 71.7% against RSV-ARI and 82.6% against RSV-LRTD (AReSVi-006/NCT04886596). We present the patient-reported outcomes (PROs) from the same trial at the end of the first RSV season in the northern hemisphere (April 2022). Methods: In this phase 3 trial, adults aged ≥60 years were randomized (1:1) to receive one dose of RSVPreF3 OA vaccine or placebo. PROs were assessed using InFLUenza Patient-Reported Outcome (FLU-PRO), Short Form-12 (SF-12), and EuroQol-5 Dimension (EQ-5D) questionnaires. Peak FLU-PRO Chest/Respiratory scores during the first 7 days from ARI episode onset were compared using a Wilcoxon test. Least squares mean (LSMean) of SF-12 physical functioning (PF) and EQ-5D health utility scores were estimated using mixed effects models. Results: In the RSVPreF3 OA group (N = 12,466), 27 first RSV-ARI episodes were observed versus 95 in the Placebo group (N = 12,494). Median peak FLU-PRO Chest/Respiratory scores were lower in RSVPreF3 OA (1.07) versus Placebo group (1.86); p = 0.0258. LSMean group differences for the PF and EQ-5D health utility score were 7.00 (95% confidence interval [CI]: -9.86, 23.85; p = 0.4125) and 0.0786 (95% CI: -0.0340, 0.1913; p = 0.1695). Conclusions: The RSVPreF3 OA vaccine, in addition to preventing infection, attenuated the severity of RSV-associated symptoms in breakthrough infections, with trends of reduced impact on PF and health utility.


Assuntos
Influenza Humana , Infecções por Vírus Respiratório Sincicial , Vacinas contra Vírus Sincicial Respiratório , Vírus Sincicial Respiratório Humano , Infecções Respiratórias , Humanos , Idoso , Pessoa de Meia-Idade , Vacinas contra Vírus Sincicial Respiratório/uso terapêutico , Infecções Irruptivas , Proteínas Virais de Fusão , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Influenza Humana/prevenção & controle , Influenza Humana/tratamento farmacológico , Anticorpos Antivirais , Anticorpos Neutralizantes
4.
Nat Commun ; 15(1): 1173, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38332002

RESUMO

Respiratory syncytial virus (RSV) is a common cause of acute lower respiratory tract infection in infants, older adults and the immunocompromised. Effective directly acting antivirals are not yet available for clinical use. To address this, we screen the ReFRAME drug-repurposing library consisting of 12,000 small molecules against RSV. We identify 21 primary candidates including RSV F and N protein inhibitors, five HSP90 and four IMPDH inhibitors. We select lonafarnib, a licensed farnesyltransferase inhibitor, and phase III candidate for hepatitis delta virus (HDV) therapy, for further follow-up. Dose-response analyses and plaque assays confirm the antiviral activity (IC50: 10-118 nM). Passaging of RSV with lonafarnib selects for phenotypic resistance and fixation of mutations in the RSV fusion protein (T335I and T400A). Lentiviral pseudotypes programmed with variant RSV fusion proteins confirm that lonafarnib inhibits RSV cell entry and that these mutations confer lonafarnib resistance. Surface plasmon resonance reveals RSV fusion protein binding of lonafarnib and co-crystallography identifies the lonafarnib binding site within RSV F. Oral administration of lonafarnib dose-dependently reduces RSV virus load in a murine infection model using female mice. Collectively, this work provides an overview of RSV drug repurposing candidates and establishes lonafarnib as a bona fide fusion protein inhibitor.


