RESUMEN
Nipah virus infection, one of the top priority diseases recognized by the World Health Organization, underscores the urgent need to develop effective countermeasures against potential epidemics and pandemics. Here, we identify a fully human single-domain antibody that targets a highly conserved cryptic epitope situated at the dimeric interface of the Nipah virus G protein (receptor binding protein, RBP), as elucidated through structures by high-resolution cryo-electron microscopy (cryo-EM). This unique binding mode disrupts the tetramerization of the G protein, consequently obstructing the activation of the F protein and inhibiting viral membrane fusion. Furthermore, our investigations reveal that this compact antibody displays enhanced permeability across the blood-brain barrier (BBB) and demonstrates superior efficacy in eliminating pseudovirus within the brain in a murine model of Nipah virus infection, particularly compared to the well-characterized antibody m102.4 in an IgG1 format. Consequently, this single-domain antibody holds promise as a therapeutic candidate to prevent Nipah virus infections and has potential implications for vaccine development.
Asunto(s)
Anticuerpos Antivirales , Microscopía por Crioelectrón , Epítopos , Infecciones por Henipavirus , Virus Nipah , Anticuerpos de Dominio Único , Virus Nipah/inmunología , Humanos , Animales , Infecciones por Henipavirus/inmunología , Infecciones por Henipavirus/prevención & control , Infecciones por Henipavirus/virología , Epítopos/inmunología , Ratones , Anticuerpos de Dominio Único/inmunología , Anticuerpos de Dominio Único/química , Anticuerpos Antivirales/inmunología , Barrera Hematoencefálica/metabolismo , Barrera Hematoencefálica/inmunología , Proteínas del Envoltorio Viral/inmunología , Proteínas del Envoltorio Viral/química , Femenino , Células HEK293RESUMEN
The zoonotic viruses pose significant threats to public health. Nipah virus (NiV) is an emerging virus transmitted from bats to humans. The NiV causes severe encephalitis and acute respiratory distress syndrome, leading to high mortality rates, with fatality rates ranging from 40% to 75%. The first emergence of the disease was found in Malaysia in 1998-1999 and later in Bangladesh, Cambodia, Timor-Leste, Indonesia, Singapore, Papua New Guinea, Vietnam, Thailand, India, and other South and Southeast Asian nations. Currently, no specific vaccines or antiviral drugs are available. The potential advantages of epitope-based vaccines include their ability to elicit specific immune responses while minimizing potential side effects. The epitopes have been identified from the conserved region of viral proteins obtained from the UniProt database. The selection of conserved epitopes involves analyzing the genetic sequences of various viral strains. The present study identified two B cell epitopes, seven cytotoxic T lymphocyte (CTL) epitopes, and seven helper T lymphocyte (HTL) epitope interactions from the NiV proteomic inventory. The antigenic and physiological properties of retrieved protein were analyzed using online servers ToxinPred, VaxiJen v2.0, and AllerTOP. The final vaccine candidate has a total combined coverage range of 80.53%. The tertiary structure of the constructed vaccine was optimized, and its stability was confirmed with the help of molecular simulation. Molecular docking was performed to check the binding affinity and binding energy of the constructed vaccine with TLR-3 and TLR-5. Codon optimization was performed in the constructed vaccine within the Escherichia coli K12 strain, to eliminate the danger of codon bias. However, these findings must require further validation to assess their effectiveness and safety. The development of vaccines and therapeutic approaches for virus infection is an ongoing area of research, and it may take time before effective interventions are available for clinical use.
Asunto(s)
Simulación por Computador , Infecciones por Henipavirus , Virus Nipah , Virus Nipah/inmunología , Humanos , Infecciones por Henipavirus/inmunología , Infecciones por Henipavirus/prevención & control , Vacunas Virales/inmunología , Epítopos de Linfocito B/inmunología , Epítopos de Linfocito B/química , Biología Computacional/métodos , Epítopos de Linfocito T/inmunología , Vacunación , Simulación del Acoplamiento Molecular , Proteínas Virales/inmunología , Proteínas Virales/química , Proteínas Virales/genética , AnimalesRESUMEN
Hendra virus (HeV) is lethal to horses and a zoonotic threat to humans in Australia, causing severe neurological and/or respiratory disease with high mortality. An equine vaccine has been available since 2012. Foals acquire antibodies from their dams by ingesting colostrum after parturition, therefore it is assumed that foals of mares vaccinated against HeV will have passive HeV antibodies circulating during the first several months of life until they are actively vaccinated. However, no studies have yet examined passive or active immunity against HeV in foals. Here, we investigated anti-HeV antibody levels in vaccinated mares and their foals. Testing for HeV neutralising antibodies is cumbersome due to the requirement for Biosafety level 4 (BSL-4) containment to conduct virus neutralisation tests (VNT). For this study, a subset of samples was tested for HeV G-specific antibodies by both an authentic VNT with infectious HeV and a microsphere-based immunoassay (MIA), revealing a strong correlation. An indicative neutralising level was then applied to the results of a larger sample set tested using the MIA. Mares had high levels of HeV-specific neutralising antibodies at the time of parturition. Foals acquired high levels of maternal antibodies which then waned to below predictive protective levels in most foals by 6 months old when vaccination commenced. Foals showed a suboptimal response to vaccination, suggesting maternal antibodies may interfere with active vaccination. The correlation analysis between the authentic HeV VNT and HeV MIA will enable further high throughput serological studies to inform optimal vaccination protocols for both broodmares and foals.
