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Bissett SL, Roy P. Impact of VP2 structure on antigenicity: comparison of BTV1 and the highly virulent BTV8 serotype. J Virol 2024:e0095324. [PMID: 39320096 DOI: 10.1128/jvi.00953-24] [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: 05/30/2024] [Accepted: 08/23/2024] [Indexed: 09/26/2024] Open
Abstract
Bluetongue virus (BTV) is an agriculturally and economically significant insect-borne virus that causes serious illness and death in sheep and other domestic and wild ruminants in large areas of the world. Numerous BTV serotypes exist, and distant serotypes exhibit unique neutralizing antibody profiles, which target the outermost capsid protein VP2. The predominant serotype-specific nature of the antibody response to VP2 is a barrier to the development of broad-spectrum prophylactic BTV vaccine candidates. Although VP2 is the main serotype determinant of BTV, the structural basis of serotype specificity has not been investigated. In this study, we utilized the recently available atomic structure of VP2 with a modeled tip domain to carry out in silico structural comparisons between distant serotypes BTV1 and BTV8. These analyses identified structural differences in the tip domain, positioned at the apex of VP2, and informed the design of mutant VP2 constructs. Dissection of tip domain antigenicity demonstrated that the region of structural difference between BTV1 and highly virulent BTV8 was a target of BTV neutralizing antibodies and that mutation of this region resulted in a loss of neutralizing antibody recognition. This study has for the first time provided insights into the structural differences, which underpin the serotype-specific neutralizing antibody response to BTV.IMPORTANCEThe immune system can protect against virus infection by producing antibodies, which bind and inhibit the virus from infecting the susceptible host. These antibodies are termed neutralizing antibodies and generally target the viral receptor binding protein, such as the VP2 of bluetongue virus (BTV). This pressure from the immune system can drive mutation of the viral protein resulting in escape from antibody-mediated neutralization and the evolution of serotypes, as is the case for BTV. Understanding the structural differences, which underpin the different BTV serotypes, could help guide the design of a BTV vaccine that targets multiple serotypes. In this study, we have mapped the VP2 structural differences between distant serotypes, to a region targeted by neutralizing antibodies, and have demonstrated for the first time how VP2 structure is the fundamental basis of serotype specificity.
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Affiliation(s)
- Sara L Bissett
- Department of Infection Biology, London School of Hygiene and Tropical, London, United Kingdom
| | - Polly Roy
- Department of Infection Biology, London School of Hygiene and Tropical, London, United Kingdom
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Drolet BS, Reister-Hendricks L, Mayo C, Rodgers C, Molik DC, McVey DS. Increased Virulence of Culicoides Midge Cell-Derived Bluetongue Virus in IFNAR Mice. Viruses 2024; 16:1474. [PMID: 39339950 PMCID: PMC11437402 DOI: 10.3390/v16091474] [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: 08/17/2024] [Revised: 09/12/2024] [Accepted: 09/13/2024] [Indexed: 09/30/2024] Open
Abstract
Bluetongue (BT) is a Culicoides midge-borne hemorrhagic disease affecting cervids and ruminant livestock species, resulting in significant economic losses from animal production and trade restrictions. Experimental animal infections using the α/β interferon receptor knockout IFNAR mouse model and susceptible target species are critical for understanding viral pathogenesis, virulence, and evaluating vaccines. However, conducting experimental vector-borne transmission studies with the vector itself are logistically difficult and experimentally problematic. Therefore, experimental infections are induced by hypodermic injection with virus typically derived from baby hamster kidney (BHK) cells. Unfortunately, for many U.S. BTV serotypes, it is difficult to replicate the severity of the disease seen in natural, midge-transmitted infections by injecting BHK-derived virus into target host animals. Using the IFNAR BTV murine model, we compared the virulence of traditional BHK cell-derived BTV-17 with C. sonorensis midge (W8) cell-derived BTV-17 to determine whether using cells of the transmission vector would provide an in vitro virulence aspect of vector-transmitted virus. At both low and high doses, mice inoculated with W8-BTV-17 had an earlier onset of viremia, earlier onset and peak of clinical signs, and significantly higher mortality compared to mice inoculated with BHK-BTV-17. Our results suggest using a Culicoides W8 cell-derived inoculum may provide an in vitro vector-enhanced infection to more closely represent disease levels seen in natural midge-transmitted infections while avoiding the logistical and experimental complexity of working with live midges.
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Affiliation(s)
- Barbara S. Drolet
- Arthropod-Borne Animal Diseases Research Unit, Agricultural Research Service, United States Department of Agriculture, Manhattan, KS 66502, USA; (L.R.-H.); (D.C.M.)
| | - Lindsey Reister-Hendricks
- Arthropod-Borne Animal Diseases Research Unit, Agricultural Research Service, United States Department of Agriculture, Manhattan, KS 66502, USA; (L.R.-H.); (D.C.M.)
| | - Christie Mayo
- Department of Microbiology, Immunology, and Pathology, Colorado State University, 1601 Campus Delivery, Fort Collins, CO 80526, USA; (C.M.); (C.R.)
| | - Case Rodgers
- Department of Microbiology, Immunology, and Pathology, Colorado State University, 1601 Campus Delivery, Fort Collins, CO 80526, USA; (C.M.); (C.R.)
| | - David C. Molik
- Arthropod-Borne Animal Diseases Research Unit, Agricultural Research Service, United States Department of Agriculture, Manhattan, KS 66502, USA; (L.R.-H.); (D.C.M.)
| | - David Scott McVey
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, P.O. Box 830905, Lincoln, NE 68583, USA;
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Gujar S, Pol JG, Kumar V, Lizarralde-Guerrero M, Konda P, Kroemer G, Bell JC. Tutorial: design, production and testing of oncolytic viruses for cancer immunotherapy. Nat Protoc 2024; 19:2540-2570. [PMID: 38769145 DOI: 10.1038/s41596-024-00985-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 02/12/2024] [Indexed: 05/22/2024]
Abstract
Oncolytic viruses (OVs) represent a novel class of cancer immunotherapy agents that preferentially infect and kill cancer cells and promote protective antitumor immunity. Furthermore, OVs can be used in combination with established or upcoming immunotherapeutic agents, especially immune checkpoint inhibitors, to efficiently target a wide range of malignancies. The development of OV-based therapy involves three major steps before clinical evaluation: design, production and preclinical testing. OVs can be designed as natural or engineered strains and subsequently selected for their ability to kill a broad spectrum of cancer cells rather than normal, healthy cells. OV selection is further influenced by multiple factors, such as the availability of a specific viral platform, cancer cell permissivity, the need for genetic engineering to render the virus non-pathogenic and/or more effective and logistical considerations around the use of OVs within the laboratory or clinical setting. Selected OVs are then produced and tested for their anticancer potential by using syngeneic, xenograft or humanized preclinical models wherein immunocompromised and immunocompetent setups are used to elucidate their direct oncolytic ability as well as indirect immunotherapeutic potential in vivo. Finally, OVs demonstrating the desired anticancer potential progress toward translation in patients with cancer. This tutorial provides guidelines for the design, production and preclinical testing of OVs, emphasizing considerations specific to OV technology that determine their clinical utility as cancer immunotherapy agents.
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Affiliation(s)
- Shashi Gujar
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada
- Beatrice Hunter Cancer Research Institute, Halifax, Nova Scotia, Canada
| | - Jonathan G Pol
- INSERM, U1138, Paris, France
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, Paris, France
- Université Paris Cité, Paris, France
- Sorbonne Université, Paris, France
- Metabolomics and Cell Biology Platforms, UMS AMICCa, Gustave Roussy, Villejuif, France
| | - Vishnupriyan Kumar
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
- Beatrice Hunter Cancer Research Institute, Halifax, Nova Scotia, Canada
| | - Manuela Lizarralde-Guerrero
- INSERM, U1138, Paris, France
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, Paris, France
- Université Paris Cité, Paris, France
- Sorbonne Université, Paris, France
- Metabolomics and Cell Biology Platforms, UMS AMICCa, Gustave Roussy, Villejuif, France
- Ecole Normale Supérieure de Lyon, Lyon, France
| | - Prathyusha Konda
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Harvard Medical School, Harvard University, Boston, MA, USA
| | - Guido Kroemer
- INSERM, U1138, Paris, France.
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, Paris, France.
- Université Paris Cité, Paris, France.
- Sorbonne Université, Paris, France.
- Metabolomics and Cell Biology Platforms, UMS AMICCa, Gustave Roussy, Villejuif, France.
- Institut Universitaire de France, Paris, France.
- Institut du Cancer Paris CARPEM, Hôpital Européen Georges Pompidou, AP-HP, Paris, France.
| | - John C Bell
- Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada.
- Department of Biochemistry, Microbiology & Immunology, University of Ottawa, Ottawa, Ontario, Canada.
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
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Jiménez-Cabello L, Utrilla-Trigo S, Calvo-Pinilla E, Lorenzo G, Illescas-Amo M, Benavides J, Moreno S, Marín-López A, Nogales A, Ortego J. Co-expression of VP2, NS1 and NS2-Nt proteins by an MVA viral vector induces complete protection against bluetongue virus. Front Immunol 2024; 15:1440407. [PMID: 39072326 PMCID: PMC11272488 DOI: 10.3389/fimmu.2024.1440407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Accepted: 06/28/2024] [Indexed: 07/30/2024] Open
Abstract
Introduction Bluetongue (BT), caused by bluetongue virus (BTV), is an important arthropod-borne livestock disease listed by the World Organization for Animal Health. Live-attenuated and inactivated vaccines have permitted to control BT but they do not simultaneously protect against the myriad of BTV serotypes. Recently, we identified the highly conserved BTV nonstructural protein NS1 and the N-terminal region of NS2 as antigens capable of conferring multiserotype protection against BTV. Methods Here, we designed Modified Vaccinia Ankara (MVA) viral vectors that expressed BTV-4 proteins VP2 or VP7 along with NS1 and NS2-Nt as well as MVAs that expressed proteins VP2, VP7 or NS1 and NS2-Nt. Results Immunization of IFNAR(-/-) mice with two doses of MVA-NS1-2A-NS2-Nt protected mice from BTV-4M infection by the induction of an antigen-specific T cell immune response. Despite rMVA expressing VP7 alone were not protective in the IFNAR(-/-) mouse model, inclusion of VP7 in the vaccine formulation amplified the cell-mediated response induced by NS1 and NS2-Nt. Expression of VP2 elicited protective non-cross-reactive neutralizing antibodies (nAbs) in immunized animals and improved the protection observed in the MVA-NS1-2A-NS2-Nt immunized mice when these three BTV antigens were co-expressed. Moreover, vaccines candidates co-expressing VP2 or VP7 along with NS1 and NS2-Nt provided multiserotype protection. We assessed protective efficacy of both vaccine candidates in sheep against virulent challenge with BTV-4M. Discussion Immunization with MVA-VP7-NS1-2A-NS2-Nt partially dumped viral replication and clinical disease whereas administration of MVA-VP2-NS1-2A-NS2-Nt promoted a complete protection, preventing viraemia and the pathology produced by BTV infection.
