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McMillen CM, Megli C, Radisic R, Skvarca LB, Hoehl RM, Boyles DA, McGaughey JJ, Bird BH, McElroy AK, Hartman AL. Vaccine strains of Rift Valley fever virus exhibit attenuation at the maternal-fetal placental interface. J Virol 2024; 98:e0098324. [PMID: 39016561 PMCID: PMC11334480 DOI: 10.1128/jvi.00983-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Accepted: 06/17/2024] [Indexed: 07/18/2024] Open
Abstract
Rift Valley fever virus (RVFV) infection causes abortions in ruminant livestock and is associated with an increased likelihood of miscarriages in women. Using sheep and human placenta explant cultures, we sought to identify tissues at the maternal-fetal interface targeted by RVFV. Sheep villi and fetal membranes were highly permissive to RVFV infection resulting in markedly higher virus titers than human cultures. Sheep cultures were most permissive to wild-type RVFV and ΔNSm infection, while live-attenuated RVFV vaccines (LAVs; MP-12, ΔNSs, and ΔNSs/ΔNSm) exhibited reduced replication. The human fetal membrane restricted wild-type and LAV replication, and when infection occurred, it was prominent on the maternal-facing side. Type I and type III interferons were induced in human villi exposed to LAVs lacking the NSs protein. This study supports the use of sheep and human placenta explants to understand vertical transmission of RVFV in mammals and whether LAVs are attenuated at the maternal-fetal interface.IMPORTANCEA direct comparison of replication of Rift Valley fever virus (RVFV) in sheep and human placental explants reveals comparative efficiencies and permissivity to infection and replication. Vaccine strains of RVFV demonstrated reduced infection and replication capacity in the mammalian placenta. This study represents the first direct cross-host comparison of the vertical transmission capacity of this high-priority emerging mosquito-transmitted virus.
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Affiliation(s)
- Cynthia M. McMillen
- University of Pittsburgh, Center for Vaccine Research, Pittsburgh, Pennsylvania, USA
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, School of Public Health, Pittsburgh, Pennsylvania, USA
| | - Christina Megli
- Division of Maternal-Fetal Medicine, Division of Reproductive Infectious Disease, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh School of Medicine and the Magee-Womens Research Institute, Pittsburgh, Pennsylvania, USA
| | - Rebecca Radisic
- One Health Institute, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Lauren B. Skvarca
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Ryan M. Hoehl
- University of Pittsburgh, Center for Vaccine Research, Pittsburgh, Pennsylvania, USA
| | - Devin A. Boyles
- University of Pittsburgh, Center for Vaccine Research, Pittsburgh, Pennsylvania, USA
| | - Jackson J. McGaughey
- University of Pittsburgh, Center for Vaccine Research, Pittsburgh, Pennsylvania, USA
| | - Brian H. Bird
- One Health Institute, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Anita K. McElroy
- University of Pittsburgh, Center for Vaccine Research, Pittsburgh, Pennsylvania, USA
- Department of Pediatrics, Division of Pediatric Infectious Disease, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Amy L. Hartman
- University of Pittsburgh, Center for Vaccine Research, Pittsburgh, Pennsylvania, USA
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, School of Public Health, Pittsburgh, Pennsylvania, USA
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2
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Borrego B, Alonso C, Moreno S, de la Losa N, Sánchez-Cordón PJ, Brun A. The Rift Valley fever (RVF) vaccine candidate 40Fp8 shows an extreme attenuation in IFNARKO mice following intranasal inoculation. PLoS Negl Trop Dis 2024; 18:e0012011. [PMID: 39159263 PMCID: PMC11361746 DOI: 10.1371/journal.pntd.0012011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 08/29/2024] [Accepted: 08/02/2024] [Indexed: 08/21/2024] Open
Abstract
Rift Valley fever (RVF) is an important zoonotic viral disease affecting several species of domestic and wild ruminants, causing major economic losses and dozens of human deaths in various geographical areas of Africa, where it is endemic. Although it is not present in Europe, there is a risk of its introduction and spread linked to globalisation and climate change. At present, the only measure that could help to prevent the disease is vaccination of flocks in areas at risk of RVF. Available live attenuated vaccines are an effective means of controlling the disease, but their use is often questioned due to residual virulence, particularly in susceptible hosts such as pregnant sheep. On the other hand, no vaccine is currently licensed for use in humans. The development of safe and effective vaccines is therefore a major area of research. In previous studies, we selected under selective mutagenic pressure a highly attenuated RVFV 56/74 virus variant called 40Fp8. This virus showed an extremely attenuated phenotype in both wild-type and immunodeficient A129 (IFNARKO) mice, yet was still able to induce protective immunity after a single inoculation, thus supporting its use as a safe, live attenuated vaccine. To further investigate its safety, in this work we have analysed the attenuation level of 40Fp8 in immunosuppressed mice (A129) when administered by the intranasal route, and compared it with other attenuated RVF viruses that are the basis of vaccines in use or in development. Our results show that 40Fp8 has a much higher attenuated level than these other viruses and confirm its potential as a candidate for safe RVF vaccine development.
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Affiliation(s)
- Belén Borrego
- Department of IMMUNOLOGY, PATHOLOGY AND CONTROL OF INFECTIOUS DISEASES, Centro de Investigación en Sanidad Animal CISA INIA/CSIC, Valdeolmos, Madrid, Spain
| | - Celia Alonso
- Department of IMMUNOLOGY, PATHOLOGY AND CONTROL OF INFECTIOUS DISEASES, Centro de Investigación en Sanidad Animal CISA INIA/CSIC, Valdeolmos, Madrid, Spain
| | - Sandra Moreno
- Department of IMMUNOLOGY, PATHOLOGY AND CONTROL OF INFECTIOUS DISEASES, Centro de Investigación en Sanidad Animal CISA INIA/CSIC, Valdeolmos, Madrid, Spain
| | - Nuria de la Losa
- Department of IMMUNOLOGY, PATHOLOGY AND CONTROL OF INFECTIOUS DISEASES, Centro de Investigación en Sanidad Animal CISA INIA/CSIC, Valdeolmos, Madrid, Spain
| | - Pedro José Sánchez-Cordón
- Department of INFECTIOUS DISEASES AND GLOBAL HEALTH, Centro de Investigación en Sanidad Animal CISA INIA/CSIC, Valdeolmos, Madrid, Spain
| | - Alejandro Brun
- Department of IMMUNOLOGY, PATHOLOGY AND CONTROL OF INFECTIOUS DISEASES, Centro de Investigación en Sanidad Animal CISA INIA/CSIC, Valdeolmos, Madrid, Spain
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3
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Alkan C, Jurado-Cobena E, Ikegami T. Distinct Pathological Changes in Preweaning Mice Infected with Live-Attenuated Rift Valley Fever Virus Strains. Viruses 2024; 16:999. [PMID: 39066162 PMCID: PMC11281583 DOI: 10.3390/v16070999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 06/18/2024] [Accepted: 06/20/2024] [Indexed: 07/28/2024] Open
Abstract
Rift Valley fever (RVF) is a mosquito-borne zoonotic viral disease endemic to Africa and the Middle East. Live-attenuated RVF vaccines have been studied for both veterinary and human use due to their strong immunogenicity and cost-effective manufacturing. The live-attenuated MP-12 vaccine has been conditionally approved for veterinary use in the U.S.A., and next-generation live-attenuated RVF vaccine candidates are being actively researched. Assessing the virulence phenotype of vaccine seeds or lots is crucial for managing vaccine safety. Previously, preweaning 19-day-old outbred CD1 mice have been used to evaluate the MP-12 strain. This study aimed to characterize the relative virulence of three live-attenuated RVF vaccine strains in 19-day-old inbred C57BL/6 mice: the recombinant MP-12 (rMP-12), the RVax-1, and the ∆NSs-∆NSm-rZH501 strains. Although this mouse model did not show dose-dependent pathogenesis, mice that succumbed to the infection exhibited distinct brain pathology. Mice infected with ∆NSs-∆NSm-rZH501 showed an infiltration of inflammatory cells associated with infected neurons, and focal lesions formed around virus-infected cells. In contrast, mice infected with rMP-12 or RVax-1 showed a minimal association of inflammatory cells in the brain, yet the virus spread diffusely. The preweaning model is likely useful for evaluating host responses to attenuated RVFV strains, although further refinement may be necessary to quantitate the virulence among different RVFV strains or vaccine lots.
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Affiliation(s)
- Cigdem Alkan
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA;
| | - Eduardo Jurado-Cobena
- Department of Microbiology and Immunology, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA;
| | - Tetsuro Ikegami
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA;
- Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
- Sealy Institute for Vaccine Sciences, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
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Bracci N, Baer A, Flor R, Petraccione K, Stocker T, Zhou W, Ammosova T, Dinglasan RR, Nekhai S, Kehn-Hall K. CK1 and PP1 regulate Rift Valley fever virus genome replication through L protein phosphorylation. Antiviral Res 2024; 226:105895. [PMID: 38679165 DOI: 10.1016/j.antiviral.2024.105895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 04/15/2024] [Accepted: 04/22/2024] [Indexed: 05/01/2024]
Abstract
Rift Valley fever virus (RVFV) is an arbovirus in the Phenuiviridae family identified initially by the large 'abortion storms' observed among ruminants; RVFV can also infect humans. In humans, there is a wide variation of clinical symptoms ranging from subclinical to mild febrile illness to hepatitis, retinitis, delayed-onset encephalitis, or even hemorrhagic fever. The RVFV is a tri-segmented negative-sense RNA virus consisting of S, M, and L segments. The L segment encodes the RNA-dependent RNA polymerase (RdRp), termed the L protein, which is responsible for both viral mRNA synthesis and genome replication. Phosphorylation of viral RdRps is known to regulate viral replication. This study shows that RVFV L protein is serine phosphorylated and identified Casein Kinase 1 alpha (CK1α) and protein phosphatase 1 alpha (PP1α) as L protein binding partners. Inhibition of CK1 and PP1 through small molecule inhibitor treatment, D4476 and 1E7-03, respectively, caused a change in the phosphorylated status of the L protein. Inhibition of PP1α resulted in increased L protein phosphorylation whereas inhibition of CK1α decreased L protein phosphorylation. It was also found that in RVFV infected cells, PP1α localized to the cytoplasmic compartment. Treatment of RVFV infected cells with CK1 inhibitors reduced virus production in both mammalian and mosquito cells. Lastly, inhibition of either CK1 or PP1 reduced viral genomic RNA levels. These data indicate that L protein is phosphorylated and that CK1 and PP1 play a crucial role in regulating the L protein phosphorylation cycle, which is critical to viral RNA production and viral replication.
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Affiliation(s)
- Nicole Bracci
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Virginia, USA; Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University, Virginia, USA
| | - Alan Baer
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Rafaela Flor
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Virginia, USA; Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University, Virginia, USA
| | - Kaylee Petraccione
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Virginia, USA; Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University, Virginia, USA
| | - Timothy Stocker
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Virginia, USA; Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University, Virginia, USA
| | - Weidong Zhou
- Center for Applied Proteomics and Molecular Medicine, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Tatiana Ammosova
- Center for Sickle Cell Disease, Department of Medicine, Howard University, Washington D.C., USA
| | - Rhoel R Dinglasan
- Emerging Pathogens Institute, University of Florida, Florida, USA; Department of Infectious Diseases & Immunology, College of Veterinary Medicine, University of Florida, Florida, USA
| | - Sergei Nekhai
- Center for Sickle Cell Disease, Department of Medicine, Howard University, Washington D.C., USA
| | - Kylene Kehn-Hall
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Virginia, USA; Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University, Virginia, USA.
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5
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Griesman T, McMillen CM, Negatu SG, Hulahan JJ, Whig K, Dohnalová L, Dittmar M, Thaiss CA, Jurado KA, Schultz DC, Hartman AL, Cherry S. The lipopeptide Pam3CSK4 inhibits Rift Valley fever virus infection and protects from encephalitis. PLoS Pathog 2024; 20:e1012343. [PMID: 38935789 PMCID: PMC11236204 DOI: 10.1371/journal.ppat.1012343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 07/10/2024] [Accepted: 06/12/2024] [Indexed: 06/29/2024] Open
Abstract
Rift Valley fever virus (RVFV) is an encephalitic bunyavirus that can infect neurons in the brain. There are no approved therapeutics that can protect from RVFV encephalitis. Innate immunity, the first line of defense against infection, canonically antagonizes viruses through interferon signaling. We found that interferons did not efficiently protect primary cortical neurons from RVFV, unlike other cell types. To identify alternative neuronal antiviral pathways, we screened innate immune ligands and discovered that the TLR2 ligand Pam3CSK4 inhibited RVFV infection, and other bunyaviruses. Mechanistically, we found that Pam3CSK4 blocks viral fusion, independent of TLR2. In a mouse model of RVFV encephalitis, Pam3CSK4 treatment protected animals from infection and mortality. Overall, Pam3CSK4 is a bunyavirus fusion inhibitor active in primary neurons and the brain, representing a new approach toward the development of treatments for encephalitic bunyavirus infections.