Asunto(s)
Anticuerpos Neutralizantes , Anticuerpos Antivirales , Virus Hendra , Infecciones por Henipavirus , Enfermedades de los Caballos , Vacunación , Vacunas Virales , Animales , Caballos , Virus Hendra/inmunología , Enfermedades de los Caballos/prevención & control , Enfermedades de los Caballos/virología , Enfermedades de los Caballos/inmunología , Anticuerpos Antivirales/sangre , Infecciones por Henipavirus/prevención & control , Infecciones por Henipavirus/veterinaria , Infecciones por Henipavirus/inmunología , Infecciones por Henipavirus/virología , Femenino , Vacunación/veterinaria , Vacunas Virales/inmunología , Vacunas Virales/administración & dosificación , Anticuerpos Neutralizantes/sangre , Inmunidad Materno-Adquirida , Animales Recién Nacidos/inmunología , Embarazo , Pruebas de Neutralización/veterinaria , Australia , Calostro/inmunologíaRESUMEN
The Nipah virus (NiV), a highly deadly bat-borne paramyxovirus, poses a substantial threat due to recurrent outbreaks in specific regions, causing severe respiratory and neurological diseases with high morbidity. Two distinct strains, NiV-Malaysia (NiV-M) and NiV-Bangladesh (NiV-B), contribute to outbreaks in different geographical areas. Currently, there are no commercially licensed vaccines or drugs available for prevention or treatment. In response to this urgent need for protection against NiV and related henipaviruses infections, we developed a novel homotypic virus-like nanoparticle (VLP) vaccine co-displaying NiV attachment glycoproteins (G) from both strains, utilizing the self-assembling properties of ferritin protein. In comparison to the NiV G subunit vaccine, our nanoparticle vaccine elicited significantly higher levels of neutralizing antibodies and provided complete protection against a lethal challenge with NiV infection in Syrian hamsters. Remarkably, the nanoparticle vaccine stimulated the production of antibodies that exhibited superior cross-reactivity to homologous or heterologous henipavirus. These findings underscore the potential utility of ferritin-based nanoparticle vaccines in providing both broad-spectrum and long-term protection against NiV and emerging zoonotic henipaviruses challenges.
Asunto(s)
Anticuerpos Neutralizantes , Anticuerpos Antivirales , Ferritinas , Infecciones por Henipavirus , Mesocricetus , Nanopartículas , Virus Nipah , Vacunas Virales , Animales , Virus Nipah/inmunología , Infecciones por Henipavirus/prevención & control , Infecciones por Henipavirus/inmunología , Ferritinas/inmunología , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , Vacunas Virales/inmunología , Vacunas Virales/administración & dosificación , Cricetinae , Vacunas de Partículas Similares a Virus/inmunología , Vacunas de Partículas Similares a Virus/administración & dosificación , Femenino , Humanos , NanovacunasRESUMEN
The Hendra and Nipah viruses (HNVs) are highly pathogenic pathogens without approved interventions for human use. In addition, the interaction pattern between the attachment (G) and fusion (F) glycoproteins required for virus entry remains unclear. Here, we isolate a panel of Macaca-derived G-specific antibodies that cross-neutralize HNVs via multiple mechanisms. The most potent antibody, 1E5, confers adequate protection against the Nipah virus challenge in female hamsters. Crystallography demonstrates that 1E5 has a highly similar binding pattern to the receptor. In cryo-electron microscopy studies, the tendency of 1E5 to bind to the upper or lower heads results in two distinct quaternary structures of G. Furthermore, we identify the extended outer loop ß1S2-ß1S3 of G and two pockets on the apical region of fusion (F) glycoprotein as the essential sites for G-F interactions. This work highlights promising drug candidates against HNVs and contributes deeper insights into the viruses.
