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1.
Sci Adv ; 10(41): eado7035, 2024 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-39392890

RESUMO

Foamy viruses (FVs) constitute a subfamily of retroviruses. Their envelope (Env) glycoprotein drives the merger of viral and cellular membranes during entry into cells. The only available structures of retroviral Envs are those from human and simian immunodeficiency viruses from the subfamily of orthoretroviruses, which are only distantly related to the FVs. We report the cryo-electron microscopy structures of the FV Env ectodomain in the pre- and post-fusion states, which unexpectedly demonstrate structural similarity with the fusion protein (F) of paramyxo- and pneumoviruses, implying an evolutionary link between the viral fusogens. We describe the structural features that are unique to the FV Env and propose a mechanistic model for its conformational change, highlighting how the interplay of its structural elements could drive membrane fusion and viral entry. The structural knowledge on the FV Env now provides a framework for functional investigations, which can benefit the design of FV Env variants with improved features for use as gene therapy vectors.


Assuntos
Microscopia Crioeletrônica , Spumavirus , Proteínas Virais de Fusão , Proteínas Virais de Fusão/química , Proteínas Virais de Fusão/metabolismo , Proteínas Virais de Fusão/genética , Spumavirus/genética , Spumavirus/ultraestrutura , Humanos , Internalização do Vírus , Modelos Moleculares , Pneumovirus/metabolismo , Pneumovirus/química , Conformação Proteica , Fusão de Membrana , Paramyxoviridae/genética , Paramyxoviridae/metabolismo , Animais
2.
J Virol ; 98(9): e0080924, 2024 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-39177356

RESUMO

Small hydrophobic (SH) proteins are a class of viral accessory proteins expressed by many members of the negative-stranded RNA viral families Paramyxoviridae and Pneumoviridae. Identified SH proteins are type I or II transmembrane (TM) proteins with a single-pass TM domain. Little is known about the functions of SH proteins; however, several possess viroporin activity, enhancing membrane permeability of infected cells or those expressing SH protein. Moreover, several SH proteins inhibit apoptosis and immune signaling pathways within infected cells, including TNF and interferon signaling, or activate inflammasomes. SH proteins are generally nonessential for viral replication in vitro, but loss of SH is often associated with reduced replication in vivo, suggesting a role in enhancing viral replication or evading host immunity. Analogous proteins are expressed by a variety of pathogens of public health importance; thus, understanding the functional importance and mechanisms of SH proteins provides insight into the pathogenesis and replication of negative-sense RNA viruses.


Assuntos
Paramyxoviridae , Proteínas Virais , Replicação Viral , Humanos , Paramyxoviridae/metabolismo , Paramyxoviridae/fisiologia , Proteínas Virais/metabolismo , Proteínas Virais/genética , Animais , Apoptose , Pneumovirus/metabolismo , Pneumovirus/fisiologia , Transdução de Sinais , Proteínas Oncogênicas de Retroviridae
3.
Antimicrob Agents Chemother ; 68(10): e0080024, 2024 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-39162479

RESUMO

Small-molecule antivirals can be used as chemical probes to stabilize transitory conformational stages of viral target proteins, facilitating structural analyses. Here, we evaluate allosteric pneumo- and paramyxovirus polymerase inhibitors that have the potential to serve as chemical probes and aid the structural characterization of short-lived intermediate conformations of the polymerase complex. Of multiple inhibitor classes evaluated, we discuss in-depth distinct scaffolds that were selected based on well-understood structure-activity relationships, insight into resistance profiles, biochemical characterization of the mechanism of action, and photoaffinity-based target mapping. Each class is thought to block structural rearrangements of polymerase domains albeit target sites and docking poses are distinct. This review highlights validated druggable targets in the paramyxo- and pneumovirus polymerase proteins and discusses discrete structural stages of the polymerase complexes required for bioactivity.


Assuntos
Antivirais , Pneumovirus , Antivirais/farmacologia , Antivirais/química , Relação Estrutura-Atividade , Pneumovirus/efeitos dos fármacos , Humanos , RNA Polimerase Dependente de RNA/antagonistas & inibidores , RNA Polimerase Dependente de RNA/química , RNA Polimerase Dependente de RNA/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/química , Proteínas Virais/antagonistas & inibidores , Proteínas Virais/metabolismo , Proteínas Virais/química
4.
N Z Vet J ; 72(4): 191-200, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38650102

