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International Journal of Biological... 2021Respiratory syncytial virus (RSV) is one of the most important viral pathogens causing respiratory tract infection in infants, the elderly and people with poor immune... (Review)
Review
Respiratory syncytial virus (RSV) is one of the most important viral pathogens causing respiratory tract infection in infants, the elderly and people with poor immune function, which causes a huge disease burden worldwide every year. It has been more than 60 years since RSV was discovered, and the palivizumab monoclonal antibody, the only approved specific treatment, is limited to use for passive immunoprophylaxis in high-risk infants; no other intervention has been approved to date. However, in the past decade, substantial progress has been made in characterizing the structure and function of RSV components, their interactions with host surface molecules, and the host innate and adaptive immune response to infection. In addition, basic and important findings have also piqued widespread interest among researchers and pharmaceutical companies searching for effective interventions for RSV infection. A large number of promising monoclonal antibodies and inhibitors have been screened, and new vaccine candidates have been designed for clinical evaluation. In this review, we first briefly introduce the structural composition, host cell surface receptors and life cycle of RSV virions. Then, we discuss the latest findings related to the pathogenesis of RSV. We also focus on the latest clinical progress in the prevention and treatment of RSV infection through the development of monoclonal antibodies, vaccines and small-molecule inhibitors. Finally, we look forward to the prospects and challenges of future RSV research and clinical intervention.
Topics: Antiviral Agents; Genome, Viral; Humans; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus, Human; Viral Vaccines
PubMed: 34671221
DOI: 10.7150/ijbs.64762 -
Viruses Sep 2023Respiratory syncytial virus (RSV) infections are a constant public health problem, especially in infants and older adults. Virtually all children will have been infected... (Review)
Review
Respiratory syncytial virus (RSV) infections are a constant public health problem, especially in infants and older adults. Virtually all children will have been infected with RSV by the age of two, and reinfections are common throughout life. Since antigenic variation, which is frequently observed among other respiratory viruses such as SARS-CoV-2 or influenza viruses, can only be observed for RSV to a limited extent, reinfections may result from short-term or incomplete immunity. After decades of research, two RSV vaccines were approved to prevent lower respiratory tract infections in older adults. Recently, the FDA approved a vaccine for active vaccination of pregnant women to prevent severe RSV disease in infants during their first RSV season. This review focuses on the host response to RSV infections mediated by epithelial cells as the first physical barrier, followed by responses of the innate and adaptive immune systems. We address possible RSV-mediated immunomodulatory and pathogenic mechanisms during infections and discuss the current vaccine candidates and alternative treatment options.
Topics: Infant; Child; Female; Pregnancy; Humans; Aged; Respiratory Syncytial Virus Infections; Reinfection; Respiratory Syncytial Viruses; Immunity; Vaccines; Respiratory Syncytial Virus Vaccines; Respiratory Syncytial Virus, Human
PubMed: 37896776
DOI: 10.3390/v15101999 -
EMBO Molecular Medicine Apr 2022In virology, the term seasonality describes variations in virus prevalence at more or less regular intervals throughout the year. Specifically, it has long been...
In virology, the term seasonality describes variations in virus prevalence at more or less regular intervals throughout the year. Specifically, it has long been recognized that outbreaks of human influenza viruses, respiratory syncytial virus (RSV), and human coronaviruses occur in temperate climates during the winter season, whereas low activity is detected during the summer months. Other human respiratory viruses, such as parainfluenza viruses, human metapneumoviruses, and rhinoviruses, show highest activity during the spring or fall season in temperate regions, depending on the virus and subtype. In tropical climates, influenza viruses circulate throughout the year and no distinct seasonal patterns are observed, although virus outbreaks tend to spike during the rainy season. Overall, seasonality is more pronounced with greater distance from the equator, and tends to be less pronounced in regions closer to the equator (Li et al, 2019).