Asunto(s)
Anticuerpos Neutralizantes , Anticuerpos Antivirales , Microscopía por Crioelectrón , Infecciones por Henipavirus , Proteínas Virales de Fusión , Animales , Anticuerpos Neutralizantes/inmunología , Femenino , Anticuerpos Antivirales/inmunología , Infecciones por Henipavirus/virología , Infecciones por Henipavirus/inmunología , Proteínas Virales de Fusión/inmunología , Proteínas Virales de Fusión/química , Humanos , Proteínas del Envoltorio Viral/inmunología , Proteínas del Envoltorio Viral/química , Virus Nipah/inmunología , Internalización del Virus/efectos de los fármacos , Henipavirus/inmunología , Cricetinae , Reacciones Cruzadas/inmunología , Virus Hendra/inmunología , Macaca , Mesocricetus , Cristalografía por Rayos XRESUMEN
Nipah virus (NiV) poses a significant threat to human and livestock populations across South and Southeast Asia. Vaccines are required to reduce the risk and impact of spillover infection events. Pigs can act as an intermediate amplifying host for NiV and, separately, provide a preclinical model for evaluating human vaccine candidate immunogenicity. The aim of this study was therefore to evaluate the immunogenicity of an mRNA vectored NiV vaccine candidate in pigs. Pigs were immunized twice with 100 µg nucleoside-modified mRNA vaccine encoding soluble G glycoprotein from the Malaysia strain of NiV, formulated in lipid nanoparticles. Potent antigen-binding and virus neutralizing antibodies were detected in serum following the booster immunization. Antibody responses effectively neutralized both the Malaysia and Bangladesh strains of NiV but showed limited neutralization of the related (about 80% amino acid sequence identity for G) Hendra virus. Antibodies were also capable of neutralizing NiV glycoprotein mediated cell-cell fusion. NiV G-specific T cell cytokine responses were also measurable following the booster immunization with evidence for induction of both CD4 and CD8 T cell responses. These data support the further evaluation of mRNA vectored NiV G as a vaccine for both pigs and humans.
Asunto(s)
Anticuerpos Neutralizantes , Anticuerpos Antivirales , Infecciones por Henipavirus , Virus Nipah , Vacunas Virales , Animales , Virus Nipah/inmunología , Virus Nipah/genética , Porcinos , Infecciones por Henipavirus/prevención & control , Infecciones por Henipavirus/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , Vacunas Virales/inmunología , Vacunas Virales/administración & dosificación , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Enfermedades de los Porcinos/inmunología , Enfermedades de los Porcinos/prevención & control , Enfermedades de los Porcinos/virología , ARN Mensajero/genética , ARN Mensajero/inmunología , Inmunogenicidad Vacunal , Inmunización Secundaria , Citocinas/inmunología , Vacunas Sintéticas/inmunología , Liposomas , NanopartículasRESUMEN
According to the 2018 WHO R&D Blueprint, Nipah virus (NiV) is a priority disease, and the development of a vaccine against NiV is strongly encouraged. According to criteria used to categorize zoonotic diseases, NiV is a stage III disease that can spread to people and cause unpredictable outbreaks. Since 2001, the NiV virus has caused annual outbreaks in Bangladesh, while in India it has caused occasional outbreaks. According to estimates, the mortality rate for infected individuals ranges from 70 to 91%. Using immunoinformatic approaches to anticipate the epitopes of the MHC-I, MHC-II, and B-cells, they were predicted using the NiV glycoprotein and nucleocapsid protein. The selected epitopes were used to develop a multi-epitope vaccine construct connected with linkers and adjuvants in order to improve immune responses to the vaccine construct. The 3D structure of the engineered vaccine was anticipated, optimized, and confirmed using a variety of computer simulation techniques so that its stability could be assessed. According to the immunological simulation tests, it was found that the vaccination elicits a targeted immune response against the NiV. Docking with TLR-3, 7, and 8 revealed that vaccine candidates had high binding affinities and low binding energies. Finally, molecular dynamic analysis confirms the stability of the new vaccine. Codon optimization and in silico cloning showed that the proposed vaccine was expressed to a high degree in Escherichia coli. The study will help in identifying a potential epitope for a vaccine candidate against NiV. The developed multi-epitope vaccine construct has a lot of potential, but they still need to be verified by in vitro & in vivo studies.