RESUMO

AIMS: To isolate canine respiratory coronavirus (CRCoV) and canine pneumovirus (CnPnV) in cell culture and to compare partial genomic sequences of CRCoV and CnPnV from New Zealand with those from other countries. METHODS: Oropharyngeal swab samples from dogs affected by canine infectious respiratory disease syndrome that were positive for CnPnV (n = 15) or CRCoV (n = 1) by virus-specific reverse transcriptase quantitative PCR (RT-qPCR) in a previous study comprised the starting material. Virus isolation was performed in HRT-18 cells for CRCoV and RAW 264.7 and Vero cells for CnPnV. The entire sequence of CnPnV G protein (1,266 nucleotides) and most (8,063/9,707 nucleotides) of the 3' region of CRCoV that codes for 10 structural and accessory proteins were amplified and sequenced. The sequences were analysed and compared with other sequences available in GenBank using standard molecular tools including phylogenetic analysis. RESULTS: Virus isolation was unsuccessful for both CRCoV and CnPnV. Pneumovirus G protein was amplified from 3/15 (20%) samples that were positive for CnPnV RNA by RT-qPCR. Two of these (NZ-048 and NZ-049) were 100% identical to each other, and 90.9% identical to the third one (NZ-007). Based on phylogenetic analysis of the G protein gene, CnPnV NZ-048 and NZ-049 clustered with sequences from the USA, Thailand and Italy in group A, and CnPnV NZ-007 clustered with sequences from the USA in group B. The characteristics of the predicted genes (length, position) and their putative protein products (size, predicted structure, presence of N- and O-glycosylation sites) of the New Zealand CRCoV sequence were consistent with those reported previously, except for the region located between open reading frame (ORF)3 (coding for S protein) and ORF6 (coding for E protein). The New Zealand virus was predicted to encode 5.9 kDa, 27 kDa and 12.7 kDa proteins, which differed from the putative coding capacity of this region reported for CRCoV from other countries. CONCLUSIONS: This report represents the first characterisation of partial genomic sequences of CRCoV and CnPnV from New Zealand. Our results suggest that the population of CnPnV circulating in New Zealand is not homogeneous, and that the viruses from two clades described overseas are also present here. Limited conclusions can be made based on only one CRCoV sequence, but the putative differences in the coding capacity of New Zealand CRCoV support the previously reported variability of this region. The reasons for such variability and its biological implications need to be further elucidated.


Assuntos
Coronavirus Canino , Doenças do Cão , Genoma Viral , Filogenia , Pneumovirus , Animais , Cães , Nova Zelândia/epidemiologia , Coronavirus Canino/genética , Coronavirus Canino/classificação , Coronavirus Canino/isolamento & purificação , Doenças do Cão/virologia , Doenças do Cão/epidemiologia , Pneumovirus/genética , Pneumovirus/classificação , Infecções por Coronavirus/veterinária , Infecções por Coronavirus/virologia , Infecções por Coronavirus/epidemiologia , Células Vero , Chlorocebus aethiops
5.
Viruses ; 15(12)2023 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-38140612

RESUMO

Novel swine orthopneumovirus (SOV) infections have been identified in pigs in the USA and some European countries but not in Asian countries, including South Korea, to date. The current study reports the first SOV infections in four domestic pig farms located in four provinces across South Korea. The detection rate of SOV in oral fluid samples using qRT-PCR was 4.4% (14/389), indicating the presence of the virus in pigs at commercial farms in Korea. Two complete genome sequences and one glycoprotein (G) gene sequence were obtained from SOV-positive samples. The complete genome analysis of KSOV-2201 and KSOV-2202 strains showed 98.2 and 95.4% homologies with a previously reported SOV, and the phylogenetic tree exhibited a high correlation with a previously reported SOV strain from the US and a canine pneumovirus (CPnV) strain from China. Based on the genetic analysis of the viral G gene, the murine pneumonia virus (MPV)-like orthopneumoviruses (MLOVs) were divided into two genogroups (G1 and G2). Seventeen CPnVs and two feline pneumoviruses were grouped into G1, while the Korean SOV strains identified in this study were grouped into G2 along with one SOV and two CPnVs. These results will contribute to expanding our understanding of the geographical distribution and genetic characteristics of the novel SOV in the global pig population.