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Affiliation(s)
- Trevor Griesman
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia Pennsylvania, United States of America
| | - Cynthia M. McMillen
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Infectious Diseases and Microbiology, University of Pittsburgh School of Public Health, Pittsburgh, Pennsylvania, United States of America
| | - Seble Getenet Negatu
- Department of Microbiology, University of Pennsylvania, Philadelphia Pennsylvania, Unites States of America
| | - Jesse J. Hulahan
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia Pennsylvania, United States of America
| | - Kanupriya Whig
- High throughput screening core, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Lenka Dohnalová
- Department of Microbiology, University of Pennsylvania, Philadelphia Pennsylvania, Unites States of America
| | - Mark Dittmar
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia Pennsylvania, United States of America
| | - Christoph A. Thaiss
- Department of Microbiology, University of Pennsylvania, Philadelphia Pennsylvania, Unites States of America
| | - Kellie A. Jurado
- Department of Microbiology, University of Pennsylvania, Philadelphia Pennsylvania, Unites States of America
| | - David C. Schultz
- High throughput screening core, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Amy L. Hartman
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Infectious Diseases and Microbiology, University of Pittsburgh School of Public Health, Pittsburgh, Pennsylvania, United States of America
| | - Sara Cherry
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia Pennsylvania, United States of America
- High throughput screening core, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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6
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McMillen CM, Megli C, Radisic R, Skvarca LB, Hoehl RM, Boyles DA, McGaughey JJ, Bird BH, McElroy AK, Hartman AL. Vaccine strains of Rift Valley fever virus exhibit attenuation at the maternal-fetal placental interface. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.31.596800. [PMID: 38854055 PMCID: PMC11160702 DOI: 10.1101/2024.05.31.596800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Rift Valley fever virus (RVFV) infection causes abortions in ruminant livestock and is associated with an increased likelihood of miscarriages in women. Using sheep and human placenta explant cultures, we sought to identify tissues at the maternal-fetal interface targeted by RVFV. Sheep villi and fetal membranes were highly permissive to RVFV infection resulting in markedly higher virus titers than human cultures. Sheep cultures were most permissive to wild-type RVFV and ΔNSm infection, while live attenuated RVFV vaccines (LAVs; MP-12, ΔNSs, and ΔNSs/ΔNSm) exhibited reduced replication. The human fetal membrane restricted wild-type and LAV replication, and when infection occurred, it was prominent in the maternal-facing side. Type-I and type-III interferons were induced in human villi exposed to LAVs lacking the NSs protein. This study supports the use of sheep and human placenta explants to understand vertical transmission of RVFV in mammals and whether LAVs are attenuated at the maternal-fetal interface.
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Affiliation(s)
- Cynthia M. McMillen
- University of Pittsburgh, Center for Vaccine Research, Pittsburgh, PA, USA
- University of Pittsburgh, Department of Infectious Diseases and Microbiology, School of Public Health, Pittsburgh, PA, USA
| | - Christina Megli
- University of Pittsburgh School of Medicine and the Magee-Womens Research Institute, Division of Maternal-Fetal Medicine, Division of Reproductive Infectious Disease, Department of Obstetrics, Gynecology and Reproductive Sciences, Pittsburgh, PA, USA
| | - Rebecca Radisic
- One Health Institute, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Lauren B. Skvarca
- University of Pittsburgh School of Medicine, Department of Pathology, Pittsburgh, PA, USA
| | - Ryan M. Hoehl
- University of Pittsburgh, Center for Vaccine Research, Pittsburgh, PA, USA
| | - Devin A. Boyles
- University of Pittsburgh, Center for Vaccine Research, Pittsburgh, PA, USA
| | | | - Brian H. Bird
- One Health Institute, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Anita K. McElroy
- University of Pittsburgh, Center for Vaccine Research, Pittsburgh, PA, USA
- University of Pittsburgh School of Medicine, Department of Pediatrics, Division of Pediatric Infectious Disease, Pittsburgh, PA, USA
| | - Amy L. Hartman
- University of Pittsburgh, Center for Vaccine Research, Pittsburgh, PA, USA
- University of Pittsburgh, Department of Infectious Diseases and Microbiology, School of Public Health, Pittsburgh, PA, USA
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7
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Rangel MV, Bourguet FA, Hall CI, Weilhammer DR. Evaluation of Inactivation Methods for Rift Valley Fever Virus in Mouse Microglia. Pathogens 2024; 13:159. [PMID: 38392897 PMCID: PMC10892077 DOI: 10.3390/pathogens13020159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/30/2024] [Accepted: 02/07/2024] [Indexed: 02/25/2024] Open
Abstract
Rift Valley fever phlebovirus (RVFV) is a highly pathogenic mosquito-borne virus with bioweapon potential due to its ability to be spread by aerosol transmission. Neurological symptoms are among the worst outcomes of infection, and understanding of pathogenesis mechanisms within the brain is limited. RVFV is classified as an overlap select agent by the CDC and USDA; therefore, experiments involving fully virulent strains of virus are tightly regulated. Here, we present two methods for inactivation of live virus within samples derived from mouse microglia cells using commercially available kits for the preparation of cells for flow cytometry and RNA extraction. Using the flow cytometry protocol, we demonstrate key differences in the response of primary murine microglia to infection with fully virulent versus attenuated RVFV.
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Affiliation(s)
- Margarita V. Rangel
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; (M.V.R.); (F.A.B.)
| | - Feliza A. Bourguet
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; (M.V.R.); (F.A.B.)
| | - Carolyn I. Hall
- Environment, Safety & Health, Biosafety & Biogovernance Functional Area, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA;
| | - Dina R. Weilhammer
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; (M.V.R.); (F.A.B.)
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8
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Moreno S, Lorenzo G, López-Valiñas Á, de la Losa N, Alonso C, Charro E, Núñez JI, Sánchez-Cordón PJ, Borrego B, Brun A. Safety and Efficacy upon Infection in Sheep with Rift Valley Fever Virus ZH548-rA2, a Triple Mutant Rescued Virus. Viruses 2024; 16:87. [PMID: 38257787 PMCID: PMC10819402 DOI: 10.3390/v16010087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 12/29/2023] [Accepted: 01/02/2024] [Indexed: 01/24/2024] Open
Abstract
The introduction of three single nucleotide mutations into the genome of the virulent RVFV ZH548 strain allows for the rescue of a fully attenuated virus in mice (ZH548-rA2). These mutations are located in the viral genes encoding the RdRp and the non-structural protein NSs. This paper shows the results obtained after the subcutaneous inoculation of ZH548-rA2 in adult sheep and the subsequent challenge with the parental virus (ZH548-rC1). Inoculation with the ZH548-rA2 virus caused no detectable clinical or pathological effect in sheep, whereas inoculation of the parental rC1 virus caused lesions compatible with viral infection characterised by the presence of scattered hepatic necrosis. Viral infection was confirmed via immunohistochemistry, with hepatocytes within the necrotic foci appearing as the main cells immunolabelled against viral antigen. Furthermore, the inoculation of sheep with the rA2 virus prevented the liver damage expected after rC1 virus inoculation, suggesting a protective efficacy in sheep which correlated with the induction of both humoral and cell-mediated immune responses.
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Affiliation(s)
- Sandra Moreno
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Consejo Superior de Investigaciones Científicas (INIA-CSIC), Valdeolmos, 28130 Madrid, Spain; (S.M.); (G.L.); (P.J.S.-C.)
| | - Gema Lorenzo
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Consejo Superior de Investigaciones Científicas (INIA-CSIC), Valdeolmos, 28130 Madrid, Spain; (S.M.); (G.L.); (P.J.S.-C.)
| | - Álvaro López-Valiñas
- Centre de Recerca en Sanitat Animal (CReSA), Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Bellaterra, 08193 Barcelona, Spain (J.I.N.)
| | - Nuria de la Losa
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Consejo Superior de Investigaciones Científicas (INIA-CSIC), Valdeolmos, 28130 Madrid, Spain; (S.M.); (G.L.); (P.J.S.-C.)
| | - Celia Alonso
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Consejo Superior de Investigaciones Científicas (INIA-CSIC), Valdeolmos, 28130 Madrid, Spain; (S.M.); (G.L.); (P.J.S.-C.)
| | - Elena Charro
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Consejo Superior de Investigaciones Científicas (INIA-CSIC), Valdeolmos, 28130 Madrid, Spain; (S.M.); (G.L.); (P.J.S.-C.)
| | - José I. Núñez
- Centre de Recerca en Sanitat Animal (CReSA), Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Bellaterra, 08193 Barcelona, Spain (J.I.N.)
| | - Pedro J. Sánchez-Cordón
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Consejo Superior de Investigaciones Científicas (INIA-CSIC), Valdeolmos, 28130 Madrid, Spain; (S.M.); (G.L.); (P.J.S.-C.)
| | - Belén Borrego
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Consejo Superior de Investigaciones Científicas (INIA-CSIC), Valdeolmos, 28130 Madrid, Spain; (S.M.); (G.L.); (P.J.S.-C.)
| | - Alejandro Brun
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Consejo Superior de Investigaciones Científicas (INIA-CSIC), Valdeolmos, 28130 Madrid, Spain; (S.M.); (G.L.); (P.J.S.-C.)
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9
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Alkan C, O’Brien T, Kenyon V, Ikegami T. Computer-Selected Antiviral Compounds: Assessing In Vitro Efficacies against Rift Valley Fever Virus. Viruses 2024; 16:88. [PMID: 38257788 PMCID: PMC10818293 DOI: 10.3390/v16010088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/03/2024] [Accepted: 01/03/2024] [Indexed: 01/24/2024] Open
Abstract
Rift Valley fever is a zoonotic viral disease transmitted by mosquitoes, impacting both humans and livestock. Currently, there are no approved vaccines or antiviral treatments for humans. This study aimed to evaluate the in vitro efficacy of chemical compounds targeting the Gc fusion mechanism. These compounds were identified through virtual screening of millions of commercially available small molecules using a structure-based artificial intelligence bioactivity predictor. In our experiments, a pretreatment with small molecule compounds revealed that 3 out of 94 selected compounds effectively inhibited the replication of the Rift Valley fever virus MP-12 strain in Vero cells. As anticipated, these compounds did not impede viral RNA replication when administered three hours after infection. However, significant inhibition of viral RNA replication occurred upon viral entry when cells were pretreated with these small molecules. Furthermore, these compounds exhibited significant inhibition against Arumowot virus, another phlebovirus, while showing no antiviral effects on tick-borne bandaviruses. Our study validates AI-based virtual high throughput screening as a rational approach for identifying effective antiviral candidates for Rift Valley fever virus and other bunyaviruses.
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Affiliation(s)
- Cigdem Alkan
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA;
| | - Terrence O’Brien
- Discovery Chemistry, Genentech, Inc., South San Francisco, CA 94080, USA;
| | | | - Tetsuro Ikegami
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA;
- Sealy Institute for Vaccine Sciences, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
- Institute for Human Infections and Immunity, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
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10
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Tercero B, Makino S. Reverse Genetics System for Rift Valley Fever Virus. Methods Mol Biol 2024; 2733:101-113. [PMID: 38064029 DOI: 10.1007/978-1-0716-3533-9_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Rift Valley fever virus (RVFV) is an important mosquito-borne virus that can cause severe disease manifestations in humans including ocular damage, vision loss, late-onset encephalitis, and hemorrhagic fever. In ruminants, RVFV can cause high mortality rates in young animals and high rates of abortion in pregnant animals resulting in an enormous negative impact on the economy of affected regions. To date, no licensed vaccines in humans or anti-RVFV therapeutics for animal or human use are available. The development of reverse genetics has facilitated the generation of recombinant infectious viruses that serve as powerful tools for investigating the molecular biology and pathogenesis of RVFV. Infectious recombinant RVFV can be rescued entirely from cDNAs containing predetermined mutations in their genomes to investigate virus-host interactions and mechanisms of pathogenesis and generate live-attenuated vaccines. In this chapter, we will describe the experimental procedures for the implementation of RVFV reverse genetics.
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Affiliation(s)
- Breanna Tercero
- Departments of Microbiology and Immunology, Galveston, TX, USA
| | - Shinji Makino
- Departments of Microbiology and Immunology, Galveston, TX, USA.
- Institute of Human Infection and Immunity, Galveston, TX, USA.
- Center for Biodefense and Emerging Infectious Diseases, Galveston, TX, USA.
- UTMB Center for Tropical Diseases, Galveston, TX, USA.
- The Sealy Institute for Vaccine Sciences, Galveston, TX, USA.
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11
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Doores KJ. Humoral immunity to phlebovirus infection. Ann N Y Acad Sci 2023; 1530:23-31. [PMID: 37936483 PMCID: PMC10952791 DOI: 10.1111/nyas.15080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
Phleboviruses are zoonotic pathogens found in parts of Africa, Asia, Europe, and North America and cause disease symptoms ranging from self-limiting febrile illness to severe disease, including hemorrhagic diathesis, encephalitis, and ocular pathologies. There are currently no approved preventative vaccines against phlebovirus infection or antivirals for the treatment of the disease. Here, we discuss the roles of neutralizing antibodies in phlebovirus infection, the antigenic targets present on the mature polyproteins Gn and Gc, progress in vaccine development, and the prospects of identifying conserved neutralizing epitopes across multiple phleboviruses. Further research in this area will pave the way for the rational design of pan-phlebovirus vaccines that will protect against both known phleboviruses but also newly emerging phleboviruses that may have pandemic potential.
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Affiliation(s)
- Katie J. Doores
- Department of Infectious Diseases, King's College LondonGuy's HospitalLondonUK
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12
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Alkan C, Jurado-Cobena E, Ikegami T. Advancements in Rift Valley fever vaccines: a historical overview and prospects for next generation candidates. NPJ Vaccines 2023; 8:171. [PMID: 37925544 PMCID: PMC10625542 DOI: 10.1038/s41541-023-00769-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 10/18/2023] [Indexed: 11/06/2023] Open
Abstract
Rift Valley fever (RVF) is a zoonotic viral disease transmitted by mosquitoes and causes abortion storms, fetal malformations, and newborn animal deaths in livestock ruminants. In humans, RVF can manifest as hemorrhagic fever, encephalitis, or retinitis. Outbreaks of RVF have been occurring in Africa since the early 20th century and continue to pose a threat to both humans and animals in various regions such as Africa, Madagascar, the Comoros, Saudi Arabia, and Yemen. The development of RVF vaccines is crucial in preventing mortality and morbidity and reducing the spread of the virus. While several veterinary vaccines have been licensed in endemic countries, there are currently no licensed RVF vaccines for human use. This review provides an overview of the existing RVF vaccines, as well as potential candidates for future studies on RVF vaccine development, including next-generation vaccines that show promise in combating the disease in both humans and animals.