Asunto(s)
Glicoproteínas , Virus Nipah , Vacunas Virales , Virus Nipah/inmunología , Vacunas Virales/inmunología , Glicoproteínas/inmunología , Glicoproteínas/química , Humanos , Infecciones por Henipavirus/prevención & control , Infecciones por Henipavirus/inmunología , Simulación por Computador , Epítopos/inmunología , Epítopos/química , Simulación de Dinámica Molecular , Nucleocápside/inmunología , Simulación del Acoplamiento MolecularRESUMEN
OBJECTIVES: Nipah and Hendra are deadly zoonotic diseases with pandemic potential. To date, no human vaccine or monoclonal antibody (mAb) has been licensed to prevent disease caused by these pathogens. The aim of this scoping review was to identify and describe all Phase I, II, and III clinical trials of vaccine candidates or mAbs candidates designed to prevent Nipah and Hendra in humans and to compare the characteristics of the vaccine candidates to characteristics outlined in the Target Product Profile drafted by the World Health Organisation as part of the WHO Research & Development Blueprint for Action to Prevent Epidemics. METHODS: We searched 23 clinical trial registries, the Cochrane Central Register of Clinical Trials, and grey literature up to June 2023 to identify vaccine and mAb candidates being evaluated in registered clinical trials. Vaccine candidate and trial characteristics were double-extracted for evaluation and the vaccine candidate characteristics were compared with the preferred and critical criteria of the World Health Organisation's Target Product Profile for Nipah virus vaccine. RESULTS: Three vaccine candidates (Hendra Virus Soluble Glycoprotein Vaccine [HeV-sG-V], PHV02, and mRNA-1215) and one mAb (m102.4) had a registered human clinical trial by June 2023. All trials were phase 1, dose-ranging trials taking place in the United States of America or Australia and enrolling healthy adults. Although all vaccine candidates meet the dose regimen and route of administration criteria of the Target Product Profile, other criteria such as measures of efficacy and reactogenicity will need to be evaluated in the future as evidence becomes available. CONCLUSION: Multiple vaccine candidates and one mAb candidate have reached the stage of human clinical trials and are reviewed here. Monitoring progress during evaluation of these candidates and candidates entering clinical trials in the future can help highlight many of the challenges that remain.
Asunto(s)
Anticuerpos Monoclonales , Virus Hendra , Infecciones por Henipavirus , Virus Nipah , Vacunas Virales , Humanos , Infecciones por Henipavirus/prevención & control , Infecciones por Henipavirus/inmunología , Anticuerpos Monoclonales/uso terapéutico , Virus Hendra/inmunología , Virus Nipah/inmunología , Vacunas Virales/inmunología , Vacunas Virales/uso terapéutico , Ensayos Clínicos como Asunto , AnimalesRESUMEN
Nipah virus is one of the most harmful emerging viruses with deadly effects on both humans and animals. Because of the severe outbreaks, in 2018, the World Health Organization focused on the urgent need for the development of effective solutions against the virus. However, up to date, there is no effective vaccine against the Nipah virus in the market. In the current study, the complete proteome of the Nipah virus (nine proteins) was analyzed for the antigenicity score and the virulence role of each protein, where we came up with fusion glycoprotein (F), glycoprotein (G), protein (V), and protein (W) as the candidates for epitope prediction. Following that, the multitope vaccine was designed based on top-ranking CTL, HTL, and BCL epitopes from the selected proteins. We used suitable linkers, adjuvant, and PADRE peptides to finalize the constructed vaccine, which was analyzed for its physicochemical features, antigenicity, toxicity, allergenicity, and solubility. The designed vaccine passed these assessments through computational analysis and, as a final step, we ran a docking analysis between the designed vaccine and TLR-3 and validated the docked complex through molecular dynamics simulation, which estimated a strong binding and supported the nomination of the designed vaccine as a putative solution for Nipah virus. Here, we describe the computational approach for design and analysis of this vaccine.
Asunto(s)
Epítopos de Linfocito B/inmunología , Epítopos de Linfocito T/inmunología , Infecciones por Henipavirus/prevención & control , Virus Nipah/inmunología , Proteoma/inmunología , Vacunas de Subunidad/administración & dosificación , Biología Computacional , Infecciones por Henipavirus/inmunología , Infecciones por Henipavirus/virología , Humanos , Simulación del Acoplamiento Molecular , Conformación Proteica , Proteoma/análisis , Proteoma/metabolismo , Vacunas de Subunidad/inmunologíaRESUMEN
Hendra virus and Nipah virus (NiV), members of the Henipavirus (HNV) genus, are zoonotic paramyxoviruses known to cause severe disease across six mammalian orders, including humans. We isolated a panel of human monoclonal antibodies (mAbs) from the B cells of an individual with prior exposure to equine Hendra virus (HeV) vaccine, targeting distinct antigenic sites. The most potent class of cross-reactive antibodies achieves neutralization by blocking viral attachment to the host cell receptors ephrin-B2 and ephrin-B3, with a second class being enhanced by receptor binding. mAbs from both classes display synergistic activity in vitro. In a stringent hamster model of NiV Bangladesh (NiVB) infection, antibodies from both classes reduce morbidity and mortality and achieve synergistic protection in combination. These candidate mAbs might be suitable for use in a cocktail therapeutic approach to achieve synergistic potency and reduce the risk of virus escape.