Assuntos
Pneumovirus , Doenças dos Suínos , Camundongos , Suínos , Animais , Gatos , Cães , Sus scrofa , Vírus Sinciciais Respiratórios , Fazendas , Filogenia , Doenças dos Suínos/epidemiologia , República da Coreia/epidemiologia
6.
PLoS One ; 18(9): e0291433, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37708173

RESUMO

INTRODUCTION: Low- and middle-income countries carry the largest burden of Respiratory syncytial virus (RSV) disease, with most deaths occurring in these settings. This study aimed to investigate the burden of RSV disease in South African children hospitalised with lower respiratory tract infection (LRTI), with specific reference to incidence, risk factors, and co-infections. METHODS: A database from a previous prospective study containing demographic, laboratory and clinical data on children hospitalised with LRTIs in Cape Town, South Africa, was used. A nasopharyngeal swab (NP) and induced sputum (IS) were tested for RSV PCR. Descriptive statistics were used to characterise the study population, and a multivariable analysis of risk factors and co-infections was done. RESULTS: RSV was detected in 142 (30.9%; 95% CI 26.7-35.3) of the included 460 study children with LRTI. The median age of RSV-positive children was 4.6 (IQR 2.4-9.7) months compared to RSV-negative children of 10.5 (IQR 4.4-21.3) months, P = <0.001. Most cases occurred in autumn and winter with 126 (89%) cases over this period. IS demonstrated greater sensitivity for RSV diagnosis with 135 cases (95.1%) detected on IS and 57 cases (40.1%) identified on NP; P<0.001. The median length of hospital stay was 3.3 (SD 4.2) days in the RSV positive group and 2.7 (SD 3.3) days in the RSV negative group; P<0.001. The median number of detected viral pathogens was 1 (IQR 0-2) in RSV-positive children (when RSV was excluded from the count) compared to 2 (IQR 2-3) in RSV negative children; P<0.001. The presence of RSV was independently associated with a reduction in the frequency of most viruses tested for on PCR. CONCLUSIONS: RSV is common in children hospitalised with LRTI and mainly affects younger children. There is an urgent need to find an effective vaccine to prevent RSV pneumonia in children worldwide, especially in LMICs that carry the greatest burden of disease.


Assuntos
Coinfecção , Pneumovirus , Infecções por Vírus Respiratório Sincicial , Infecções Respiratórias , Humanos , Criança , Lactente , África do Sul/epidemiologia , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções Respiratórias/epidemiologia , Vírus Sinciciais Respiratórios
7.
Emerg Microbes Infect ; 12(2): 2239938, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37470510

RESUMO

Respiratory disease is a significant economic issue in pig farming, with a complex aetiology that includes swine influenza A viruses (swIAV), which are common in European domestic pig populations. The most recent human influenza pandemic in 2009 showed swIAV's zoonotic potential. Monitoring pathogens and disease control are critical from a preventive standpoint, and are based on quick, sensitive, and specific diagnostic assays capable of detecting and distinguishing currently circulating swIAV in clinical samples. For passive surveillance, a set of multiplex quantitative reverse transcription real-time PCRs (mRT-qPCR) and MinION-directed sequencing was updated and deployed. Several lineages and genotypes of swIAV were shown to be dynamically developing, including novel reassortants between human pandemic H1N1 and the avian-derived H1 lineage of swIAV. Despite this, nearly 70% (842/1216) of individual samples from pigs with respiratory symptoms were swIAV-negative, hinting to different aetiologies. The complex and synergistic interactions of swIAV infections with other viral and bacterial infectious agents contribute to the aggravation of pig respiratory diseases. Using a newly developed mRT-qPCR for the combined detection of swIAV and the recently described porcine respirovirus 1 (PRV1) and swine orthopneumovirus (SOV) widespread co-circulation of PRV1 (19.6%, 238/1216 samples) and SOV (14.2%, 173/1216 samples) was evident. Because of the high incidence of PRV1 and SOV infections in pigs with respiratory disease, these viruses may emerge as new allies in the porcine respiratory disease syndrome.


Assuntos
Infecções por Orthomyxoviridae , Infecções por Pneumovirus , Doenças Respiratórias , Infecções por Respirovirus , Doenças dos Suínos , Alemanha/epidemiologia , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/virologia , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/veterinária , Vírus da Influenza A/genética , Respirovirus/genética , Infecções por Respirovirus/epidemiologia , Infecções por Respirovirus/veterinária , Doenças Respiratórias/veterinária , Doenças Respiratórias/virologia , Infecções por Pneumovirus/epidemiologia , Infecções por Pneumovirus/veterinária , Pneumovirus/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Reação em Cadeia da Polimerase em Tempo Real , Filogenia
8.
Front Cell Infect Microbiol ; 13: 1125135, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37153148