Assuntos
Dibenzocicloeptenos , Piridinas , Infecções por Vírus Respiratório Sincicial , Animais , Feminino , Camundongos , Reposicionamento de Medicamentos , Piperidinas/farmacologia , Piperidinas/uso terapêutico , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico , Proteínas Virais de Fusão/genética , Proteínas Virais de Fusão/química
5.
Nat Commun ; 15(1): 1335, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38351001

RESUMO

Many pathogenic viruses rely on class I fusion proteins to fuse their viral membrane with the host cell membrane. To drive the fusion process, class I fusion proteins undergo an irreversible conformational change from a metastable prefusion state to an energetically more stable postfusion state. Mounting evidence underscores that antibodies targeting the prefusion conformation are the most potent, making it a compelling vaccine candidate. Here, we establish a computational design protocol that stabilizes the prefusion state while destabilizing the postfusion conformation. With this protocol, we stabilize the fusion proteins of the RSV, hMPV, and SARS-CoV-2 viruses, testing fewer than a handful of designs. The solved structures of these designed proteins from all three viruses evidence the atomic accuracy of our approach. Furthermore, the humoral response of the redesigned RSV F protein compares to that of the recently approved vaccine in a mouse model. While the parallel design of two conformations allows the identification of energetically sub-optimal positions for one conformation, our protocol also reveals diverse molecular strategies for stabilization. Given the clinical significance of viruses using class I fusion proteins, our algorithm can substantially contribute to vaccine development by reducing the time and resources needed to optimize these immunogens.


Assuntos
Vacinas , Proteínas Virais de Fusão , Animais , Camundongos , Anticorpos Neutralizantes , Anticorpos Antivirais , Conformação Proteica
6.
Infection ; 52(2): 597-609, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38332255

RESUMO

PURPOSE: Respiratory syncytial virus (RSV) is one of the leading causes of severe respiratory disease in infants and adults. While vaccines and monoclonal therapeutic antibodies either are or will shortly become available, correlates of protection remain unclear. For this purpose, we developed an RSV multiplex immunoassay that analyses antibody titers toward the post-F, Nucleoprotein, and a diverse mix of G proteins. METHODS: A bead-based multiplex RSV immunoassay was developed, technically validated to standard FDA bioanalytical guidelines, and clinically validated using samples from human challenge studies. RSV antibody titers were then investigated in children aged under 2 and a population-based cohort. RESULTS: Technical and clinical validation showed outstanding performance, while methodological developments enabled identification of the subtype of previous infections through use of the diverse G proteins for approximately 50% of samples. As a proof of concept to show the suitability of the assay in serosurveillance studies, we then evaluated titer decay and age-dependent antibody responses within population cohorts. CONCLUSION: Overall, the developed assay shows robust performance, is scalable, provides additional information on infection subtype, and is therefore ideally suited to be used in future population cohort studies.


Assuntos
Infecções por Vírus Respiratório Sincicial , Vírus Sincicial Respiratório Humano , Criança , Lactente , Adulto , Humanos , Infecções por Vírus Respiratório Sincicial/diagnóstico , Proteínas Virais de Fusão , Anticorpos Antivirais , Anticorpos Monoclonais , Imunoensaio , Proteínas de Ligação ao GTP , Anticorpos Neutralizantes
7.
J Gen Virol ; 105(1)2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38231539

RESUMO

Respiratory syncytial virus (RSV) has two main surface glycoproteins, the attachment glycoprotein (G) and the fusion (F) protein, which together mediate viral entry. Attachment is mediated by the RSV-G protein, while the RSV-F protein makes specific contact with the cellular insulin-like growth factor 1 receptor (IGF1R). This interaction leads to IGF1R activation and initiates a signalling cascade that calls the co-receptor, nucleolin, from the nucleus to the cell surface, where it can trigger viral fusion. We performed molecular docking analysis, which provided a potential set of 35 residues in IGF1R that may be important for interactions with RSV-F. We used alanine-scanning mutagenesis to generate IGF1R mutants and assessed their abundance and maturation, as well as the effect of mutation on RSV infection. We identified several mutations that appear to inhibit IGF1R maturation; but surprisingly, these mutations had no significant effect on RSV infection. This suggests that maturation of IGF1R may not be required for RSV infection. Additionally, we identified one residue, S788, that, when mutated, significantly reduced RSV infection. Further analysis revealed that this mutation disrupted a hydrogen bonding network that may be important for both IGF1R maturation and RSV infection.