Asunto(s)
Anticuerpos Monoclonales/farmacología , Anticuerpos Neutralizantes/farmacología , Antivirales/farmacología , Efrina-B2/antagonistas & inhibidores , Efrina-B3/antagonistas & inhibidores , Infecciones por Henipavirus/prevención & control , Henipavirus/patogenicidad , Receptores Virales/antagonistas & inhibidores , Animales , Especificidad de Anticuerpos , Chlorocebus aethiops , Reacciones Cruzadas , Modelos Animales de Enfermedad , Quimioterapia Combinada , Efrina-B2/inmunología , Efrina-B2/metabolismo , Efrina-B3/inmunología , Efrina-B3/metabolismo , Femenino , Infecciones por Henipavirus/inmunología , Infecciones por Henipavirus/metabolismo , Infecciones por Henipavirus/virología , Interacciones Huésped-Patógeno , Humanos , Mesocricetus , Receptores Virales/inmunología , Receptores Virales/metabolismo , Células VeroRESUMEN
Pandemics are a consequence of a series of processes that span scales from viral biology at 10-9 m to global transmission at 106 m. The pathogen passes from one host species to another through a sequence of events that starts with an infected reservoir host and entails interspecific contact, innate immune responses, receptor protein structure within the potential host, and the global spread of the novel pathogen through the naive host population. Each event presents a potential barrier to the onward passage of the virus and should be characterized with an integrated transdisciplinary approach. Epidemic control is based on the prevention of exposure, infection, and disease. However, the ultimate pandemic prevention is prevention of the spillover event itself. Here, we focus on the potential for preventing the spillover of henipaviruses, a group of viruses derived from bats that frequently cross species barriers, incur high human mortality, and are transmitted among humans via stuttering chains. We outline the transdisciplinary approach needed to prevent the spillover process and, therefore, future pandemics.
Asunto(s)
Quirópteros/virología , Salud Global , Infecciones por Henipavirus/prevención & control , Henipavirus/patogenicidad , Pandemias/prevención & control , Virosis/prevención & control , Zoonosis/virología , Animales , Infecciones por Henipavirus/epidemiología , Infecciones por Henipavirus/inmunología , Infecciones por Henipavirus/transmisión , Especificidad del Huésped , Humanos , Inmunidad Innata , Virus Nipah/patogenicidad , Virosis/inmunología , Virosis/transmisión , Zoonosis/prevención & control , Zoonosis/transmisiónRESUMEN
In this manuscript, COVID-19, Ebola virus disease, Nipah virus infection, SARS, and MERS are suggested to be considered for a novel immunological reclassification as acute onset immune dysrhythmia syndrome (n-AIDS) due to altered monocytic, Th1/Th2, as well as cytokines and chemokines balances. n-AIDs is postulated to be the cause of the acute respiratory distress and multi-inflammatory syndromes which are described with fatal COVID-19, and immunomodulators are suggested to effectively manage the mentioned diseases as well as for other disorders caused by Th1/Th2 imbalance. Meanwhile, para COVID syndrome is suggested to describe various immune-related complications, whether before or after recovery, and to embrace a potential of a latent infection, that might be discovered later, as occurred with Ebola virus disease. Finally, our hypothesis has evolved out of our real-life practice that uses immunomodulatory drugs to manage COVID-19 safely and effectively.
Asunto(s)
COVID-19/inmunología , Citocinas/inmunología , Fiebre Hemorrágica Ebola/inmunología , Infecciones por Henipavirus/inmunología , Síndrome de Inmunodeficiencia Adquirida/inmunología , Quimiocinas/inmunología , Infecciones por Coronavirus/tratamiento farmacológico , Infecciones por Coronavirus/inmunología , Fiebre Hemorrágica Ebola/tratamiento farmacológico , Infecciones por Henipavirus/tratamiento farmacológico , Humanos , Factores Inmunológicos/uso terapéutico , Linfocitos/inmunología , SARS-CoV-2/fisiología , Síndrome Respiratorio Agudo Grave/tratamiento farmacológico , Síndrome Respiratorio Agudo Grave/inmunología , Tratamiento Farmacológico de COVID-19RESUMEN
Nipah virus (NiV) is a highly pathogenic zoonotic virus with a broad species tropism, originating in pteropid bats. Human outbreaks of NiV disease occur almost annually, often with high case-fatality rates. The specific events that lead to pathogenesis are not well defined, but the disease has both respiratory and encephalitic components, with relapsing encephalitis occurring in some cases more than a year after initial infection. Several cell types are targets of NiV, dictated by the expression of the ephrin-B2/3 ligand on the cell's outer membrane, which interact with the NiV surface proteins. Vascular endothelial cells (ECs) are major targets of infection. Cytopathic effects (CPE), characterized by syncytia formation and cell death, and an ensuing vasculitis, are a major feature of the disease. Smooth muscle cells (SMCs) of the tunica media that line small blood vessels are infected in humans and animal models of NiV disease, although pathology or histologic changes associated with antigen-positive SMCs have not been reported. To gain an understanding of the possible contributions that SMCs might have in the development of NiV disease, we investigated the susceptibility and potential cytopathogenic changes of human SMCs to NiV infection in vitro. SMCs were permissive for NiV infection and resulted in high titers and prolonged NiV production, despite a lack of cytopathogenicity, and in the absence of detectable ephrin-B2/3. These results indicate that SMC might be important contributors to disease by producing progeny NiV during an infection, without suffering cytopathogenic consequences.