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Affiliation(s)
- Cigdem Alkan
- Department of Pathology, The University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
| | - Eduardo Jurado-Cobena
- Department of Microbiology and Immunology, The University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
| | - Tetsuro Ikegami
- Department of Pathology, The University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA.
- The Sealy Institute for Vaccine Sciences, The University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA.
- The Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA.
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13
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Devignot S, Sha TW, Burkard TR, Schmerer P, Hagelkruys A, Mirazimi A, Elling U, Penninger JM, Weber F. Low-density lipoprotein receptor-related protein 1 (LRP1) as an auxiliary host factor for RNA viruses. Life Sci Alliance 2023; 6:e202302005. [PMID: 37072184 PMCID: PMC10114362 DOI: 10.26508/lsa.202302005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 04/04/2023] [Accepted: 04/05/2023] [Indexed: 04/20/2023] Open
Abstract
Viruses with an RNA genome are often the cause of zoonotic infections. In order to identify novel pro-viral host cell factors, we screened a haploid insertion-mutagenized mouse embryonic cell library for clones that are resistant to Rift Valley fever virus (RVFV). This screen returned the low-density lipoprotein receptor-related protein 1 (LRP1) as a top hit, a plasma membrane protein involved in a wide variety of cell activities. Inactivation of LRP1 in human cells reduced RVFV RNA levels already at the attachment and entry stages of infection. Moreover, the role of LRP1 in promoting RVFV infection was dependent on physiological levels of cholesterol and on endocytosis. In the human cell line HuH-7, LRP1 also promoted early infection stages of sandfly fever Sicilian virus and La Crosse virus, but had a minor effect on late infection by vesicular stomatitis virus, whereas encephalomyocarditis virus was entirely LRP1-independent. Moreover, siRNA experiments in human Calu-3 cells demonstrated that also SARS-CoV-2 infection benefitted from LRP1. Thus, we identified LRP1 as a host factor that supports infection by a spectrum of RNA viruses.
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Affiliation(s)
- Stephanie Devignot
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, Giessen, Germany
| | - Tim Wai Sha
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, Giessen, Germany
| | - Thomas R Burkard
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna, Austria
| | - Patrick Schmerer
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, Giessen, Germany
| | - Astrid Hagelkruys
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna, Austria
| | - Ali Mirazimi
- Public Health Agency of Sweden, Solna, Sweden
- Department of Laboratory Medicine, Karolinska Institutet, Solna, Sweden
| | - Ulrich Elling
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna, Austria
| | - Josef M Penninger
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna, Austria
- Department of Medical Genetics, Life Sciences Institute, University of British Columbia, Vancouver, Canada
| | - Friedemann Weber
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, Giessen, Germany
- German Centre for Infection Research (DZIF), Partner Site Giessen, Giessen, Germany
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14
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Ahmed EM, Boseila AA, Hanora AS, Solyman SM. Antiviral and protective effect of small interfering RNAs against rift valley fever virus in vitro. Mol Biol Rep 2023:10.1007/s11033-023-08455-9. [PMID: 37231214 DOI: 10.1007/s11033-023-08455-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 04/12/2023] [Indexed: 05/27/2023]
Abstract
BACKGROUND Rift Valley Fever Virus (RVFV) is an arbovirus, a zoonotic disease that resurfaces as a potential hazard beyond geographic boundaries. Fever that can proceed to encephalitis, retinitis, hemorrhagic fever, and death is the main manifestation observed in human infections. RVFV has no authorized medication. The RNA interference (RNAi) gene silencing pathway is extremely well conserved. By targeting specific genes, small interfering RNA (siRNA) can be used to suppress viral replication. The aim of this study was to design specific siRNAs against RVFV and evaluate their prophylactic and antiviral effects on the Vero cells. METHODS AND RESULTS Various siRNAs were designed using different bioinformatics tools. Three unique candidates were tested against an Egyptian sheep cell culture-adapted strain BSL-2 that suppressed RVFV N mRNA expression. SiRNAs were transfected a day before RVFV infection (pre-transfection), and 1 h after the viral infection (post-transfection), and were evaluated to detect the silencing activity and gene expression decrease using real-time PCR and a TCID50 endpoint test. The degree of N protein expression was determined by western blot 48 h after viral infection. D2 which targets the (488-506 nucleotides), the middle region of RVFV N mRNA was the most effective siRNA at 30 nM concentration, it almost eliminates N mRNA expression when utilized as antiviral or preventive therapy. siRNAs had a stronger antiviral silencing impact when they were post-transfected into Vero cells. CONCLUSION Pre and post-transfection of siRNAs significantly reduced RVFV titer in cell lines, offering novel and potentially effective anti-RVFV epidemics and epizootics therapy.
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Affiliation(s)
- Engy M Ahmed
- Egyptian Drug Authority (EDA), Giza, Egypt
- Microbiology & Immunology Department, College of Pharmacy, Suez Canal University, Ismailia, Egypt
| | | | - Amro S Hanora
- Microbiology & Immunology Department, College of Pharmacy, Suez Canal University, Ismailia, Egypt.
| | - Samar M Solyman
- Microbiology & Immunology Department, College of Pharmacy, Suez Canal University, Ismailia, Egypt
- Microbiology & Immunology Department, Faculty of Pharmacy, Sinai University Kantara branch, Ismailia, Egypt
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15
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Chen T, Ding Z, Lan J, Wong G. Advances and perspectives in the development of vaccines against highly pathogenic bunyaviruses. Front Cell Infect Microbiol 2023; 13:1174030. [PMID: 37274315 PMCID: PMC10234439 DOI: 10.3389/fcimb.2023.1174030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Accepted: 05/03/2023] [Indexed: 06/06/2023] Open
Abstract
Increased human activities around the globe and the rapid development of once rural regions have increased the probability of contact between humans and wild animals. A majority of bunyaviruses are of zoonotic origin, and outbreaks may result in the substantial loss of lives, economy contraction, and social instability. Many bunyaviruses require manipulation in the highest levels of biocontainment, such as Biosafety Level 4 (BSL-4) laboratories, and the scarcity of this resource has limited the development speed of vaccines for these pathogens. Meanwhile, new technologies have been created, and used to innovate vaccines, like the mRNA vaccine platform and bioinformatics-based antigen design. Here, we summarize current vaccine developments for three different bunyaviruses requiring work in the highest levels of biocontainment: Crimean-Congo Hemorrhagic Fever Virus (CCHFV), Rift Valley Fever Virus (RVFV), and Hantaan virus (HTNV), and provide perspectives and potential future directions that can be further explored to advance specific vaccines for humans and livestock.
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Affiliation(s)
- Tong Chen
- Viral Hemorrhagic Fevers Research Unit, Chinese Academy of Sciences (CAS) Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences (CAS), Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Zhe Ding
- Viral Hemorrhagic Fevers Research Unit, Chinese Academy of Sciences (CAS) Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences (CAS), Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jiaming Lan
- Viral Hemorrhagic Fevers Research Unit, Chinese Academy of Sciences (CAS) Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences (CAS), Shanghai, China
| | - Gary Wong
- Viral Hemorrhagic Fevers Research Unit, Chinese Academy of Sciences (CAS) Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences (CAS), Shanghai, China
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16
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Laureti M, Lee RX, Bennett A, Wilson LA, Sy VE, Kohl A, Dietrich I. Rift Valley Fever Virus Primes Immune Responses in Aedes aegypti Cells. Pathogens 2023; 12:563. [PMID: 37111448 PMCID: PMC10146816 DOI: 10.3390/pathogens12040563] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/25/2023] [Accepted: 04/03/2023] [Indexed: 04/29/2023] Open
Abstract
The ongoing global emergence of arthropod-borne (arbo) viruses has accelerated research into the interactions of these viruses with the immune systems of their vectors. Only limited information exists on how bunyaviruses, such as Rift Valley fever virus (RVFV), are sensed by mosquito immunity or escape detection. RVFV is a zoonotic phlebovirus (Bunyavirales; Phenuiviridae) of veterinary and human public health and economic importance. We have shown that the infection of mosquitoes with RVFV triggers the activation of RNA interference pathways, which moderately restrict viral replication. Here, we aimed to better understand the interactions between RVFV and other vector immune signaling pathways that might influence RVFV replication and transmission. For this, we used the immunocompetent Aedes aegypti Aag2 cell line as a model. We found that bacteria-induced immune responses restricted RVFV replication. However, virus infection alone did not alter the gene expression levels of immune effectors. Instead, it resulted in the marked enhancement of immune responses to subsequent bacterial stimulation. The gene expression levels of several mosquito immune pattern recognition receptors were altered by RVFV infection, which may contribute to this immune priming. Our findings imply that there is a complex interplay between RVFV and mosquito immunity that could be targeted in disease prevention strategies.
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Affiliation(s)
| | - Rui-Xue Lee
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Road, Glasgow G61 1QH, UK
| | - Amelia Bennett
- The Pirbright Institute, Ash Road, Pirbright GU24 0NF, UK
- Department of Life Sciences, Faculty of Science, Claverton Down, University of Bath, Bath BA2 7AY, UK
| | - Lucas Aladar Wilson
- The Pirbright Institute, Ash Road, Pirbright GU24 0NF, UK
- Institute of Medical Sciences, School of Medicine, Medical Sciences and Nutrition, Foresterhill, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | | | - Alain Kohl
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Road, Glasgow G61 1QH, UK
| | - Isabelle Dietrich
- The Pirbright Institute, Ash Road, Pirbright GU24 0NF, UK
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Road, Glasgow G61 1QH, UK
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17
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Wichgers Schreur PJ, Bird BH, Ikegami T, Bermúdez-Méndez E, Kortekaas J. Perspectives of Next-Generation Live-Attenuated Rift Valley Fever Vaccines for Animal and Human Use. Vaccines (Basel) 2023; 11:vaccines11030707. [PMID: 36992291 DOI: 10.3390/vaccines11030707] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/10/2023] [Accepted: 03/14/2023] [Indexed: 03/31/2023] Open
Abstract
Live-attenuated Rift Valley fever (RVF) vaccines transiently replicate in the vaccinated host, thereby effectively initiating an innate and adaptive immune response. Rift Valley fever virus (RVFV)-specific neutralizing antibodies are considered the main correlate of protection. Vaccination with classical live-attenuated RVF vaccines during gestation in livestock has been associated with fetal malformations, stillbirths, and fetal demise. Facilitated by an increased understanding of the RVFV infection and replication cycle and availability of reverse genetics systems, novel rationally-designed live-attenuated candidate RVF vaccines with improved safety profiles have been developed. Several of these experimental vaccines are currently advancing beyond the proof-of-concept phase and are being evaluated for application in both animals and humans. We here provide perspectives on some of these next-generation live-attenuated RVF vaccines and highlight the opportunities and challenges of these approaches to improve global health.
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Affiliation(s)
- Paul J Wichgers Schreur
- Department of Virology and Molecular Biology, Wageningen Bioveterinary Research, Wageningen University & Research, 8221 RA Lelystad, The Netherlands
- BunyaVax B.V., 8221 RA Lelystad, The Netherlands
| | - Brian H Bird
- One Health Institute, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Tetsuro Ikegami
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
- The Sealy Institute for Vaccine Sciences, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
- The Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
| | - Erick Bermúdez-Méndez
- Department of Virology and Molecular Biology, Wageningen Bioveterinary Research, Wageningen University & Research, 8221 RA Lelystad, The Netherlands
- Laboratory of Virology, Wageningen University & Research, 6708 PB Wageningen, The Netherlands
| | - Jeroen Kortekaas
- Department of Virology and Molecular Biology, Wageningen Bioveterinary Research, Wageningen University & Research, 8221 RA Lelystad, The Netherlands
- Laboratory of Virology, Wageningen University & Research, 6708 PB Wageningen, The Netherlands
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18
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Ayers VB, Huang YJS, Dunlop JI, Kohl A, Brennan B, Higgs S, Vanlandingham DL. Immunogenicity of a Candidate Live Attenuated Vaccine for Rift Valley Fever Virus with a Two-Segmented Genome. Viral Immunol 2023; 36:33-40. [PMID: 36399689 PMCID: PMC9885543 DOI: 10.1089/vim.2022.0104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Rift Valley fever virus (RVFV) is an emerging arbovirus that affects both ruminants and humans. RVFV causes severe and recurrent outbreaks in Africa and the Arabian Peninsula with a significant risk for emergence into new locations. Although there are a variety of RVFV veterinary vaccines for use in endemic areas, there is currently no licensed vaccine for human use; therefore, there is a need to develop and assess new vaccines. Herein, we report a live-attenuated recombinant vaccine candidate for RVFV, based on the previously described genomic reconfiguration of the conditionally licensed MP12 vaccine. There are two general strategies used to develop live-attenuated RVFV vaccines, one being serial passage of wild-type RVFV strains to select attenuated mutants such as Smithburn, Clone 13, and MP12 vaccine strains. The second strategy has utilized reverse genetics to attenuate RVFV strains by introducing deletions or insertions within the viral genome. The novel candidate vaccine characterized in this report contains a two-segmented genome that lacks the medium viral segment (M) and two virulence genes (nonstructural small and nonstructural medium). The vaccine candidate, named r2segMP12, was evaluated for the production of neutralizing antibodies to RVFV in outbred CD-1 mice. The immune response induced by the r2segMP12 vaccine candidate was directly compared to the immune response induced by the rMP12 parental strain vaccine. Our study demonstrated that a single immunization with the r2segMP12 vaccine candidate at 105 plaque-forming units elicited a higher neutralizing antibody response than the rMP12 vaccine at the same vaccination titer without the need for a booster.