Assuntos
Receptor IGF Tipo 1 , Infecções por Vírus Respiratório Sincicial , Vírus Sincicial Respiratório Humano , Proteínas Virais de Fusão , Humanos , Alanina/genética , Simulação de Acoplamento Molecular , Mutagênese , Receptor IGF Tipo 1/genética , Vírus Sincicial Respiratório Humano/genética , Proteínas Virais de Fusão/genética
8.
Virology ; 591: 109985, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38227992

RESUMO

Evidence for a stable interaction between the respiratory syncytial virus (RSV) F and G proteins on the surface of virus filaments was provided using antibody immunoprecipitation studies on purified RSV particles, and by the in situ analysis on the surface of RSV-infected cells using the proximity ligation assay. Imaging of the F and G protein distribution on virus filaments suggested that this protein complex was localised at the distal ends of the virus filaments, and suggested that this protein complex played a direct role in mediating efficient localised cell-to-cell virus transmission. G protein expression was required for efficient localised cell-to-cell transmission of RSV in cell monolayers which provided evidence that this protein complex mediates efficient multiple cycle infection. Collectively, these data provide evidence that F and G proteins form a complex on the surface of RSV particles, and that a role for this protein complex in promoting virus transmission is suggested.


Assuntos
Infecções por Vírus Respiratório Sincicial , Vacinas contra Vírus Sincicial Respiratório , Vírus Sincicial Respiratório Humano , Humanos , Proteínas Virais de Fusão/genética , Citoesqueleto , Processamento de Proteína Pós-Traducional , Proteínas de Ligação ao GTP/metabolismo , Anticorpos Antivirais
9.
J Virol ; 98(2): e0137223, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38214525

RESUMO

Nipah virus (NiV) and Hendra virus (HeV) are pathogenic paramyxoviruses that cause mild-to-severe disease in humans. As members of the Henipavirus genus, NiV and HeV use an attachment (G) glycoprotein and a class I fusion (F) glycoprotein to invade host cells. The F protein rearranges from a metastable prefusion form to an extended postfusion form to facilitate host cell entry. Prefusion NiV F elicits higher neutralizing antibody titers than postfusion NiV F, indicating that stabilization of prefusion F may aid vaccine development. A combination of amino acid substitutions (L104C/I114C, L172F, and S191P) is known to stabilize NiV F in its prefusion conformation, although the extent to which substitutions transfer to other henipavirus F proteins is not known. Here, we perform biophysical and structural studies to investigate the mechanism of prefusion stabilization in F proteins from three henipaviruses: NiV, HeV, and Langya virus (LayV). Three known stabilizing substitutions from NiV F transfer to HeV F and exert similar structural and functional effects. One engineered disulfide bond, located near the fusion peptide, is sufficient to stabilize the prefusion conformations of both HeV F and LayV F. Although LayV F shares low overall sequence identity with NiV F and HeV F, the region around the fusion peptide exhibits high sequence conservation across all henipaviruses. Our findings indicate that substitutions targeting this site of conformational change might be applicable to prefusion stabilization of other henipavirus F proteins and support the use of NiV as a prototypical pathogen for henipavirus vaccine antigen design.IMPORTANCEPathogenic henipaviruses such as Nipah virus (NiV) and Hendra virus (HeV) cause respiratory symptoms, with severe cases resulting in encephalitis, seizures, and coma. The work described here shows that the NiV and HeV fusion (F) proteins share common structural features with the F protein from an emerging henipavirus, Langya virus (LayV). Sequence alignment alone was sufficient to predict which known prefusion-stabilizing amino acid substitutions from NiV F would stabilize the prefusion conformations of HeV F and LayV F. This work also reveals an unexpected oligomeric interface shared by prefusion HeV F and NiV F. Together, these advances lay a foundation for future antigen design targeting henipavirus F proteins. In this way, Nipah virus can serve as a prototypical pathogen for the development of protective vaccines and monoclonal antibodies to prepare for potential henipavirus outbreaks.