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Affiliation(s)
- Luis Jiménez-Cabello
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Madrid, Spain
| | - Sergio Utrilla-Trigo
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Madrid, Spain
| | - Eva Calvo-Pinilla
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Madrid, Spain
| | - Gema Lorenzo
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Madrid, Spain
| | - Miguel Illescas-Amo
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Madrid, Spain
| | - Julio Benavides
- Instituto de Ganadería de Montaña, CSIC-Universidad de León, León, Spain
| | - Sandra Moreno
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Madrid, Spain
| | - Alejandro Marín-López
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, United States
| | - Aitor Nogales
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Madrid, Spain
| | - Javier Ortego
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Madrid, Spain
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Utrilla-Trigo S, Jiménez-Cabello L, Marín-López A, Illescas-Amo M, Andrés G, Calvo-Pinilla E, Lorenzo G, van Rijn PA, Ortego J, Nogales A. Engineering recombinant replication-competent bluetongue viruses expressing reporter genes for in vitro and non-invasive in vivo studies. Microbiol Spectr 2024; 12:e0249323. [PMID: 38353566 PMCID: PMC10923215 DOI: 10.1128/spectrum.02493-23] [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: 06/14/2023] [Accepted: 12/22/2023] [Indexed: 03/06/2024] Open
Abstract
Bluetongue virus (BTV) is the causative agent of the important livestock disease bluetongue (BT), which is transmitted via Culicoides bites. BT causes severe economic losses associated with its considerable impact on health and trade of animals. By reverse genetics, we have designed and rescued reporter-expressing recombinant (r)BTV expressing NanoLuc luciferase (NLuc) or Venus fluorescent protein. To generate these viruses, we custom synthesized a modified viral segment 5 encoding NS1 protein with the reporter genes located downstream and linked by the Porcine teschovirus-1 (PTV-1) 2A autoproteolytic cleavage site. Therefore, fluorescent signal or luciferase activity is only detected after virus replication and expression of non-structural proteins. Fluorescence or luminescence signals were detected in cells infected with rBTV/Venus or rBTV/NLuc, respectively. Moreover, the marking of NS2 protein confirmed that reporter genes were only expressed in BTV-infected cells. Growth kinetics of rBTV/NLuc and rBTV/Venus in Vero cells showed replication rates similar to those of wild-type and rBTV. Infectivity studies of these recombinant viruses in IFNAR(-/-) mice showed a higher lethal dose for rBTV/NLuc and rBTV/Venus than for rBTV indicating that viruses expressing the reporter genes are attenuated in vivo. Interestingly, luciferase activity was detected in the plasma of viraemic mice infected with rBTV/NLuc. Furthermore, luciferase activity quantitatively correlated with RNAemia levels of infected mice throughout the infection. In addition, we have investigated the in vivo replication and dissemination of BTV in IFNAR (-/-) mice using BTV/NLuc and non-invasive in vivo imaging systems.IMPORTANCEThe use of replication-competent viruses that encode a traceable fluorescent or luciferase reporter protein has significantly contributed to the in vitro and in vivo study of viral infections and the development of novel therapeutic approaches. In this work, we have generated rBTV that express fluorescent or luminescence proteins to track BTV infection both in vitro and in vivo. Despite the availability of vaccines, BTV and other related orbivirus are still associated with a significant impact on animal health and have important economic consequences worldwide. Our studies may contribute to the advance in orbivirus research and pave the way for the rapid development of new treatments, including vaccines.
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Affiliation(s)
- Sergio Utrilla-Trigo
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Valdeolmos, Madrid, Spain
| | - Luis Jiménez-Cabello
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Valdeolmos, Madrid, Spain
| | - Alejandro Marín-López
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Miguel Illescas-Amo
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Valdeolmos, Madrid, Spain
| | - Germán Andrés
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Valdeolmos, Madrid, Spain
| | - Eva Calvo-Pinilla
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Valdeolmos, Madrid, Spain
| | - Gema Lorenzo
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Valdeolmos, Madrid, Spain
| | - Piet A. van Rijn
- Department of Virology, Wageningen Bioveterinary Research (WBVR), Lelystad, the Netherlands
- Department of Biochemistry, Centre for Human Metabolomics, North-West University, Potchefstroom, South Africa
| | - Javier Ortego
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Valdeolmos, Madrid, Spain
| | - Aitor Nogales
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Valdeolmos, Madrid, Spain
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Whole-Genome Sequence and Assembly of Eight Africa Horse Sickness Virus Strains Collected in Namibia and South Africa. Microbiol Resour Announc 2023; 12:e0103422. [PMID: 36920210 PMCID: PMC10112199 DOI: 10.1128/mra.01034-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Abstract
In this report, we describe eight complete genome sequences of African horse sickness virus (AHSV) strains belonging to four different serotypes, namely, AHSV-5, AHSV-6, AHSV-8, and AHSV-9. Samples were collected in Namibia and South Africa from infected horses between 2000 and 2011. As expected, phylogenetic analyses of the variable outer capsid protein VP2 genomic sequences of AHSV-6 and AHSV-8 show higher nucleotide identity between the isolated viruses than that of the relevant reference strains. The full-genome sequence of AHSV will provide useful information on its geographical origin, and it will also be instrumental for comparing the distribution of the Namibian isolate with that of global isolates.
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Mahapatra CS, Sharma P, Biswas SK, Chand K. Development of ELISA for the detection of antibodies against VP2 protein of bluetongue virus serotype-1. J Immunol Methods 2022; 511:113386. [PMID: 36384199 DOI: 10.1016/j.jim.2022.113386] [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: 04/01/2022] [Revised: 09/23/2022] [Accepted: 11/10/2022] [Indexed: 11/14/2022]
Abstract
Serotype-specific diagnosis of bluetongue virus (BTV) is necessary for sero-surveillance and taking effective control measures. The VP2 is the major serotype determining protein and BTV-1 is the most predominant serotype in India. In the present study, an indirect ELISA (i-ELISA) was optimized for the detection of serotype-specific antibody against BTV-1 serotype. The VP2 protein of BTV-1 was expressed in a prokaryotic expression system and used to optimize i-ELISA to detect VP2 antibodies of BTV-1 in serum samples of both small and large ruminants. Serum samples (n = 363) classified as positive and negative for antibodies to BTV-1 by serum neutralization test (SNT) and also positive and negative for BTV antibodies by c-ELSIA kit (VMRD, USA) were used to determine the cut-off value, diagnostic sensitivity (DSn), and diagnostic specificity (D-Sp) using receiver operating characteristic (ROC) analysis. The percent positivity (PP) value >30.10% was accepted as the cut-off for i-ELISA at which DSn of 99.52% and D-Sp of 99.35% was observed with a 95% confidence interval. Further, there was no cross-reactivity with other available BTV serotypes in the country. The study indicated serotype-specific i-ELISA is sensitive, specific and suitable alternative to tedious SNT method for determining serotype. The assay will also help in the serotype-specific epidemiological studies and implementation of future control strategies including vaccination and selection of suitable serotype as a vaccine candidate.
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Affiliation(s)
- Chayna Singha Mahapatra
- Division of Virology, ICAR-Indian Veterinary Research Institute, Mukteswar Campus, 263138 Nainital, Uttarakhand, India
| | - Priya Sharma
- Division of Virology, ICAR-Indian Veterinary Research Institute, Mukteswar Campus, 263138 Nainital, Uttarakhand, India
| | - Sanchay Kumar Biswas
- Division of Virology, ICAR-Indian Veterinary Research Institute, Mukteswar Campus, 263138 Nainital, Uttarakhand, India
| | - Karam Chand
- Division of Virology, ICAR-Indian Veterinary Research Institute, Mukteswar Campus, 263138 Nainital, Uttarakhand, India.
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Field-Reassortment of Bluetongue Virus Illustrates Plasticity of Virus Associated Phenotypic Traits in the Arthropod Vector and Mammalian Host In Vivo. J Virol 2022; 96:e0053122. [PMID: 35727032 PMCID: PMC9278112 DOI: 10.1128/jvi.00531-22] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Segmented RNA viruses are a taxonomically diverse group that can infect plant, wildlife, livestock and human hosts. A shared feature of these viruses is the ability to exchange genome segments during coinfection of a host by a process termed "reassortment." Reassortment enables rapid evolutionary change, but where transmission involves a biological arthropod vector, this change is constrained by the selection pressures imposed by the requirement for replication in two evolutionarily distant hosts. In this study, we use an in vivo, host-arbovirus-vector model to investigate the impact of reassortment on two phenotypic traits, virus infection rate in the vector and virulence in the host. Bluetongue virus (BTV) (Reoviridae) is the causative agent of bluetongue (BT), an economically important disease of domestic and wild ruminants and deer. The genome of BTV comprises 10 linear segments of dsRNA, and the virus is transmitted between ruminants by Culicoides biting midges (Diptera: Ceratopogonidae). Five strains of BTV representing three serotypes (BTV-1, BTV-4, and BTV-8) were isolated from naturally infected ruminants in Europe and ancestral/reassortant lineage status assigned through full genome sequencing. Each strain was then assessed in parallel for the ability to replicate in vector Culicoides and to cause BT in sheep. Our results demonstrate that two reassortment strains, which themselves became established in the field, had obtained high replication ability in C. sonorensis from one of the ancestral virus strains, which allowed inferences of the genome segments conferring this phenotypic trait. IMPORTANCE Reassortment between virus strains can lead to major shifts in the transmission parameters and virulence of segmented RNA viruses, with consequences for spread, persistence, and impact. The ability of these pathogens to adapt rapidly to their environment through this mechanism presents a major challenge in defining the conditions under which emergence can occur. Utilizing a representative mammalian host-insect vector infection and transmission model, we provide direct evidence of this phenomenon in closely related ancestral and reassortant strains of BTV. Our results demonstrate that efficient infection of Culicoides observed for one of three ancestral BTV strains was also evident in two reassortant strains that had subsequently emerged in the same ecosystem.
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Bluetongue Virus Infection of Goats: Re-Emerged European Serotype 8 vs. Two Atypical Serotypes. Viruses 2022; 14:v14051034. [PMID: 35632775 PMCID: PMC9144285 DOI: 10.3390/v14051034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/29/2022] [Accepted: 05/10/2022] [Indexed: 01/27/2023] Open
Abstract
In recent years, numerous atypical Bluetongue virus (BTV) strains have been discovered all around the world. Atypical BTV strains are phylogenetically distinct from the classical BTV serotypes 1–24 and differ in terms of several biological features. For the first time, the atypical strains BTV-25-GER2018 and BTV-33-MNG3/2016 as well as the re-emerged classical strain BTV-8-GER2018 were evaluated comparatively in a pathogenesis study in goats—the natural host of atypical BTV. A substantial number of in-contact animals were included in this study to detect potential contact transmissions of the virus. After infection, EDTA blood, ocular, nasal and oral swab samples as well as serum were collected regularly and were used for virological and serological analyses, respectively. Our study showed differences in the immunological reaction between the two atypical BTV strains (no group-specific antibody detection) and the classical BTV strain BTV-8-GER2018 (group-specific antibody detection). Furthermore, we observed an increase in the total WBC count (neutrophils and lymphocytes) in goats infected with the atypical BTV strains. No horizontal transmission was seen for all three strains. Our study suggests that the atypical BTVs used in the trial differ from classical BTVs in their immunopathogenesis. However, no evidence of direct contact transmission was found.
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Full Genome Sequencing of Three Sedoreoviridae Viruses Isolated from Culicoides spp. (Diptera, Ceratopogonidae) in China. Viruses 2022; 14:v14050971. [PMID: 35632713 PMCID: PMC9145729 DOI: 10.3390/v14050971] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/02/2022] [Accepted: 05/03/2022] [Indexed: 11/23/2022] Open
Abstract
Sedoreoviridae is a family of viruses belonging to the order Reovirales and comprises six genera, two of which, Orbivirus and Seadornavirus, contain arboviruses that cause disease in humans and livestock. Areas such as Yunnan Province in southwestern China, have high arboviral activity due in part to warm and wet summers, which support high populations of biting flies such as mosquitoes and Culicoides. Three viral isolates previously obtained from Culicoides collected at cattle farms in Shizong County of Yunnan Province, China, between 2019 and 2020 were completely sequenced and identified as Banna virus (BAV) genotype A of Seadornavirus and serotypes 1 and 7 of epizootic hemorrhagic disease virus (EHDV) of Orbivirus. These results suggest that Culicoidestainanus and C. orientalis are potential vectors of BAV and EHDV, respectively, and represent the first association of a BAV with C. tainanus and of an arbovirus with C. orientalis. Analysis using VP9 generally agreed with the current groupings within this genus based on VP12, although the classification for some strains should be corrected. Furthermore, the placement of Kadipiro virus (KDV) and Liao ning virus (LNV) in Seadornavirus may need confirmation as phylogenetic analysis placed these viruses as sister to other species in the genus.
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Evaluation of two artificial infection methods of live ticks as tools for studying interactions between tick-borne viruses and their tick vectors. Sci Rep 2022; 12:491. [PMID: 35017574 PMCID: PMC8752753 DOI: 10.1038/s41598-021-04498-9] [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: 08/30/2021] [Accepted: 12/08/2021] [Indexed: 12/30/2022] Open
Abstract
Up to 170 tick-borne viruses (TBVs) have been identified to date. However, there is a paucity of information regarding TBVs and their interaction with respective vectors, limiting the development of new effective and urgently needed control methods. To overcome this gap of knowledge, it is essential to reproduce transmission cycles under controlled laboratory conditions. In this study we assessed an artificial feeding system (AFS) and an immersion technique (IT) to infect Ixodes ricinus ticks with tick-borne encephalitis (TBE) and Kemerovo (KEM) virus, both known to be transmitted predominantly by ixodid ticks. Both methods permitted TBEV acquisition by ticks and we further confirmed virus trans-stadial transmission and onward transmission to a vertebrate host. However, only artificial feeding system allowed to demonstrate both acquisition by ticks and trans-stadial transmission for KEMV. Yet we did not observe transmission of KEMV to mice (IFNAR-/- or BALB/c). Artificial infection methods of ticks are important tools to study tick-virus interactions. When optimally used under laboratory settings, they provide important insights into tick-borne virus transmission cycles.