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Affiliation(s)
- Victoria B. Ayers
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, USA.,Biosecurity Research Institute, Kansas State University, Manhattan, Kansas, USA
| | - Yan-Jang S. Huang
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, USA.,Biosecurity Research Institute, Kansas State University, Manhattan, Kansas, USA
| | - James I. Dunlop
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Alain Kohl
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Benjamin Brennan
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Stephen Higgs
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, USA.,Biosecurity Research Institute, Kansas State University, Manhattan, Kansas, USA
| | - Dana L. Vanlandingham
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, USA.,Biosecurity Research Institute, Kansas State University, Manhattan, Kansas, USA.,Address correspondence to: Dr. Dana L. Vanlandingham, Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA
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19
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de Glanville WA, Allan KJ, Nyarobi JM, Thomas KM, Lankester F, Kibona TJ, Claxton JR, Brennan B, Carter RW, Crump JA, Halliday JEB, Ladbury G, Mmbaga BT, Mramba F, Nyasebwa OM, Rubach MP, Rostal MK, Sanka P, Swai ES, Szemiel AM, Willett BJ, Cleaveland S. An outbreak of Rift Valley fever among peri-urban dairy cattle in northern Tanzania. Trans R Soc Trop Med Hyg 2022; 116:1082-1090. [PMID: 36040309 PMCID: PMC9623736 DOI: 10.1093/trstmh/trac076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 07/12/2022] [Accepted: 08/01/2022] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Human and animal cases of Rift Valley fever (RVF) are typically only reported during large outbreaks. The occurrence of RVF cases that go undetected by national surveillance systems in the period between these outbreaks is considered likely. The last reported cases of RVF in Tanzania occurred during a large outbreak in 2007-2008. METHODS Samples collected between 2017 and 2019 from livestock suffering abortion across northern Tanzania were retrospectively tested for evidence of RVF virus infection using serology and reverse transcription quantitative polymerase chain reaction (RT-qPCR). RESULTS A total of 14 RVF-associated cattle abortions were identified among dairy cattle in a peri-urban area surrounding the town of Moshi. RVF cases occurred from May to August 2018 and were considered to represent an undetected, small-scale RVF outbreak. Milk samples from 3 of 14 cases (21%) were found to be RT-qPCR positive. Genotyping revealed circulation of RVF viruses from two distinct lineages. CONCLUSIONS RVF outbreaks can occur more often in endemic settings than would be expected on the basis of detection by national surveillance. The occurrence of RVF cases among peri-urban dairy cattle and evidence for viral shedding in milk, also highlights potentially emerging risks for RVF associated with increasing urban and peri-urban livestock populations.
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Affiliation(s)
- William A de Glanville
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
- University of Global Health Equity, Kigali 6955, Rwanda
| | - Kathryn J Allan
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
- School of Veterinary Medicine, University of Glasgow, Glasgow G61 1QH, UK
| | - James M Nyarobi
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
- Nelson Mandela African Institution of Science and Technology, Arusha 255, Tanzania
| | - Kate M Thomas
- Centre for International Health, University of Otago, Dunedin 9054, New Zealand
- Kilimanjaro Clinical Research Institute, Moshi 2236, Tanzania
| | - Felix Lankester
- Paul G. Allen School for Global Health, Washington State University, Pullman, WA 99164, USA
- Global Animal Health Tanzania, Arusha 1642, Tanzania
| | - Tito J Kibona
- Nelson Mandela African Institution of Science and Technology, Arusha 255, Tanzania
| | - John R Claxton
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Benjamin Brennan
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, G61 1QH, UK
| | - Ryan W Carter
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
| | - John A Crump
- Centre for International Health, University of Otago, Dunedin 9054, New Zealand
- Division of Infectious Diseases and International Health, Duke University Medical Center, Durham, NC 27710, USA
- Duke Global Health Institute, Duke University, Durham, NC 27710, USA
- Kilimanjaro Christian Medical University College, Tumaini University, Moshi 3010, Tanzania
| | - Jo E B Halliday
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Georgia Ladbury
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Blandina T Mmbaga
- Kilimanjaro Clinical Research Institute, Moshi 2236, Tanzania
- Division of Infectious Diseases and International Health, Duke University Medical Center, Durham, NC 27710, USA
- Kilimanjaro Christian Medical University College, Tumaini University, Moshi 3010, Tanzania
| | - Furaha Mramba
- Tanzania Veterinary Laboratory Agency, Dar es Salaam 9254, Tanzania
| | | | - Matthew P Rubach
- Division of Infectious Diseases and International Health, Duke University Medical Center, Durham, NC 27710, USA
- Duke Global Health Institute, Duke University, Durham, NC 27710, USA
- Programme in Emerging Infectious Diseases, Duke-National University of Singapore, Singapore 169857, Singapore
| | - Melinda K Rostal
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
- EcoHealth Alliance, New York, NY 10018, USA
| | - Paul Sanka
- Tanzania Veterinary Laboratory Agency, Dar es Salaam 9254, Tanzania
| | | | - Agnieszka M Szemiel
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, G61 1QH, UK
| | - Brian J Willett
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, G61 1QH, UK
| | - Sarah Cleaveland
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
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20
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Evaluations of rationally designed rift valley fever vaccine candidate RVax-1 in mosquito and rodent models. NPJ Vaccines 2022; 7:109. [PMID: 36131104 PMCID: PMC9492667 DOI: 10.1038/s41541-022-00536-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 09/01/2022] [Indexed: 12/14/2022] Open
Abstract
Rift Valley fever (RVF) is a mosquito-borne zoonosis endemic to Africa and the Arabian Peninsula, which causes large outbreaks among humans and ruminants. Single dose vaccinations using live-attenuated RVF virus (RVFV) support effective prevention of viral spread in endemic countries. Due to the segmented nature of RVFV genomic RNA, segments of vaccine strain-derived genomic RNA could be incorporated into wild-type RVFV within co-infected mosquitoes or animals. Rationally designed vaccine candidate RVax-1 displays protective epitopes fully identical to the previously characterized MP-12 vaccine. Additionally, all genome segments of RVax-1 contribute to the attenuation phenotype, which prevents the formation of pathogenic reassortant strains. This study demonstrated that RVax-1 cannot replicate efficiently in orally fed Aedes aegypti mosquitoes, while retaining strong immunogenicity and protective efficacy in an inbred mouse model, which were indistinguishable from the MP-12 vaccine. These findings support further development of RVax-1 as the next generation MP-12-based vaccine for prevention of Rift Valley fever in humans and animals.
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21
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Campbell CL, Snell TK, Bennett S, Wyckoff JH, Heaslip D, Flatt J, Harris EK, Hartman DA, Lian E, Bird BH, Stenglein MD, Bowen RA, Kading RC. Safety study of Rift Valley Fever human vaccine candidate (DDVax) in mosquitoes. Transbound Emerg Dis 2022; 69:2621-2633. [PMID: 34890118 PMCID: PMC9788258 DOI: 10.1111/tbed.14415] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 11/20/2021] [Accepted: 11/30/2021] [Indexed: 12/30/2022]
Abstract
Rift Valley fever virus (RVFV) is a mosquito-borne pathogen with significant human and veterinary health consequences that periodically emerges in epizootics. RVFV causes fetal loss and death in ruminants and in humans can lead to liver and renal disease, delayed-onset encephalitis, retinitis, and in some cases severe haemorrhagic fever. A live attenuated vaccine candidate (DDVax), was developed by the deletion of the virulence factors NSs and NSm from a clinical isolate, ZH501, and has proven safe and immunogenic in rodents, pregnant sheep and non-human primates. Deletion of NSm also severely restricted mosquito midgut infection and inhibited vector-borne transmission. To demonstrate environmental safety, this study investigated the replication, dissemination and transmission efficiency of DDVax in mosquitoes following oral exposure compared to RVFV strains MP-12 and ZH501. Infection and dissemination profiles were also measured in mosquitoes 7 days after they fed on goats inoculated with DDvax or MP-12. We hypothesized that DDVax would infect mosquitoes at significantly lower rates than other RVFV strains and, due to lack of NSm, be transmission incompetent. Exposure of Ae. aegypti and Cx. tarsalis to 8 log10 plaque forming units (PFU)/ml DDVax by artificial bloodmeal resulted in significantly reduced DDVax infection rates in mosquito bodies compared to controls. Plaque assays indicated negligible transmission of infectious DDVax in Cx. tarsalis saliva (1/140 sampled) and none in Ae. aegypti saliva (0/120). Serum from goats inoculated with DDVax or MP-12 did not harbour detectable infectious virus by plaque assay at 1, 2 or 3 days post-inoculation. Infectious virus was, however, recovered from Aedes and Culex bodies that fed on goats vaccinated with MP-12 (13.8% and 4.6%, respectively), but strikingly, DDvax-positive mosquito bodies were greatly reduced (4%, and 0%, respectively). Furthermore, DDVax did not disseminate to legs/wings in any of the goat-fed mosquitoes. Collectively, these results are consistent with a beneficial environmental safety profile.
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Affiliation(s)
- Corey L. Campbell
- Department of MicrobiologyImmunology, and PathologyCenter for Vector‐Borne Infectious DiseasesColorado State UniversityFort CollinsColorado
| | - Trey K. Snell
- Department of MicrobiologyImmunology, and PathologyCenter for Vector‐Borne Infectious DiseasesColorado State UniversityFort CollinsColorado
| | - Susi Bennett
- Department of MicrobiologyImmunology, and PathologyCenter for Vector‐Borne Infectious DiseasesColorado State UniversityFort CollinsColorado
| | - John H. Wyckoff
- BioMARC, Infectious Diseases Research Center, Colorado State UniversityFort CollinsColorado
| | - Darragh Heaslip
- BioMARC, Infectious Diseases Research Center, Colorado State UniversityFort CollinsColorado
| | - Jordan Flatt
- BioMARC, Infectious Diseases Research Center, Colorado State UniversityFort CollinsColorado
| | - Emma K. Harris
- Department of MicrobiologyImmunology, and PathologyCenter for Vector‐Borne Infectious DiseasesColorado State UniversityFort CollinsColorado
| | - Daniel A. Hartman
- Department of MicrobiologyImmunology, and PathologyCenter for Vector‐Borne Infectious DiseasesColorado State UniversityFort CollinsColorado
| | - Elena Lian
- Department of MicrobiologyImmunology, and PathologyCenter for Vector‐Borne Infectious DiseasesColorado State UniversityFort CollinsColorado
| | - Brian H. Bird
- School of Veterinary MedicineOne Health InstituteUniversity of CaliforniaDavisCalifornia
| | - Mark D. Stenglein
- Department of MicrobiologyImmunology, and PathologyCenter for Vector‐Borne Infectious DiseasesColorado State UniversityFort CollinsColorado
| | - Richard A. Bowen
- Department of MicrobiologyImmunology, and PathologyCenter for Vector‐Borne Infectious DiseasesColorado State UniversityFort CollinsColorado
| | - Rebekah C. Kading
- Department of MicrobiologyImmunology, and PathologyCenter for Vector‐Borne Infectious DiseasesColorado State UniversityFort CollinsColorado
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Kandeel M, Al-Mubarak AIA. Camel viral diseases: Current diagnostic, therapeutic, and preventive strategies. Front Vet Sci 2022; 9:915475. [PMID: 36032287 PMCID: PMC9403476 DOI: 10.3389/fvets.2022.915475] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 07/25/2022] [Indexed: 12/03/2022] Open
Abstract
Many pathogenic viruses infect camels, generally regarded as especially hardy livestock because of their ability to thrive in harsh and arid conditions. Transmission of these viruses has been facilitated by the commercialization of camel milk and meat and their byproducts, and vaccines are needed to prevent viruses from spreading. There is a paucity of information on the effectiveness of viral immunizations in camels, even though numerous studies have looked into the topic. More research is needed to create effective vaccines and treatments for camels. Because Camels are carriers of coronavirus, capable of producing a powerful immune response to recurrent coronavirus infections. As a result, camels may be a suitable model for viral vaccine trials since vaccines are simple to create and can prevent viral infection transfer from animals to humans. In this review, we present available data on the diagnostic, therapeutic, and preventative strategies for the following viral diseases in camels, most of which result in significant economic loss: camelpox, Rift Valley fever, peste des petits ruminants, bovine viral diarrhea, bluetongue, rotavirus, Middle East respiratory syndrome, and COVID-19. Although suitable vaccines have been developed for controlling viral infections and perhaps interrupting the transmission of the virus from the affected animals to blood-feeding vectors, there is a paucity of information on the effectiveness of viral immunizations in camels and more research is needed. Recent therapeutic trials that include specific antivirals or supportive care have helped manage viral infections.