RESUMO

Acute respiratory infections are a group of diseases caused by viruses, bacteria, and parasites that mainly affect children until the age of 5 and immunocompromised senior adults. In Mexico, these infections are the main cause of morbidity in children, with more than 26 million cases of respiratory infections reported by the Secretariat of Health, in 2019. The human respiratory syncytial virus (hRSV), the human metapneumovirus (hMPV), and the human parainfluenza-2 (hPIV-2) are responsible for many respiratory infections. Currently, palivizumab, a monoclonal antibody against the fusion protein F, is the treatment of choice against hRSV infections. This protein is being studied for the design of antiviral peptides that act by inhibiting the fusion of the virus and the host cell. Therefore, we examined the antiviral activity of the HRA2pl peptide, which competes the heptad repeat A domain of the F protein of hMPV. The recombinant peptide was obtained using a viral transient expression system. The effect of the fusion peptide was evaluated with an in vitro entry assay. Moreover, the effectiveness of HRA2pl was examined in viral isolates from clinical samples obtained from patients with infections caused by hRSV, hMPV, or hPIV-2, by evaluating the viral titer and the syncytium size. The HRA2pl peptide affected the viruses' capacity of entry, resulting in a 4-log decrease in the viral titer compared to the untreated viral strains. Additionally, a 50% reduction in the size of the syncytium was found. These results demonstrate the antiviral potential of HRA2pl in clinical samples, paving the way toward clinical trials.


Assuntos
Metapneumovirus , Infecções por Paramyxoviridae , Pneumovirus , Vírus Sincicial Respiratório Humano , Infecções Respiratórias , Criança , Adulto , Humanos , Antivirais/uso terapêutico , Infecções por Paramyxoviridae/tratamento farmacológico , Peptídeos/farmacologia , Peptídeos/química , Infecções Respiratórias/tratamento farmacológico
9.
Front Immunol ; 13: 1044621, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36451824

RESUMO

Rhinovirus (RV) and respiratory syncytial virus (RSV) are common causes of bronchiolitis. Unlike an RSV etiology, an RV etiology is associated with a markedly increased risk of asthma. We investigated the cytokine profiles of RV- and RSV-induced first wheezing episode and their correlation with prognosis. We recruited 52 sole RV- and 11 sole RSV-affected children with a severe first wheezing episode. Peripheral blood mononuclear cells (PBMCs) were isolated during acute illness and 2 weeks later and stimulated in vitro with anti-CD3/anti-CD28. Culture medium samples were analyzed for 56 different cytokines by multiplex ELISA. Recurrences were prospectively followed for 4 years. In adjusted analyses, the cytokine response from PBMCs in the RV group was characterized by decreased expression of interleukin 1 receptor antagonist (IL-1RA), interleukin 1 beta (IL-1ß), and monocyte chemoattractant protein-1 (MCP-1) and increased expression of eosinophil chemotactic protein 2 (eotaxin-2), thymus- and activation-regulated chemokine (TARC), and epithelial-derived neutrophil-activating peptide 78 (ENA-78) in the acute phase and increased expression of fractalkine in the convalescent phase compared to those in the RSV group. An analysis of the change in cytokine expression between study points revealed an increased expression of fractalkine and IL-1ß and decreased expression of I-309 (CCL1) and TARC in the RV group compared to those in the RSV group.. Considering hospitalization time, a significant non-adjusted group × cytokine interaction was observed in the levels of interferon gamma (IFN-γ), macrophage-derived chemokine (MDC), IL-1RA, and vascular endothelial growth factor (VEGF), indicating that a higher expression of cytokine was associated with shorter hospitalization time in the RSV group but not in the RV group. A significant interaction was also found in interleukin 6 (IL-6), but the cytokine response was not associated with hospitalization time in the RSV or RV group. In the RV group, increased expression of I-309 (CCL1) and TARC was associated with fewer relapses within 2 months, and decreased expression of interleukin 13 (IL-13) and increased expression of I-309 (CCL1) were associated with less relapses within 12 months. Differences in cytokine response from PBMCs were observed between RV- and RSV-induced first severe wheezing episode. Our findings also reveal new biomarkers for short- and medium-term prognosis in first-time wheezing children infected with RV or RSV.