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12
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Abstract
Bluetongue virus (BTV), a member of Orbivirus genus, is transmitted by biting midges (gnats, Culicoides sp) and is one of the most widespread animal pathogens, causing serious outbreaks in domestic animals, particularly in sheep, with high economic impact. The non-enveloped BTV particle is a double-capsid structure of seven proteins and a genome of ten double-stranded RNA segments. Although the outermost spike-like VP2 acts as the attachment protein during BTV entry, no specific host receptor has been identified for BTV. Recent high-resolution cryo-electron (cryoEM) structures and biological data have suggested that VP2 may interact with sialic acids (SAs). To confirm this, we have generated protein-based nanoparticles displaying multivalent VP2 and used them to probe glycan arrays. The data show that VP2 binds α2,3-linked SA with high affinity but also binds α2,6-linked SA. Further, Maackia Amurensis Lectin II (MAL II) and Sambucus Nigra Lectin (SNA), which specifically bind α2,3-linked and α2,6-linked SAs respectively, inhibited BTV infection and virus growth in susceptible sheep cells while SNA alone inhibited virus growth in Culicoides-derived cells. A combination of hydrogen deuterium exchange mass spectrometry and site-directed mutagenesis allowed the identification of the specific SA binding residues of VP2. This study provides direct evidence that sialic acids act as key receptor for BTV and that the outer capsid protein VP2 specifically binds SA during BTV entry in both mammalian and insect cells. Importance To date no receptor has been assigned for non-enveloped bluetongue virus. To determine if the outermost spike-like VP2 protein is responsible for host cell attachment via interaction with sialic acids, we first generated a protein-based VP2-nanoparticle, for the multivalent presentation of recombinant VP2 protein. Using nanoparticles-displaying VP2 to probe a glycan array, we identified that VP2 binds both α2,3-linked and α2,6-linked sialic acids. Lectin inhibitors targeting both linkages of sialic acids showed strong inhibition to BTV infection and progeny virus production in mammalian cells, however the inhibition was only seen with the lectin targeting α2,6-linked sialic acid in insect vector cells. In addition, we identified the VP2 sialic acid binding sites in the exposed tip domain. Our data provides direct evidence that sialic acids act as key receptors for BTV attachment and entry in to both mammalian and insect cells.
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13
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Saminathan M, Singh KP, Khorajiya JH, Dinesh M, Vineetha S, Maity M, Rahman AF, Misri J, Malik YS, Gupta VK, Singh RK, Dhama K. An updated review on bluetongue virus: epidemiology, pathobiology, and advances in diagnosis and control with special reference to India. Vet Q 2021; 40:258-321. [PMID: 33003985 PMCID: PMC7655031 DOI: 10.1080/01652176.2020.1831708] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Bluetongue (BT) is an economically important, non-contagious viral disease of domestic and wild ruminants. BT is caused by BT virus (BTV) and it belongs to the genus Orbivirus and family Reoviridae. BTV is transmitted by Culicoides midges and causes clinical disease in sheep, white-tailed deer, pronghorn antelope, bighorn sheep, and subclinical manifestation in cattle, goats and camelids. BT is a World Organization for Animal Health (OIE) listed multispecies disease and causes great socio-economic losses. To date, 28 serotypes of BTV have been reported worldwide and 23 serotypes have been reported from India. Transplacental transmission (TPT) and fetal abnormalities in ruminants had been reported with cell culture adopted live-attenuated vaccine strains of BTV. However, emergence of BTV-8 in Europe during 2006, confirmed TPT of wild-type/field strains of BTV. Diagnosis of BT is more important for control of disease and to ensure BTV-free trade of animals and their products. Reverse transcription polymerase chain reaction, agar gel immunodiffusion assay and competitive enzyme-linked immunosorbent assay are found to be sensitive and OIE recommended tests for diagnosis of BTV for international trade. Control measures include mass vaccination (most effective method), serological and entomological surveillance, forming restriction zones and sentinel programs. Major hindrances with control of BT in India are the presence of multiple BTV serotypes, high density of ruminant and vector populations. A pentavalent inactivated, adjuvanted vaccine is administered currently in India to control BT. Recombinant vaccines with DIVA strategies are urgently needed to combat this disease. This review is the first to summarise the seroprevalence of BTV in India for 40 years, economic impact and pathobiology.
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Affiliation(s)
- Mani Saminathan
- Division of Pathology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India
| | - Karam Pal Singh
- Division of Pathology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India
| | | | - Murali Dinesh
- Division of Pathology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India
| | - Sobharani Vineetha
- Division of Pathology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India
| | - Madhulina Maity
- Division of Pathology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India
| | - At Faslu Rahman
- Division of Pathology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India
| | - Jyoti Misri
- Animal Science Division, Indian Council of Agricultural Research, New Delhi, India
| | - Yashpal Singh Malik
- Division of Biological Standardization, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India
| | - Vivek Kumar Gupta
- Centre for Animal Disease Research and Diagnosis, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India
| | - Raj Kumar Singh
- Director, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India
| | - Kuldeep Dhama
- Division of Pathology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India
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14
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Fay PC, Mohd Jaafar F, Batten C, Attoui H, Saunders K, Lomonossoff GP, Reid E, Horton D, Maan S, Haig D, Daly JM, Mertens PPC. Serological Cross-Reactions between Expressed VP2 Proteins from Different Bluetongue Virus Serotypes. Viruses 2021; 13:1455. [PMID: 34452321 PMCID: PMC8402635 DOI: 10.3390/v13081455] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 07/14/2021] [Accepted: 07/19/2021] [Indexed: 01/26/2023] Open
Abstract
Bluetongue (BT) is a severe and economically important disease of ruminants that is widely distributed around the world, caused by the bluetongue virus (BTV). More than 28 different BTV serotypes have been identified in serum neutralisation tests (SNT), which, along with geographic variants (topotypes) within each serotype, reflect differences in BTV outer-capsid protein VP2. VP2 is the primary target for neutralising antibodies, although the basis for cross-reactions and serological variations between and within BTV serotypes is poorly understood. Recombinant BTV VP2 proteins (rVP2) were expressed in Nicotiana benthamiana, based on sequence data for isolates of thirteen BTV serotypes (primarily from Europe), including three 'novel' serotypes (BTV-25, -26 and -27) and alternative topotypes of four serotypes. Cross-reactions within and between these viruses were explored using rabbit anti-rVP2 sera and post BTV-infection sheep reference-antisera, in I-ELISA (with rVP2 target antigens) and SNT (with reference strains of BTV-1 to -24, -26 and -27). Strong reactions were generally detected with homologous rVP2 proteins or virus strains/serotypes. The sheep antisera were largely serotype-specific in SNT, but more cross-reactive by ELISA. Rabbit antisera were more cross-reactive in SNT, and showed widespread, high titre cross-reactions against homologous and heterologous rVP2 proteins in ELISA. Results were analysed and visualised by antigenic cartography, showing closer relationships in some, but not all cases, between VP2 topotypes within the same serotype, and between serotypes belonging to the same 'VP2 nucleotype'.
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Affiliation(s)
- Petra C. Fay
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Loughborough LE12 5RD, UK; (P.C.F.); (E.R.); (D.H.); (J.M.D.)
- The Pirbright Institute, Surrey, Woking GU24 ONF, UK;
| | - Fauziah Mohd Jaafar
- UMR VIROLOGIE 1161, INRAE, Ecole Nationale Vétérinaire d’Alfort, ANSES, Université Paris-Est, F-94700 Maisons-Alfort, France; (F.M.J.); (H.A.)
| | - Carrie Batten
- The Pirbright Institute, Surrey, Woking GU24 ONF, UK;
| | - Houssam Attoui
- UMR VIROLOGIE 1161, INRAE, Ecole Nationale Vétérinaire d’Alfort, ANSES, Université Paris-Est, F-94700 Maisons-Alfort, France; (F.M.J.); (H.A.)
| | - Keith Saunders
- John Innes Centre, Department of Biochemistry and Metabolism, Norwich Research Park, Norwich NR4 7UH, UK; (K.S.); (G.P.L.)
| | - George P. Lomonossoff
- John Innes Centre, Department of Biochemistry and Metabolism, Norwich Research Park, Norwich NR4 7UH, UK; (K.S.); (G.P.L.)
| | - Elizabeth Reid
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Loughborough LE12 5RD, UK; (P.C.F.); (E.R.); (D.H.); (J.M.D.)
| | - Daniel Horton
- Pathology and Infectious Diseases, School of Veterinary Medicine, University of Surrey, Guildford GU2 7XH, UK;
| | - Sushila Maan
- Department of Animal Biotechnology, Lala Lajpat Rai University of Veterinary & Animal Sciences, Hisar 125004, India;
| | - David Haig
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Loughborough LE12 5RD, UK; (P.C.F.); (E.R.); (D.H.); (J.M.D.)
| | - Janet M. Daly
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Loughborough LE12 5RD, UK; (P.C.F.); (E.R.); (D.H.); (J.M.D.)
| | - Peter P. C. Mertens
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Loughborough LE12 5RD, UK; (P.C.F.); (E.R.); (D.H.); (J.M.D.)
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15
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Wang A, Du J, Feng H, Zhou J, Chen Y, Liu Y, Jiang M, Jia R, Tian Y, Zhang G. Identification of a novel bluetongue virus 1 specific B cell epitope using monoclonal antibodies against the VP2 protein. Int J Biol Macromol 2021; 183:1393-1401. [PMID: 33984384 DOI: 10.1016/j.ijbiomac.2021.05.053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/10/2021] [Accepted: 05/06/2021] [Indexed: 11/25/2022]
Abstract
Bluetongue (BT) is a non-contact infectious disease caused by Bluetongue virus (BTV), which can be transmitted by vector insects such as Culicoides and Aedes mosquitoes. The BTV VP2 protein encoded by the L2 gene is located at the outermost layer of the virus particle, plays a key role on mediating the adsorption and entry of virus, and it is also a main antigenic protein widely used for vaccine development. In this study, the BTV1 VP2 gene was cloned into pFastBac™Dual vector, and expressed in insect Sf21 cells. Immunized mice with purified recombinant VP2 protein can induce higher levels of antibodies. Three anti BTV1 VP2 monoclonal antibodies (mAbs) were generated (17E9C6, 17E9C8, 17E9H12), and showed high specific reactivity with recombinant VP2 protein and inactivated BTV1 virus. Finally, a novel linear B-cell epitope 296-KEPAD-300 on recombinant VP2 protein was identified by using three mAbs react with a series of continue-truncated peptides. The results of this study may provide new information on the structure and function of BTV1 VP2 protein and lay a foundation for the development of BTV1 diagnostic and prophylactic methods.
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Affiliation(s)
- Aiping Wang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Jinran Du
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Hua Feng
- Key Laboratory of Animal Immunology of the Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
| | - Jingming Zhou
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yumei Chen
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yankai Liu
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Min Jiang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Rui Jia
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yuanyuan Tian
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Gaiping Zhang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China.
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16
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Toh X, Wang Y, Rajapakse MP, Lee B, Songkasupa T, Suwankitwat N, Kamlangdee A, Judith Fernandez C, Huangfu T. Use of nanopore sequencing to characterize african horse sickness virus (AHSV) from the African horse sickness outbreak in thailand in 2020. Transbound Emerg Dis 2021; 69:1010-1019. [PMID: 33682298 DOI: 10.1111/tbed.14056] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 03/03/2021] [Accepted: 03/03/2021] [Indexed: 12/01/2022]
Abstract
African horse sickness (AHS) is a highly infectious and deadly disease despite availability of vaccines. Molecular characterization of African horse sickness virus (AHSV) detected from the March 2020 Thailand outbreak was carried out by whole-genome sequencing using Nanopore with a Sequence-Independent Single Primer Amplification (SISPA) approach. Nucleotide sequence of the whole genome was compared with closest matching AHSV strains using phylogenetic analyses and the AHSV-1 virus shared high sequence identity with isolates from the same outbreak. Substitution analysis revealed non-synonymous and synonymous substitutions in the VP2 gene as compared to circulating South African strains. The use of sequencing technologies, such as Nanopore with SISPA, has enabled rapid detection, identification and detailed genetic characterization of the AHS virus for informed decision-making and implementation of disease control measures. Active genetic information sharing has also allowed emergence of AHSV to be better monitored on a global basis.