Asunto(s)
Células Endoteliales , Infecciones por Henipavirus , Miocitos del Músculo Liso , Animales , Chlorocebus aethiops , Susceptibilidad a Enfermedades , Células Endoteliales/inmunología , Células Endoteliales/virología , Infecciones por Henipavirus/inmunología , Infecciones por Henipavirus/virología , Humanos , Miocitos del Músculo Liso/inmunología , Miocitos del Músculo Liso/virología , Virus Nipah , Células Vero , Replicación ViralRESUMEN
Hendra virus (HeV) and Nipah virus (NiV) are henipaviruses (HNVs) causing respiratory illness and severe encephalitis in humans, with fatality rates of 50-100%. There are no licensed therapeutics or vaccines to protect humans. HeV and NiV use a receptor-binding glycoprotein (G) and a fusion glycoprotein (F) to enter host cells. HNV F and G are the main targets of the humoral immune response, and the presence of neutralizing antibodies is a correlate of protection against NiV and HeV in experimentally infected animals. We describe here two cross-reactive F-specific antibodies, 1F5 and 12B2, that neutralize NiV and HeV through inhibition of membrane fusion. Cryo-electron microscopy structures reveal that 1F5 and 12B2 recognize distinct prefusion-specific, conserved quaternary epitopes and lock F in its prefusion conformation. We provide proof-of-concept for using antibody cocktails for neutralizing NiV and HeV and define a roadmap for developing effective countermeasures against these highly pathogenic viruses.
Asunto(s)
Anticuerpos Antivirales/inmunología , Anticuerpos ampliamente neutralizantes/inmunología , Virus Hendra/inmunología , Virus Nipah/inmunología , Proteínas Virales de Fusión/inmunología , Animales , Anticuerpos Monoclonales Humanizados/inmunología , Células CHO , Cricetulus , Reacciones Cruzadas , Células HEK293 , Infecciones por Henipavirus/inmunología , Infecciones por Henipavirus/prevención & control , Humanos , Ratones , Internalización del VirusRESUMEN
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.
Asunto(s)
Anticuerpos Neutralizantes/farmacología , Anticuerpos Antivirales/farmacología , COVID-19/diagnóstico , Infecciones por Henipavirus/diagnóstico , Ensayos Analíticos de Alto Rendimiento , Infecciones por Virus Sincitial Respiratorio/diagnóstico , Proteínas Virales de Fusión/antagonistas & inhibidores , Animales , Anticuerpos Neutralizantes/aislamiento & purificación , Anticuerpos Neutralizantes/metabolismo , Anticuerpos Antivirales/aislamiento & purificación , Anticuerpos Antivirales/metabolismo , COVID-19/inmunología , COVID-19/virología , Fusión Celular , Convalecencia , Genes Reporteros , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Células HEK293 , Infecciones por Henipavirus/inmunología , Infecciones por Henipavirus/virología , Humanos , Sueros Inmunes/química , Luciferasas/genética , Luciferasas/metabolismo , Modelos Moleculares , Virus Nipah/inmunología , Virus Nipah/patogenicidad , Conformación Proteica , Infecciones por Virus Sincitial Respiratorio/inmunología , Infecciones por Virus Sincitial Respiratorio/virología , Virus Sincitial Respiratorio Humano/inmunología , Virus Sincitial Respiratorio Humano/patogenicidad , SARS-CoV-2/inmunología , SARS-CoV-2/patogenicidad , Porcinos , Inhibidores de Proteínas Virales de Fusión/química , Inhibidores de Proteínas Virales de Fusión/metabolismo , Inhibidores de Proteínas Virales de Fusión/farmacología , Proteínas Virales de Fusión/genética , Proteínas Virales de Fusión/inmunologíaRESUMEN
