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Hallam HJ, Lokugamage N, Ikegami T. Rescue of infectious Arumowot virus from cloned cDNA: Posttranslational degradation of Arumowot virus NSs protein in human cells. PLoS Negl Trop Dis 2019; 13:e0007904. [PMID: 31751340 PMCID: PMC6894884 DOI: 10.1371/journal.pntd.0007904] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 12/05/2019] [Accepted: 11/04/2019] [Indexed: 12/11/2022] Open
Abstract
Rift Valley fever (RVF) is a mosquito-borne zoonotic disease endemic to Africa and the Middle East, affecting both humans and ruminants. There are no licensed vaccines or antivirals available for humans, whereas research using RVF virus (RVFV) is strictly regulated in many countries with safety concerns. Nonpathogenic Arumowot virus (AMTV), a mosquito-borne phlebovirus in Africa, is likely useful for the screening of broad-acting antiviral candidates for phleboviruses including RVFV, as well as a potential vaccine vector for RVF. In this study, we aimed to generate T7 RNA polymerase-driven reverse genetics system for AMTV. We hypothesized that recombinant AMTV (rAMTV) is viable, and AMTV NSs protein is dispensable for efficient replication of rAMTV in type-I interferon (IFN)-incompetent cells, whereas AMTV NSs proteins support robust viral replication in type-I IFN-competent cells. The study demonstrated the rescue of rAMTV and that lacking the NSs gene (rAMTVΔNSs), that expressing green fluorescent protein (GFP) (rAMTV-GFP) or that expressing Renilla luciferase (rAMTV-rLuc) from cloned cDNA. The rAMTV-rLuc and the RVFV rMP12-rLuc showed a similar susceptibility to favipiravir or ribavirin. Interestingly, neither of rAMTV nor rAMTVΔNSs replicated efficiently in human MRC-5 or A549 cells, regardless of the presence of NSs gene. Little accumulation of AMTV NSs protein occurred in those cells, which was restored via treatment with proteasomal inhibitor MG132. In murine MEF or Hepa1-6 cells, rAMTV, but not rAMTVΔNSs, replicated efficiently, with an inhibition of IFN-β gene upregulation. This study showed an establishment of the first reverse genetics for AMTV, a lack of stability of AMTV NSs proteins in human cells, and an IFN-β gene antagonist function of AMTV NSs proteins in murine cells. The AMTV can be a nonpathogenic surrogate model for studying phleboviruses including RVFV.
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Affiliation(s)
- Hoai J. Hallam
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
| | - Nandadeva Lokugamage
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
| | - Tetsuro Ikegami
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
- Sealy Institute for Vaccine Sciences, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
- Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
- * E-mail:
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Braack L, Gouveia de Almeida AP, Cornel AJ, Swanepoel R, de Jager C. Mosquito-borne arboviruses of African origin: review of key viruses and vectors. Parasit Vectors 2018; 11:29. [PMID: 29316963 PMCID: PMC5759361 DOI: 10.1186/s13071-017-2559-9] [Citation(s) in RCA: 138] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 11/27/2017] [Indexed: 12/28/2022] Open
Abstract
Key aspects of 36 mosquito-borne arboviruses indigenous to Africa are summarized, including lesser or poorly-known viruses which, like Zika, may have the potential to escape current sylvatic cycling to achieve greater geographical distribution and medical importance. Major vectors are indicated as well as reservoir hosts, where known. A series of current and future risk factors is addressed. It is apparent that Africa has been the source of most of the major mosquito-borne viruses of medical importance that currently constitute serious global public health threats, but that there are several other viruses with potential for international challenge. The conclusion reached is that increased human population growth in decades ahead coupled with increased international travel and trade is likely to sustain and increase the threat of further geographical spread of current and new arboviral disease.
