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Advances in Virus Research 2017The Bunyavirales Order encompasses nine families of enveloped viruses containing a single-stranded negative-sense RNA genome divided into three segments. The small (S)... (Review)
Review
The Bunyavirales Order encompasses nine families of enveloped viruses containing a single-stranded negative-sense RNA genome divided into three segments. The small (S) and large (L) segments encode proteins participating in genome replication in the infected cell cytoplasm. The middle (M) segment encodes the viral glycoproteins Gn and Gc, which are derived from a precursor polyprotein by host cell proteases. Entry studies are available only for a few viruses in the Order, and in each case they were shown to enter cells via receptor-mediated endocytosis. The acidic endosomal pH triggers the fusion of the viral envelope with the membrane of an endosome. Structural studies on two members of this Order, the phleboviruses and the hantaviruses, have shown that the membrane fusion protein Gc displays a class II fusion protein fold and is homologous to its counterparts in flaviviruses and alphaviruses, which are positive-sense, single-stranded RNA viruses. We analyze here recent data on the structure and function of the structure of the phlebovirus Gc and hantavirus Gn and Gc glycoproteins, and extrapolate common features identified in the amino acid sequences to understand also the structure and function of their counterparts in other families of the Bunyavirales Order. Our analysis also identified clear structural homology between the hantavirus Gn and alphavirus E2 glycoproteins, which make a heterodimer with the corresponding fusion proteins Gc and E1, respectively, revealing that not only the fusion protein has been conserved across viral families.
Topics: Alphavirus; Animals; Biological Evolution; Bunyaviridae Infections; Endosomes; Genome, Viral; Orthohantavirus; Humans; Models, Molecular; Phlebovirus; Phylogeny; Protein Folding; RNA, Viral; Structural Homology, Protein; Viral Fusion Proteins; Virus Internalization
PubMed: 28433053
DOI: 10.1016/bs.aivir.2017.02.002 -
The American Journal of Tropical... Dec 2015
Topics: Animal Migration; Animals; Birds; Bunyaviridae Infections; Female; Humans; Male; Phlebovirus
PubMed: 26657299
DOI: 10.4269/ajtmh.15-0524b -
Viruses Jul 2016Bunyaviruses are enveloped viruses with a tripartite RNA genome that can pose a serious threat to animal and human health. Members of the Phlebovirus genus of the family... (Review)
Review
Bunyaviruses are enveloped viruses with a tripartite RNA genome that can pose a serious threat to animal and human health. Members of the Phlebovirus genus of the family Bunyaviridae are transmitted by mosquitos and ticks to humans and include highly pathogenic agents like Rift Valley fever virus (RVFV) and severe fever with thrombocytopenia syndrome virus (SFTSV) as well as viruses that do not cause disease in humans, like Uukuniemi virus (UUKV). Phleboviruses and other bunyaviruses use their envelope proteins, Gn and Gc, for entry into target cells and for assembly of progeny particles in infected cells. Thus, binding of Gn and Gc to cell surface factors promotes viral attachment and uptake into cells and exposure to endosomal low pH induces Gc-driven fusion of the viral and the vesicle membranes. Moreover, Gn and Gc facilitate virion incorporation of the viral genome via their intracellular domains and Gn and Gc interactions allow the formation of a highly ordered glycoprotein lattice on the virion surface. Studies conducted in the last decade provided important insights into the configuration of phlebovirus Gn and Gc proteins in the viral membrane, the cellular factors used by phleboviruses for entry and the mechanisms employed by phlebovirus Gc proteins for membrane fusion. Here, we will review our knowledge on the glycoprotein biogenesis and the role of Gn and Gc proteins in the phlebovirus replication cycle.
Topics: Animals; Glycoproteins; Humans; Phlebovirus; Viral Envelope Proteins; Viral Proteins; Virus Assembly; Virus Internalization; Virus Release
PubMed: 27455305
DOI: 10.3390/v8070202 -
Viruses Feb 2021is a large family of arthropod-borne viruses with over 100 species worldwide. Several cause severe diseases in both humans and livestock. Global warming and the... (Review)
Review
is a large family of arthropod-borne viruses with over 100 species worldwide. Several cause severe diseases in both humans and livestock. Global warming and the apparent geographical expansion of arthropod vectors are good reasons to seriously consider these viruses potential agents of emerging diseases. With an increasing frequency and number of epidemics, some phenuiviruses represent a global threat to public and veterinary health. This review focuses on the early stage of phenuivirus infection in mammalian host cells. We address current knowledge on each step of the cell entry process, from virus binding to penetration into the cytosol. Virus receptors, endocytosis, and fusion mechanisms are discussed in light of the most recent progress on the entry of banda-, phlebo-, and uukuviruses, which together constitute the three prominent genera in the family.