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Affiliation(s)
- Xinyu Toh
- Center for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Singapore
| | - Yifan Wang
- Center for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Singapore
| | | | - Bernett Lee
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), Singapore
| | - Tapanut Songkasupa
- Virology section, Department of Livestock Development, National Institute of Animal Health, Bangkok, Thailand
| | - Nutthakarn Suwankitwat
- Virology section, Department of Livestock Development, National Institute of Animal Health, Bangkok, Thailand
| | - Attapon Kamlangdee
- Faculty of Veterinary Medicine, Kasetsart university, Kamphaengsean, Thailand
| | - Charlene Judith Fernandez
- Center for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Singapore
| | - Taoqi Huangfu
- Center for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Singapore
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17
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Roy P. Bluetongue virus assembly and exit pathways. Adv Virus Res 2020; 108:249-273. [PMID: 33837718 DOI: 10.1016/bs.aivir.2020.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Bluetongue virus (BTV) is an insect-vectored emerging pathogen of wild ruminants and livestock in many parts of the world. The virion particle is a complex structure of consecutive layers of protein surrounding a genome of 10 double-stranded (ds) RNA segments. BTV has been studied extensively as a model system for large, nonenveloped dsRNA viruses. A combination of recombinant proteins and particles together with reverse genetics, high-resolution structural analysis by X-ray crystallography and cryo-electron microscopy techniques have been utilized to provide an order for the assembly of the capsid shell and the protein sequestration required for it. Further, a reconstituted in vitro assembly system and RNA-RNA interaction assay, have defined the individual steps required for the assembly and packaging of the 10-segmented RNA genome. In addition, various microscopic techniques have been utilized to illuminate the stages of virus maturation and its egress via multiple pathways. These findings have not only given an overall understanding of BTV assembly and morphogenesis but also indicated that similar assembly and egress pathways are likely to be used by related viruses and provided an informed starting point for intervention or prevention.
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Affiliation(s)
- Polly Roy
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom.
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18
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Guo Y, Huang L, Bi K, Xu Q, Bu Z, Wang F, Sun E. Recombinant bluetongue virus with hemagglutinin epitopes in VP2 has potential as a labeled vaccine. Vet Microbiol 2020; 248:108825. [PMID: 32891953 DOI: 10.1016/j.vetmic.2020.108825] [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: 03/14/2020] [Accepted: 08/11/2020] [Indexed: 11/15/2022]
Abstract
Bluetongue (BT) is an arbovirus-borne disease of ruminants caused by bluetongue virus (BTV) that has the potential to have a serious economic impact. Currently available commercial vaccines include attenuated vaccines and inactivated vaccines, both of which have achieved great success in the prevention and control of BTV. However, these vaccines cannot distinguish between infected animals and immunized animals. To control outbreaks of BTV, the development of labeled vaccines is urgently needed. In this study, we used the plasmid-based reverse genetics system (RGS) of BTV to rescue four recombinant viruses in which HA (influenza hemagglutinin) tags were inserted at different sites of VP2. In vitro, the recombinant tagged viruses exhibited morphologies, plaque, and growth kinetics similar to the parental BTV-16, and expressed both VP2 and HA tag. Subsequently, the selected recombinant tagged viruses were prepared as inactivated vaccines to immunize IFNAR(-/-) mice and sheep, and serological detection results of anti-HA antibody provided discriminative detection. In summary, we used plasmid-based RGS to rescue BTV recombinant viruses with HA tags inserted into VP2, and detected several sites on VP2 that can accommodate HA tags. Some of the recombinant tagged viruses have potential to be developed into distinctive inactivated vaccines.
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Affiliation(s)
- Yunze Guo
- Department of Veterinary Pathology, Laboratory of Clinical Diagnosis and Treatment Technology in Animal Disease, Ministry of Agriculture, College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, 010018, China; The Key Laboratory of Veterinary Public Health, Ministry of Agriculture, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150069, China
| | - Liping Huang
- The Key Laboratory of Veterinary Public Health, Ministry of Agriculture, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150069, China
| | - Kaixuan Bi
- Department of Veterinary Pathology, Laboratory of Clinical Diagnosis and Treatment Technology in Animal Disease, Ministry of Agriculture, College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, 010018, China
| | - Qingyuan Xu
- The Key Laboratory of Veterinary Public Health, Ministry of Agriculture, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150069, China
| | - Zhigao Bu
- The Key Laboratory of Veterinary Public Health, Ministry of Agriculture, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150069, China
| | - Fenglong Wang
- Department of Veterinary Pathology, Laboratory of Clinical Diagnosis and Treatment Technology in Animal Disease, Ministry of Agriculture, College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, 010018, China.
| | - Encheng Sun
- The Key Laboratory of Veterinary Public Health, Ministry of Agriculture, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150069, China.
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19
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Roy P. Highly efficient vaccines for Bluetongue virus and a related Orbivirus based on reverse genetics. Curr Opin Virol 2020; 44:35-41. [PMID: 32610251 DOI: 10.1016/j.coviro.2020.05.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 04/30/2020] [Accepted: 05/04/2020] [Indexed: 10/24/2022]
Abstract
Bluetongue virus (BTV) reverse genetics (RG), available since 2007, has allowed the dissection of the virus replication cycle, including discovery of a primary replication stage. This information has allowed the generation of Entry-Competent-Replication-Abortive (ECRA) vaccines, which enter cells and complete primary replication but fail to complete the later stage. A series of vaccine trials in sheep and cattle either with a single ECRA serotype or a cocktail of multiple ECRA serotypes have demonstrated that these vaccines provide complete protection against virulent virus challenge without cross-serotype interference. Similarly, an RG system developed for the related African Horse Sickness virus, which causes high mortality in equids has provided AHSV ECRA vaccines that are protective in horses. ECRA vaccines were incapable of productive replication in animals despite being competent for cell entry. This technology allows rapid generation of emerging Orbivirus vaccines and offers immunogenicity and safety levels that surpass attenuated or recombinant routes.
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Affiliation(s)
- Polly Roy
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, United Kingdom.
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20
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Haegeman A, Vandaele L, De Leeuw I, Oliveira AP, Nauwynck H, Van Soom A, De Clercq K. Failure to Remove Bluetongue Serotype 8 Virus (BTV-8) From in vitro Produced and in vivo Derived Bovine Embryos and Subsequent Transmission of BTV-8 to Recipient Cows After Embryo Transfer. Front Vet Sci 2019; 6:432. [PMID: 31867345 PMCID: PMC6907088 DOI: 10.3389/fvets.2019.00432] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 11/15/2019] [Indexed: 11/13/2022] Open
Abstract
The behavior of BTV-8 in cattle is different from most other serotypes not only with regards to clinical signs but certainly with respect to virus transmission (transplacental, contact). Therefore, the possibility of virus transmission by means of embryo transfer was examined by in vitro exposure of in vitro produced and in vivo derived bovine blastocysts to BTV-8 followed by different washing protocols, including longer exposure times (up to 120 s) to 0.25% trypsin at room temperature or at 37°C. None of the washing protocols used was successful in removing the viral genome completely from the in vitro produced and in vivo derived embryos as was demonstrated by real-time PCR. Moreover, BTV-8 virus was transmitted to recipient cows after embryo transfer of in vivo derived BTV8-exposed embryos, which had been subjected to routine decontamination as recommended by IETS, consisting of 5 washes in PBS followed by a double treatment of 0.25% trypsin for 45s at 37°C, and an additional 5 washes in PBS with 2% FCS. This study clearly demonstrates the necessity of vigorous application of the directives for screening of potential donors and the collected embryos, especially in regions with BTV-8, to prevent transmission of the disease.
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Affiliation(s)
- Andy Haegeman
- Unit of Exotic and Particular Diseases, Sciensano, Brussels, Belgium
| | - Leen Vandaele
- Department of Reproduction, Obstetrics and Herd Health, Ghent University, Merelbeke, Belgium
| | - Ilse De Leeuw
- Unit of Exotic and Particular Diseases, Sciensano, Brussels, Belgium
| | - André P Oliveira
- Department of Reproduction, Obstetrics and Herd Health, Ghent University, Merelbeke, Belgium.,EPAMIG, Escola de Veterinaria da UFMG, Bolsista CAPES, Belo Horizonte, Brazil
| | - Hans Nauwynck
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Ann Van Soom
- Department of Reproduction, Obstetrics and Herd Health, Ghent University, Merelbeke, Belgium
| | - Kris De Clercq
- Unit of Exotic and Particular Diseases, Sciensano, Brussels, Belgium
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21
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Dennis SJ, Meyers AE, Hitzeroth II, Rybicki EP. African Horse Sickness: A Review of Current Understanding and Vaccine Development. Viruses 2019; 11:E844. [PMID: 31514299 PMCID: PMC6783979 DOI: 10.3390/v11090844] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/30/2019] [Accepted: 09/04/2019] [Indexed: 01/05/2023] Open
Abstract
African horse sickness is a devastating disease that causes great suffering and many fatalities amongst horses in sub-Saharan Africa. It is caused by nine different serotypes of the orbivirus African horse sickness virus (AHSV) and it is spread by Culicoid midges. The disease has significant economic consequences for the equine industry both in southern Africa and increasingly further afield as the geographic distribution of the midge vector broadens with global warming and climate change. Live attenuated vaccines (LAV) have been used with relative success for many decades but carry the risk of reversion to virulence and/or genetic re-assortment between outbreak and vaccine strains. Furthermore, the vaccines lack DIVA capacity, the ability to distinguish between vaccine-induced immunity and that induced by natural infection. These concerns have motivated interest in the development of new, more favourable recombinant vaccines that utilize viral vectors or are based on reverse genetics or virus-like particle technologies. This review summarizes the current understanding of AHSV structure and the viral replication cycle and also evaluates existing and potential vaccine strategies that may be applied to prevent or control the disease.
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Affiliation(s)
- Susan J Dennis
- Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, Rondebosch 7701, Cape Town, South Africa.
| | - Ann E Meyers
- Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, Rondebosch 7701, Cape Town, South Africa.
| | - Inga I Hitzeroth
- Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, Rondebosch 7701, Cape Town, South Africa.
| | - Edward P Rybicki
- Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, Rondebosch 7701, Cape Town, South Africa.
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Observatory 7925, Cape Town, South Africa.
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Stevens LM, Moffat K, Cooke L, Nomikou K, Mertens PPC, Jackson T, Darpel KE. A low-passage insect-cell isolate of bluetongue virus uses a macropinocytosis-like entry pathway to infect natural target cells derived from the bovine host. J Gen Virol 2019; 100:568-582. [PMID: 30843784 DOI: 10.1099/jgv.0.001240] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Bluetongue virus (BTV) causes an economically important disease in domestic and wildlife ruminants and is transmitted by Culicoides biting midges. In ruminants, BTV has a wide cell tropism that includes endothelial cells of vascular and lymphatic vessels as important cell targets for virus replication, and several cell types of the immune system including monocytes, macrophages and dendritic cells. Thus, cell-entry represents a particular challenge for BTV as it infects many different cell types in widely diverse vertebrate and invertebrate hosts. Improved understanding of BTV cell-entry could lead to novel antiviral approaches that can block virus transmission from cell to cell between its invertebrate and vertebrate hosts. Here, we have investigated BTV cell-entry using endothelial cells derived from the natural bovine host (BFA cells) and purified whole virus particles of a low-passage, insect-cell isolate of a virulent strain of BTV-1. Our results show that the main entry pathway for infection of BFA cells is dependent on actin and dynamin, and shares certain characteristics with macropinocytosis. The ability to use a macropinocytosis-like entry route could explain the diverse cell tropism of BTV and contribute to the efficiency of transmission between vertebrate and invertebrate hosts.