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Affiliation(s)
- Mahmoud Kandeel
- Department of Biomedical Sciences, College of Veterinary Medicine, King Faisal University, Al-Hofuf, Saudi Arabia
- Department of Pharmacology, Faculty of Veterinary Medicine, Kafrelsheikh University, Kafrelsheikh, Egypt
- *Correspondence: Mahmoud Kandeel
| | - Abdullah I. A. Al-Mubarak
- Department of Biomedical Sciences, College of Veterinary Medicine, King Faisal University, Al-Hofuf, Saudi Arabia
- Department of Pharmacology, Faculty of Veterinary Medicine, Kafrelsheikh University, Kafrelsheikh, Egypt
- Department of Microbiology, College of Veterinary Medicine, King Faisal University, Al-Hofuf, Saudi Arabia
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Michaely LM, Rissmann M, Keller M, König R, von Arnim F, Eiden M, Rohn K, Baumgärtner W, Groschup M, Ulrich R. NSG-Mice Reveal the Importance of a Functional Innate and Adaptive Immune Response to Overcome RVFV Infection. Viruses 2022; 14:v14020350. [PMID: 35215938 PMCID: PMC8880686 DOI: 10.3390/v14020350] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 01/20/2022] [Accepted: 02/03/2022] [Indexed: 12/12/2022] Open
Abstract
Rift Valley fever (RVF) is a zoonotic disease caused by RVF Phlebovirus (RVFV). The RVFV MP-12 vaccine strain is known to exhibit residual virulence in the case of a deficient interferon type 1 response. The hypothesis of this study is that virus replication and severity of lesions induced by the MP-12 strain in immunocompromised mice depend on the specific function of the disturbed pathway. Therefore, 10 strains of mice with deficient innate immunity (B6-IFNARtmAgt, C.129S7(B6)-Ifngtm1Ts/J, B6-TLR3tm1Flv, B6-TLR7tm1Aki, NOD/ShiLtJ), helper T-cell- (CD4tm1Mak), cytotoxic T-cell- (CD8atm1Mak), B-cell- (Igh-Jtm1DhuN?+N2), combined T- and B-cell- (NU/J) and combined T-, B-, natural killer (NK) cell- and macrophage-mediated immunity (NOD.Cg-PrkdcscidIl2rgtm1WjI/SzJ (NSG) mice) were subcutaneously infected with RVFV MP-12. B6-IFNARtmAgt mice were the only strain to develop fatal disease due to RVFV-induced severe hepatocellular necrosis and apoptosis. Notably, no clinical disease and only mild multifocal hepatocellular necrosis and apoptosis were observed in NSG mice, while immunohistochemistry detected the RVFV antigen in the liver and the brain. No or low virus expression and no lesions were observed in the other mouse strains. Conclusively, the interferon type 1 response is essential for early control of RVFV replication and disease, whereas functional NK cells, macrophages and lymphocytes are essential for virus clearance.
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Affiliation(s)
- Lukas Mathias Michaely
- Department of Pathology, University of Veterinary Medicine Hannover, Foundation, Bünteweg 17, 30559 Hannover, Germany;
- Center for Systems Neuroscience Hannover, University of Veterinary Medicine Hannover, Foundation, Bünteweg 2, 30559 Hannover, Germany
| | - Melanie Rissmann
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Südufer 10, 17493 Greifswald-Insel Riems, Germany; (M.R.); (M.K.); (R.K.); (F.v.A.); (M.E.); (M.G.)
| | - Markus Keller
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Südufer 10, 17493 Greifswald-Insel Riems, Germany; (M.R.); (M.K.); (R.K.); (F.v.A.); (M.E.); (M.G.)
| | - Rebecca König
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Südufer 10, 17493 Greifswald-Insel Riems, Germany; (M.R.); (M.K.); (R.K.); (F.v.A.); (M.E.); (M.G.)
| | - Felicitas von Arnim
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Südufer 10, 17493 Greifswald-Insel Riems, Germany; (M.R.); (M.K.); (R.K.); (F.v.A.); (M.E.); (M.G.)
| | - Martin Eiden
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Südufer 10, 17493 Greifswald-Insel Riems, Germany; (M.R.); (M.K.); (R.K.); (F.v.A.); (M.E.); (M.G.)
| | - Karl Rohn
- Institute for Biometry, Epidemiology and Information Processing, University of Veterinary Medicine Hannover, Foundation, Bünteweg 2, 30559 Hannover, Germany;
| | - Wolfgang Baumgärtner
- Department of Pathology, University of Veterinary Medicine Hannover, Foundation, Bünteweg 17, 30559 Hannover, Germany;
- Center for Systems Neuroscience Hannover, University of Veterinary Medicine Hannover, Foundation, Bünteweg 2, 30559 Hannover, Germany
- Correspondence: ; Tel.: +49-511-953-8620; Fax: +49-511-953-8675
| | - Martin Groschup
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Südufer 10, 17493 Greifswald-Insel Riems, Germany; (M.R.); (M.K.); (R.K.); (F.v.A.); (M.E.); (M.G.)
| | - Reiner Ulrich
- Institute of Veterinary-Pathology, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany;
- Department of Experimental Animal Facilities and Biorisk Management, Friedrich-Loeffler-Institut, Südufer 10, 17493 Greifswald-Insel Riems, Germany
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Schön K, Lepenies B, Goyette-Desjardins G. Impact of Protein Glycosylation on the Design of Viral Vaccines. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2021; 175:319-354. [PMID: 32935143 DOI: 10.1007/10_2020_132] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Glycans play crucial roles in various biological processes such as cell proliferation, cell-cell interactions, and immune responses. Since viruses co-opt cellular biosynthetic pathways, viral glycosylation mainly depends on the host cell glycosylation machinery. Consequently, several viruses exploit the cellular glycosylation pathway to their advantage. It was shown that viral glycosylation is strongly dependent on the host system selected for virus propagation and/or protein expression. Therefore, the use of different expression systems results in various glycoforms of viral glycoproteins that may differ in functional properties. These differences clearly illustrate that the choice of the expression system can be important, as the resulting glycosylation may influence immunological properties. In this review, we will first detail protein N- and O-glycosylation pathways and the resulting glycosylation patterns; we will then discuss different aspects of viral glycosylation in pathogenesis and in vaccine development; and finally, we will elaborate on how to harness viral glycosylation in order to optimize the design of viral vaccines. To this end, we will highlight specific examples to demonstrate how glycoengineering approaches and exploitation of different expression systems could pave the way towards better self-adjuvanted glycan-based viral vaccines.
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Affiliation(s)
- Kathleen Schön
- Immunology Unit and Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, Hanover, Germany
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Bernd Lepenies
- Immunology Unit and Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, Hanover, Germany.
| | - Guillaume Goyette-Desjardins
- Immunology Unit and Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, Hanover, Germany.
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25
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Sandfly Fever Sicilian Virus-Leishmania major co-infection modulates innate inflammatory response favoring myeloid cell infections and skin hyperinflammation. PLoS Negl Trop Dis 2021; 15:e0009638. [PMID: 34310619 PMCID: PMC8341699 DOI: 10.1371/journal.pntd.0009638] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 08/05/2021] [Accepted: 07/09/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The leishmaniases are a group of sandfly-transmitted diseases caused by species of the protozoan parasite, Leishmania. With an annual incidence of 1 million cases, 1 billion people living in Leishmania-endemic regions, and nearly 30,000 deaths each year, leishmaniasis is a major global public health concern. While phlebotomine sandflies are well-known as vectors of Leishmania, they are also the vectors of various phleboviruses, including Sandfly Fever Sicilian Virus (SFSV). Cutaneous leishmaniasis (CL), caused by Leishmania major (L. major), among other species, results in development of skin lesions on the infected host. Importantly, there exists much variation in the clinical manifestation between individuals. We propose that phleboviruses, vectored by and found in the same sandfly guts as Leishmania, may be a factor in determining CL severity. It was reported by our group that Leishmania exosomes are released into the gut of the sandfly vector and co-inoculated during blood meals, where they exacerbate CL skin lesions. We hypothesized that, when taking a blood meal, the sandfly vector infects the host with Leishmania parasites and exosomes as well as phleboviruses, and that this viral co-infection results in a modulation of leishmaniasis. METHODOLOGY/PRINCIPAL FINDINGS In vitro, we observed modulation by SFSV in MAP kinase signaling as well as in the IRF3 pathway that resulted in a pro-inflammatory phenotype. Additionally, we found that SFSV and L. major co-infection resulted in an exacerbation of leishmaniasis in vivo, and by using endosomal (Toll-like receptor) TLR3, and MAVS knock-out mice, deduced that SFSV's hyperinflammatory effect was TLR3- and MAVS-dependent. Critically, we observed that L. major and SFSV co-infected C57BL/6 mice demonstrated significantly higher parasite burden than mice solely infected with L. major. Furthermore, viral presence increased leukocyte influx in vivo. This influx was accompanied by elevated total extracellular vesicle numbers. Interestingly, L. major displayed higher infectiveness with coincident phleboviral infection compared to L. major infection alone. CONCLUSION/SIGNIFICANCE Overall our work represents novel findings that contribute towards understanding the causal mechanisms governing cutaneous leishmaniasis pathology. Better comprehension of the potential role of viral co-infection could lead to treatment regimens with enhanced effectiveness.
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Rift Valley Fever: a Threat to Pregnant Women Hiding in Plain Sight? J Virol 2021; 95:JVI.01394-19. [PMID: 33597209 DOI: 10.1128/jvi.01394-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 01/30/2021] [Indexed: 12/18/2022] Open
Abstract
The potential for emerging mosquito-borne viruses to cause fetal infection in pregnant women was overlooked until the Zika fever outbreak several years ago. Rift Valley fever virus (RVFV) is an emerging arbovirus with a long history of fetal infection and death in pregnant livestock. The effect of RVFV infection on pregnant women is not well understood. This Gem examines the effects that this important emerging pathogen has during pregnancy, its potential impact on pregnant women, and the current research efforts designed to understand and mitigate adverse effects of RVFV infection during pregnancy.
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Development of a Simian RNA Polymerase I Promoter-Driven Reverse Genetics for the Rescue of Recombinant Rift Valley Fever Virus from Vero Cells. J Virol 2021; 95:JVI.02004-20. [PMID: 33441343 PMCID: PMC8092696 DOI: 10.1128/jvi.02004-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Rift Valley fever (RVF), which has been designated as a priority disease by the World Health Organization (WHO), is one of the most pathogenic zoonotic diseases endemic to Africa and the Arabian Peninsula. Human vaccine preparation requires the use of appropriate cell substrates to support efficient production of seed vaccine with minimum concerns of tumorigenicity, oncogenicity, or adventitious agents. Vero cells, which were derived from the African green monkey kidney, represent one of the few mammalian cell lines that are used for vaccine manufacturing. This study demonstrated the rescue of RVFV MP-12 infectious clones in Vero cells using plasmids encoding the Macaca mulatta RNA polymerase I promoter. Although Vero cells demonstrated an approximately 20% transfection efficiency, only 0.5% of transfected cells showed the replication of viral genomic RNA, supported by the co-expression of RVFV N and L helper proteins. RVFV Infectious clones were detectable in the culture supernatants approximately 4 to 9 days posttransfection reaching maximum titers during the following 5 days. The re-amplification of rescued recombinant MP-12 (rMP-12) in Vero cells led to an increase in the genetic subpopulations, affecting the viral phenotype via amino acid substitutions in the NSs gene, whereas the rMP-12 re-amplified in human diploid MRC-5 cells did not increase viral sub-populations with NSs gene mutations. The strategy in which RVFV infectious clones are rescued in Vero cells and then subsequently amplified in MRC-5 cells will support the vaccine seed lot systems of live-attenuated recombinant RVFV vaccines for human use.IMPORTANCE RVF is a mosquito-transmitted, viral, zoonotic disease endemic to Africa and the Arabian Peninsula, and its spread outside of the endemic area will potentially cause devastating economic damages and serious public health problems. Different from classical live-attenuated vaccines, live-attenuated recombinant vaccines allow rational improvement of vaccine production efficiency, protective efficacy, and vaccine safety via the genetic engineering. This study demonstrated the generation of infectious Rift Valley fever (RVF) virus from cloned cDNA using Vero cells, which are one of a few mammalian cell lines used for vaccine manufacturing. Subsequent re-amplification of virus clones in Vero cells unexpectedly increased viral subpopulations encoding unfavorable mutations, whereas viral re-amplification in human diploid MRC-5 cells could minimize the emergence of such mutants. Rescue of recombinant RVFV from Vero cells and re-amplification in MRC-5 cells will support the vaccine seed lot systems of live-attenuated recombinant RVFV vaccines for human use.
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Borrego B, Brun A. A Hyper-Attenuated Variant of Rift Valley Fever Virus Generated by a Mutagenic Drug (Favipiravir) Unveils Potential Virulence Markers. Front Microbiol 2021; 11:621463. [PMID: 33633696 PMCID: PMC7900410 DOI: 10.3389/fmicb.2020.621463] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 12/21/2020] [Indexed: 12/16/2022] Open
Abstract
Rift Valley fever virus (RVFV) is a mosquito-borne bunyavirus that causes Rift Valley fever (RVF), a zoonotic disease of wild and domestic ruminants, causing serious economic losses and a threat to human health that could be controlled by vaccination. Though RVF vaccines are available for livestock, no RVF vaccines have been licensed for veterinary use in non-endemic countries nor for human populations in RVF risk areas. In a recent work, we showed that favipiravir, a promising drug with antiviral activity against a number of RNA viruses, led to the extinction of RVFV from infected cell cultures. Nevertheless, certain drug concentrations allowed the recovery of a virus variant showing increased resistance to favipiravir. In this work, we characterized this novel resistant variant both at genomic and phenotypic level in vitro and in vivo. Interestingly, the resistant virus displayed reduced growth rates in C6/36 insect cells but not in mammalian cell lines, and was highly attenuated but still immunogenic in vivo. Some amino acid substitutions were identified in the viral RNA-dependent RNA-polymerase (RdRp) gene and in the virus encoded type I-interferon (IFN-I) antagonist NSs gene, in catalytic core motifs and nuclear localization associated positions, respectively. These data may help to characterize novel potential virulence markers, offering additional strategies for further safety improvements of RVF live attenuated vaccine candidates.