Assuntos
Vírus Hendra , Infecções por Henipavirus , Henipavirus , Vírus Nipah , Proteínas Virais , Humanos , Glicoproteínas/metabolismo , Vírus Hendra/fisiologia , Henipavirus/fisiologia , Vírus Nipah/genética , Vírus Nipah/metabolismo , Peptídeos/metabolismo , Proteínas Virais de Fusão , Proteínas Virais/metabolismo
10.
Antiviral Res ; 221: 105791, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38160942

RESUMO

Human respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections (LRTI) in young children and elderly people worldwide. Recent significant progress in our understanding of the structure and function of RSV proteins has led to the discovery of several clinical candidates targeting RSV fusion and replication. These include both the development of novel small molecule interventions and the isolation of potent monoclonal antibodies. In this review, we summarize the state-of-the-art of RSV drug discovery, with a focus on the characteristics of the candidates that reached the clinical stage of development. We also discuss the lessons learned from failed and discontinued clinical developments and highlight the challenges that remain for development of RSV therapies.


Assuntos
Infecções por Vírus Respiratório Sincicial , Vacinas contra Vírus Sincicial Respiratório , Vírus Sincicial Respiratório Humano , Infecções Respiratórias , Criança , Humanos , Idoso , Pré-Escolar , Anticorpos Monoclonais/uso terapêutico , Vacinas contra Vírus Sincicial Respiratório/uso terapêutico , Proteínas Virais de Fusão , Anticorpos Antivirais , Anticorpos Neutralizantes
11.
mBio ; 15(1): e0212223, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38117059

RESUMO

IMPORTANCE: Human metapneumovirus (hMPV) is an important respiratory pathogen for which no licensed antivirals or vaccines exist. Single-domain antibodies represent promising antiviral biologics that can be easily produced and formatted. We describe the isolation and detailed characterization of two hMPV-neutralizing single-domain antibodies that are directed against the fusion protein F. One of these single-domain antibodies broadly neutralizes hMPV A and B strains, can prevent proteolytic maturation of F, and binds to an epitope in the F trimer interface. This suggests that hMPV pre-F undergoes trimer opening or "breathing" on infectious virions, exposing a vulnerable site for neutralizing antibodies. Finally, we show that this single-domain antibody, fused to a human IgG1 Fc, can protect cotton rats against hMPV replication, an important finding for potential future clinical applications.


Assuntos
Metapneumovirus , Anticorpos de Domínio Único , Humanos , Metapneumovirus/genética , Metapneumovirus/metabolismo , Anticorpos Antivirais , Anticorpos Neutralizantes , Epitopos , Proteínas Virais de Fusão/metabolismo
12.
Euro Surveill ; 28(49)2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-38062945

RESUMO

To advance our understanding of respiratory syncytial virus (RSV) impact through genomic surveillance, we describe two PCR-based sequencing systems, (i) RSVAB-WGS for generic whole-genome sequencing and (ii) RSVAB-GF, which targets major viral antigens, G and F, and is used as a complement for challenging cases with low viral load. These methods monitor RSV genetic diversity to inform molecular epidemiology, vaccine effectiveness and treatment strategies, contributing also to the standardisation of surveillance in a new era of vaccines.