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Affiliation(s)
- Lisa M Stevens
- 1The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK.,2University of Surrey, Guildford, Surrey, GU2 7XH, UK.,‡Present address: Animal and Plant Health Agency, Woodham Lane, New Haw, KT15 3NB, UK
| | - Katy Moffat
- 1The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK
| | - Lyndsay Cooke
- 1The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK.,2University of Surrey, Guildford, Surrey, GU2 7XH, UK
| | - Kyriaki Nomikou
- 1The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK.,§Present address: School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonnington, Leicestershire, LE12 5RD, UK
| | - Peter P C Mertens
- 1The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK.,§Present address: School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonnington, Leicestershire, LE12 5RD, UK
| | - Terry Jackson
- 1The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK
| | - Karin E Darpel
- 2University of Surrey, Guildford, Surrey, GU2 7XH, UK.,1The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK
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Mapping the pH Sensors Critical for Host Cell Entry by a Complex Nonenveloped Virus. J Virol 2019; 93:JVI.01897-18. [PMID: 30518645 PMCID: PMC6363992 DOI: 10.1128/jvi.01897-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 11/19/2018] [Indexed: 11/23/2022] Open
Abstract
Virus entry into a susceptible cell is the first step of infection and a significant point at which infection can be prevented. To enter effectively, viruses must sense the cellular environment and, when appropriate, initiate a series of changes that eventually jettison the protective shell and deposit virus genes into the cytoplasm. Many viruses sense pH, but how this happens and the events that follow are often poorly understood. Here, we address this question for a large multilayered bluetongue virus. We show key residues in outer capsid proteins, a pH-sensing histidine of a zinc finger within the receptor-binding VP2 protein, and certain histidine residues in the membrane-penetrating VP5 protein that detect cellular pH, leading to irreversible changes and propel the virus through the cell membrane. Our data reveal a novel mechanism of cell entry for a nonenveloped virus and highlight mechanisms which may also be used by other viruses. Bluetongue virus (BTV), in the family Reoviridae, is an insect-borne, double-capsid virus causing hemorrhagic disease in livestock around the world. Here, we elucidate how outer capsid proteins VP2 and VP5 coordinate cell entry of BTV. To identify key functional residues, we used atomic-level structural data to guide mutagenesis of VP2 and VP5 and a series of biological and biochemical approaches, including site-directed mutagenesis, reverse genetics-based virus recovery, expression and characterization of individual recombinant mutant proteins, and various in vitro and in vivo assays. We demonstrate the dynamic nature of the conformational change process, revealing that a unique zinc finger (CCCH) in VP2 acts as the major low pH sensor, coordinating VP2 detachment, subsequently allowing VP5 to sense low pH via specific histidine residues at key positions. We show that single substitution of only certain histidine residues has a lethal effect, indicating that the location of histidine in VP5 is critical to inducing changes in VP5 conformation that facilitates membrane penetration. Further, we show that the VP5 anchoring domain alone recapitulates sensing of low pH. Our data reveal a novel, multiconformational process that overcomes entry barriers faced by this multicapsid nonenveloped virus. IMPORTANCE Virus entry into a susceptible cell is the first step of infection and a significant point at which infection can be prevented. To enter effectively, viruses must sense the cellular environment and, when appropriate, initiate a series of changes that eventually jettison the protective shell and deposit virus genes into the cytoplasm. Many viruses sense pH, but how this happens and the events that follow are often poorly understood. Here, we address this question for a large multilayered bluetongue virus. We show key residues in outer capsid proteins, a pH-sensing histidine of a zinc finger within the receptor-binding VP2 protein, and certain histidine residues in the membrane-penetrating VP5 protein that detect cellular pH, leading to irreversible changes and propel the virus through the cell membrane. Our data reveal a novel mechanism of cell entry for a nonenveloped virus and highlight mechanisms which may also be used by other viruses.
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Van den Bergh C, Coetzee P, Venter EH. Reassortment of bluetongue virus vaccine serotypes in cattle. J S Afr Vet Assoc 2018; 89:e1-e7. [PMID: 30551703 PMCID: PMC6295955 DOI: 10.4102/jsava.v89i0.1649] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 10/17/2018] [Accepted: 10/17/2018] [Indexed: 11/01/2022] Open
Abstract
Bluetongue is primarily a disease of sheep in South Africa, while cattle and goats are mostly subclinically infected. The viraemia of bluetongue virus in cattle lasts much longer than in sheep and the role of cattle in the epidemiology of bluetongue in South Africa is poorly understood. Bluetongue virus has a segmented double-stranded ribonucleic acid genome and reassortment of genomes is a common feature. The aim of the study was to investigate whether reassortment occurs between vaccine and field strains when simultaneously administered to cattle. Six cattle between the ages of 6 and 12 months were infected with five strains of modified live vaccine bluetongue virus and a virulent field isolate of bluetongue virus 4. Blood samples were subsequently collected daily from these animals from day 1 to day 39 post-inoculation. Viruses were directly isolated during viraemia from the buffy coat on Vero cells using the plaque forming unit method. Analysis of plaques indicated that no reassortants between virulent field and vaccine strains occurred and the virulent bluetongue virus 4 was identified as the predominant virus strain. However, a reassortant virus between two bluetongue virus vaccine strains was isolated from the buffy coat. Whole genome sequences from the vaccine viruses were compared to the suspected reassortant and it was found that segment 8 exchanged between the bluetongue virus 8 and bluetongue virus 9 vaccine strains. The use of the live-attenuated bluetongue virus multivalent vaccine in South Africa causes circulation of different vaccine serotypes in Culicoides spp. and susceptible hosts and cattle might provide the ideal host for reassortment to occur.
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25
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Yadav PD, Shete AM, Nyayanit DA, Albarino CG, Jain S, Guerrero LW, Kumar S, Patil DY, Nichol ST, Mourya DT. Identification and characterization of novel mosquito-borne (Kammavanpettai virus) and tick-borne (Wad Medani) reoviruses isolated in India. J Gen Virol 2018; 99:991-1000. [PMID: 29939123 DOI: 10.1099/jgv.0.001102] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
In 1954, a virus named Wad Medani virus (WMV) was isolated from Hyalomma marginatum ticks from Maharashtra State, India. In 1963, another virus was isolated from Sturnia pagodarum birds in Tamil Nadu, India, and named Kammavanpettai virus (KVPTV) based on the site of its isolation. Originally these virus isolates could not be identified with conventional methods. Here we describe next-generation sequencing studies leading to the determination of their complete genome sequences, and identification of both virus isolates as orbiviruses (family Reoviridae). Sequencing data showed that KVPTV has an AT-rich genome, whereas the genome of WMV is GC-rich. The size of the KVPTV genome is 18 234 nucleotides encoding proteins ranging 238-1290 amino acids (aa) in length. Similarly, the size of the WMV genome is 16 941 nucleotides encoding proteins ranging 214-1305 amino acids in length. Phylogenetic analysis of the VP1 gene, along with the capsid genes VP5 and VP7, revealed that KVPTV is likely a novel mosquito-borne virus and WMV is a tick-borne orbivirus. This study focuses on the phylogenetic comparison of these newly identified orbiviruses with mosquito-, tick- and Culicoides-borne orbiviruses isolated in India and other countries.
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Affiliation(s)
- Pragya D Yadav
- 1Maximum Containment Laboratory, National Institute of Virology, Pune, Maharashtra, India
| | - Anita M Shete
- 1Maximum Containment Laboratory, National Institute of Virology, Pune, Maharashtra, India
| | - Dimpal A Nyayanit
- 1Maximum Containment Laboratory, National Institute of Virology, Pune, Maharashtra, India
| | - Cesar G Albarino
- 2Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, National Center for Emerging Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Shilpi Jain
- 1Maximum Containment Laboratory, National Institute of Virology, Pune, Maharashtra, India
| | - Lisa W Guerrero
- 2Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, National Center for Emerging Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Sandeep Kumar
- 1Maximum Containment Laboratory, National Institute of Virology, Pune, Maharashtra, India
| | - Deepak Y Patil
- 1Maximum Containment Laboratory, National Institute of Virology, Pune, Maharashtra, India
| | - Stuart T Nichol
- 2Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, National Center for Emerging Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Devendra T Mourya
- 1Maximum Containment Laboratory, National Institute of Virology, Pune, Maharashtra, India
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Schade-Weskott ML, van Schalkwyk A, Koekemoer JJO. A correlation between capsid protein VP2 and the plaque morphology of African horse sickness virus in cell culture. Virus Genes 2018; 54:527-535. [PMID: 29730763 DOI: 10.1007/s11262-018-1567-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 04/30/2018] [Indexed: 12/29/2022]
Abstract
The attenuated live virus vaccine that is used in South Africa to protect against African horse sickness infection was developed more than 50 years ago. With the selection of the vaccine strains by cell culture passage, a correlation between the size of plaques formed in monolayer Vero cultures and attenuation of virus virulence in horses was found. The large plaque phenotype was used as an indication of cell culture adaptation and strongly correlated with attenuation of virulence in horses. There was never any investigation into the genetic causes of either the variation in plaque size, or the loss of virulence. An understanding of the underlying mechanisms of attenuation would benefit the production of a safer AHSV vaccine. To this end, the genomes of different strains of two African horse sickness isolates, producing varying plaque sizes, were compared and the differences between them identified. This comparison suggested that proteins VP2, VP3, VP5 and NS3 were most likely involved in the determination of the plaque phenotype. Comparison between genome sequences (obtained from GenBank) of low and high passage strains from two additional serotypes indicated that VP2 was the only protein with amino acid substitutions in all four serotypes. The amino acid substitutions all occurred within the same hydrophilic area, resulting in increased hydrophilicity of VP2 in the large plaque strains.
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Affiliation(s)
- Mathilde L Schade-Weskott
- Agricultural Research Council - Onderstepoort Veterinary Institute, 100 Old Soutpan Rd, Pretoria, South Africa.
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa.
| | - Antoinette van Schalkwyk
- Agricultural Research Council - Onderstepoort Veterinary Institute, 100 Old Soutpan Rd, Pretoria, South Africa
| | - J J O Koekemoer
- Agricultural Research Council - Onderstepoort Veterinary Institute, 100 Old Soutpan Rd, Pretoria, South Africa
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Mohamed DKA, Du J, Gao S, Tian Z, Zhang G, Huang D, Du R, Kang B, Liu G, Luo J, Yin H. Evaluation of the immune response afforded by a subunit vaccine candidate against bluetongue virus in mice and sheep. Vet Microbiol 2018; 219:40-48. [PMID: 29778203 DOI: 10.1016/j.vetmic.2018.04.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 04/03/2018] [Accepted: 04/03/2018] [Indexed: 10/17/2022]
Abstract
Bluetongue virus (BTV), a vector-borne pathogen, is the causative agent of bluetongue disease in ruminants. In view of the recent emergence of BTV in regions previously known to be free from the disease and/or specific serotypes or strains, optimization of the currently available vaccination strategies to control the spread of vector-borne bluetongue is crucial. The main objective of the current study was to develop a subunit vaccine candidate targeting BTV-16, a strain previously isolated in China from sheep with obvious clinical signs. To this end, five polyhistidine-tagged recombinant proteins (BTV-16 VP2, VP3, VP7, NS2 and a truncated version of VP5 (VP5-41amino acids) were expressed using the baculovirus or Escherichia coli expression system for characterization of protective activity. To determine ovine and murine immune responses to the five proteins, sheep and mice were immunized twice at 4- and 2-week intervals, respectively, with one of two different protein combinations in MontanideTM ISA201 VG adjuvant or placebo. Data from the competitive enzyme linked immunosorbent assay revealed significantly higher antibody titers in immunized than control animals. Expressed VP5 and NS2 induced a protein-specific humoral response. Interestingly, a serum neutralization test against the BTV-1 serotype showed promising cross-serotype immune response by the vaccine. Based on the collective data, we suggest that these recombinant purified proteins present promising candidates for the design of effective novel vaccines against BTV.
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Affiliation(s)
- Darien Kheder Ali Mohamed
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu, 730046, PR China
| | - Junzheng Du
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu, 730046, PR China.
| | - Shandian Gao
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu, 730046, PR China
| | - Zhancheng Tian
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu, 730046, PR China
| | - Guorui Zhang
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu, 730046, PR China
| | - Dexuan Huang
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu, 730046, PR China
| | - Rongsheng Du
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu, 730046, PR China
| | - Biao Kang
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu, 730046, PR China
| | - Guangyuan Liu
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu, 730046, PR China
| | - Jianxun Luo
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu, 730046, PR China
| | - Hong Yin
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu, 730046, PR China; Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, PR China.
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28
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Roy P. Bluetongue virus structure and assembly. Curr Opin Virol 2017; 24:115-123. [PMID: 28609677 DOI: 10.1016/j.coviro.2017.05.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 05/19/2017] [Accepted: 05/24/2017] [Indexed: 01/09/2023]
Abstract
Bluetongue virus (BTV) is an insect-vectored emerging pathogen of wild ruminants and livestock in many parts of the world. The virion particle is a complex structure of consecutive layers of protein surrounding a genome of ten double-stranded (ds) RNA segments. BTV has been studied as a model system for large, non-enveloped dsRNA viruses. Several new techniques have been applied to define the virus-encoded enzymes required for RNA replication to provide an order for the assembly of the capsid shell and the protein sequestration required for it. Further, a reconstituted in vitro system has defined the individual steps of the assembly and packaging of the genomic RNA. These findings illuminate BTV assembly and indicate the pathways that related viruses might use to provide an informed starting point for intervention or prevention.
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Affiliation(s)
- Polly Roy
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, WC1E 7HT, UK.