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Affiliation(s)
| | - Alejandro Brun
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain
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The NSs Protein Encoded by the Virulent Strain of Rift Valley Fever Virus Targets the Expression of Abl2 and the Actin Cytoskeleton of the Host, Affecting Cell Mobility, Cell Shape, and Cell-Cell Adhesion. J Virol 2020; 95:JVI.01768-20. [PMID: 33087469 DOI: 10.1128/jvi.01768-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 10/04/2020] [Indexed: 12/18/2022] Open
Abstract
Rift Valley fever virus (RVFV) is a highly pathogenic zoonotic arbovirus endemic in many African countries and the Arabian Peninsula. Animal infections cause high rates of mortality and abortion among sheep, goats, and cattle. In humans, an estimated 1 to 2% of RVFV infections result in severe disease (encephalitis, hepatitis, or retinitis) with a high rate of lethality when associated with hemorrhagic fever. The RVFV NSs protein, which is the main virulence factor, counteracts the host innate antiviral response to favor viral replication and spread. However, the mechanisms underlying RVFV-induced cytopathic effects and the role of NSs in these alterations remain for the most part unknown. In this work, we have analyzed the effects of NSs expression on the actin cytoskeleton while conducting infections with the NSs-expressing virulent (ZH548) and attenuated (MP12) strains of RVFV and the non-NSs-expressing avirulent (ZH548ΔNSs) strain, as well as after the ectopic expression of NSs. In macrophages, fibroblasts, and hepatocytes, NSs expression prevented the upregulation of Abl2 (a major regulator of the actin cytoskeleton) expression otherwise induced by avirulent infections and identified here as part of the antiviral response. The presence of NSs was also linked to an increased mobility of ZH548-infected cells compared to ZH548ΔNSs-infected fibroblasts and to strong changes in cell morphology in nonmigrating hepatocytes, with reduction of lamellipodia, cell spreading, and dissolution of adherens junctions reminiscent of the ZH548-induced cytopathic effects observed in vivo Finally, we show evidence of the presence of NSs within long actin-rich structures associated with NSs dissemination from NSs-expressing toward non-NSs-expressing cells.IMPORTANCE Rift Valley fever virus (RVFV) is a dangerous human and animal pathogen that was ranked by the World Health Organization in 2018 as among the eight pathogens of most concern for being likely to cause wide epidemics in the near future and for which there are no, or insufficient, countermeasures. The focus of this work is to address the question of the mechanisms underlying RVFV-induced cytopathic effects that participate in RVFV pathogenicity. We demonstrate here that RVFV targets cell adhesion and the actin cytoskeleton at the transcriptional and cellular level, affecting cell mobility and inducing cell shape collapse, along with distortion of cell-cell adhesion. All these effects may participate in RVFV-induced pathogenicity, facilitate virulent RVFV dissemination, and thus constitute interesting potential targets for future development of antiviral therapeutic strategies that, in the case of RVFV, as with several other emerging arboviruses, are presently lacking.
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Monath TP, Kortekaas J, Watts DM, Christofferson RC, Desiree LaBeaud A, Gowen B, Peters CJ, Smith DR, Swanepoel R, Morrill JC, Ksiazek TG, Pittman PR, Bird BH, Bettinger G. Theoretical risk of genetic reassortment should not impede development of live, attenuated Rift Valley fever (RVF) vaccines commentary on the draft WHO RVF Target Product Profile. Vaccine X 2020; 5:100060. [PMID: 32337506 PMCID: PMC7176985 DOI: 10.1016/j.jvacx.2020.100060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/08/2020] [Accepted: 03/21/2020] [Indexed: 11/29/2022] Open
Abstract
WHO published draft Target Product Profiles (TPPs) for Rift Valley Fever virus (RVFV) vaccines. The TPPs contain restrictive requirements aimed at reducing the risk of genetic reassortment. We find no evidence for reassortment despite use of live RVFV vaccines. If genetic reassortment occurred with wild-type RVFV it would be of no consequence. The hypothetical risks of reassortment do not outweigh the benefits of vaccination
In November 2019, The World Health Organization (WHO) issued a draft set of Target Product Profiles (TPPs) describing optimal and minimally acceptable targets for vaccines against Rift Valley fever (RVF), a Phlebovirus with a three segmented genome, in both humans and ruminants. The TPPs contained rigid requirements to protect against genomic reassortment of live, attenuated vaccines (LAVs) with wild-type RVF virus (RVFV), which place undue constraints on development and regulatory approval of LAVs. We review the current LAVs in use and in development, and conclude that there is no evidence that reassortment between LAVs and wild-type RVFV has occurred during field use, that such a reassortment event if it occurred would have no untoward consequence, and that the TPPs should be revised to provide a more balanced assessment of the benefits versus the theoretical risks of reassortment.
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Affiliation(s)
- Thomas P Monath
- Managing Partner and Chief Scientific Officer, Crozet BioPharma LLC, Devens, MA, USA
| | - Jeroen Kortekaas
- Professor of Veterinary Arbovirology, Department of Virology, Wageningen Bioveterinary Research, Lelystad, the Netherlands
| | - Douglas M Watts
- Executive Director of Vet Services, and Director of Biosafety Level 3 Laboratory and Co-Director of BBRC Infectious Disease and Immunology, University of Texas at El Paso, El Paso, TX, USA
| | - Rebecca C Christofferson
- Pathobiological Sciences, Louisiana State University, School of Veterinary Medicine, Baton Rouge, LA, USA
| | - Angelle Desiree LaBeaud
- Professor of Pediatrics (Infectious Diseases), Stanford University School of Medicine, Senior Fellow at the Woods Institute for the Environment and Professor of Health Research and Policy (Epidemiology) at the Lucile Salter Packard Children's Hospital, Stanford, CA, USA
| | | | - Clarence J Peters
- Professor (Emeritus) Departments of Microbiology & Immunology and Pathology Director (Emeritus) for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, TX, USA
| | - Darci R Smith
- Immunodiagnostics Department, Naval Medical Research Center, Biological Defense Research Directorate, Fort Detrick, MD, USA
| | - Robert Swanepoel
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Gauteng, South Africa
| | - John C Morrill
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Thomas G Ksiazek
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Phillip R Pittman
- U.S. Army Medical Research Institute of Infectious Diseases, Medical Research and Materiel Command, Fort Detrick, Frederick, MD, USA
| | - Brian H Bird
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA.,University of California, Davis, One Health Institute, School of Veterinary Medicine, Davis 956164, CA, USA
| | - George Bettinger
- USAID Rift Valley Fever Vaccine Project at The University of Texas at El Paso, El Paso, TX, USA
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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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Abstract
Introduction: Rift Valley fever (RVF) outbreaks can cause devastating economic loss and public health concerns. RVF virus (RVFV: genus Phlebovirus family Phenuiviridae) is transmitted by mosquitoes, causes abortion in sheep, cattle, and goats, and severe diseases in humans including hemorrhagic fever, encephalitis, or retinitis. RVFV has spread from sub-Saharan Africa into Madagascar, Egypt, Saudi Arabia, and Yemen.Area covered: There are a few licensed veterinary RVF vaccines in endemic countries, whereas no licensed RVF vaccines are available for human use. There are two Investigational New Drug (IND) RVF candidate vaccines used in clinical trials. This review will discuss the development of two IND vaccines for RVF over the past 20-40 years, and further innovation for future RVF vaccines applicable for the use in endemic areas.Expert opinion: Vaccination for human RVF can protect at-risk personnel against severe RVF illness. Formalin-inactivated RVF candidate vaccine requires three doses to induce protective immunity, whereas the live-attenuated MP-12 candidate vaccine retains strong immunogenicity. Further innovation in safety, immunogenicity, and thermostability will facilitate future RVF vaccines for humans.
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Affiliation(s)
- Tetsuro Ikegami
- Department of Pathology, The University of Texas Medical Branch, Galveston, TX, USA.,Sealy Center for Vaccine Development, The University of Texas Medical Branch, Galveston, TX, USA.,Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch, Galveston, TX, USA
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Abstract
Rift Valley fever (RVF) is a mosquito-borne viral zoonosis that was first discovered in Kenya in 1930 and is now endemic throughout multiple African countries and the Arabian Peninsula. RVF virus primarily infects domestic livestock (sheep, goats, cattle) causing high rates of neonatal mortality and abortion, with human infection resulting in a wide variety of clinical outcomes, ranging from self-limiting febrile illness to life-threatening haemorrhagic diatheses, and miscarriage in pregnant women. Since its discovery, RVF has caused many outbreaks in Africa and the Arabian Peninsula with major impacts on human and animal health. However, options for the control of RVF outbreaks are limited by the lack of licensed human vaccines or therapeutics. For this reason, RVF is prioritized by the World Health Organization for urgent research and development of countermeasures for the prevention and control of future outbreaks. In this review, we highlight the current understanding of RVF, including its epidemiology, pathogenesis, clinical manifestations and status of vaccine development.
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Affiliation(s)
- Daniel Wright
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- The Jenner Institute, University of Oxford, Oxford OX1 2JD, UK
| | - Jeroen Kortekaas
- Wageningen Bioveterinary Research, Lelystad, The Netherlands
- Laboratory of Virology, Wageningen University, Wageningen, The Netherlands
| | - Thomas A. Bowden
- Wellcome Centre for Human Genetics, Division of Structural Biology, University of Oxford, Oxford OX1 2JD, UK
| | - George M. Warimwe
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford OX1 2JD, UK
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Boumart Z, Daouam S, Bamouh Z, Jazouli M, Tadlaoui KO, Dungu B, Bettinger G, Watts DM, Elharrak M. Safety and immunogenicity of a live attenuated Rift Valley Fever recombinant arMP-12ΔNSm21/384 vaccine candidate for sheep, goats and calves. Vaccine 2019; 37:1642-1650. [PMID: 30773401 DOI: 10.1016/j.vaccine.2019.01.067] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Revised: 01/21/2019] [Accepted: 01/24/2019] [Indexed: 01/03/2023]
Abstract
Rift Valley fever (RVF) causes serious health and economic losses to the livestock industry as well as a significant cause of human disease. The prevention of RVF in Africa is a global priority, however, available vaccines have only been partially effective. Therefore, the objective of this study was to evaluate the safety and immunogenicity of a live, attenuated recombinant RVFV arMP-12ΔNSm21/384 nucleotide deletion vaccine candidate in domestic ruminants. Evaluation involved testing to determine the infectivity titer of the vaccine virus in Vero cells for industrial scale up vaccine production. Safety experiments were conducted to determine the potential of the vaccine virus to revert to virulence by serial passages in sheep, the possibility of virus spread from vaccinated sheep and calves to unvaccinated animals, and the potential health effects of administering overdoses of the vaccine to sheep, goats and calves. The immunogenicity of 3 doses of 104, 105 and 106 Tissue Culture Infectious Doses50% (TCID50) of the vaccine was assessed in 3 groups of 10 sheep and 3 groups of 10 goats, and doses of 105, 106 and 107 TCID50 was evaluated in 3 groups of 10 calves subcutaenous vaccintation. The results showed that the infectivity titer of the vaccine virus was 108.4 TCID50/ml, that the vaccine did not spread from vaccinated to un-vaccinated animals, there was no evidence of reversion to virulence in sheep and the vaccine overdoses did not cause any adverse effects. The immunogenicity among sheep, goats and calves indicated that doses of 104-106 TCID50 elicited detectable antibody by day 7 post-vaccination (PV) with antibody titers ranging from 0.6 log to 2.1 log on day 14 PV with sustained titers through day 28 PV. Overall, these findings indicated that the RVFV arMP-12ΔNSm21/384 vaccine is a promising candidate for the prevention of RVF among domestic ruminants.
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Affiliation(s)
- Z Boumart
- Research and Development Dept., Multi-Chemical Industry, Lot. 157, Z I, Sud-Ouest (ERAC) B.P.: 278, Mohammedia 28810, Morocco.
| | - S Daouam
- Research and Development Dept., Multi-Chemical Industry, Lot. 157, Z I, Sud-Ouest (ERAC) B.P.: 278, Mohammedia 28810, Morocco.
| | - Z Bamouh
- Research and Development Dept., Multi-Chemical Industry, Lot. 157, Z I, Sud-Ouest (ERAC) B.P.: 278, Mohammedia 28810, Morocco.
| | - M Jazouli
- Research and Development Dept., Multi-Chemical Industry, Lot. 157, Z I, Sud-Ouest (ERAC) B.P.: 278, Mohammedia 28810, Morocco.
| | - K O Tadlaoui
- Research and Development Dept., Multi-Chemical Industry, Lot. 157, Z I, Sud-Ouest (ERAC) B.P.: 278, Mohammedia 28810, Morocco.
| | - B Dungu
- Research and Development Dept., Multi-Chemical Industry, Lot. 157, Z I, Sud-Ouest (ERAC) B.P.: 278, Mohammedia 28810, Morocco.
| | - G Bettinger
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, USA.
| | - D M Watts
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, USA.
| | - M Elharrak
- Research and Development Dept., Multi-Chemical Industry, Lot. 157, Z I, Sud-Ouest (ERAC) B.P.: 278, Mohammedia 28810, Morocco.