Assuntos
Infecções por Vírus Respiratório Sincicial , Vacinas contra Vírus Sincicial Respiratório , Vírus Sincicial Respiratório Humano , Humanos , Infecções por Vírus Respiratório Sincicial/diagnóstico , Infecções por Vírus Respiratório Sincicial/epidemiologia , Proteínas Virais de Fusão/genética , Vacinas contra Vírus Sincicial Respiratório/genética , Vírus Sincicial Respiratório Humano/genética , Genômica , Sequenciamento Completo do Genoma , Anticorpos Antivirais
13.
J Virol ; 97(12): e0134323, 2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-37975688

RESUMO

IMPORTANCE: Vaccinia virus infection requires virus-cell membrane fusion to complete entry during endocytosis; however, it contains a large viral fusion protein complex of 11 viral proteins that share no structure or sequence homology to all the known viral fusion proteins, including type I, II, and III fusion proteins. It is thus very challenging to investigate how the vaccinia fusion complex works to trigger membrane fusion with host cells. In this study, we crystallized the ectodomain of vaccinia H2 protein, one component of the viral fusion complex. Furthermore, we performed a series of mutational, biochemical, and molecular analyses and identified two surface loops containing 170LGYSG174 and 125RRGTGDAW132 as the A28-binding region. We also showed that residues in the N-terminal helical region (amino acids 51-90) are also important for H2 function.


Assuntos
Fusão de Membrana , Vírus Vaccinia , Proteínas Virais de Fusão , Internalização do Vírus , Vírus Vaccinia/química , Vírus Vaccinia/genética , Vírus Vaccinia/metabolismo , Proteínas Virais de Fusão/química , Proteínas Virais de Fusão/genética , Proteínas Virais de Fusão/metabolismo
14.
PLoS Pathog ; 19(11): e1011500, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37948471

RESUMO

Host cell entry of vaccinia virus (a poxvirus) proceeds through multiple steps that involve many viral proteins to mediate cell infection. Upon binding to cells, vaccinia virus membrane fuses with host membranes via a viral entry fusion protein complex comprising 11 proteins: A16, A21, A28, F9, G3, G9, H2, J5, L1, L5 and O3. Despite vaccinia virus having two infectious forms, mature and enveloped, that have different membrane layers, both forms require an identical viral entry fusion complex for membrane fusion. Components of the poxvirus entry fusion complex that have been structurally assessed to date share no known homology with all other type I, II and III viral fusion proteins, and the large number of fusion protein components renders it a unique system to investigate poxvirus-mediated membrane fusion. Here, we determined the NMR structure of a truncated version of vaccinia A28 protein. We also expressed a soluble H2 protein and showed that A28 interacts with H2 protein at a 1:1 ratio in vitro. Furthermore, we performed extensive in vitro alanine mutagenesis to identify A28 protein residues that are critical for H2 binding, entry fusion complex formation, and virus-mediated membrane fusion. Finally, we used molecular dynamic simulations to model full-length A28-H2 subcomplex in membranes. In summary, we characterized vaccinia virus A28 protein and determined residues important in its interaction with H2 protein and membrane components. We also provide a structural model of the A28-H2 protein interaction to illustrate how it forms a 1:1 subcomplex on a modeled membrane.


Assuntos
Poxviridae , Vaccinia , Humanos , Vírus Vaccinia/metabolismo , Simulação de Dinâmica Molecular , Proteínas Virais de Fusão/metabolismo , Poxviridae/metabolismo , Internalização do Vírus
15.
Int J Mol Sci ; 24(22)2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-38003610

RESUMO

Membrane-spanning portions of proteins' polypeptide chains are commonly known as their transmembrane domains (TMDs). The structural organisation and dynamic behaviour of TMDs from proteins of various families, be that receptors, ion channels, enzymes etc., have been under scrutiny on the part of the scientific community for the last few decades. The reason for such attention is that, apart from their obvious role as an "anchor" in ensuring the correct orientation of the protein's extra-membrane domains (in most cases functionally important), TMDs often actively and directly contribute to the operation of "the protein machine". They are capable of transmitting signals across the membrane, interacting with adjacent TMDs and membrane-proximal domains, as well as with various ligands, etc. Structural data on TMD arrangement are still fragmentary at best due to their complex molecular organisation as, most commonly, dynamic oligomers, as well as due to the challenges related to experimental studies thereof. Inter alia, this is especially true for viral fusion proteins, which have been the focus of numerous studies for quite some time, but have provoked unprecedented interest in view of the SARS-CoV-2 pandemic. However, despite numerous structure-centred studies of the spike (S) protein effectuating target cell entry in coronaviruses, structural data on the TMD as part of the entire spike protein are still incomplete, whereas this segment is known to be crucial to the spike's fusogenic activity. Therefore, in attempting to bring together currently available data on the structure and dynamics of spike proteins' TMDs, the present review aims to tackle a highly pertinent task and contribute to a better understanding of the molecular mechanisms underlying virus-mediated fusion, also offering a rationale for the design of novel efficacious methods for the treatment of infectious diseases caused by SARS-CoV-2 and related viruses.