The Nipah virus (NiV) phosphoprotein (P) gene encodes four proteins. Three of these-P, V, and W-possess a common N-terminal domain but distinct C termini. These proteins interact with immune modulators. Previous studies demonstrated that P, V, and W bind STAT1 and STAT4 and that V also interacts with STAT2 but not with STAT3. The STAT1 and STAT2 interactions block interferon (IFN)-induced STAT tyrosine phosphorylation. To more fully characterize the interactions of P, V, and W with the STATs, we screened for interaction of each viral protein with STATs 1 to 6 by coimmunoprecipitation. We demonstrate that NiV P, V, and W interact with STAT4 through their common N-terminal domain and block STAT4 activity, based on a STAT4 response element reporter assay. Although none of the NiV proteins interact with STAT3 or STAT6, NiV V, but not P or W, interacts with STAT5 through its unique C terminus. Furthermore, the interaction of NiV V with STAT5 was not disrupted by overexpression of the N-terminal binding STAT1 or the C-terminal binding MDA5. NiV V also inhibits a STAT5 response element reporter assay. Residues 114 to 140 of the common N-terminal domain of the NiV P gene products were found to be sufficient to bind STAT1 and STAT4. Analysis of STAT1-STAT3 chimeras suggests that the P gene products target the STAT1 SH2 domain. When fused to GST, the 114-140 peptide is sufficient to decrease STAT1 phosphorylation in IFN-ß-stimulated cells, suggesting that this peptide could potentially be fused to heterologous proteins to confer inhibition of STAT1- and STAT4-dependent responses.IMPORTANCE How Nipah virus (NiV) antagonizes innate immune responses is incompletely understood. The P gene of NiV encodes the P, V, and W proteins. These proteins have a common N-terminal sequence that is sufficient to bind to STAT1 and STAT2 and block IFN-induced signal transduction. This study sought to more fully understand how P, V, and W engage with the STAT family of transcription factors to influence their functions. The results identify a novel interaction of V with STAT5 and demonstrate V inhibition of STAT5 function. We also demonstrate that the common N-terminal residues 114 to 140 of P, V, and W are critical for inhibition of STAT1 and STAT4 function, map the interaction to the SH2 region of STAT1, and show that a fusion construct with this peptide significantly inhibits cytokine-induced STAT1 phosphorylation. These data clarify how these important virulence factors modulate innate antiviral defenses.
Asunto(s)
Núcleo Celular/química , Infecciones por Henipavirus/metabolismo , Virus Nipah/fisiología , Factores de Transcripción STAT/metabolismo , Proteínas Virales/metabolismo , Células HEK293 , Infecciones por Henipavirus/inmunología , Infecciones por Henipavirus/virología , Humanos , Inmunidad Innata/inmunología , Fosforilación , Factores de Transcripción STAT/genética , Transducción de Señal , Transactivadores/metabolismo , Proteínas Virales/genéticaRESUMEN
Nipah Virus (NiV) has been designated as a priority disease with an urgent need for therapeutic development by World Health Organization. The monoclonal antibody m102.4 binds to the immunodominant NiV receptor-binding glycoprotein (GP), and potently neutralizes NiV, indicating its potential as a therapeutic agent. Although the co-crystal structure of m102.3, an m102.4 derivative, in complex with the GP of the related Hendra Virus (HeV) has been solved, the structural interaction between m102.4 and NiV is uncharacterized. Herein, we used structure-guided alanine-scanning mutagenesis to map the functional epitope and paratope residues that govern the antigen-antibody interaction. Our results revealed that the binding of m102.4 is mediated predominantly by two residues in the HCDR3 region, which is unusually small for an antibody-antigen interaction. We performed computational docking to generate a structural model of m102.4-NiV interaction. Our model indicates that m102.4 targets the common hydrophobic central cavity and a hydrophilic rim on the GP, as observed for the m102.3-HeV co-crystal, albeit with Fv orientation differences. In summary, our study provides insight into the m102.4-NiV interaction, demonstrating that structure-guided alanine-scanning and computational modeling can serve as the starting point for additional antibody reengineering (e.g. affinity maturation) to generate potential therapeutic candidates.