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Affiliation(s)
- Leo Braack
- School of Health Systems & Public Health, University of Pretoria, Pretoria, South Africa.
| | - A Paulo Gouveia de Almeida
- Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal.,Department of Medical Virology, University of Pretoria, Pretoria, South Africa
| | - Anthony J Cornel
- School of Health Systems & Public Health, University of Pretoria, Pretoria, South Africa.,Department of Entomology and Nematology, Mosquito Control Research Laboratory, Kearney Agricultural Center, UC Davis, Parlier, CA, USA
| | - Robert Swanepoel
- Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, South Africa
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Risk analysis of inter-species reassortment through a Rift Valley fever phlebovirus MP-12 vaccine strain. PLoS One 2017; 12:e0185194. [PMID: 28926632 PMCID: PMC5604998 DOI: 10.1371/journal.pone.0185194] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 09/07/2017] [Indexed: 11/20/2022] Open
Abstract
Rift Valley fever (RVF) is a mosquito-borne zoonotic disease endemic to Africa and the Arabian Peninsula. The causative agent, Rift Valley fever phlebovirus (RVFV), belongs to the genus Phlebovirus in the family Phenuiviridae and causes high rates of abortions in ruminants, and hemorrhagic fever, encephalitis, or blindness in humans. Viral maintenance by mosquito vectors has led to sporadic RVF outbreaks in ruminants and humans in endemic countries, and effective vaccination of animals and humans may minimize the impact of this disease. A live-attenuated MP-12 vaccine strain is one of the best characterized RVFV strains, and was conditionally approved as a veterinary vaccine in the U.S. Live-attenuated RVF vaccines including MP-12 strain may form reassortant strains with other bunyavirus species. This study thus aimed to characterize the occurrence of genetic reassortment between the MP-12 strain and bunyavirus species closely related to RVFV. The Arumowot virus (AMTV) and Gouleako goukovirus (GOLV), are transmitted by mosquitoes in Africa. The results of this study showed that GOLV does not form detectable reassortant strains with the MP-12 strain in co-infected C6/36 cells. The AMTV also did not form any reassortant strains with MP-12 strain in co-infected C6/36 cells, due to the incompatibility among N, L, and Gn/Gc proteins. A lack of reassortant formation could be due to a functional incompatibility of N and L proteins derived from heterologous species, and due to a lack of packaging via heterologous Gn/Gc proteins. The MP-12 strain did, however, randomly exchange L-, M-, and S-segments with a genetic variant strain, rMP12-GM50, in culture cells. The MP-12 strain is thus unlikely to form any reassortant strains with AMTV or GOLV in nature.
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Hacioglu S, Dincer E, Isler CT, Karapinar Z, Ataseven VS, Ozkul A, Ergunay K. A Snapshot Avian Surveillance Reveals West Nile Virus and Evidence of Wild Birds Participating in Toscana Virus Circulation. Vector Borne Zoonotic Dis 2017; 17:698-708. [PMID: 28832259 DOI: 10.1089/vbz.2017.2138] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
INTRODUCTION Birds are involved in the epidemiology of several vector-borne viruses, as amplification hosts for viruses, dissemination vehicles for the vectors, and sources of emerging strains in cross-species transmission. Turkey provides diverse habitats for a variety of wild birds and is located along major bird migration routes. This study was undertaken to provide a cross-sectional screening of avian specimens for a spectrum of vector-borne viruses. MATERIALS AND METHODS The specimens were collected in Hatay province, in the Mediterranean coast of the Anatolian peninsula, located in the convergence zone of the known migration routes. Generic PCR assays were used for the detection of members of Nairovirus, Flavivirus, and Phlebovirus genera of Flaviviridae and Bunyaviridae families. The circulating viruses were characterized via sequencing and selected specimens were inoculated onto Vero cell lines for virus isolation. RESULTS AND DISCUSSION Specimens from 72 wild birds belonging in 8 orders and 14 species were collected. A total of 158 specimens that comprise 32 sera (20.3%) from 7 species and 126 tissues (79.7%) from 14 species were screened. Eight specimens (8/158, 5%), obtained from 4 individuals (4/72, 5.5%), were positive. West Nile virus (WNV) lineage 1 sequences were characterized in the spleen, heart, and kidney tissues from a lesser spotted eagle (Clanga pomarina), which distinctly clustered from sequences previously identified in Turkey. Toscana virus (TOSV) genotype A and B sequences were identified in brain and kidney tissues from a greater flamingo (Phoenicopterus roseus), a great white pelican (Pelecanus onocrotalus), and a black stork (Ciconia nigra), without successful virus isolation. Partial amino acid sequences of the viral nucleocapsid protein revealed previously unreported substitutions. This study documents the involvement of avians in WNV dispersion in Anatolia as well in TOSV life cycle.
