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Virus Research Feb 2003Avian pneumovirus (APV, Turkey rhinotracheitis virus) and Human metapneumovirus (hMPV) are pathogens of birds and humans, respectively, that are associated with upper... (Review)
Review
Avian pneumovirus (APV, Turkey rhinotracheitis virus) and Human metapneumovirus (hMPV) are pathogens of birds and humans, respectively, that are associated with upper respiratory tract infections. Based on their different genomic organization and low level of nucleotide (nt) and amino acid (aa) identity with paramyxoviruses in the genus Pneumovirus, APV and hMPV have been classified into a new genus referred to as Metapneumovirus. First isolated in 1970s, APV strains have since been isolated in Europe, Africa, middle east, and United States (US) and classified in four subgroups, APV/A, APV/B, APV/C, and APV/D based on nt and predicted aa sequence identity. Although it was first isolated in 2001, serological evidence indicates that hMPV may have been present in human population from as early as the 1950s. There is only one subgroup of hMPV so far, whose nt and aa sequence identity indicates that it is more closely related to APV/C than to APV/A, APV/B, or APV/D.
Topics: Amino Acid Sequence; Animals; Bird Diseases; Chickens; Ducks; Humans; Metapneumovirus; Molecular Sequence Data; Paramyxoviridae Infections; Poultry Diseases; Sequence Analysis, DNA; Turkeys
PubMed: 12573494
DOI: 10.1016/s0168-1702(02)00256-3 -
The Journal of Infectious Diseases Mar 2021
Topics: Communicable Diseases; Humans; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses
PubMed: 33350442
DOI: 10.1093/infdis/jiaa755 -
Journal of Theoretical Biology Sep 2021Respiratory syncytial virus (RSV) is a common, contagious infection of the lungs and the respiratory tract. RSV is characterized by syncytia, which are multinuclear...
Respiratory syncytial virus (RSV) is a common, contagious infection of the lungs and the respiratory tract. RSV is characterized by syncytia, which are multinuclear cells created by cells that have fused together. We use a mathematical model to study how different assumptions about the viral production and lifespan of syncytia change the resulting infection time course. We find that the effect of syncytia on viral titer is only apparent when the basic reproduction number for infection via syncytia formation is similar to the reproduction number for cell free viral transmission. When syncytia fusion rate is high, we find the presence of syncytia can lead to slowly growing infections if viral production is suppressed in syncytia. Our model provides insight into how the presence of syncytia can affect the time course of a viral infection.
Topics: Giant Cells; Humans; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus, Human; Virus Diseases
PubMed: 33964289
DOI: 10.1016/j.jtbi.2021.110749 -
BMB Reports Apr 2014Respiratory syncytial virus (RSV) is the leading cause of respiratory infection in infants and young children. Severe clinical manifestation of RSV infection is a... (Review)
Review
Respiratory syncytial virus (RSV) is the leading cause of respiratory infection in infants and young children. Severe clinical manifestation of RSV infection is a bronchiolitis, which is common in infants under six months of age. Recently, RSV has been recognized as an important cause of respiratory infection in older populations with cardiovascular morbidity or immunocompromised patients. However, neither a vaccine nor an effective antiviral therapy is currently available. Moreover, the interaction between the host immune system and the RSV pathogen during an infection is not well understood. The innate immune system recognizes RSV through multiple mechanisms. The first innate immune RSV detectors are the pattern recognition receptors (PRRs), including toll-like receptors (TLRs), retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs), and nucleotide-biding oligomerization domain (NOD)-like receptors (NLRs). The following is a review of studies associated with various PRRs that are responsible for RSV virion recognition and subsequent induction of the antiviral immune response during RSV infection.
Topics: Humans; Immunity, Innate; Receptors, Pattern Recognition; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses
PubMed: 24568879
DOI: 10.5483/bmbrep.2014.47.4.050 -
Journal of Biosciences Nov 2008Human metapneumovirus is a recently recognized pathogen of acute respiratory tract infection (ARI) in children as well as elderly and immunocompromised adults.The virus... (Review)
Review
Human metapneumovirus is a recently recognized pathogen of acute respiratory tract infection (ARI) in children as well as elderly and immunocompromised adults.The virus belongs to the family Paramyxoviridae, sub family Pneumovirinae and genus Metapneumovirus. Through genetic analysis it has been characterized into two groups A and B which are further divided into four sub-lineages. The virus is difficult to grow in tissue culture and hence reverse transcriptase-polymerase chain reaction (RT-PCR) for N and L gene is the method of choice for diagnosis. The virus has been seen in all countries with seasonal distribution in winter months for temperate and spring/summer for tropical countries. F gene is the most conserved among different lineages and efforts are underway to design recombination vaccine using F gene.