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29
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van Zyl AR, Meyers AE, Rybicki EP. Development of plant-produced protein body vaccine candidates for bluetongue virus. BMC Biotechnol 2017; 17:47. [PMID: 28558675 PMCID: PMC5450216 DOI: 10.1186/s12896-017-0370-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 05/22/2017] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Bluetongue is a disease of domestic and wild ruminants caused by bluetongue virus serotypes (BTV), which have caused serious outbreaks worldwide. Commercially available vaccines are live-attenuated or inactivated virus strains: these are effective, but there is the risk of reversion to virulence or reassortment with circulating strains for live virus, and residual live virus for the inactivated vaccines. The live-attenuated virus vaccines are not able to distinguish naturally infected animals from vaccinated animals (DIVA compliant). Recombinant vaccines are preferable to minimize the risks associated with these vaccines, and would also enable the development of candidate vaccines that are DIVA-compliant. RESULTS In this study, two novel protein body (PB) plant-produced vaccines were developed, Zera®-VP2ep and Zera®-VP2. Zera®-VP2ep contained B-cell epitope sequences of multiple BTV serotypes and Zera®-VP2 contained the full-length BTV-8 VP2 codon-optimised sequence. In addition to fulfilling the DIVA requirement, Zera®-VP2ep was aimed at being multivalent with the ability to stimulate an immune response to several BTV serotypes. Both these candidate vaccines were successfully made in N. benthamiana via transient Agrobacterium-mediated expression, and in situ TEM analysis showed that the expressed proteins accumulated within the cytoplasm of plant cells in dense membrane-defined PBs. The peptide sequences included in Zera®-VP2ep contained epitopes that bound antibodies produced against native VP2. Preliminary murine immunogenicity studies showed that the PB vaccine candidates elicited anti-VP2 immune responses in mice without the use of adjuvant. CONCLUSIONS These proof of concept results demonstrate that Zera®-VP2ep and Zera®-VP2 have potential as BTV vaccines and their development should be further investigated.
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Affiliation(s)
- Albertha R. van Zyl
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag X3, Rondebosch, 7700 South Africa
| | - Ann E. Meyers
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag X3, Rondebosch, 7700 South Africa
| | - Edward P. Rybicki
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag X3, Rondebosch, 7700 South Africa
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Observatory, Cape Town, 7925 South Africa
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Structural Protein VP2 of African Horse Sickness Virus Is Not Essential for Virus Replication In Vitro. J Virol 2017; 91:JVI.01328-16. [PMID: 27903804 DOI: 10.1128/jvi.01328-16] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 11/23/2016] [Indexed: 12/25/2022] Open
Abstract
The Reoviridae family consists of nonenveloped multilayered viruses with a double-stranded RNA genome consisting of 9 to 12 genome segments. The Orbivirus genus of the Reoviridae family contains African horse sickness virus (AHSV), bluetongue virus, and epizootic hemorrhagic disease virus, which cause notifiable diseases and are spread by biting Culicoides species. Here, we used reverse genetics for AHSV to study the role of outer capsid protein VP2, encoded by genome segment 2 (Seg-2). Expansion of a previously found deletion in Seg-2 indicates that structural protein VP2 of AHSV is not essential for virus replication in vitro In addition, in-frame replacement of RNA sequences in Seg-2 by that of green fluorescence protein (GFP) resulted in AHSV expressing GFP, which further confirmed that VP2 is not essential for virus replication. In contrast to virus replication without VP2 expression in mammalian cells, virus replication in insect cells was strongly reduced, and virus release from insect cells was completely abolished. Further, the other outer capsid protein, VP5, was not copurified with virions for virus mutants without VP2 expression. AHSV without VP5 expression, however, could not be recovered, indicating that outer capsid protein VP5 is essential for virus replication in vitro Our results demonstrate for the first time that a structural viral protein is not essential for orbivirus replication in vitro, which opens new possibilities for research on other members of the Reoviridae family. IMPORTANCE Members of the Reoviridae family cause major health problems worldwide, ranging from lethal diarrhea caused by rotavirus in humans to economic losses in livestock production caused by different orbiviruses. The Orbivirus genus contains many virus species, of which bluetongue virus, epizootic hemorrhagic disease virus, and African horse sickness virus (AHSV) cause notifiable diseases according to the World Organization of Animal Health. Recently, it has been shown that nonstructural proteins NS3/NS3a and NS4 are not essential for virus replication in vitro, whereas it is generally assumed that structural proteins VP1 to -7 of these nonenveloped, architecturally complex virus particles are essential. Here we demonstrate for the first time that structural protein VP2 of AHSV is not essential for virus replication in vitro Our findings are very important for virologists working in the field of nonenveloped viruses, in particular reoviruses.
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31
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Marzook NB, Newsome TP. Viruses That Exploit Actin-Based Motility for Their Replication and Spread. Handb Exp Pharmacol 2016; 235:237-261. [PMID: 27757755 DOI: 10.1007/164_2016_41] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The actin cytoskeleton is a crucial part of the eukaryotic cell. Viruses depend on host cells for their replication, and, as a result, many have developed ways of manipulating the actin network to promote their spread. This chapter reviews the various ways in which viruses utilize the actin cytoskeleton at discrete steps in their life cycle, from entry into the host cell, replication, and assembly of new progeny to virus release. Various actin inhibitors that function in different ways to affect proper actin dynamics can be used to parse the role of actin at these steps.
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Affiliation(s)
- N Bishara Marzook
- The School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Timothy P Newsome
- The School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia.
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32
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African horse sickness virus infects BSR cells through macropinocytosis. Virology 2016; 497:217-232. [PMID: 27497184 DOI: 10.1016/j.virol.2016.07.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 07/11/2016] [Accepted: 07/12/2016] [Indexed: 11/23/2022]
Abstract
Cellular pathways involved in cell entry by African horse sickness virus (AHSV), a member of the Orbivirus genus within the Reoviridae family, have not yet been determined. Here, we show that acidic pH is required for productive infection of BSR cells by AHSV-4, suggesting that the virus is likely internalized by an endocytic pathway. We subsequently analyzed the major endocytic routes using specific inhibitors and determined the consequences for AHSV-4 entry into BSR cells. The results indicated that virus entry is dynamin dependent, but clathrin- and lipid raft/caveolae-mediated endocytic pathways were not used by AHSV-4 to enter and infect BSR cells. Instead, binding of AHSV-4 to BSR cells stimulated uptake of a macropinocytosis-specific cargo and inhibition of Na(+)/H(+) exchangers, actin polymerization and cellular GTPases and kinases involved in macropinocytosis significantly inhibited AHSV-4 infection. Altogether, the data suggest that AHSV-4 infects BSR cells by utilizing macropinocytosis as the primary entry pathway.
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Bluetongue Virus NS4 Protein Is an Interferon Antagonist and a Determinant of Virus Virulence. J Virol 2016; 90:5427-39. [PMID: 27009961 PMCID: PMC4934764 DOI: 10.1128/jvi.00422-16] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 03/16/2016] [Indexed: 12/24/2022] Open
Abstract
Bluetongue virus (BTV) is the causative agent of bluetongue, a major infectious disease of ruminants with serious consequences to both animal health and the economy. The clinical outcome of BTV infection is highly variable and dependent on a variety of factors related to both the virus and the host. In this study, we show that the BTV nonstructural protein NS4 favors viral replication in sheep, the animal species most affected by bluetongue. In addition, NS4 confers a replication advantage on the virus in interferon (IFN)-competent primary sheep endothelial cells and immortalized cell lines. We determined that in cells infected with an NS4 deletion mutant (BTV8ΔNS4), there is increased synthesis of type I IFN compared to cells infected with wild-type BTV-8. In addition, using RNA sequencing (RNA-seq), we show that NS4 modulates the host IFN response and downregulates mRNA levels of type I IFN and interferon-stimulated genes. Moreover, using reporter assays and protein synthesis assays, we show that NS4 downregulates the activities of a variety of promoters, such as the cytomegalovirus immediate-early promoter, the IFN-β promoter, and a promoter containing interferon-stimulated response elements (ISRE). We also show that the NS4 inhibitory activity on gene expression is related to its nucleolar localization. Furthermore, NS4 does not affect mRNA splicing or cellular translation. The data obtained in this study strongly suggest that BTV NS4 is an IFN antagonist and a key determinant of viral virulence.
IMPORTANCE Bluetongue is one of the main infectious diseases of ruminants and is caused by bluetongue virus (BTV), an arthropod-borne virus transmitted from infected to susceptible animals by Culicoides biting midges. Bluetongue has a variable clinical outcome that can be related to both virus and host factors. It is therefore critical to understand the interplay between BTV and the host immune responses. In this study, we show that a nonstructural protein of BTV (NS4) is critical to counteract the innate immune response of the host. Infection of cells with a BTV mutant lacking NS4 results in increased synthesis of IFN-β and upregulation of interferon-stimulated genes. In addition, we show that NS4 is a virulence factor for BTV by favoring viral replication in sheep, the animal species most susceptible to bluetongue.
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Drolet BS, van Rijn P, Howerth EW, Beer M, Mertens PP. A Review of Knowledge Gaps and Tools for Orbivirus Research. Vector Borne Zoonotic Dis 2016; 15:339-47. [PMID: 26086555 DOI: 10.1089/vbz.2014.1701] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Although recognized as causing emerging and re-emerging disease outbreaks worldwide since the late 1800 s, there has been growing interest in the United States and Europe in recent years in orbiviruses, their insect vectors, and the diseases they cause in domestic livestock and wildlife. This is due, in part, to the emergence of bluetongue (BT) in northern Europe in 2006-2007 resulting in a devastating outbreak, as well as severe BT outbreaks in sheep and epizootic hemorrhagic disease (EHD) outbreaks in deer and cattle in the United States. Of notable concern is the isolation of as many as 10 new BT virus (BTV) serotypes in the United States since 1999 and their associated unknowns, such as route of introduction, virulence to mammals, and indigenous competent vectors. This review, based on a gap analysis workshop composed of international experts on orbiviruses conducted in 2013, gives a global perspective of current basic virological understanding of orbiviruses, with particular attention to BTV and the closely related epizootic hemorrhagic disease virus (EHDV), and identifies a multitude of basic virology research gaps, critical for predicting and preventing outbreaks.
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Affiliation(s)
- Barbara S Drolet
- 1 US Department of Agriculture, Agricultural Research Service, Arthropod-Borne Animal Diseases Research Unit , Manhattan, Kansas
| | - Piet van Rijn
- 2 Department of Virology, Central Veterinary Institute of Wageningen University (CVI), The Netherlands; Department of Biochemistry, Centre for Human Metabonomics, North-West University , South Africa
| | - Elizabeth W Howerth
- 3 Department of Pathology, College of Veterinary Medicine, University of Georgia , Athens, Georgia
| | - Martin Beer
- 4 Institute of Diagnostic Virology, Friedrich-Loeffler-Institut , Insel Riems, Germany
| | - Peter P Mertens
- 5 Vector-Borne Diseases Programme, The Pirbright Institute , Pirbright, Woking, United Kingdom
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Patel A, Mohl BP, Roy P. Entry of Bluetongue Virus Capsid Requires the Late Endosome-specific Lipid Lysobisphosphatidic Acid. J Biol Chem 2016; 291:12408-19. [PMID: 27036941 PMCID: PMC4933286 DOI: 10.1074/jbc.m115.700856] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Indexed: 12/03/2022] Open
Abstract
The entry of viruses into host cells is one of the key processes of infection. The mechanisms of cellular entry for enveloped virus have been well studied. The fusion proteins as well as the facilitating cellular lipid factors involved in the viral fusion entry process have been well characterized. The process of non-enveloped virus cell entry, in comparison, remains poorly defined, particularly for large complex capsid viruses of the family Reoviridae, which comprises a range of mammalian pathogens. These viruses enter cells without the aid of a limiting membrane and thus cannot fuse with host cell membranes to enter cells. Instead, these viruses are believed to penetrate membranes of the host cell during endocytosis. However, the molecular mechanism of this process is largely undefined. Here we show, utilizing an in vitro liposome penetration assay and cell biology, that bluetongue virus (BTV), an archetypal member of the Reoviridae, utilizes the late endosome-specific lipid lysobisphosphatidic acid for productive membrane penetration and viral entry. Further, we provide preliminary evidence that lipid lysobisphosphatidic acid facilitates pore expansion during membrane penetration, suggesting a mechanism for lipid factor requirement of BTV. This finding indicates that despite the lack of a membrane envelope, the entry process of BTV is similar in specific lipid requirements to enveloped viruses that enter cells through the late endosome. These results are the first, to our knowledge, to demonstrate that a large non-enveloped virus of the Reoviridae has specific lipid requirements for membrane penetration and host cell entry.
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Affiliation(s)
- Avnish Patel
- From the Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Bjorn-Patrick Mohl
- From the Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Polly Roy
- From the Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
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van Zyl AR, Meyers AE, Rybicki EP. Transient Bluetongue virus serotype 8 capsid protein expression in Nicotiana benthamiana. ACTA ACUST UNITED AC 2015; 9:15-24. [PMID: 28352588 PMCID: PMC5360979 DOI: 10.1016/j.btre.2015.12.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 11/27/2015] [Accepted: 12/01/2015] [Indexed: 12/11/2022]
Abstract
Expression of BTV-8 capsid genes results in CLPs and VLPs in Nicotiana benthamiana. Density of infiltrated Agrobacterium cells influences protein expression levels. CLPs/VLPs can be purified from leaf extracts using density gradient centrifugation. CLPs/VLPs are present in paracrystalline arrays within the plant cell cytoplasm.