Assuntos
Fusão de Membrana , Proteínas Virais de Fusão , Humanos , Fusão de Membrana/fisiologia , Domínios Proteicos , Proteínas Virais de Fusão/metabolismo , Peptídeos , SARS-CoV-2/metabolismo
16.
J Virol ; 97(12): e0105223, 2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-38032197

RESUMO

IMPORTANCE: Human metapneumovirus (hMPV) is a common pathogen causing lower respiratory tract infections worldwide and can develop severe symptoms in high-risk populations such as infants, the elderly, and immunocompromised patients. There are no approved hMPV vaccines or neutralizing antibodies available for therapeutic or prophylactic use. The trimeric hMPV fusion F protein is the major target of neutralizing antibodies in human sera. Understanding the immune recognition of antibodies to hMPV-F antigen will provide critical insights into developing efficacious hMPV monoclonal antibodies and vaccines.


Assuntos
Metapneumovirus , Infecções por Paramyxoviridae , Idoso , Humanos , Anticorpos Neutralizantes , Anticorpos Antivirais , Epitopos , Metapneumovirus/fisiologia , Infecções por Paramyxoviridae/imunologia , Proteínas Virais de Fusão , Vacinas Virais/imunologia
17.
J Virol ; 97(11): e0077123, 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-37902399

RESUMO

IMPORTANCE: Respiratory syncytial virus (RSV) can cause serious illness in older adults (i.e., those aged ≥60 years). Because options for RSV prophylaxis and treatment are limited, the prevention of RSV-mediated illness in older adults remains an important unmet medical need. Data from prior studies suggest that Fc-effector functions are important for protection against RSV infection. In this work, we show that the investigational Ad26.RSV.preF/RSV preF protein vaccine induced Fc-effector functional immune responses in adults aged ≥60 years who were enrolled in a phase 1/2a regimen selection study of Ad26.RSV.preF/RSV preF protein. These results demonstrate the breadth of the immune responses induced by the Ad26.RSV.preF/RSV preF protein vaccine.


Assuntos
Infecções por Vírus Respiratório Sincicial , Vacinas contra Vírus Sincicial Respiratório , Idoso , Humanos , Anticorpos Neutralizantes , Anticorpos Antivirais , Fragmentos Fc das Imunoglobulinas , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Vacinas contra Vírus Sincicial Respiratório/imunologia , Vírus Sincicial Respiratório Humano , Proteínas Virais de Fusão/imunologia
18.
J Biol Chem ; 299(11): 105323, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37805138

RESUMO

Human respiratory syncytial virus (RSV) is the leading cause of infantile bronchiolitis in the developed world and of childhood deaths in resource-poor settings. The elderly and the immunosuppressed are also affected. It is a major unmet target for vaccines and antiviral drugs. RSV assembles and buds from the host cell plasma membrane by forming infectious viral particles which are mostly filamentous. A key interaction during RSV assembly is the interaction of the matrix (M) protein with cell plasma membrane lipids forming a layer at assembly sites. Although the structure of RSV M protein dimer is known, it is unclear how the viral M proteins interact with cell membrane lipids, and with which one, to promote viral assembly. Here, we demonstrate that M proteins are able to cluster at the plasma membrane by selectively binding with phosphatidylserine (PS). Our in vitro studies suggest that M binds PS lipid as a dimer and upon M oligomerization, PS clustering is observed. In contrast, the presence of other negatively charged lipids like PI(4, 5)P2 does not enhance M binding beyond control zwitterionic lipids, while cholesterol negatively affects M interaction with membrane lipids. Moreover, we show that the initial binding of the RSV M protein with PS lipids is independent of the cytoplasmic tail of the fusion (F) glycoprotein (FCT). Here, we highlight that M binding on membranes occurs directly through PS lipids, this interaction is electrostatic in nature, and M oligomerization generates PS clusters.