Topics: Genes, Viral; Genome, Viral; Humans; Metapneumovirus; Paramyxoviridae Infections; Respiratory Syncytial Virus Infections; Viral Vaccines
PubMed: 19208974
DOI: 10.1007/s12038-008-0067-y -
Virus Research May 2019Pneumoviruses represent a major public health burden across the world. Respiratory syncytial virus (RSV) and human metapneumovirus (HMPV), two of the most recognizable... (Review)
Review
Pneumoviruses represent a major public health burden across the world. Respiratory syncytial virus (RSV) and human metapneumovirus (HMPV), two of the most recognizable pediatric infectious agents, belong to this family. These viruses are enveloped with a non-segmented negative-sense RNA genome, and their replication occurs in specialized cytosolic organelles named inclusion bodies (IB). The critical role of IBs in replication of pneumoviruses has begun to be elucidated, and our current understanding suggests they are highly dynamic structures. From IBs, newly synthesized nucleocapsids are transported to assembly sites, potentially via the actin cytoskeleton, to be incorporated into nascent virions. Released virions, which generally contain one genome, can then diffuse in the extracellular environment to target new cells and reinitiate the process of infection. This is a challenging business for virions, which must face several risks including the extracellular immune responses. In addition, several recent studies suggest that successful infection may be achieved more rapidly by multiple, rather than single, genomic copies being deposited into a target cell. Interestingly, recent data indicate that pneumoviruses have several mechanisms that permit their transmission en bloc, i.e. transmission of multiple genomes at the same time. These mechanisms include the well-studied syncytia formation as well as the newly described formation of long actin-based intercellular extensions. These not only permit en bloc viral transmission, but also bypass assembly of complete virions. In this review we describe several aspects of en bloc viral transmission and how these mechanisms are reshaping our understanding of pneumovirus replication, assembly and spread.
Topics: Animals; Cell Line; Humans; Metapneumovirus; Mice; Paramyxoviridae Infections; Pneumovirus; RNA, Viral; Virion; Virus Assembly; Virus Replication
PubMed: 30844414
DOI: 10.1016/j.virusres.2019.03.002 -
Clinical Microbiology Reviews Apr 2004Pneumoviruses are single-stranded, negative-sense, nonsegmented RNA viruses of the family Paramyxoviridae, subfamily Pneumovirinae, and include pathogens that infect... (Review)
Review
Pneumoviruses are single-stranded, negative-sense, nonsegmented RNA viruses of the family Paramyxoviridae, subfamily Pneumovirinae, and include pathogens that infect humans (respiratory syncytial virus and human metapneumovirus), domestic mammals (bovine, ovine, and caprine respiratory syncytial viruses), rodents (pneumonia virus of mice), and birds (avian metapneumovirus). Among the topics considered in this review are recent studies focused on the roles of the individual virus-encoded components in promoting virus replication as well as in altering and evading innate antiviral host defenses. Advances in the molecular technology of pneumoviruses and the emergence of recombinant pneumoviruses that are leading to improved virus-based vaccine formulations are also discussed. Since pneumovirus infection in natural hosts is associated with a profound inflammatory response that persists despite adequate antiviral therapy, we also review the recent experimental treatment strategies that have focused on combined antiviral, anti-inflammatory, and immunomodulatory approaches.
Topics: Animals; Antiviral Agents; Cattle; Cell Line; Disease Models, Animal; History, 15th Century; Humans; Paramyxoviridae Infections; Pneumovirinae
PubMed: 15084507
DOI: 10.1128/CMR.17.2.390-412.2004 -
American Journal of Respiratory Cell... Dec 2018
Topics: Antiviral Agents; Homeostasis; Respiratory Syncytial Viruses; Viruses
PubMed: 30230347
DOI: 10.1165/rcmb.2018-0268ED -
Viruses Dec 2012Human metapneumovirus (hMPV) is a recently identified RNA virus belonging to the Paramyxoviridae family, which includes several major human and animal pathogens.... (Review)
Review
Human metapneumovirus (hMPV) is a recently identified RNA virus belonging to the Paramyxoviridae family, which includes several major human and animal pathogens. Epidemiological studies indicate that hMPV is a significant human respiratory pathogen with worldwide distribution. It is associated with respiratory illnesses in children, adults, and immunocompromised patients, ranging from upper respiratory tract infections to severe bronchiolitis and pneumonia. Interferon (IFN) represents a major line of defense against virus infection, and in response, viruses have evolved countermeasures to inhibit IFN production as well as IFN signaling. Although the strategies of IFN evasion are similar, the specific mechanisms by which paramyxoviruses inhibit IFN responses are quite diverse. In this review, we will present an overview of the strategies that hMPV uses to subvert cellular signaling in airway epithelial cells, the major target of infection, as well as in primary immune cells.
Topics: Humans; Immune Evasion; Immunity, Innate; Interferons; Metapneumovirus; Viral Proteins; Virulence Factors
PubMed: 23223197
DOI: 10.3390/v4123551 -
Current Opinion in Virology Aug 2015The study of human respiratory syncytial virus pathogenesis and immunity has been hampered by its exquisite host specificity, and the difficulties encountered in... (Review)
Review
The study of human respiratory syncytial virus pathogenesis and immunity has been hampered by its exquisite host specificity, and the difficulties encountered in adapting this virus to a murine host. The reasons for this obstacle are not well understood, but appear to reflect, at least in part, the inability of the virus to block the interferon response in any but the human host. This review addresses some of the issues encountered in mouse models of respiratory syncytial virus infection, and describes the advantages and disadvantages of alternative model systems.
Topics: Animals; Disease Models, Animal; Humans; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus, Human
PubMed: 26176495
DOI: 10.1016/j.coviro.2015.06.003