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Affiliation(s)
- Sabri Hacioglu
- 1 Department of Virology, Faculty of Veterinary Medicine, Ankara University , Ankara, Turkey
| | - Ender Dincer
- 2 Advanced Technology Education, Research and Application Center, Mersin University , Mersin, Turkey
| | - Cafer Tayer Isler
- 3 Department of Surgery, Faculty of Veterinary Medicine, Mustafa Kemal University , Hatay, Turkey
| | - Zeynep Karapinar
- 4 Department of Virology, Faculty of Veterinary Medicine, Yuzuncu Yıl University , Van, Turkey
| | - Veysel Soydal Ataseven
- 5 Department of Virology, Faculty of Veterinary Medicine, Mustafa Kemal University , Hatay, Turkey
| | - Aykut Ozkul
- 1 Department of Virology, Faculty of Veterinary Medicine, Ankara University , Ankara, Turkey
| | - Koray Ergunay
- 6 Virology Unit, Department of Medical Microbiology, Faculty of Medicine, Hacettepe University , Ankara, Turkey
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Ikegami T. Rift Valley fever vaccines: an overview of the safety and efficacy of the live-attenuated MP-12 vaccine candidate. Expert Rev Vaccines 2017; 16:601-611. [PMID: 28425834 DOI: 10.1080/14760584.2017.1321482] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Rift Valley fever (RVF) is a mosquito-borne zoonotic viral disease endemic to Africa and the Arabian Peninsula. High rates of abortion among infected ruminants and hemorrhagic fever in infected humans are major public health concerns. Commercially available veterinary RVF vaccines are important for preventing the spread of the Rift Valley fever virus (RVFV) in endemic countries; however, RVFV outbreaks continue to occur frequently in endemic countries in the 21st century. In the U.S., the live-attenuated MP-12 vaccine has been developed for both animal and human vaccination. This vaccine strain is well attenuated, and a single dose induces neutralizing antibodies in both ruminants and humans. Areas covered: This review describes scientific evidences of MP-12 vaccine efficacy and safety, as well as MP-12 variants recently developed by reverse genetics, in comparison with other RVF vaccines. Expert commentary: The containment of active RVF outbreaks and long-term protection from RVF exposure to infected mosquitoes are important goals for RVF vaccination. MP-12 vaccine will allow immediate vaccination of susceptible animals in case of an unexpected RVF outbreak in the U.S., whereas MP-12 vaccine may be also useful for the RVF control in endemic regions.
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Affiliation(s)
- Tetsuro Ikegami
- a Department of Pathology, Sealy Center for Vaccine Development, Center for Biodefense and Emerging Infectious Diseases , The University of Texas Medical Branch , Galveston , TX , USA
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Simo Tchetgna HD, Nakoune E, Selekon B, Gessain A, Manuguerra JC, Kazanji M, Berthet N. Molecular Characterization of the Kamese Virus, an Unassigned Rhabdovirus, Isolated from Culex pruina in the Central African Republic. Vector Borne Zoonotic Dis 2017; 17:447-451. [PMID: 28350284 DOI: 10.1089/vbz.2016.2068] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Rhabdoviridae is one of the most diversified families of RNA viruses whose members infect a wide range of plants, animals, and arthropods. The members of this family are classified into 13 genera and >150 unassigned viruses. Here, we sequenced the complete genome of a rhabdovirus belonging to the Hart Park serogroup, the Kamese virus (KAMV), isolated in 1977 from Culex pruina in the Central African Republic. The genomic sequence showed an organization typical of rhabdoviruses with additional genes in the P-M and G-L intergenic regions, as already reported for the Hart Park serogroup. Our Kamese strain (ArB9074) had 98% and 78.8% nucleotide sequence similarity with the prototypes of the KAMV and Mossuril virus isolated in Uganda and Mozambique in two different Culex species, respectively. Moreover, the protein sequences had 98-100% amino acid similarity with the prototype of the KAMV, except for an additional gene (U3) that showed a divergence of 6%. These molecular data show that our strain of the KAMV is genetically close to the Culex annuliorus strain that was circulating in Uganda in 1967. However, this study suggests the need to improve our knowledge of the KAMV to better understand its behavior, its life cycle, and its potential reservoirs.