Bluetongue virus (BTV) causes severe disease in domestic and wild ruminants, and has recently caused several outbreaks in Europe. Current vaccines include live-attenuated and inactivated viruses; while these are effective, there is risk of reversion to virulence by mutation or reassortment with wild type viruses. Subunit or virus-like particle (VLP) vaccines are safer options: VLP vaccines produced in insect cells by expression of the four BTV capsid proteins are protective against challenge; however, this is a costly production method. We investigated production of BTV VLPs in plants via Agrobacterium-mediated transient expression, an inexpensive production system very well suited to developing country use. Leaves infiltrated with recombinant pEAQ-HT vectors separately encoding the four BTV-8 capsid proteins produced more proteins than recombinant pTRA vectors. Plant expression using the pEAQ-HT vector resulted in both BTV-8 core-like particles (CLPs) and VLPs; differentially controlling the concentration of infiltrated bacteria significantly influenced yield of the VLPs. In situ localisation of assembled particles was investigated by using transmission electron microscopy (TEM) and it was shown that a mixed population of core-like particles (CLPs, consisting of VP3 and VP7) and VLPs were present as paracrystalline arrays in the cytoplasm of plant cells co-expressing all four capsid proteins.
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Affiliation(s)
- Albertha R van Zyl
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag X3, Rondebosch 7700, South Africa
| | - Ann E Meyers
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag X3, Rondebosch 7700, South Africa
| | - Edward P Rybicki
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag X3, Rondebosch 7700, South Africa
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Vermaak E, Theron J. Virus uncoating is required for apoptosis induction in cultured mammalian cells infected with African horse sickness virus. J Gen Virol 2015; 96:1811-20. [PMID: 25783475 DOI: 10.1099/vir.0.000124] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Elaine Vermaak
- Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria 0002, South Africa
| | - Jacques Theron
- Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria 0002, South Africa
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Application of bluetongue Disabled Infectious Single Animal (DISA) vaccine for different serotypes by VP2 exchange or incorporation of chimeric VP2. Vaccine 2014; 33:812-8. [PMID: 25510389 DOI: 10.1016/j.vaccine.2014.12.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 12/01/2014] [Accepted: 12/02/2014] [Indexed: 01/05/2023]
Abstract
Bluetongue is a disease of ruminants caused by the bluetongue virus (BTV). Bluetongue outbreaks can be controlled by vaccination, however, currently available vaccines have several drawbacks. Further, there are at least 26 BTV serotypes, with low cross protection. A next-generation vaccine based on live-attenuated BTV without expression of non-structural proteins NS3/NS3a, named Disabled Infectious Single Animal (DISA) vaccine, was recently developed for serotype 8 by exchange of the serotype determining outer capsid protein VP2. DISA vaccines are replicating vaccines but do not cause detectable viremia, and induce serotype specific protection. Here, we exchanged VP2 of laboratory strain BTV1 for VP2 of European serotypes 2, 4, 8 and 9 using reverse genetics, without observing large effects on virus growth. Exchange of VP2 from serotype 16 and 25 was however not possible. Therefore, chimeric VP2 proteins of BTV1 containing possible immunogenic regions of these serotypes were studied. BTV1, expressing 1/16 chimeric VP2 proteins was functional in virus replication in vitro and contained neutralizing epitopes of both serotype 1 and 16. For serotype 25 this approach failed. We combined VP2 exchange with the NS3/NS3a negative phenotype in BTV1 as previously described for serotype 8 DISA vaccine. DISA vaccine with 1/16 chimeric VP2 containing amino acid region 249-398 of serotype 16 raised antibodies in sheep neutralizing both BTV1 and BTV16. This suggests that DISA vaccine could be protective for both parental serotypes present in chimeric VP2. We here demonstrate the application of the BT DISA vaccine platform for several serotypes and further extend the application for serotypes that are unsuccessful in single VP2 exchange.
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Du J, Bhattacharya B, Ward TH, Roy P. Trafficking of bluetongue virus visualized by recovery of tetracysteine-tagged virion particles. J Virol 2014; 88:12656-68. [PMID: 25142589 PMCID: PMC4248949 DOI: 10.1128/jvi.01815-14] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 08/13/2014] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Bluetongue virus (BTV), a member of the Orbivirus genus in the Reoviridae family, is a double-capsid insect-borne virus enclosing a genome of 10 double-stranded RNA segments. Like those of other members of the family, BTV virions are nonenveloped particles containing two architecturally complex capsids. The two proteins of the outer capsid, VP2 and VP5, are involved in BTV entry and in the delivery of the transcriptionally active core to the cell cytoplasm. Although the importance of the endocytic pathway in BTV entry has been reported, detailed analyses of entry and the role of each protein in virus trafficking have not been possible due to the lack of availability of a tagged virus. Here, for the first time, we report on the successful manipulation of a segmented genome of a nonenveloped capsid virus by the introduction of tags that were subsequently fluorescently visualized in infected cells. The genetically engineered fluorescent BTV particles were observed to enter live cells immediately after virus adsorption. Further, we showed the separation of VP2 from VP5 during virus entry and confirmed that while VP2 is shed from virions in early endosomes, virus particles still consisting of VP5 were trafficked sequentially from early to late endosomes. Since BTV infects both mammalian and insect cells, the generation of tagged viruses will allow visualization of the trafficking of BTV farther downstream in different host cells. In addition, the tagging technology has potential for transferable application to other nonenveloped complex viruses. IMPORTANCE Live-virus trafficking in host cells has been highly informative on the interactions between virus and host cells. Although the insertion of fluorescent markers into viral genomes has made it possible to study the trafficking of enveloped viruses, the physical constraints of architecturally complex capsid viruses have imposed practical limitations. In this study, we have successfully genetically engineered the segmented RNA genome of bluetongue virus (BTV), a complex nonenveloped virus belonging to the Reoviridae family. The resulting fluorescent virus particles could be visualized in virus entry studies of both live and fixed cells. This is the first time a structurally complex capsid virus has been successfully genetically manipulated to generate virus particles that could be visualized in infected cells.
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Affiliation(s)
- Junzheng Du
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Bishnupriya Bhattacharya
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Theresa H Ward
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Polly Roy
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Kochinger S, Renevey N, Hofmann MA, Zimmer G. Vesicular stomatitis virus replicon expressing the VP2 outer capsid protein of bluetongue virus serotype 8 induces complete protection of sheep against challenge infection. Vet Res 2014; 45:64. [PMID: 24928313 PMCID: PMC4063687 DOI: 10.1186/1297-9716-45-64] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 05/22/2014] [Indexed: 12/28/2022] Open
Abstract
Bluetongue virus (BTV) is an arthropod-borne pathogen that causes an often fatal, hemorrhagic disease in ruminants. Different BTV serotypes occur throughout many temperate and tropical regions of the world. In 2006, BTV serotype 8 (BTV-8) emerged in Central and Northern Europe for the first time. Although this outbreak was eventually controlled using inactivated virus vaccines, the epidemic caused significant economic losses not only from the disease in livestock but also from trade restrictions. To date, BTV vaccines that allow simple serological discrimination of infected and vaccinated animals (DIVA) have not been approved for use in livestock. In this study, we generated recombinant RNA replicon particles based on single-cycle vesicular stomatitis virus (VSV) vectors. Immunization of sheep with infectious VSV replicon particles expressing the outer capsid VP2 protein of BTV-8 resulted in induction of BTV-8 serotype-specific neutralizing antibodies. After challenge with a virulent BTV-8 strain, the vaccinated animals neither developed signs of disease nor showed viremia. In contrast, immunization of sheep with recombinant VP5 - the second outer capsid protein of BTV - did not confer protection. Discrimination of infected from vaccinated animals was readily achieved using an ELISA for detection of antibodies against the VP7 antigen. These data indicate that VSV replicon particles potentially represent a safe and efficacious vaccine platform with which to control future outbreaks by BTV-8 or other serotypes, especially in previously non-endemic regions where discrimination between vaccinated and infected animals is crucial.
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Affiliation(s)
| | | | | | - Gert Zimmer
- Institute of Virology and Immunology (IVI), Sensemattstrasse 293, CH-3147 Mittelhäusern, Switzerland.
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Mohd Jaafar F, Belhouchet M, Vitour D, Adam M, Breard E, Zientara S, Mertens PPC, Attoui H. Immunisation with bacterial expressed VP2 and VP5 of bluetongue virus (BTV) protect α/β interferon-receptor knock-out (IFNAR(-/-)) mice from homologous lethal challenge. Vaccine 2014; 32:4059-67. [PMID: 24886956 DOI: 10.1016/j.vaccine.2014.05.056] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 04/22/2014] [Accepted: 05/15/2014] [Indexed: 12/23/2022]
Abstract
BTV-4 structural proteins VP2 (as two domains: VP2D1 and VP2D2), VP5 (lacking the first 100 amino acids: VP5Δ1-100) and full-length VP7, expressed in bacteria as soluble glutathione S-transferase (GST) fusion-proteins, were used to immunise Balb/c and α/β interferon receptor knock-out (IFNAR(-/-)) mice. Neutralising antibody (NAbs) titres (expressed as log10 of the reciprocal of the last dilution of mouse serum which reduced plaque number by ≥50%) induced by the VP2 domains ranged from 1.806 to 2.408 in Balb/c and IFNAR(-/-) mice. The immunised IFNAR(-/-) mice challenged with a homologous live BTV-4 survived and failed to develop signs of infection (ocular discharge and apathy). Although subsequent attempts to isolate virus were unsuccessful (possibly reflecting presence of neutralising antibodies), a transient/low level viraemia was detected by real time RT-PCR. In contrast, mice immunised with the two VP2 domains with or without VP5Δ1-100 and VP7, then challenged with the heterologous serotype, BTV-8, all died by day 7 post-infection. We conclude that immunisation with bacterially-expressed VP2 domains can induce strong serotype-specific NAb responses. Bacterial expression could represent a cost effective and risk-free alternative to the use of live or inactivated vaccines, particularly if viruses prove to be difficult to propagate in cell culture (like BTV-25). A vaccine based on bacterially expressed VP2 and VP5 of BTV is also DIVA-compatible.
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Affiliation(s)
- Fauziah Mohd Jaafar
- Vector-borne Viral Diseases Programme, The Pirbright Institute, Pirbright, Woking, Surrey GU240NF, United Kingdom
| | - Mourad Belhouchet
- Vector-borne Viral Diseases Programme, The Pirbright Institute, Pirbright, Woking, Surrey GU240NF, United Kingdom
| | - Damien Vitour
- Anses, INRA, ENVA-UPEC, UMR 1161 Virology Unit, French Agency for Food, Environmental and Occupational Health and Safety, Maisons-Alfort, 94703 France
| | - Micheline Adam
- Anses, INRA, ENVA-UPEC, UMR 1161 Virology Unit, French Agency for Food, Environmental and Occupational Health and Safety, Maisons-Alfort, 94703 France
| | - Emmanuel Breard
- Anses, INRA, ENVA-UPEC, UMR 1161 Virology Unit, French Agency for Food, Environmental and Occupational Health and Safety, Maisons-Alfort, 94703 France
| | - Stéphan Zientara
- Anses, INRA, ENVA-UPEC, UMR 1161 Virology Unit, French Agency for Food, Environmental and Occupational Health and Safety, Maisons-Alfort, 94703 France
| | - Peter P C Mertens
- Vector-borne Viral Diseases Programme, The Pirbright Institute, Pirbright, Woking, Surrey GU240NF, United Kingdom
| | - Houssam Attoui
- Vector-borne Viral Diseases Programme, The Pirbright Institute, Pirbright, Woking, Surrey GU240NF, United Kingdom.