Assuntos
Infecções por Enterovirus , Pneumovirus , Vírus Sincicial Respiratório Humano , Criança , Humanos , Rhinovirus , Sons Respiratórios , Citocinas , Quimiocina CX3CL1 , Leucócitos Mononucleares , Proteína Antagonista do Receptor de Interleucina 1 , Fator A de Crescimento do Endotélio Vascular , Interleucina-6 , Recidiva
10.
Sci Transl Med ; 14(650): eabo5032, 2022 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-35731888

RESUMO

Respiratory syncytial virus (RSV) is a substantial cause of morbidity and mortality globally. A candidate RSV prefusion (pre-F)-stabilized subunit vaccine, DS-Cav1, has previously been shown to elicit potent and durable neutralizing activity in a phase 1 clinical trial in healthy adults. Here, we used fluorescently labeled probes and flow cytometry to evaluate the antigen specificity and phenotype of RSV F-specific B cells longitudinally after DS-Cav1 immunization. Peripheral blood mononuclear cells (PBMCs) collected at time points before the first immunization through the end of the trial at 44 weeks were assessed by flow cytometry. Our data demonstrate a rapid increase in the frequency of pre-F-specific IgG+ and IgA+ B cells after the first immunization and a modest increase after a second immunization at week 12. Nearly all F-specific B cells down-regulated CD21 and up-regulated the proliferation marker CD71 after the first immunization, with less pronounced activation after the second immunization. Memory B cells (CD27+CD21+) specific for pre-F remained elevated above baseline at 44 weeks after vaccination. DS-Cav1 vaccination also activated human metapneumovirus (HMPV) cross-reactive B cells capable of binding prefusion-stabilized HMPV F protein and increased HMPV F-binding antibodies and neutralizing activity for HMPV in some participants. In summary, vaccination with RSV pre-F resulted in the expansion and activation of RSV and HMPV F-specific B cells that were maintained above baseline for at least 10 months and could contribute to long-term pneumovirus immunity.


Assuntos
Pneumovirus , Infecções por Vírus Respiratório Sincicial , Vacinas contra Vírus Sincicial Respiratório , Vírus Sincicial Respiratório Humano , Anticorpos Neutralizantes , Anticorpos Antivirais , Humanos , Leucócitos Mononucleares , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Vírus Sincicial Respiratório Humano/genética , Proteínas Virais de Fusão/genética
11.
Viruses ; 14(1)2022 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-35062301

RESUMO

Human respiratory syncytial virus (hRSV) infection brings a wide spectrum of clinical outcomes, from a mild cold to severe bronchiolitis or even acute interstitial pneumonia. Among the known factors influencing this clinical diversity, genetic background has often been mentioned. In parallel, recent evidence has also pointed out that an early infectious experience affects heterologous infections severity. Here, we analyzed the importance of these two host-related factors in shaping the immune response in pneumoviral disease. We show that a prior gammaherpesvirus infection improves, in a genetic background-dependent manner, the immune system response against a subsequent lethal dose of pneumovirus primary infection notably by inducing a systematic expansion of the CD8+ bystander cell pool and by modifying the resident alveolar macrophages (AMs) phenotype to induce immediate cyto/chemokinic responses upon pneumovirus exposure, thereby drastically attenuating the host inflammatory response without affecting viral replication. Moreover, we show that these AMs present similar rapid and increased production of neutrophil chemokines both in front of pneumoviral or bacterial challenge, confirming recent studies attributing a critical antibacterial role of primed AMs. These results corroborate other recent studies suggesting that the innate immunity cells are themselves capable of memory, a capacity hitherto reserved for acquired immunity.


Assuntos
Patrimônio Genético , Infecções por Herpesviridae/imunologia , Macrófagos Alveolares/imunologia , Infecções por Pneumovirus/imunologia , Pneumovirus/imunologia , Rhadinovirus/imunologia , Animais , Linfócitos T CD8-Positivos/imunologia , Citocinas/metabolismo , Feminino , Infecções por Herpesviridae/genética , Infecções por Herpesviridae/patologia , Infecções por Herpesviridae/virologia , Imunidade Inata , Inflamação/imunologia , Pulmão/imunologia , Pulmão/patologia , Pulmão/virologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Monócitos/imunologia , Infecções Pneumocócicas/imunologia , Pneumovirus/fisiologia , Infecções por Pneumovirus/genética , Infecções por Pneumovirus/patologia , Infecções por Pneumovirus/virologia , Rhadinovirus/fisiologia
12.
mBio ; 12(6): e0262121, 2021 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-34724816