Topics: Humans; Influenza, Human; Metapneumovirus; Orthomyxoviridae; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus, Human; Respiratory Tract Infections; Viruses
PubMed: 35157360
DOI: 10.15252/emmm.202115352 -
Cell Reports Jun 2022Emerging infectious diseases, especially if caused by bat-borne viruses, significantly affect public health and the global economy. There is an urgent need to understand... (Review)
Review
Emerging infectious diseases, especially if caused by bat-borne viruses, significantly affect public health and the global economy. There is an urgent need to understand the mechanism of interspecies transmission, particularly to humans. Viral genetics; host factors, including polymorphisms in the receptors; and ecological, environmental, and population dynamics are major parameters to consider. Here, we describe the taxonomy, geographic distribution, and unique traits of bats associated with their importance as virus reservoirs. Then, we summarize the origin, intermediate hosts, and the current understanding of interspecies transmission of Middle East respiratory syndrome coronavirus (MERS-CoV), severe acute respiratory syndrome coronavirus (SARS-CoV), SARS-CoV-2, Nipah, Hendra, Ebola, Marburg virus, and rotaviruses. Finally, the molecular interactions of viral surface proteins with host cell receptors are examined, and a comparison of these interactions in humans, intermediate hosts, and bats is conducted. This uncovers adaptive mutations in virus spike protein that facilitate cross-species transmission and risk factors associated with the emergence of novel viruses from bats.
Topics: Animals; COVID-19; Chiroptera; Filoviridae; Henipavirus; Humans; Rotavirus; SARS-CoV-2; Viruses
PubMed: 35679864
DOI: 10.1016/j.celrep.2022.110969 -
Clinical Infectious Diseases : An... Aug 2022To combat the coronavirus disease 2019 (COVID-19) pandemic, nonpharmaceutical interventions (NPIs) were implemented worldwide, which impacted a broad spectrum of acute... (Observational Study)
Observational Study
BACKGROUND
To combat the coronavirus disease 2019 (COVID-19) pandemic, nonpharmaceutical interventions (NPIs) were implemented worldwide, which impacted a broad spectrum of acute respiratory infections (ARIs).
METHODS
Etiologically diagnostic data from 142 559 cases with ARIs, who were tested for 8 viral pathogens (influenza virus [IFV], respiratory syncytial virus [RSV], human parainfluenza virus [HPIV], human adenovirus [HAdV], human metapneumovirus [HMPV], human coronavirus [HCoV], human bocavirus [HBoV], and human rhinovirus [HRV]) between 2012 and 2021, were analyzed to assess the changes in respiratory infections in China during the first COVID-19 pandemic year compared with pre-pandemic years.
RESULTS
Test-positive rates of all respiratory viruses decreased during 2020, compared to the average levels during 2012-2019, with changes ranging from -17.2% for RSV to -87.6% for IFV. Sharp decreases mostly occurred between February and August when massive NPIs remained active, although HRV rebounded to the historical level during the summer. While IFV and HMPV were consistently suppressed year-round, RSV, HPIV, HCoV, HRV, and HBoV resurged and went beyond historical levels during September 2020-January 2021, after NPIs were largely relaxed and schools reopened. Resurgence was more prominent among children <18 years and in northern China. These observations remain valid after accounting for seasonality and long-term trend of each virus.
CONCLUSIONS
Activities of respiratory viral infections were reduced substantially in the early phases of the COVID-19 pandemic, and massive NPIs were likely the main driver. Lifting of NPIs can lead to resurgence of viral infections, particularly in children.
