-
Virology May 2015Ebola viruses and Marburg viruses, members of the filovirus family, cause severe hemorrhagic fever. The ability of these viruses to potently counteract host innate... (Review)
Review
Ebola viruses and Marburg viruses, members of the filovirus family, cause severe hemorrhagic fever. The ability of these viruses to potently counteract host innate immune responses is thought to be an important component of viral pathogenesis. Several mechanisms of filoviral innate immune evasion have been defined and are reviewed here. These mechanisms include suppression of type I interferon (IFN) production; inhibition of IFN-signaling and mechanisms that either prevent cell stress responses or allow the virus to replicate in the face of such responses. A greater understanding of these innate immune evasion mechanisms may suggest novel therapeutic approaches for these deadly pathogens.
Topics: Ebolavirus; Host-Pathogen Interactions; Humans; Immune Evasion; Interferon Type I; Marburgvirus; Virus Replication
PubMed: 25843618
DOI: 10.1016/j.virol.2015.03.030 -
Intervirology 1978Iit is proposed that the family paramyxovirdae shall comprise three genera: paramyxovirus, Morbillivirus, and Pneumovirus.
Iit is proposed that the family paramyxovirdae shall comprise three genera: paramyxovirus, Morbillivirus, and Pneumovirus.
Topics: Measles virus; Paramyxoviridae
PubMed: 681143
DOI: 10.1159/000148979 -
PLoS Pathogens Sep 2023The Pneumoviridae family of viruses includes human metapneumovirus (HMPV) and respiratory syncytial virus (RSV). The closely related Paramyxoviridae family includes...
Structure-based design of a single-chain triple-disulfide-stabilized fusion-glycoprotein trimer that elicits high-titer neutralizing responses against human metapneumovirus.
The Pneumoviridae family of viruses includes human metapneumovirus (HMPV) and respiratory syncytial virus (RSV). The closely related Paramyxoviridae family includes parainfluenza viruses (PIVs). These three viral pathogens cause acute respiratory tract infections with substantial disease burden in the young, the elderly, and the immune-compromised. While promising subunit vaccines are being developed with prefusion-stabilized forms of the fusion glycoproteins (Fs) of RSV and PIVs, for which neutralizing titers elicited by the prefusion (pre-F) conformation of F are much higher than for the postfusion (post-F) conformation, with HMPV, pre-F and post-F immunogens described thus far elicit similar neutralizing responses, and it has been unclear which conformation, pre-F or post-F, would be the most effective HMPV F-vaccine immunogen. Here, we investigate the impact of further stabilizing HMPV F in the pre-F state. We replaced the furin-cleavage site with a flexible linker, creating a single chain F that yielded increased amounts of pre-F stabilized trimers, enabling the generation and assessment of F trimers stabilized by multiple disulfide bonds. Introduced prolines could increase both expression yields and antigenic recognition by the pre-F specific antibody, MPE8. The cryo-EM structure of a triple disulfide-stabilized pre-F trimer with the variable region of antibody MPE8 at 3.25-Å resolution confirmed the formation of designed disulfides and provided structural details on the MPE8 interface. Immunogenicity assessments in naïve mice showed the triple disulfide-stabilized pre-F trimer could elicit high titer neutralization, >10-fold higher than elicited by post-F. Immunogenicity assessments in pre-exposed rhesus macaques showed the triple disulfide-stabilized pre-F could recall high neutralizing titers after a single immunization, with little discrimination in the recall response between pre-F and post-F immunogens. However, the triple disulfide-stabilized pre-F adsorbed HMPV-directed responses from commercially available pooled human immunoglobulin more fully than post-F. Collectively, these results suggest single-chain triple disulfide-stabilized pre-F trimers to be promising HMPV-vaccine antigens.