Asunto(s)
Alanina/genética , Anticuerpos Monoclonales/metabolismo , Simulación por Computador , Glicoproteínas/metabolismo , Infecciones por Henipavirus/virología , Virus Nipah/metabolismo , Proteínas del Envoltorio Viral/metabolismo , Alanina/química , Animales , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/química , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/metabolismo , Complejo Antígeno-Anticuerpo/química , Complejo Antígeno-Anticuerpo/inmunología , Complejo Antígeno-Anticuerpo/metabolismo , Epítopos/inmunología , Glicoproteínas/química , Glicoproteínas/genética , Infecciones por Henipavirus/inmunología , Infecciones por Henipavirus/metabolismo , Humanos , Mutagénesis Sitio-Dirigida , Virus Nipah/inmunología , Virus Nipah/aislamiento & purificación , Elementos Estructurales de las Proteínas/inmunología , Proteínas del Envoltorio Viral/química , Proteínas del Envoltorio Viral/genéticaRESUMEN
Hendra virus (HeV) and Nipah virus (NiV) are bat-borne zoonotic para-myxoviruses identified in the mid- to late 1990s in outbreaks of severe disease in livestock and people in Australia and Malaysia, respectively. HeV repeatedly re-emerges in Australia while NiV continues to cause outbreaks in South Asia (Bangladesh and India), and these viruses have remained transboundary threats. In people and several mammalian species, HeV and NiV infections present as a severe systemic and often fatal neurologic and/or respiratory disease. NiV stands out as a potential pandemic threat because of its associated high case-fatality rates and capacity for human-to-human transmission. The development of effective vaccines, suitable for people and livestock, against HeV and NiV has been a research focus. Here, we review the progress made in NiV and HeV vaccine development, with an emphasis on those approaches that have been tested in established animal challenge models of NiV and HeV infection and disease.
Asunto(s)
Enfermedades Transmisibles Emergentes/prevención & control , Virus Hendra/inmunología , Infecciones por Henipavirus/prevención & control , Virus Nipah/inmunología , Vacunas Virales/inmunología , Animales , Anticuerpos Antivirales/inmunología , Quirópteros/virología , Enfermedades Transmisibles Emergentes/inmunología , Enfermedades Transmisibles Emergentes/virología , Modelos Animales de Enfermedad , Infecciones por Henipavirus/inmunología , Humanos , Ratones , Zoonosis Virales/prevención & control , Zoonosis Virales/transmisiónRESUMEN
Nipah and Hendra viruses are highly pathogenic, zoonotic henipaviruses that encode proteins that inhibit the host's innate immune response. The W protein is one of four products encoded from the P gene and binds a number of host proteins to regulate signalling pathways. The W protein is intrinsically disordered, a structural attribute that contributes to its diverse host protein interactions. Here, we review the role of W in innate immune suppression through inhibition of both pattern recognition receptor (PRR) pathways and interferon (IFN)-responsive signalling. PRR stimulation leading to activation of IRF-3 and IFN release is blocked by henipavirus W, and unphosphorylated STAT proteins are sequestered within the nucleus of host cells by W, thereby inhibiting the induction of IFN stimulated genes. We examine the critical role of nuclear transport in multiple functions of W and how specific binding of importin-alpha (Impα) isoforms, and the 14-3-3 group of regulatory proteins suggests further modulation of these processes. Overall, the disordered nature and multiple functions of W warrant further investigation to understand henipavirus pathogenesis and may reveal insights aiding the development of novel therapeutics.
Asunto(s)
Transporte Activo de Núcleo Celular/inmunología , Virus Hendra/metabolismo , Infecciones por Henipavirus/inmunología , Proteínas Intrínsecamente Desordenadas/metabolismo , Virus Nipah/metabolismo , Membrana Nuclear/metabolismo , Transducción de Señal/inmunología , Proteínas Virales/metabolismo , Infecciones por Henipavirus/metabolismo , Infecciones por Henipavirus/virología , Interacciones Microbiota-Huesped/inmunología , Humanos , Inmunidad Innata , Interferones/metabolismo , Proteínas Intrínsecamente Desordenadas/química , Receptores de Reconocimiento de Patrones/metabolismo , Proteínas Virales/químicaRESUMEN
Kaposi's sarcoma-associated herpesvirus (KSHV) and Epstein-Barr Virus (EBV) establish life-long infections and are associated with malignancies. Striking geographic variation in incidence and the fact that virus alone is insufficient to cause disease, suggests other co-factors are involved. Here we present epidemiological analysis and genome-wide association study (GWAS) in 4365 individuals from an African population cohort, to assess the influence of host genetic and non-genetic factors on virus antibody responses. EBV/KSHV co-infection (OR = 5.71(1.58-7.12)), HIV positivity (OR = 2.22(1.32-3.73)) and living in a more rural area (OR = 1.38(1.01-1.89)) are strongly associated with immunogenicity. GWAS reveals associations with KSHV antibody response in the HLA-B/C region (p = 6.64 × 10-09). For EBV, associations are identified for VCA (rs71542439, p = 1.15 × 10-12). Human leucocyte antigen (HLA) and trans-ancestry fine-mapping substantiate that distinct variants in HLA-DQA1 (p = 5.24 × 10-44) are driving associations for EBNA-1 in Africa. This study highlights complex interactions between KSHV and EBV, in addition to distinct genetic architectures resulting in important differences in pathogenesis and transmission.