Topics: COVID-19; Child; Human bocavirus; Humans; Metapneumovirus; Orthomyxoviridae; Pandemics; Parainfluenza Virus 1, Human; Respiratory Syncytial Virus, Human; Respiratory Tract Infections; Virus Diseases; Viruses
PubMed: 34788811
DOI: 10.1093/cid/ciab942 -
Journal of Virology Oct 2020, known as nonsegmented negative-sense (NNS) RNA viruses, are a class of pathogenic and sometimes deadly viruses that include rabies virus (RABV), human respiratory... (Review)
Review
, known as nonsegmented negative-sense (NNS) RNA viruses, are a class of pathogenic and sometimes deadly viruses that include rabies virus (RABV), human respiratory syncytial virus (HRSV), and Ebola virus (EBOV). Unfortunately, no effective vaccines and antiviral therapeutics against many are currently available. Viral polymerases have been attractive and major antiviral therapeutic targets. Therefore, polymerases have been extensively investigated for their structures and functions. mimic RNA synthesis of their eukaryotic counterparts by utilizing multifunctional RNA polymerases to replicate entire viral genomes and transcribe viral mRNAs from individual viral genes as well as synthesize 5' methylated cap and 3' poly(A) tail of the transcribed viral mRNAs. The catalytic subunit large protein (L) and cofactor phosphoprotein (P) constitute the polymerases. In this review, we discuss the shared and unique features of RNA synthesis, the monomeric multifunctional enzyme L, and the oligomeric multimodular adapter P of We outline the structural analyses of the polymerases since the first structure of the vesicular stomatitis virus (VSV) L protein determined in 2015 and highlight multiple high-resolution cryo-electron microscopy (cryo-EM) structures of the polymerases of , namely, VSV, RABV, HRSV, human metapneumovirus (HMPV), and human parainfluenza virus (HPIV), that have been reported in recent months (2019 to 2020). We compare the structures of those polymerases grouped by virus family, illustrate the similarities and differences among those polymerases, and reveal the potential RNA synthesis mechanisms and models of highly conserved We conclude by the discussion of remaining questions, evolutionary perspectives, and future directions.
Topics: Animals; Cryoelectron Microscopy; Humans; Metapneumovirus; Models, Molecular; Mononegavirales; Protein Conformation; RNA, Messenger; RNA, Viral; RNA-Dependent RNA Polymerase; Rabies virus; Respiratory Syncytial Virus, Human; Vesicular stomatitis Indiana virus; Viral Proteins; Virus Replication
PubMed: 32847861
DOI: 10.1128/JVI.00175-20 -
Science (New York, N.Y.) Jan 2022The COVID-19 pandemic has underscored the critical need for broad-spectrum therapeutics against respiratory viruses. Respiratory syncytial virus (RSV) is a major threat...
The COVID-19 pandemic has underscored the critical need for broad-spectrum therapeutics against respiratory viruses. Respiratory syncytial virus (RSV) is a major threat to pediatric patients and older adults. We describe 4′-fluorouridine (4′-FlU, EIDD-2749), a ribonucleoside analog that inhibits RSV, related RNA viruses, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with high selectivity index in cells and human airway epithelia organoids. Polymerase inhibition within in vitro RNA-dependent RNA polymerase assays established for RSV and SARS-CoV-2 revealed transcriptional stalling after incorporation. Once-daily oral treatment was highly efficacious at 5 milligrams per kilogram (mg/kg) in RSV-infected mice or 20 mg/kg in ferrets infected with different SARS-CoV-2 variants of concern, initiated 24 or 12 hours after infection, respectively. These properties define 4′-FlU as a broad-spectrum candidate for the treatment of RSV, SARS-CoV-2, and related RNA virus infections.
Topics: Administration, Oral; Animals; Antiviral Agents; COVID-19; Cell Line; Coronavirus RNA-Dependent RNA Polymerase; Disease Models, Animal; Female; Ferrets; Humans; Mice; Mice, Inbred BALB C; Microbial Sensitivity Tests; Mononegavirales; RNA-Dependent RNA Polymerase; Respiratory Mucosa; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus, Human; SARS-CoV-2; Transcription, Genetic; Uracil Nucleotides; Virus Replication; COVID-19 Drug Treatment
PubMed: 34855509
DOI: 10.1126/science.abj5508 -
Cell Jul 2022Stem cell research endeavors to generate specific subtypes of classically defined "cell types." Here, we generate >90% pure human artery or vein endothelial cells from...
Stem cell research endeavors to generate specific subtypes of classically defined "cell types." Here, we generate >90% pure human artery or vein endothelial cells from pluripotent stem cells within 3-4 days. We specified artery cells by inhibiting vein-specifying signals and vice versa. These cells modeled viral infection of human vasculature by Nipah and Hendra viruses, which are extraordinarily deadly (∼57%-59% fatality rate) and require biosafety-level-4 containment. Generating pure populations of artery and vein cells highlighted that Nipah and Hendra viruses preferentially infected arteries; arteries expressed higher levels of their viral-entry receptor. Virally infected artery cells fused into syncytia containing up to 23 nuclei, which rapidly died. Despite infecting arteries and occupying ∼6%-17% of their transcriptome, Nipah and Hendra largely eluded innate immune detection, minimally eliciting interferon signaling. We thus efficiently generate artery and vein cells, introduce stem-cell-based toolkits for biosafety-level-4 virology, and explore the arterial tropism and cellular effects of Nipah and Hendra viruses.