Topics: Aged; Humans; Animals; Mice; Metapneumovirus; Macaca mulatta; Antibodies; Respiratory Syncytial Virus, Human; Antigens, Viral; Disulfides; Glycoproteins; Parainfluenza Virus 1, Human
PubMed: 37738240
DOI: 10.1371/journal.ppat.1011584 -
Current Opinion in Virology Jun 2017The paramyxovirus family comprises major human and animal pathogens such as measles virus (MeV), mumps virus (MuV), the parainfluenzaviruses, Newcastle disease virus... (Review)
Review
The paramyxovirus family comprises major human and animal pathogens such as measles virus (MeV), mumps virus (MuV), the parainfluenzaviruses, Newcastle disease virus (NDV), and the highly pathogenic zoonotic hendra (HeV) and nipah (NiV) viruses. Paramyxovirus particles are pleomorphic, with a lipid envelope, nonsegmented RNA genomes of negative polarity, and densely packed glycoproteins on the virion surface. A number of crystal structures of different paramyxovirus proteins and protein fragments were solved, but the available information concerning overall virion organization remains limited. However, recent studies have reported cryo-electron tomography-based reconstructions of Sendai virus (SeV), MeV, NDV, and human parainfluenza virus type 3 (HPIV3) particles and a surface assessment of NiV-derived virus-like particles (VLPs), which have yielded innovative hypotheses concerning paramyxovirus particle assembly, budding, and organization. Following a summary of the current insight into paramyxovirus virion morphology, this review will focus on discussing the implications of these particle reconstructions on the present models of paramyxovirus assembly and infection.
Topics: Cryoelectron Microscopy; Electron Microscope Tomography; Genome, Viral; Humans; Measles virus; Newcastle disease virus; Nipah Virus; Paramyxoviridae; Viral Fusion Proteins; Viral Matrix Proteins; Virion; Virus Assembly; Virus Release
PubMed: 28601688
DOI: 10.1016/j.coviro.2017.05.004 -
Current Topics in Microbiology and... 2017This chapter describes the various strategies filoviruses use to escape host immune responses with a focus on innate immune and cell death pathways. Since filovirus... (Review)
Review
This chapter describes the various strategies filoviruses use to escape host immune responses with a focus on innate immune and cell death pathways. Since filovirus replication can be efficiently blocked by interferon (IFN), filoviruses have evolved mechanisms to counteract both type I IFN induction and IFN response signaling pathways. Intriguingly, marburg- and ebolaviruses use different strategies to inhibit IFN signaling. This chapter also summarizes what is known about the role of IFN-stimulated genes (ISGs) in filovirus infection. These fall into three categories: those that restrict filovirus replication, those whose activation is inhibited by filoviruses, and those that have no measurable effect on viral replication. In addition to innate immunity, mammalian cells have evolved strategies to counter viral infections, including the induction of cell death and stress response pathways, and we summarize our current knowledge of how filoviruses interact with these pathways. Finally, this chapter delves into the interaction of EBOV with myeloid dendritic cells and macrophages and the associated inflammatory response, which differs dramatically between these cell types when they are infected with EBOV. In summary, we highlight the multifaceted nature of the host-viral interactions during filoviral infections.
Topics: Animals; Ebolavirus; Filoviridae; Host-Pathogen Interactions; Immunity, Innate; Interferons; Virus Replication
PubMed: 28685291
DOI: 10.1007/82_2017_13 -
Animal Health Research Reviews Dec 2012In 2008, avian bornaviruses (ABV) were identified as the cause of proventricular dilatation disease (PDD). PDD is a significant condition of captive parrots first... (Review)
Review
In 2008, avian bornaviruses (ABV) were identified as the cause of proventricular dilatation disease (PDD). PDD is a significant condition of captive parrots first identified in the late 1970s. ABV infection has subsequently been shown to be widespread in wild waterfowl across the United States and Canada where the virus infects 10-20% of some populations of ducks, geese and swans. In most cases birds appear to be healthy and unaffected by the presence of the virus; however, infection can also result in severe non-suppurative encephalitis and lesions similar to those seen in parrots with PDD. ABVs are genetically diverse with seven identified genotypes in parrots and one in canaries. A unique goose genotype (ABV-CG) predominates in waterfowl in Canada and the northern United States. ABV appears to be endemic in North American waterfowl, in comparison to what appears to be an emerging disease in parrots. It is not known whether ABV can spread between waterfowl and parrots. The discovery of ABV infection in North American waterfowl suggests that European waterfowl should be evaluated for the presence of ABV, and also as a possible reservoir species for Borna disease virus (BDV), a related neurotropic virus affecting horses and sheep in central Europe. Although investigations have suggested that BDV is likely derived from a wildlife reservoir, for which the shrew and water vole are currently prime candidates, we suggest that the existence of other mammalian and avian reservoirs should not be discounted.