RESUMO

Multiple enveloped RNA viruses of the family Paramyxoviridae and Pneumoviridae, like measles virus (MeV), Nipah virus (NiV), canine distemper virus (CDV), or respiratory syncytial virus (RSV), are of high clinical relevance. Each year a huge number of lives are lost as a result of these viral infections. Worldwide, MeV infection alone is responsible for over a hundred thousand deaths each year despite available vaccine. Therefore, there is an urgent need for treatment options to counteract these viral infections. The development of antiviral drugs in general stands as a huge challenge due to the rapid emergence of viral escape mutants. Here, we disclose the discovery of a small-molecule antiviral, compound 1 (ZHAWOC9045), active against several pneumo-/paramyxoviruses, including MeV, NiV, CDV, RSV, and parainfluenza virus type 5 (PIV-5). A series of mechanistic characterizations revealed that compound 1 targets a host factor which is indispensable for viral genome replication. Drug resistance profiling against a paramyxovirus model (CDV) demonstrated no detectable adaptation despite prolonged time of investigation, thereby mitigating the rapid emergence of escape variants. Furthermore, a thorough structure-activity relationship analysis of compound 1 led to the invention of 100-times-more potent-derivatives, e.g., compound 2 (ZHAWOC21026). Collectively, we present in this study an attractive host-directed pneumoviral/paramyxoviral replication inhibitor with potential therapeutic application. IMPORTANCE Measles virus, respiratory syncytial virus, canine distemper virus, and Nipah virus are some of the clinically significant RNA viruses that threaten substantial number of lives each year. Limited to no availability of treatment options for these viral infections makes it arduous to handle the outbreaks. This highlights the major importance of developing antivirals to fight not only ongoing infections but also potential future epidemics. Most of the discovered antivirals, in clinical trials currently, are virus targeted, which consequently poses the challenge of rapid emergence of escape variants. Here, we present compound 1 (ZHAWOC9045), discovered to target viral replication in a host-dependent manner, thereby exhibiting broad-spectrum activity against several members of the family Pneumo-/Paramyxoviridae. The inability of viruses to mutate against the inhibitor mitigated the critical issue of generation of escape variants. Importantly, compound 1 was successfully optimized to a highly potent variant, compound 2 (ZHAWOC21026), with a promising profile for pharmacological intervention.


Assuntos
Antivirais/farmacologia , Paramyxoviridae/fisiologia , Pneumovirus/fisiologia , Replicação Viral/efeitos dos fármacos , Antivirais/química , Descoberta de Drogas , Humanos , Paramyxoviridae/genética , Infecções por Paramyxoviridae/tratamento farmacológico , Infecções por Paramyxoviridae/virologia , Pneumovirus/genética , Infecções por Pneumovirus/tratamento farmacológico , Infecções por Pneumovirus/virologia
13.
Int J Mol Sci ; 22(4)2021 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-33546457

RESUMO

Mononegavirales phosphoproteins (P) are essential co-factors of the viral polymerase by serving as a linchpin between the catalytic subunit and the ribonucleoprotein template. They have highly diverged, but their overall architecture is conserved. They are multidomain proteins, which all possess an oligomerization domain that separates N- and C-terminal domains. Large intrinsically disordered regions constitute their hallmark. Here, we exemplify their structural features and interaction potential, based on the Pneumoviridae P proteins. These P proteins are rather small, and their oligomerization domain is the only part with a defined 3D structure, owing to a quaternary arrangement. All other parts are either flexible or form short-lived secondary structure elements that transiently associate with the rest of the protein. Pneumoviridae P proteins interact with several viral and cellular proteins that are essential for viral transcription and replication. The combination of intrinsic disorder and tetrameric organization enables them to structurally adapt to different partners and to act as adaptor-like platforms to bring the latter close in space. Transient structures are stabilized in complex with protein partners. This class of proteins gives an insight into the structural versatility of non-globular intrinsically disordered protein domains.


Assuntos
Modelos Moleculares , Fosfoproteínas/química , Fosfoproteínas/metabolismo , Pneumovirus/metabolismo , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteínas Virais/química , Proteínas Virais/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Regulação Viral da Expressão Gênica , Humanos , Proteínas Intrinsicamente Desordenadas/química , Proteínas Intrinsicamente Desordenadas/metabolismo , Mononegavirais , Fosfoproteínas/genética , Pneumovirus/genética , Ligação Proteica , Dobramento de Proteína , Vírus Sincicial Respiratório Humano , Relação Estrutura-Atividade , Proteínas Virais/genética
14.
Viral Immunol ; 34(1): 18-26, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32429800

RESUMO

The resolution revolution of cryo-electron microscopy (cryo-EM) has made a significant impact on the structural analysis of the Pneumoviridae multifunctional RNA polymerases. In recent months, several high-resolution structures of apo RNA polymerases of Pneumoviridae, which includes the human respiratory syncytial virus (HRSV) and human metapneumovirus (HMPV), have been determined by single-particle cryo-EM. These structures illustrated high similarities and minor differences between the Pneumoviridae polymerases and revealed the potential mechanisms of the Pneumoviridae RNA synthesis.