Topics: Arteries; Endothelial Cells; Hendra Virus; Humans; Nipah Virus; Pluripotent Stem Cells; Tropism
PubMed: 35738284
DOI: 10.1016/j.cell.2022.05.024 -
Viruses Sep 2023Hendra virus (HeV) and Nipah virus (NiV) are zoonotic paramyxoviruses in the genus (HNV) that emerged nearly thirty years ago. Outbreaks of HeV and NiV have led to... (Review)
Review
Hendra virus (HeV) and Nipah virus (NiV) are zoonotic paramyxoviruses in the genus (HNV) that emerged nearly thirty years ago. Outbreaks of HeV and NiV have led to severe respiratory disease and encephalitis in humans and animals characterized by a high mortality rate. Despite the grave threat HNVs pose to public health and global biosecurity, no approved medical countermeasures for human use currently exist against HeV or NiV. To develop candidate vaccines and therapeutics and advance the field's understanding of HNV pathogenesis, animal models of HeV and NiV have been instrumental and remain indispensable. Various species, including rodents, ferrets, and nonhuman primates (NHPs), have been employed for HNV investigations. Among these, NHPs have demonstrated the closest resemblance to human HNV disease, although other animal models replicate some key disease features. Here, we provide a comprehensive review of the currently available animal models (mice, hamsters, guinea pigs, ferrets, cats, dogs, nonhuman primates, horses, and swine) to support HNV research. We also discuss the strengths and limitations of each model for conducting pathogenesis and transmission studies on HeV and NiV and for the evaluation of medical countermeasures.
Topics: Cricetinae; Animals; Humans; Guinea Pigs; Horses; Mice; Dogs; Ferrets; Henipavirus Infections; Hendra Virus; Nipah Virus; Disease Models, Animal; Primates
PubMed: 37896758
DOI: 10.3390/v15101980 -
Clinical Infectious Diseases : An... Jul 2022Respiratory syncytial virus (RSV), parainfluenza virus (PIV), and human metapneumovirus (hMPV) are increasingly associated with chronic lung allograft dysfunction (CLAD)... (Meta-Analysis)
Meta-Analysis
Respiratory Syncytial Virus, Human Metapneumovirus, and Parainfluenza Virus Infections in Lung Transplant Recipients: A Systematic Review of Outcomes and Treatment Strategies.
BACKGROUND
Respiratory syncytial virus (RSV), parainfluenza virus (PIV), and human metapneumovirus (hMPV) are increasingly associated with chronic lung allograft dysfunction (CLAD) in lung transplant recipients (LTR). This systematic review primarily aimed to assess outcomes of RSV/PIV/hMPV infections in LTR and secondarily to assess evidence regarding the efficacy of ribavirin.
METHODS
Relevant databases were queried and study outcomes extracted using a standardized method and summarized.
RESULTS
Nineteen retrospective and 12 prospective studies were included (total 1060 cases). Pooled 30-day mortality was low (0-3%), but CLAD progression 180-360 days postinfection was substantial (pooled incidences 19-24%) and probably associated with severe infection. Ribavirin trended toward effectiveness for CLAD prevention in exploratory meta-analysis (odds ratio [OR] 0.61, [0.27-1.18]), although results were highly variable between studies.
CONCLUSIONS
RSV/PIV/hMPV infection was followed by a high CLAD incidence. Treatment options, including ribavirin, are limited. There is an urgent need for high-quality studies to provide better treatment options for these infections.
Topics: Humans; Lung; Metapneumovirus; Parainfluenza Virus 1, Human; Parainfluenza Virus 2, Human; Paramyxoviridae Infections; Prospective Studies; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus, Human; Respiratory Tract Infections; Retrospective Studies; Ribavirin; Transplant Recipients
PubMed: 35022697
DOI: 10.1093/cid/ciab969