Topics: Animals; Bird Diseases; Birds; Borna disease virus; Bornaviridae; Mononegavirales Infections
PubMed: 23253163
DOI: 10.1017/S1466252312000205 -
Animal Health Research Reviews Dec 2016Bornaviruses cause neurologic diseases in several species of birds, especially parrots, waterfowl and finches. The characteristic lesions observed in these birds include... (Review)
Review
Bornaviruses cause neurologic diseases in several species of birds, especially parrots, waterfowl and finches. The characteristic lesions observed in these birds include encephalitis and gross dilatation of the anterior stomach - the proventriculus. The disease is thus known as proventricular dilatation disease (PDD). PDD is characterized by extreme proventricular dilatation, blockage of the passage of digesta and consequent death by starvation. There are few clinical resemblances between this and the bornaviral encephalitides observed in mammals. Nevertheless, there are common virus-induced pathogenic pathways shared across this disease spectrum that are explored in this review. Additionally, a review of the literature relating to gastroparesis in humans and the control of gastric mobility in mammals and birds points to several plausible mechanisms by which bornaviral infection may result in extreme proventricular dilatation.
Topics: Animals; Bird Diseases; Birds; Bornaviridae; Dilatation; Mononegavirales Infections; Proventriculus
PubMed: 28155804
DOI: 10.1017/S1466252316000189 -
The Journal of General Virology Jul 2021Members of the family produce enveloped virions containing a linear negative-sense non-segmented RNA genome of about 9 kb. Bornaviruses are found in mammals, birds,...
Members of the family produce enveloped virions containing a linear negative-sense non-segmented RNA genome of about 9 kb. Bornaviruses are found in mammals, birds, reptiles and fish. The most-studied viruses with public health and veterinary impact are Borna disease virus 1 and variegated squirrel bornavirus 1, both of which cause fatal encephalitis in humans. Several orthobornaviruses cause neurological and intestinal disorders in birds, mostly parrots. Endogenous bornavirus-like sequences occur in the genomes of various animals. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family , which is available at ictv.global/report/bornaviridae.
Topics: Animals; Borna Disease; Borna disease virus; Bornaviridae; Genome, Viral; Host Specificity; Humans; Virion; Virus Replication
PubMed: 34227935
DOI: 10.1099/jgv.0.001613 -
Microbiology and Immunology 1982
Review
Topics: Capsid; Cell Membrane; Chemical Phenomena; Chemistry; Defective Viruses; Glycoproteins; Lipids; Newcastle disease virus; Parainfluenza Virus 1, Human; Paramyxoviridae; Phosphorylation; Respirovirus; Viral Matrix Proteins; Viral Proteins; Virion
PubMed: 6287180
DOI: 10.1111/j.1348-0421.1982.tb00180.x -
Molecular and Cellular Biochemistry Jan 1980Measles is one of widely spread virus infections that is a major cause of deaths in some tropical areas. The measles virus is a member of the genus of Morbillivirus of... (Review)
Review
Measles is one of widely spread virus infections that is a major cause of deaths in some tropical areas. The measles virus is a member of the genus of Morbillivirus of the family of Paramyxoviridae. The virions contain six polypeptides, including one glycoprotein; two of them are surface proteins that possess hemagglutinating and hemolytic activities, one of them is polymerase. Replication of the measles virus is similar to that of other Paramyxoviruses. Besides the acute infection for measles virus a persistent infection is characteristic that affects central nervous system and inner organs. Molecular mechanisms of it were studied and the results are discussed to explain the pathogenesis of subacute sclerosing panencephalitis, systemic lupus erythematosus and other diseases in which measles or measles-like virus may be involved.
Topics: Animals; Cells, Cultured; Centrifugation, Density Gradient; Cytoplasm; Glycoproteins; Humans; Measles virus; Nucleoproteins; Peptides; RNA, Messenger; RNA, Viral; Radioimmunoassay; SSPE Virus; Viral Proteins; Virion; Virus Replication
PubMed: 6988693
DOI: 10.1007/BF00230955