Assuntos
Vírus Sincicial Respiratório Humano , Humanos , Membrana Celular/metabolismo , Lipídeos de Membrana/metabolismo , Fosfatidilserinas/metabolismo , Proteínas Virais de Fusão/metabolismo , Vírion/metabolismo , Montagem de Vírus , Proteínas da Matriz Viral/genética , Proteínas da Matriz Viral/metabolismo , Linhagem Celular Tumoral
19.
Sci Adv ; 9(43): eadj7611, 2023 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-37878713

RESUMO

Respiratory syncytial virus (RSV) can lead to serious disease in infants, and no approved RSV vaccine is available for infants. This first in-human clinical trial evaluated a single dose of BLB201, a PIV5-vectored RSV vaccine administrated via intranasal route, for safety and immunogenicity in RSV-seropositive healthy adults (33 to 75 years old). No severe adverse events (SAEs) were reported. Solicited local and systemic AEs were reported by <50% of participants and were mostly mild in intensity. Vaccine virus shedding was detected in 17% of participants. Nasal RSV-specific immunoglobulin A responses were detected in 48%, the highest level observed in adults among all intranasal RSV vaccines evaluated in humans. RSV-neutralizing antibodies titers in serum rose ≥1.5-fold. Peripheral blood RSV F-specific CD4+ and CD8+ T cells increased from ≤0.06% at baseline to ≥0.26 and 0.4% after vaccination, respectively, in >93% participants. The safety and immunogenicity profile of BLB201 in RSV-seropositive adults supports the further clinical development of BLB201.


Assuntos
Vírus da Parainfluenza 5 , Infecções por Vírus Respiratório Sincicial , Vacinas contra Vírus Sincicial Respiratório , Vírus Sincicial Respiratório Humano , Humanos , Adulto , Pessoa de Meia-Idade , Idoso , Vacinas contra Vírus Sincicial Respiratório/efeitos adversos , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Linfócitos T CD8-Positivos , Anticorpos Antivirais , Proteínas Virais de Fusão
20.
Paediatr Drugs ; 25(6): 729-734, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37831328

RESUMO

Pfizer is developing a bivalent respiratory syncytial virus (RSV) prefusion F subunit vaccine (RSVpreF; ABRYSVO™) for preventing RSV illness in infants and individuals aged ≥ 60 years. RSVpreF received approval for vaccination of pregnant individuals to help protect infants against RSV illness on 21 August 2023 in the USA. RSVpreF is also approved in the USA (31 May 2023) for active immunization of individuals aged ≥ 60 years for the prevention of lower respiratory tract disease (LRTD) caused by RSV. In the EU, RSVpreF has received approval for both indications, and it has been submitted for regulatory approval in Canada (both indications) and in Japan (maternal immunization to protect infants). This article summarizes the milestones in the development of RSVpreF leading to the approval for use in pregnant individuals to prevent LRTD in infants.


Assuntos
Infecções por Vírus Respiratório Sincicial , Vacinas contra Vírus Sincicial Respiratório , Feminino , Gravidez , Humanos , Lactente , Vacinas contra Vírus Sincicial Respiratório/uso terapêutico , Anticorpos Antivirais , Proteínas Virais de Fusão , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Vírus Sinciciais Respiratórios , Vacinas de Subunidades
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