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Lang Y, Li Y, Jasperson D, Henningson J, Lee J, Ma J, Li Y, Duff M, Liu H, Bai D, McVey S, Richt JA, Ikegami T, Wilson WC, Ma W. Identification and evaluation of antivirals for Rift Valley fever virus. Vet Microbiol 2019; 230:110-116. [PMID: 30827375 DOI: 10.1016/j.vetmic.2019.01.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 01/25/2019] [Accepted: 01/28/2019] [Indexed: 11/16/2022]
Abstract
Rift Valley fever virus (RVFV) is the causative agent of Rift Valley fever (RVF) that affects both livestock and humans. There are neither fully licensed RVF vaccines available for human or animal use, nor effective antiviral drugs approved for human use in the U.S. To identify antiviral compounds effective for RVF, we developed and employed a cell-based high-throughput assay using a recombinant RVFV MP-12 strain, which expresses Renilla luciferase in place of the NSs protein, to screen 727 small compounds purchased from the National Institutes of Health. Twenty-three compounds were initially identified using the screening assay. Two compounds, 6-azauridine and mitoxantrone, also inhibited the replication of the parental MP-12 strain encoding the NSs gene, with limited cytotoxic effects. The respective 50% inhibitory concentrations were 29.07 μM and 79.85 μM when tested with the parental MP-12 strain at a multiplicity of infection of 2. The compounds were further evaluated using the STAT-1 KO mouse model. At one hour post intranasal inoculation of MP-12 strain, mice were intranasally treated with each indicated compound twice daily. Mice treated with either placebo or 6-azauridine displayed severe weight loss and reached the threshold for euthanasia with obvious neurologic symptoms. Onset of disease was, however, delayed in mice treated with either ribavirin or mitoxantrone. The results indicated that mitoxantrone can reduce the severity of diseases in RVFV-infected mice. Our studies build the foundation for the initial screening and efficacy studies of RVF antivirals in a BSL-2 environment, avoiding the higher risks of BSL-3 exposure with wild-type virus.
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Affiliation(s)
- Yuekun Lang
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Yonghai Li
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Dane Jasperson
- USDA, ARS, Arthropod-Borne Animal Diseases Research Unit (ABADRU), Center for Grain and Animal Health Research, Manhattan, KS, USA
| | - Jamie Henningson
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Jinhwa Lee
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Jingjiao Ma
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Yuhao Li
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Michael Duff
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Haixia Liu
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Dingping Bai
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Scott McVey
- USDA, ARS, Arthropod-Borne Animal Diseases Research Unit (ABADRU), Center for Grain and Animal Health Research, Manhattan, KS, USA
| | - Juergen A Richt
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Tetsuro Ikegami
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
| | - William C Wilson
- USDA, ARS, Arthropod-Borne Animal Diseases Research Unit (ABADRU), Center for Grain and Animal Health Research, Manhattan, KS, USA
| | - Wenjun Ma
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA.
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Molecular aspects of Rift Valley fever virus and the emergence of reassortants. Virus Genes 2018; 55:1-11. [PMID: 30426314 DOI: 10.1007/s11262-018-1611-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 11/03/2018] [Indexed: 10/27/2022]
Abstract
Rift Valley fever phlebovirus (RVFV) is a mosquito-transmitted pathogen endemic to sub-Saharan Africa and the Arabian Peninsula. RVFV is a threat to both animal and human health and has costly economic consequences mainly related to livestock production and trade. Competent hosts and vectors for RVFV are widespread, existing outside of endemic countries including the USA. Thus, the possibility of RVFV spreading to the USA or other countries worldwide is of significant concern. RVFV (genus Phlebovirus) is comprised of an enveloped virion containing a three-segmented, negative-stranded RNA genome that is able to undergo genetic reassortment. Reassortment has the potential to produce viruses that are more pathogenic, easily transmissible, and that have wider vector or host range. This is especially concerning because of the wide use of live attenuated vaccine strains throughout endemic countries. This review focuses on the molecular aspects of RVFV, genetic diversity of RVFV strains, and RVFV reassortment.
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37
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Clarke LL, Ruder MG, Mead DG, Howerth EW. Heartland Virus Exposure in White-Tailed Deer in the Southeastern United States, 2001-2015. Am J Trop Med Hyg 2018; 99:1346-1349. [PMID: 30255829 PMCID: PMC6221220 DOI: 10.4269/ajtmh.18-0555] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 08/17/2018] [Indexed: 12/25/2022] Open
Abstract
Heartland virus (HRTV) is a North American phlebovirus suspected to be transmitted by the lone star tick Amblyomma americanum. White-tailed deer (WTD) have been shown to develop HRTV-neutralizing antibodies following experimental infection. To further define the geographic distribution of HRTV through retrospective sampling of WTD, sera from the WTD herd health serum archive at the Southeastern Cooperative Wildlife Disease Study between 2001 and 2015 were analyzed using serum neutralization. Of 783 serum samples tested, 57 (7.3%) were positive for HRTV-neutralizing antibodies. Deer with moderate to heavy tick burdens were more likely seropositive. Seropositive samples were obtained from deer originating from states with documented human cases of HRTV-associated disease. Seropositive samples were identified from years before the recognition of the first human case in 2009. Overall, this study indicates that WTD in the southeastern United States have been exposed to HRTV as early as 2001 and that the presence of seropositive animals corresponds roughly with reported human HRTV-associated disease.
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Affiliation(s)
| | - Mark G. Ruder
- Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia
| | - Daniel G. Mead
- Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia
| | - Elizabeth W. Howerth
- Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, Georgia
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Ayari-Fakhfakh E, Ghram A, Albina E, Cêtre-Sossah C. Expression of cytokines following vaccination of goats with a recombinant capripoxvirus vaccine expressing Rift Valley fever virus proteins. Vet Immunol Immunopathol 2018; 197:15-20. [PMID: 29475501 DOI: 10.1016/j.vetimm.2018.01.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 12/20/2017] [Accepted: 01/03/2018] [Indexed: 11/29/2022]
Abstract
The mosquito-borne Rift Valley fever virus (RVFV) causes severe diseases in domesticated animals including cattle, sheep, camels and goats. Capripoxviruses (CPV) are suitable vectors for multivalent vaccine development. A recombinant rKS1-based CPV expressing the gene encoding the viral glycoprotein Gn of RVFV has been shown to induce protection in mice and sheep. The aim of this study was to evaluate the immunogenicity induced by this candidate vaccine in goats, and the level of cytokines produced by RVFV-specific Th1 and Th2 lymphocytes. The results of this study suggest that Th2 mediates immunity mainly through the significant production of IL4, which, coupled with a decrease in IFN-γ, may be involved in the replication of the capripoxvirus expressing the GN of RVFV. CD4+ cells may play the role of helper cells in B cell responses and neutralizing antibody production in the anti-CPV humoral response, leading to strong immunity against RVFV.
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Affiliation(s)
- Emna Ayari-Fakhfakh
- IRVT (Institut de la Recherche Vétérinaire de Tunisie), Tunis, Tunisie; Institut Pasteur de Tunis, Tunis, Tunisie; Université Tunis El Manar, Tunis, Tunisie; ASTRE, Univ Montpellier, CIRAD, INRA, Montpellier, France
| | | | - Emmanuel Albina
- ASTRE, Univ Montpellier, CIRAD, INRA, Montpellier, France; CIRAD, UMR ASTRE, F-97170 Petit-Bourg, Guadeloupe, France
| | - Catherine Cêtre-Sossah
- ASTRE, Univ Montpellier, CIRAD, INRA, Montpellier, France; CIRAD, UMR ASTRE, F-34398 Sainte-Clotilde, La Réunion, France.
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Attenuation and protective efficacy of Rift Valley fever phlebovirus rMP12-GM50 strain. Vaccine 2017; 35:6634-6642. [PMID: 29061350 DOI: 10.1016/j.vaccine.2017.10.036] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 09/20/2017] [Accepted: 10/12/2017] [Indexed: 11/24/2022]
Abstract
Rift Valley fever (RVF) is a mosquito-borne zoonotic disease endemic to Africa and the Arabian Peninsula that affects sheep, cattle, goats, camels, and humans. Effective vaccination of susceptible ruminants is important for the prevention of RVF outbreaks. Live-attenuated RVF vaccines are in general highly immunogenic in ruminants, whereas residual virulence might be a concern for vulnerable populations. It is also important for live-attenuated strains to encode unique genetic markers for the differentiation from wild-type RVFV strains. In this study, we aimed to strengthen the attenuation profile of the MP-12 vaccine strain via the introduction of 584 silent mutations. To minimize the impact on protective efficacy, codon usage and codon pair bias were not de-optimized. The resulting rMP12-GM50 strain showed 100% protective efficacy with a single intramuscular dose, raising a 1:853 mean titer of plaque reduction neutralization test. Moreover, outbred mice infected with one of three pathogenic reassortant ZH501 strains, which encoded rMP12-GM50 L-, M-, or S-segments, showed 90%, 50%, or 30% survival, respectively. These results indicate that attenuation of the rMP12-GM50 strain is significantly attenuated via the L-, M-, and S-segments. Recombinant RVFV vaccine strains encoding similar silent mutations will be also useful for the surveillance of reassortant strains derived from vaccine strains in endemic countries.
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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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Lokugamage N, Ikegami T. Genetic stability of Rift Valley fever virus MP-12 vaccine during serial passages in culture cells. NPJ Vaccines 2017; 2:20. [PMID: 29167748 PMCID: PMC5627234 DOI: 10.1038/s41541-017-0021-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 05/24/2017] [Accepted: 06/06/2017] [Indexed: 12/15/2022] Open
Abstract
Rift Valley fever (RVF) is a mosquito-borne zoonotic disease endemic to Africa which affects both ruminants and humans. RVF causes serious damage to the livestock industry and is also a threat to public health. The Rift Valley fever virus has a segmented negative-stranded RNA genome consisting of Large (L)-, Medium (M)-, and Small (S)-segments. The live-attenuated MP-12 vaccine is immunogenic in livestock and humans, and is conditionally licensed for veterinary use in the U.S. The MP-12 strain encodes 23 mutations (nine amino acid substitutions) and is attenuated through a combination of mutations in the L-, M-, and S-segments. Among them, the M-U795C, M-A3564G, and L-G3104A mutations contribute to viral attenuation through the L- and M-segments. The M-U795C, M-A3564G, L-U533C, and L-G3750A mutations are also independently responsible for temperature-sensitive (ts) phenotype. We hypothesized that a serial passage of the MP-12 vaccine in culture cells causes reversions of the MP-12 genome. The MP-12 vaccine and recombinant rMP12-ΔNSs16/198 were serially passaged 25 times. Droplet digital PCR analysis revealed that the reversion occurred at L-G3750A during passages of MP-12 in Vero or MRC-5 cells. The reversion also occurred at M-A3564G and L-U533C of rMP12-ΔNSs16/198 in Vero cells. Reversion mutations were not found in MP-12 or the variant, rMP12-TOSNSs, in the brains of mice with encephalitis. This study characterized genetic stability of the MP-12 vaccine and the potential risk of reversion mutation at the L-G3750A ts mutation after excessive viral passages in culture cells.
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Affiliation(s)
- Nandadeva Lokugamage
- Department of Pathology, The University of Texas Medical Branch at Galveston, 301 University Blvd., Galveston, TX 77555 USA
| | - Tetsuro Ikegami
- Department of Pathology, The University of Texas Medical Branch at Galveston, 301 University Blvd., Galveston, TX 77555 USA
- The Sealy Center for Vaccine Development, The University of Texas Medical Branch at Galveston, 301 University Blvd., Galveston, TX 77555 USA
- The Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch at Galveston, 301 University Blvd., Galveston, TX 77555 USA
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42
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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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43
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Rissmann M, Ulrich R, Schröder C, Hammerschmidt B, Hanke D, Mroz C, Groschup MH, Eiden M. Vaccination of alpacas against Rift Valley fever virus: Safety, immunogenicity and pathogenicity of MP-12 vaccine. Vaccine 2016; 35:655-662. [PMID: 28012779 DOI: 10.1016/j.vaccine.2016.12.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 11/25/2016] [Accepted: 12/01/2016] [Indexed: 02/07/2023]
Abstract
Rift Valley fever (RVF) is an emerging zoonosis of major public health concern in Africa and Arabia. Previous outbreaks attributed camelids a significant role in the epidemiology of Rift Valley fever virus (RVFV), making them an important target species for vaccination. Using three alpacas as model-organisms for dromedary camels, the safety, immunogenicity and pathogenicity of the MP-12 vaccine were evaluated in this study. To compare both acute and subacute effects, animals were euthanized at 3 and 31days post infection (dpi). Clinical monitoring, analysis of liver enzymes and hematological parameters demonstrated the tolerability of the vaccine, as no significant adverse effects were observed. Comprehensive analysis of serological parameters illustrated the immunogenicity of the vaccine, eliciting high neutralizing antibody titers and antibodies targeting different viral antigens. RVFV was detected in serum and liver of the alpaca euthanized 3dpi, whereas no virus was detectable at 31dpi. Viral replication was confirmed by detection of various RVFV-antigens in hepatocytes by immunohistochemistry and the presence of mild multifocal necrotizing hepatitis. In conclusion, results indicate that MP-12 is a promising vaccine candidate but still has a residual pathogenicity, which requires further investigation.
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Affiliation(s)
- M Rissmann
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - R Ulrich
- Department of Experimental Animal Facilities and Biorisk Management, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - C Schröder
- Department of Experimental Animal Facilities and Biorisk Management, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - B Hammerschmidt
- Department of Experimental Animal Facilities and Biorisk Management, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - D Hanke
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - C Mroz
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - M H Groschup
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - M Eiden
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany.