Assuntos
Microscopia Crioeletrônica , RNA Polimerases Dirigidas por DNA/ultraestrutura , Pneumovirus/enzimologia , Humanos , Vírus Sincicial Respiratório Humano/enzimologia
15.
Viruses ; 12(12)2020 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-33276587

RESUMO

The paramyxo- and pneumovirus family includes a wide range of viruses that can cause respiratory and/or systemic infections in humans and animals. The significant disease burden of these viruses is further exacerbated by the limited therapeutics that are currently available. Host cellular proteins that can antagonize or limit virus replication are therefore a promising area of research to identify candidate molecules with the potential for host-targeted therapies. Host proteins known as host cell restriction factors are constitutively expressed and/or induced in response to virus infection and include proteins from interferon-stimulated genes (ISGs). Many ISG proteins have been identified but relatively few have been characterized in detail and most studies have focused on studying their antiviral activities against particular viruses, such as influenza A viruses and human immunodeficiency virus (HIV)-1. This review summarizes current literature regarding host cell restriction factors against paramyxo- and pneumoviruses, on which there is more limited data. Alongside discussion of known restriction factors, this review also considers viral countermeasures in overcoming host restriction, the strengths and limitations in different experimental approaches in studies reported to date, and the challenges in reconciling differences between in vitro and in vivo data. Furthermore, this review provides an outlook regarding the landscape of emerging technologies and tools available to study host cell restriction factors, as well as the suitability of these proteins as targets for broad-spectrum antiviral therapeutics.


Assuntos
Interações Hospedeiro-Patógeno , Infecções por Paramyxoviridae/virologia , Paramyxovirinae/fisiologia , Infecções por Pneumovirus/virologia , Pneumovirus/fisiologia , Animais , Biomarcadores , Regulação Viral da Expressão Gênica , Especificidade de Hospedeiro , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Imunidade Inata , Infecções por Paramyxoviridae/genética , Infecções por Paramyxoviridae/metabolismo , Infecções por Pneumovirus/genética , Infecções por Pneumovirus/metabolismo , Tropismo Viral , Replicação Viral
16.
PLoS Pathog ; 16(10): e1008942, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33035266

RESUMO

Human metapneumovirus (hMPV) is a leading cause of viral respiratory infection in children, and can cause severe lower respiratory tract infection in infants, the elderly, and immunocompromised patients. However, there remain no licensed vaccines or specific treatments for hMPV infection. Although the hMPV fusion (F) protein is the sole target of neutralizing antibodies, the immunological properties of hMPV F remain poorly understood. To further define the humoral immune response to the hMPV F protein, we isolated two new human monoclonal antibodies (mAbs), MPV458 and MPV465. Both mAbs are neutralizing in vitro and were determined to target a unique antigenic site using competitive biolayer interferometry. We determined both MPV458 and MPV465 have higher affinity for monomeric hMPV F than trimeric hMPV F. MPV458 was co-crystallized with hMPV F, and the mAb primarily interacts with an alpha helix on the F2 region of the hMPV F protein. Surprisingly, the major epitope for MPV458 lies within the trimeric interface of the hMPV F protein, suggesting significant breathing of the hMPV F protein must occur for host immune recognition of the novel epitope. In addition, significant glycan interactions were observed with a somatically mutated light chain framework residue. The data presented identifies a novel epitope on the hMPV F protein for epitope-based vaccine design, and illustrates a new mechanism for human antibody neutralization of viral glycoproteins.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Pneumovirus/imunologia , Anticorpos Neutralizantes/farmacologia , Epitopos/imunologia , Humanos , Metapneumovirus/imunologia , Infecções por Paramyxoviridae/virologia , Vírus Sincicial Respiratório Humano/imunologia , Proteínas Virais de Fusão/imunologia
18.
Mucosal Immunol ; 13(5): 799-813, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32424182