Topics: Animals; Bunyaviridae Infections; Endocytosis; Humans; Mammals; Phlebovirus; Virus Attachment; Virus Internalization
PubMed: 33672975
DOI: 10.3390/v13020299 -
Virologie (Montrouge, France) Jun 2019Phleboviruses constitute a large group of arthropod-borne viruses (arboviruses), mainly transmitted to their hosts by sandflies and ticks, occasionally by mosquitoes.... (Review)
Review
Phleboviruses constitute a large group of arthropod-borne viruses (arboviruses), mainly transmitted to their hosts by sandflies and ticks, occasionally by mosquitoes. These viruses have a worldwide distribution and many cause serious diseases - often fatal - in both domestic animals and humans. The global warming, the apparent wide distribution of arthropod reservoirs, and the increasing number of outbreaks show that phleboviruses must be taken seriously as emerging disease agents. This review proposes to focus on the early steps of phlebovirus infection, from virus binding to penetration into the cytosol. We address the most recent knowledge and advances in the entry of these viruses into vertebrate host cells, including virus receptors, cellular factors, endocytic pathways, and fusion.
Topics: Animals; Animals, Domestic; Arboviruses; Humans; Phlebovirus; Psychodidae; Ticks
PubMed: 31210134
DOI: 10.1684/vir.2019.0780 -
Journal of Medical Virology Nov 2023Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging tick-borne virus, causing thrombocytopenia and hemorrhagic fever, with a fatality rate ranging...
Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging tick-borne virus, causing thrombocytopenia and hemorrhagic fever, with a fatality rate ranging from 12% to 30%. SFTSV possesses Gn and Gc glycoproteins, which are responsible for host cell receptor attachment and membrane fusion, respectively, to infect host cells. We have previously reported a protein subunit vaccine candidate (sGn-H-FT) of the SFTSV soluble Gn head region (sGn-H) fused with self-assembling ferritin (FT) nanoparticles, displaying strong protective immunogenicity. In this study, we present messenger RNA (mRNA) vaccine candidates encoding sGn-H or sGn-H-FT, both of which exhibit potent in vivo immunogenicity and protection capacity. Mice immunized with either sGn-H or sGn-H-FT mRNA lipid nanoparticle (LNP) vaccine produced strong total antibodies and neutralizing antibodies (NAbs) against sGn-H. Importantly, NAb titers remained high for an extended period. Finally, mice immunized with sGn-H or sGn-H-FT mRNA LNP vaccine were fully protected from a lethal dose of SFTSV challenge, showing no fatality. These findings underscore the promise of sGn-H and sGn-H-FT as vaccine antigen candidates capable of providing protective immunity against SFTSV infection.
Topics: Animals; Mice; Viral Envelope Proteins; Phlebovirus; Vaccines, Synthetic; RNA, Messenger; mRNA Vaccines
PubMed: 37909776
DOI: 10.1002/jmv.29203 -
Journal of Medical Virology Jun 2022The newly established virus family Phenuiviridae in Bunyavirales harbors viruses infecting three kingdoms of host organisms (animals, plants, and fungi), which is rare... (Review)
Review
The newly established virus family Phenuiviridae in Bunyavirales harbors viruses infecting three kingdoms of host organisms (animals, plants, and fungi), which is rare in known virus families. Many phenuiviruses are arboviruses and replicate in two distinct hosts (e.g., insects and humans or rice). Multiple phenuivirid species, such as Dabie bandavirus, Rift Valley fever phlebovirus, and Rice stripe tenuivirus, are highly pathogenic to humans, animals, or plants. They impose heavy global burdens on human health, livestock industry, and agriculture and are research hotspots. In recent years the taxonomy of Phenuiviridae has been expanded greatly, and research on phenuiviruses has made significant progress. With these advances, this review drew a novel panorama regarding the biomedical significance, distribution, morphology, genomics, taxonomy, evolution, replication, transmission, pathogenesis, and control of phenuiviruses, to aid researchers in various fields to recognize this highly adaptive and important virus family and conduct relevant risk analysis.