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44
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Faburay B, Richt JA. Short Interfering RNA Inhibits Rift Valley Fever Virus Replication and Degradation of Protein Kinase R in Human Cells. Front Microbiol 2016; 7:1889. [PMID: 27933051 PMCID: PMC5121222 DOI: 10.3389/fmicb.2016.01889] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Accepted: 11/10/2016] [Indexed: 12/30/2022] Open
Abstract
Rift Valley fever virus (RVFV) is a mosquito-borne zoonotic pathogen causing severe outbreaks in humans and livestock in sub-Saharan Africa and the Arabian Peninsula. Human infections are characterized by fever, sometimes leading to encephalitis, retinitis, hemorrhagic fever, and occasionally death. There are currently no fully licensed vaccines or effective therapies for human use. Gene silencing mediated by double-stranded short interfering RNA (siRNA) is a sequence-specific, highly conserved mechanism in eukaryotes, which serves as an antiviral defense mechanism. Here, we demonstrate that siRNA duplexes directed against the RVFV nucleoprotein can effectively inhibit RVFV replication in human (MRC5 cells) and African green monkey cells (Vero E6 cells). Using these cells, we demonstrate that individual or complex siRNAs, targeting the RVFV nucleoprotein gene completely abrogate viral protein expression and prevent degradation of the host innate antiviral factor, protein kinase R (PKR). Importantly, pre-treatment of cells with the nucleoprotein-specific siRNAs markedly reduces the virus titer. The antiviral effect of the siRNAs was not attributable to interferon or the interferon response effector molecule, PKR. Thus, the antiviral activity of RVFV nucleoprotein-specific siRNAs may provide novel therapeutic strategy against RVFV infections in animals and humans.
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Affiliation(s)
- Bonto Faburay
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan KS, USA
| | - Juergen A Richt
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan KS, USA
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45
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Yamaoka S, Ebihara H. The two faces of Rift Valley fever virus virulence factor NSs: The development of a vaccine and the elucidation of pathogenesis. Virulence 2016; 7:856-859. [PMID: 27432532 DOI: 10.1080/21505594.2016.1213938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Affiliation(s)
- Satoko Yamaoka
- a Molecular Virology and Host-Pathogen Interaction Unit, Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Hamilton , MT , USA
| | - Hideki Ebihara
- a Molecular Virology and Host-Pathogen Interaction Unit, Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Hamilton , MT , USA
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46
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Lang Y, Henningson J, Jasperson D, Li Y, Lee J, Ma J, Li Y, Cao N, Liu H, Wilson W, Richt J, Ruder M, McVey S, Ma W. Mouse model for the Rift Valley fever virus MP12 strain infection. Vet Microbiol 2016; 195:70-77. [PMID: 27771072 DOI: 10.1016/j.vetmic.2016.09.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 08/25/2016] [Accepted: 09/20/2016] [Indexed: 01/08/2023]
Abstract
Rift Valley fever virus (RVFV), a Category A pathogen and select agent, is the causative agent of Rift Valley fever. To date, no fully licensed vaccine is available in the U.S. for human or animal use and effective antiviral drugs have not been identified. The RVFV MP12 strain is conditionally licensed for use for veterinary purposes in the U.S. which was excluded from the select agent rule of Health and Human Services and the U.S. Department of Agriculture. The MP12 vaccine strain is commonly used in BSL-2 laboratories that is generally not virulent in mice. To establish a small animal model that can be used in a BSL-2 facility for antiviral drug development, we investigated susceptibility of six mouse strains (129S6/SvEv, STAT-1 KO, 129S1/SvlmJ, C57BL/6J, NZW/LacJ, BALB/c) to the MP12 virus infection via an intranasal inoculation route. Severe weight loss, obvious clinical and neurologic signs, and 50% mortality was observed in the STAT-1 KO mice, whereas the other 5 mouse strains did not display obvious and/or severe disease. Virus replication and histopathological lesions were detected in brain and liver of MP12-infected STAT-1 KO mice that developed the acute-onset hepatitis and delayed-onset encephalitis. In conclusion, the STAT-1 KO mouse strain is susceptible to MP12 virus infection, indicating that it can be used to investigate RVFV antivirals in a BSL-2 environment.
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Affiliation(s)
- Yuekun Lang
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Jamie Henningson
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Dane Jasperson
- USDA, ARS, Arthropod-Borne Animal Diseases Research Unit (ABADRU), Center for Grain and Animal Health Research, Manhattan, KS, USA
| | - Yonghai Li
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Jinhwa Lee
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Jingjiao Ma
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Yuhao Li
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Nan Cao
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Haixia Liu
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - William Wilson
- USDA, ARS, Arthropod-Borne Animal Diseases Research Unit (ABADRU), Center for Grain and Animal Health Research, Manhattan, KS, USA
| | - Juergen Richt
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Mark Ruder
- USDA, ARS, Arthropod-Borne Animal Diseases Research Unit (ABADRU), Center for Grain and Animal Health Research, Manhattan, KS, USA
| | - Scott McVey
- USDA, ARS, Arthropod-Borne Animal Diseases Research Unit (ABADRU), Center for Grain and Animal Health Research, Manhattan, KS, USA
| | - Wenjun Ma
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA.
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Baba M, Masiga DK, Sang R, Villinger J. Has Rift Valley fever virus evolved with increasing severity in human populations in East Africa? Emerg Microbes Infect 2016; 5:e58. [PMID: 27329846 PMCID: PMC4932650 DOI: 10.1038/emi.2016.57] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 03/08/2016] [Accepted: 03/16/2016] [Indexed: 11/19/2022]
Abstract
Rift Valley fever (RVF) outbreaks have occurred across eastern Africa from 1912 to 2010 approximately every 4–15 years, most of which have not been accompanied by significant epidemics in human populations. However, human epidemics during RVF outbreaks in eastern Africa have involved 478 deaths in 1998, 1107 reported cases with 350 deaths from 2006 to 2007 and 1174 cases with 241 deaths in 2008. We review the history of RVF outbreaks in eastern Africa to identify the epidemiological factors that could have influenced its increasing severity in humans. Diverse ecological factors influence outbreak frequency, whereas virus evolution has a greater impact on its virulence in hosts. Several factors could have influenced the lack of information on RVF in humans during earlier outbreaks, but the explosive nature of human RVF epidemics in recent years mirrors the evolutionary trend of the virus. Comparisons between isolates from different outbreaks have revealed an accumulation of genetic mutations and genomic reassortments that have diversified RVF virus genomes over several decades. The threat to humans posed by the diversified RVF virus strains increases the potential public health and socioeconomic impacts of future outbreaks. Understanding the shifting RVF epidemiology as determined by its evolution is key to developing new strategies for outbreak mitigation and prevention of future human RVF casualties.
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Affiliation(s)
- Marycelin Baba
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi 00100, Kenya.,Department of Medical Laboratory Science, PMB 1069, University of Maiduguri, Maiduguri 600230, Nigeria
| | - Daniel K Masiga
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi 00100, Kenya
| | - Rosemary Sang
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi 00100, Kenya
| | - Jandouwe Villinger
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi 00100, Kenya
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48
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Nishiyama S, Slack OAL, Lokugamage N, Hill TE, Juelich TL, Zhang L, Smith JK, Perez D, Gong B, Freiberg AN, Ikegami T. Attenuation of pathogenic Rift Valley fever virus strain through the chimeric S-segment encoding sandfly fever phlebovirus NSs or a dominant-negative PKR. Virulence 2016; 7:871-881. [PMID: 27248570 DOI: 10.1080/21505594.2016.1195528] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Rift Valley fever is a mosquito-borne zoonotic disease affecting ruminants and humans. Rift Valley fever virus (RVFV: family Bunyaviridae, genus Phlebovirus) causes abortions and fetal malformations in ruminants, and hemorrhagic fever, encephalitis, or retinitis in humans. The live-attenuated MP-12 vaccine is conditionally licensed for veterinary use in the US. However, this vaccine lacks a marker for the differentiation of vaccinated from infected animals (DIVA). NSs gene is dispensable for RVFV replication, and thus, rMP-12 strains lacking NSs gene is applicable to monitor vaccinated animals. However, the immunogenicity of MP-12 lacking NSs was not as high as parental MP-12. Thus, chimeric MP-12 strains encoding NSs from either Toscana virus (TOSV), sandfly fever Sicilian virus (SFSV) or Punta Toro virus Adames strain (PTA) were characterized previously. Although chimeric MP-12 strains are highly immunogenic, the attenuation through the S-segment remains unknown. Using pathogenic ZH501 strain, we aimed to demonstrate the attenuation of ZH501 strain through chimeric S-segment encoding either the NSs of TOSV, SFSV, PTA, or Punta Toro virus Balliet strain (PTB). In addition, we characterized rZH501 encoding a human dominant-negative PKR (PKRΔE7), which also enhances the immunogenicity of MP-12. Study done on mice revealed that attenuation of rZH501 occurred through the S-segment encoding either PKRΔE7 or SFSV NSs. However, rZH501 encoding either TOSV, PTA, or PTB NSs in the S-segment uniformly caused lethal encephalitis. Our results indicated that the S-segments encoding PKRΔE7 or SFSV NSs are attenuated and thus applicable toward next generation MP-12 vaccine candidates that encode a DIVA marker.
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Affiliation(s)
- Shoko Nishiyama
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Olga A L Slack
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Nandadeva Lokugamage
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Terence E Hill
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Terry L Juelich
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,b Galveston National Laboratory, The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Lihong Zhang
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,b Galveston National Laboratory, The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Jennifer K Smith
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,b Galveston National Laboratory, The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - David Perez
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Bin Gong
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,b Galveston National Laboratory, The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,c The Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Alexander N Freiberg
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,b Galveston National Laboratory, The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,c The Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,d The Sealy Center for Vaccine Development, The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Tetsuro Ikegami
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,c The Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,d The Sealy Center for Vaccine Development, The University of Texas Medical Branch at Galveston , Galveston , TX , USA
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49
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Mutational Analysis of the Rift Valley Fever Virus Glycoprotein Precursor Proteins for Gn Protein Expression. Viruses 2016; 8:v8060151. [PMID: 27231931 PMCID: PMC4926171 DOI: 10.3390/v8060151] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 05/17/2016] [Accepted: 05/19/2016] [Indexed: 01/17/2023] Open
Abstract
The Rift Valley fever virus (RVFV) M-segment encodes the 78 kD, NSm, Gn, and Gc proteins. The 1st AUG generates the 78 kD-Gc precursor, the 2nd AUG generates the NSm-Gn-Gc precursor, and the 3rd AUG makes the NSm’-Gn-Gc precursor. To understand biological changes due to abolishment of the precursors, we quantitatively measured Gn secretion using a reporter assay, in which a Gaussia luciferase (gLuc) protein is fused to the RVFV M-segment pre-Gn region. Using the reporter assay, the relative expression of Gn/gLuc fusion proteins was analyzed among various AUG mutants. The reporter assay showed efficient secretion of Gn/gLuc protein from the precursor made from the 2nd AUG, while the removal of the untranslated region upstream of the 2nd AUG (AUG2-M) increased the secretion of the Gn/gLuc protein. Subsequently, recombinant MP-12 strains encoding mutations in the pre-Gn region were rescued, and virological phenotypes were characterized. Recombinant MP-12 encoding the AUG2-M mutation replicated slightly less efficiently than the control, indicating that viral replication is further influenced by the biological processes occurring after Gn expression, rather than the Gn abundance. This study showed that, not only the abolishment of AUG, but also the truncation of viral UTR, affects the expression of Gn protein by the RVFV M-segment.
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50
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The L, M, and S Segments of Rift Valley Fever Virus MP-12 Vaccine Independently Contribute to a Temperature-Sensitive Phenotype. J Virol 2016; 90:3735-44. [PMID: 26819307 DOI: 10.1128/jvi.02241-15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 01/14/2016] [Indexed: 02/06/2023] Open
Abstract
UNLABELLED Rift Valley fever (RVF) is endemic to Africa, and the mosquito-borne disease is characterized by "abortion storms" in ruminants and by hemorrhagic fever, encephalitis, and blindness in humans. Rift Valley fever virus (RVFV; family Bunyaviridae, genus Phlebovirus) has a tripartite negative-stranded RNA genome (L, M, and S segments). A live-attenuated vaccine for RVF, the MP-12 vaccine, is conditionally licensed for veterinary use in the United States. MP-12 is fully attenuated by the combination of the partially attenuated L, M, and S segments. Temperature sensitivity (ts) limits viral replication at a restrictive temperature and may be involved with viral attenuation. In this study, we aimed to characterize the ts mutations for MP-12. The MP-12 vaccine showed restricted replication at 38°C and replication shutoff (100-fold or greater reduction in virus titer compared to that at 37°C) at 39°C in Vero and MRC-5 cells. Using rZH501 reassortants with either the MP-12 L, M, or S segment, we found that all three segments encode a temperature-sensitive phenotype. However, the ts phenotype of the S segment was weaker than that of the M or L segment. We identified Gn-Y259H, Gc-R1182G, L-V172A, and L-M1244I as major ts mutations for MP-12. The ts mutations in the L segment decreased viral RNA synthesis, while those in the M segment delayed progeny production from infected cells. We also found that a lack of NSs and/or 78kD/NSm protein expression minimally affected the ts phenotype. Our study revealed that MP-12 is a unique vaccine carrying ts mutations in the L, M, and S segments. IMPORTANCE Rift Valley fever (RVF) is a mosquito-borne viral disease endemic to Africa, characterized by high rates of abortion in ruminants and severe diseases in humans. Vaccination is important to prevent the spread of disease, and a live-attenuated MP-12 vaccine is currently the only vaccine with a conditional license in the United States. This study determined the temperature sensitivity (ts) of MP-12 vaccine to understand virologic characteristics. Our study revealed that MP-12 vaccine contains ts mutations independently in the L, M, and S segments and that MP-12 displays a restrictive replication at 38°C.
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