RESUMO

Human respiratory syncytial virus (RSV) is a pneumovirus that causes severe infections in infants worldwide. Despite intensive research, safe and effective vaccines against RSV have remained elusive. The main reason is that RSV infection of children previously immunized with formalin-inactivated-RSV vaccines has been associated with exacerbated pathology, a phenomenon called RSV vaccine-enhanced respiratory disease. In parallel, despite the high RSV prevalence, only a minor proportion of children develop severe diseases. Interestingly, variation in the immune responses against RSV or following RSV vaccination could be linked with differences of exposure to microbes during childhood. Gammaherpesviruses (γHVs), such as the Epstein-Barr virus, are persistent viruses that deeply influence the immune system of their host and could therefore affect the development of pneumovirus-induced immunopathologies for the long term. Here, we showed that a previous ɣHV infection protects against both pneumovirus vaccine-enhanced disease and pneumovirus primary infection and that CD8 T cells are essential for this protection. These observations shed a new light on the understanding of pneumovirus-induced diseases and open new perspectives for the development of vaccine strategies.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Suscetibilidade a Doenças , Gammaherpesvirinae/imunologia , Interações Hospedeiro-Patógeno/imunologia , Infecções por Pneumovirus/etiologia , Infecções por Pneumovirus/metabolismo , Pneumovirus/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Modelos Animais de Doenças , Humanos , Imunofenotipagem , Leucócitos/imunologia , Leucócitos/metabolismo , Leucócitos/patologia , Pulmão/imunologia , Pulmão/metabolismo , Pulmão/patologia , Camundongos , Interações Microbianas , Infecções por Pneumovirus/patologia , Infecções por Vírus Respiratório Sincicial/etiologia , Infecções por Vírus Respiratório Sincicial/metabolismo , Vírus Sincicial Respiratório Humano/imunologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Vacinação , Vacinas Virais/imunologia
19.
Viruses ; 12(3)2020 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-32245118

RESUMO

Paramyxoviruses and pneumoviruses infect cells through fusion (F) protein-mediated merger of the viral envelope with target membranes. Members of these families include a range of major human and animal pathogens, such as respiratory syncytial virus (RSV), measles virus (MeV), human parainfluenza viruses (HPIVs), and highly pathogenic Nipah virus (NiV). High-resolution F protein structures in both the metastable pre- and the postfusion conformation have been solved for several members of the families and a number of F-targeting entry inhibitors have progressed to advanced development or clinical testing. However, small-molecule RSV entry inhibitors have overall disappointed in clinical trials and viral resistance developed rapidly in experimental settings and patients, raising the question of whether the available structural information may provide a path to counteract viral escape through proactive inhibitor engineering. This article will summarize current mechanistic insight into F-mediated membrane fusion and examine the contribution of structural information to the development of small-molecule F inhibitors. Implications are outlined for future drug target selection and rational drug engineering strategies.


Assuntos
Antivirais/química , Antivirais/farmacologia , Descoberta de Drogas , Paramyxovirinae/fisiologia , Pneumovirus/fisiologia , Internalização do Vírus/efeitos dos fármacos , Animais , Sítios de Ligação , Descoberta de Drogas/métodos , Humanos , Modelos Moleculares , Infecções por Paramyxoviridae/tratamento farmacológico , Infecções por Paramyxoviridae/virologia , Paramyxovirinae/efeitos dos fármacos , Pneumovirus/efeitos dos fármacos , Infecções por Pneumovirus/tratamento farmacológico , Infecções por Pneumovirus/virologia , Ligação Proteica , Relação Estrutura-Atividade
20.
Front Immunol ; 10: 2778, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31849961

RESUMO

The pneumoviruses respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) are two widespread human pathogens that can cause severe disease in the young, the elderly, and the immunocompromised. Despite the discovery of RSV over 60 years ago, and hMPV nearly 20 years ago, there are no approved vaccines for either virus. Antibody-mediated immunity is critical for protection from RSV and hMPV, and, until recently, knowledge of the antibody epitopes on the surface glycoproteins of RSV and hMPV was very limited. However, recent breakthroughs in the recombinant expression and stabilization of pneumovirus fusion proteins have facilitated in-depth characterization of antibody responses and structural epitopes, and have provided an enormous diversity of new monoclonal antibody candidates for therapeutic development. These new data have primarily focused on the RSV F protein, and have led to a wealth of new vaccine candidates in preclinical and clinical trials. In contrast, the major structural antibody epitopes remain unclear for the hMPV F protein. Overall, this review will cover recent advances in characterizing the antigenic sites on the RSV and hMPV F proteins.


Assuntos
Anticorpos Antivirais/imunologia , Epitopos/imunologia , Infecções por Pneumovirus/epidemiologia , Infecções por Pneumovirus/imunologia , Pneumovirus/imunologia , Proteínas Virais de Fusão/imunologia , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/química , Antígenos Virais/química , Antígenos Virais/imunologia , Efeitos Psicossociais da Doença , Epitopos/química , Saúde Global , Humanos , Infecções por Pneumovirus/virologia , Ligação Proteica/imunologia , Vigilância em Saúde Pública , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções por Vírus Respiratório Sincicial/imunologia , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/imunologia , Relação Estrutura-Atividade , Proteínas Virais de Fusão/química
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