Topics: Animals; Arboviruses; Genomics; Humans; Phlebovirus; RNA Viruses
PubMed: 35072274
DOI: 10.1002/jmv.27618 -
Advances in Experimental Medicine and... 2023Rift Valley fever virus (RVFV) is a member of the Phlebovirus genus, one of the 20 genera in the Phenuiviridae family. RVFV causes disease in animals and humans and is...
Rift Valley fever virus (RVFV) is a member of the Phlebovirus genus, one of the 20 genera in the Phenuiviridae family. RVFV causes disease in animals and humans and is transmitted by sandflies or ticks. However, research into RVFV is limited by the requirement for biosafety level 3 (BSL-3) containment. Pseudotyped virus overcomes this limitation as it can be handled in a BSL-2 environment. Pseudotyped RVFV possesses an identical envelope protein structure to that of the authentic virus, simulating the same process of receptor binding and membrane fusion to host cells. Pseudotyped phleboviruses are therefore useful tools to study the infection mechanism of these viruses and for the screening of inhibitory drugs and the development of therapeutic monoclonal antibodies.
Topics: Animals; Humans; Phlebovirus; Rift Valley Fever; Viral Pseudotyping; Rift Valley fever virus
PubMed: 36920701
DOI: 10.1007/978-981-99-0113-5_13 -
Viruses Aug 2022According to ICTV, there are currently 66 known phlebovirus species. More than 40 of these viruses were isolated or detected in phlebotomine sandflies and some of them... (Review)
Review
According to ICTV, there are currently 66 known phlebovirus species. More than 40 of these viruses were isolated or detected in phlebotomine sandflies and some of them are known pathogens. In Portugal, information about sandfly-borne phleboviruses is scarce and scattered sandfly-borne diseases are neglected and often not considered in differential diagnoses. The main objective of this work was to gather the existing information and to raise awareness about the circulating phleboviruses in this country. To date, Massilia and Alcube phleboviruses have been isolated from sandflies in southern Portugal. Human infections with Toscana and Sicilian phleboviruses have been reported, as well as seroprevalence in cats and dogs. More studies are needed in order to understand if the viruses isolated during the entomological surveys have an impact on human health and to fully understand the real importance of the already recognized pathogens in our country.
Topics: Animals; Cats; Dogs; Humans; Phlebotomus Fever; Phlebovirus; Portugal; Psychodidae; Seroepidemiologic Studies
PubMed: 36016390
DOI: 10.3390/v14081768 -
Veterinary Research Communications Feb 2022Tick-borne viruses and bacteria that can cause diseases of animals and humans have high impact and are of concern as significant threats to human health worldwide. In...
Tick-borne viruses and bacteria that can cause diseases of animals and humans have high impact and are of concern as significant threats to human health worldwide. In this research, we screened microorganisms related to those pathogens in ticks from dogs, a cat, and a cow. The techniques used were PCR, DNA sequencing and phylogenetic analysis to detect and classify the microorganisms [Flavivirus, severe fever with thrombocytopenia syndrome virus (SFTSV), Phlebovirus, Coronavirus, Canine Parvovirus, eubacteria, Coxiella and Rickettsia]. A novel virus named Phlebovirus-like-AYUT and Stenotrophomonas maltophilia bacteria were found in one individual tick (Rhipicephalus sanguineus s.l.) from a dog. All tick samples were negative for Rickettsia, while 9/21 (42.9 %) were positive for Coxiella bacteria. The novel virus "Phlebovirus-like-AYUT" (the name derives from Phra Nakhon Si Ayutthaya Province in Thailand) was resolved by phylogenetic analysis of the partial L segment by maximum likelihood (ML) method using MEGA X. The phylogenetic tree also indicated that the virus was related to Phlebovirus in brown dog ticks reported in Trinidad and Tobago. In contrast, Phlebovirus-like-AYUT was in a distinct clade from Lihan tick Phlebovirus-Thailand (LTPV), which was previously found in cow ticks, Rhipicephalus microplus, in Nan Province, Thailand. This study reports the Stenotrophomonas maltophilia bacterium with a novel Phlebovirus-like-AYUT in a brown dog tick. The roles of this bacterium in a virus-positive tick or in viral transmission from animal host requires further investigation.
Topics: Animals; Cattle; Cattle Diseases; Coinfection; Dog Diseases; Dogs; Female; Phlebovirus; Phylogeny; Rhipicephalus sanguineus; Stenotrophomonas maltophilia; Thailand
PubMed: 34725749
DOI: 10.1007/s11259-021-09855-7