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Affiliation(s)
| | - Emmanuel Nakoune
- 2 Virology Department, Institut Pasteur de Bangui , Bangui, Central African Republic
| | - Benjamin Selekon
- 2 Virology Department, Institut Pasteur de Bangui , Bangui, Central African Republic
| | - Antoine Gessain
- 3 Epidemiology and Physiopathology of Oncogenic Viruses, Institut Pasteur , Paris, France .,4 Centre National de Recherche Scientifique (CNRS) UMR3569 , Paris, France
| | - Jean-Claude Manuguerra
- 5 Unité Environnement et Risques Infectieux, Cellule d'Intervention Biologique d'Urgence, Institut Pasteur , Paris, France
| | - Mirdad Kazanji
- 2 Virology Department, Institut Pasteur de Bangui , Bangui, Central African Republic
| | - Nicolas Berthet
- 1 Centre International de Recherches Médicales de Franceville (CIRMF) , Franceville, Gabon .,4 Centre National de Recherche Scientifique (CNRS) UMR3569 , Paris, France .,5 Unité Environnement et Risques Infectieux, Cellule d'Intervention Biologique d'Urgence, Institut Pasteur , Paris, France
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Nakouné E, Kamgang B, Berthet N, Manirakiza A, Kazanji M. Rift Valley Fever Virus Circulating among Ruminants, Mosquitoes and Humans in the Central African Republic. PLoS Negl Trop Dis 2016; 10:e0005082. [PMID: 27760144 PMCID: PMC5070846 DOI: 10.1371/journal.pntd.0005082] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 09/28/2016] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Rift Valley fever virus (RVFV) causes a viral zoonosis, with discontinuous epizootics and sporadic epidemics, essentially in East Africa. Infection with this virus causes severe illness and abortion in sheep, goats, and cattle as well as other domestic animals. Humans can also be exposed through close contact with infectious tissues or by bites from infected mosquitoes, primarily of the Aedes and Culex genuses. Although the cycle of RVFV infection in savannah regions is well documented, its distribution in forest areas in central Africa has been poorly investigated. METHODOLOGY/PRINCIPAL FINDINGS To evaluate current circulation of RVFV among livestock and humans living in the Central African Republic (CAR), blood samples were collected from sheep, cattle, and goats and from people at risk, such as stock breeders and workers in slaughterhouses and livestock markets. The samples were tested for anti-RVFV immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies. We also sequenced the complete genomes of two local strains, one isolated in 1969 from mosquitoes and one isolated in 1985 from humans living in forested areas. The 1271 animals sampled comprised 727 cattle, 325 sheep, and 219 goats at three sites. The overall seroprevalence of anti-RVFV IgM antibodies was 1.9% and that of IgG antibodies was 8.6%. IgM antibodies were found only during the rainy season, but the frequency of IgG antibodies did not differ significantly by season. No evidence of recent RVFV infection was found in 335 people considered at risk; however, 16.7% had evidence of past infection. Comparison of the nucleotide sequences of the strains isolated in the CAR with those isolated in other African countries showed that they belonged to the East/Central African cluster. CONCLUSION AND SIGNIFICANCE This study confirms current circulation of RVFV in CAR. Further studies are needed to determine the potential vectors involved and the virus reservoirs.
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Affiliation(s)
- Emmanuel Nakouné
- Laboratoire de Virologie, Institut Pasteur de Bangui, Bangui, Central African Republic
| | - Basile Kamgang
- Laboratoire de Virologie, Institut Pasteur de Bangui, Bangui, Central African Republic
- Research Unit Liverpool School of Tropical Medicine, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, Yaoundé, Cameroon
- * E-mail:
| | - Nicolas Berthet
- Department of Zoonosis and Emerging Diseases, Centre International Recherches Médicales de Franceville Gabon, Franceville, Gabon
| | - Alexandre Manirakiza
- Laboratoire de Virologie, Institut Pasteur de Bangui, Bangui, Central African Republic
| | - Mirdad Kazanji
- Laboratoire de Virologie, Institut Pasteur de Bangui, Bangui, Central African Republic
- Institut Pasteur de la Guyane, Cayenne, French Guiana
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