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Factors that affect the intracellular localization and trafficking of African horse sickness virus core protein, VP7. Virology 2014; 456-457:279-91. [DOI: 10.1016/j.virol.2014.03.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 01/26/2014] [Accepted: 03/29/2014] [Indexed: 11/21/2022]
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Rojas JM, Peña L, Martín V, Sevilla N. Ovine and murine T cell epitopes from the non-structural protein 1 (NS1) of bluetongue virus serotype 8 (BTV-8) are shared among viral serotypes. Vet Res 2014; 45:30. [PMID: 24621015 PMCID: PMC3995764 DOI: 10.1186/1297-9716-45-30] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Accepted: 02/27/2014] [Indexed: 11/24/2022] Open
Abstract
Bluetongue virus (BTV) is a non-enveloped dsRNA virus that causes a haemorrhagic disease mainly in sheep. It is an economically important Orbivirus of the Reoviridae family. In order to estimate the importance of T cell responses during BTV infection, it is essential to identify the epitopes targeted by the immune system. In the present work, we selected potential T cell epitopes (3 MHC-class II-binding and 8 MHC-class I binding peptides) for the C57BL/6 mouse strain from the BTV-8 non-structural protein NS1, using H2b-binding predictive algorithms. Peptide binding assays confirmed all MHC-class I predicted peptides bound MHC-class I molecules. The immunogenicity of these 11 predicted peptides was then determined using splenocytes from BTV-8-inoculated C57BL/6 mice. Four MHC-class I binding peptides elicited specific IFN-γ production and generated cytotoxic T lymphocytes (CTL) in BTV-8 infected mice. CTL specific for 2 of these peptides were also able to recognise target cells infected with different BTV serotypes. Similarly, using a combination of IFN-γ ELISPOT, intracellular cytokine staining and proliferation assays, two MHC-class II peptides were identified as CD4+ T cell epitopes in BTV-8 infected mice. Importantly, two peptides were also consistently immunogenic in sheep infected with BTV-8 using IFN-γ ELISPOT assays. Both of these peptides stimulated CD4+ T cells that cross-reacted with other BTV serotypes. The characterisation of these T cell epitopes can help develop vaccines protecting against a broad spectrum of BTV serotypes and differentiate infected from vaccinated animals.
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Affiliation(s)
| | | | | | - Noemí Sevilla
- Centro de Investigación en Sanidad Animal (CISA-INIA), Instituto Nacional de Investigación Agraria y Alimentaria, Valdeolmos, Madrid, Spain.
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Coetzee P, Van Vuuren M, Stokstad M, Myrmel M, van Gennip RGP, van Rijn PA, Venter EH. Viral replication kinetics and in vitro cytopathogenicity of parental and reassortant strains of bluetongue virus serotype 1, 6 and 8. Vet Microbiol 2014; 171:53-65. [PMID: 24685608 DOI: 10.1016/j.vetmic.2014.03.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 02/19/2014] [Accepted: 03/03/2014] [Indexed: 01/16/2023]
Abstract
Bluetongue virus (BTV), a segmented dsRNA virus, is the causative agent of bluetongue (BT), an economically important viral haemorrhagic disease of ruminants. Bluetongue virus can exchange its genome segments in mammalian or insect cells that have been co-infected with more than one strain of the virus. This process, may potentially give rise to the generation of novel reassortant strains that may differ from parental strains in regards to their phenotypic characteristics. To investigate the potential effects of reassortment on the virus' phenotype, parental as well as reassortant strains of BTV serotype 1, 6, 8, that were derived from attenuated and wild type strains by reverse genetics, were studied in vitro for their virus replication kinetics and cytopathogenicity in mammalian (Vero) cell cultures. The results indicate that genetic reassortment can affect viral replication kinetics, the cytopathogenicity and extent/mechanism of cell death in infected cell cultures. In particular, some reassortants of non-virulent vaccine (BTV-1 and BTV-6) and virulent field origin (BTV-8) demonstrate more pronounced cytopathic effects compared to their parental strains. Some reassortant strains in addition replicated to high titres in vitro despite being composed of genome segments from slow and fast replicating parental strains. The latter result may have implications for the level of viraemia in the mammalian host and subsequent uptake and transmission of reassortant strains (and their genome segments) by Culicoides vectors. Increased rates of CPE induction could further suggest a higher virulence for reassortant strains in vivo. Overall, these findings raise questions in regards to the use of modified-live virus (MLV) vaccines and risk of reassortment in the field. To further address these questions, additional experimental infection studies using insects and/or animal models should be conducted, to determine whether these results have significant implications in vivo.
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Affiliation(s)
- Peter Coetzee
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, Pretoria 0110, South Africa; Department of Production Animal Clinical Sciences, Norwegian University of Life Sciences, P.O. Box 8146, 0033 Oslo, Norway.
| | - Moritz Van Vuuren
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, Pretoria 0110, South Africa.
| | - Maria Stokstad
- Department of Production Animal Clinical Sciences, Norwegian University of Life Sciences, P.O. Box 8146, 0033 Oslo, Norway.
| | - Mette Myrmel
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, P.O. Box 8146, 0033 Oslo, Norway.
| | - René G P van Gennip
- Department of Virology, Central Veterinary Institute of Wageningen University, P.O. Box 65, 8200 AB, Lelystad, The Netherlands.
| | - Piet A van Rijn
- Department of Virology, Central Veterinary Institute of Wageningen University, P.O. Box 65, 8200 AB, Lelystad, The Netherlands; Department of Biochemistry, Centre for Human Metabonomics, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa.
| | - Estelle H Venter
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, Pretoria 0110, South Africa.
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Purification, stability, and immunogenicity analyses of five bluetongue virus proteins for use in development of a subunit vaccine that allows differentiation of infected from vaccinated animals. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2014; 21:443-52. [PMID: 24451327 DOI: 10.1128/cvi.00776-13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Bluetongue virus (BTV) causes bluetongue disease, a vector-borne disease of ruminants. The recent northerly spread of BTV serotype 8 in Europe resulted in outbreaks characterized by clinical signs in cattle, including unusual teratogenic effects. Vaccination has been shown to be crucial for controlling the spread of vector-borne diseases such as BTV. With the aim of developing a novel subunit vaccine targeting BTV-8 that allows differentiation of infected from vaccinated animals, five His-tagged recombinant proteins, VP2 and VP5 of BTV-8 and NS1, NS2, and NS3 of BTV-2, were expressed in baculovirus or Escherichia coli expression systems for further study. Optimized purification protocols were determined for VP2, NS1, NS2, and NS3, which remained stable for detection for at least 560 to 610 days of storage at +4°C or -80°C, and Western blotting using sera from vaccinated or experimentally infected cattle indicated that VP2 and NS2 were recognized by BTV-specific antibodies. To characterize murine immune responses to the four proteins, mice were subcutaneously immunized twice at a 4-week interval with one of three protein combinations plus immunostimulating complex ISCOM-Matrix adjuvant or with ISCOM-Matrix alone (n = 6 per group). Significantly higher serum IgG antibody titers specific for VP2 and NS2 were detected in immunized mice than were detected in controls. VP2, NS1, and NS2 but not NS3 induced specific lymphocyte proliferative responses upon restimulation of spleen cells from immunized mice. The data suggest that these recombinant purified proteins, VP2, NS1, and NS2, could be an important part of a novel vaccine design against BTV-8.
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The molecular biology of Bluetongue virus replication. Virus Res 2013; 182:5-20. [PMID: 24370866 DOI: 10.1016/j.virusres.2013.12.017] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 12/10/2013] [Accepted: 12/11/2013] [Indexed: 01/17/2023]
Abstract
The members of Orbivirus genus within the Reoviridae family are arthropod-borne viruses which are responsible for high morbidity and mortality in ruminants. Bluetongue virus (BTV) which causes disease in livestock (sheep, goat, cattle) has been in the forefront of molecular studies for the last three decades and now represents the best understood orbivirus at a molecular and structural level. The complex nature of the virion structure has been well characterised at high resolution along with the definition of the virus encoded enzymes required for RNA replication; the ordered assembly of the capsid shell as well as the protein and genome sequestration required for it; and the role of host proteins in virus entry and virus release. More recent developments of Reverse Genetics and Cell-Free Assembly systems have allowed integration of the accumulated structural and molecular knowledge to be tested at meticulous level, yielding higher insight into basic molecular virology, from which the rational design of safe efficacious vaccines has been possible. This article is centred on the molecular dissection of BTV with a view to understanding the role of each protein in the virus replication cycle. These areas are important in themselves for BTV replication but they also indicate the pathways that related viruses, which includes viruses that are pathogenic to man and animals, might also use providing an informed starting point for intervention or prevention.
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Thuenemann EC, Meyers AE, Verwey J, Rybicki EP, Lomonossoff GP. A method for rapid production of heteromultimeric protein complexes in plants: assembly of protective bluetongue virus-like particles. PLANT BIOTECHNOLOGY JOURNAL 2013; 11:839-46. [PMID: 23647743 DOI: 10.1111/pbi.12076] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 03/14/2013] [Accepted: 03/31/2013] [Indexed: 05/03/2023]
Abstract
Plant expression systems based on nonreplicating virus-based vectors can be used for the simultaneous expression of multiple genes within the same cell. They therefore have great potential for the production of heteromultimeric protein complexes. This work describes the efficient plant-based production and assembly of Bluetongue virus-like particles (VLPs), requiring the simultaneous expression of four distinct proteins in varying amounts. Such particles have the potential to serve as a safe and effective vaccine against Bluetongue virus (BTV), which causes high mortality rates in ruminants and thus has a severe effect on the livestock trade. Here, VLPs produced and assembled in Nicotiana benthamiana using the cowpea mosaic virus-based HyperTrans (CPMV-HT) and associated pEAQ plant transient expression vector system were shown to elicit a strong antibody response in sheep. Furthermore, they provided protective immunity against a challenge with a South African BTV-8 field isolate. The results show that transient expression can be used to produce immunologically relevant complex heteromultimeric structures in plants in a matter of days. The results have implications beyond the realm of veterinary vaccines and could be applied to the production of VLPs for human use or the coexpression of multiple enzymes for the manipulation of metabolic pathways.
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Affiliation(s)
- Eva C Thuenemann
- Department of Biological Chemistry, John Innes Centre, Norwich, UK
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Evaluation of the immunogenicity of an experimental subunit vaccine that allows differentiation between infected and vaccinated animals against bluetongue virus serotype 8 in cattle. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2013; 20:1115-22. [PMID: 23720365 DOI: 10.1128/cvi.00229-13] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Bluetongue virus (BTV), the causative agent of bluetongue in ruminants, is an emerging virus in northern Europe. The 2006 outbreak of BTV serotype 8 (BTV-8) in Europe was marked by an unusual teratogenic effect and a high frequency of clinical signs in cattle. Conventional control strategies targeting small ruminants were therefore extended to include cattle. Since cattle were not routinely vaccinated before 2006, the immune responses to BTV have not been studied extensively in this species. With the aims of developing a subunit vaccine against BTV-8 for differentiation between infected and vaccinated animals based on viral protein 7 (VP7) antibody detection and of improving the current understanding of the immunogenicity of BTV proteins in cattle, the immune responses induced by recombinant VP2 (BTV-8) and nonstructural protein 1 (NS1) and NS2 (BTV-2) were studied. Cows were immunized twice (with a 3-week interval) with the experimental vaccine, a commercial inactivated vaccine, or a placebo. The two vaccines induced similar neutralizing antibody responses to BTV-8. Furthermore, the antibody responses detected against VP2, NS1, and NS2 were strongest in the animals immunized with the experimental vaccine, and for the first time, a serotype cross-reactive antibody response to NS2 was shown in cattle vaccinated with the commercial vaccine. The two vaccines evoked measurable T cell responses against NS1, thereby supporting a bovine cross-reactive T cell response. Finally, VP7 seroconversion was observed after vaccination with the commercial vaccine, as in natural infections, but not after vaccination with the experimental vaccine, indicating that the experimental vaccine may allow the differentiation of vaccinated animals from infected animals regardless of BTV serotype. The experimental vaccine will be further evaluated during a virulent challenge in a high-containment facility.
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Wang WS, Sun EC, Xu QY, Yang T, Qin YL, Zhao J, Feng YF, Li JP, Wei P, Zhang CY, Wu DL. Identification of two novel BTV16-specific B cell epitopes using monoclonal antibodies against the VP2 protein. Appl Microbiol Biotechnol 2013; 97:5933-42. [DOI: 10.1007/s00253-013-4779-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 02/12/2013] [Accepted: 02/13/2013] [Indexed: 11/29/2022]
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Bhattacharya B, Roy P. Cellular phosphoinositides and the maturation of bluetongue virus, a non-enveloped capsid virus. Virol J 2013; 10:73. [PMID: 23497128 PMCID: PMC3599530 DOI: 10.1186/1743-422x-10-73] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 03/01/2013] [Indexed: 12/26/2022] Open
Abstract
Background Bluetongue virus (BTV), a member of Orbivirus genus in the Reoviridae family is a double capsid virus enclosing a genome of 10 double-stranded RNA segments. A non-structural protein of BTV, NS3, which is associated with cellular membranes and interacts with outer capsid proteins, has been shown to be involved in virus morphogenesis in infected cells. In addition, studies have also shown that during the later stages of virus infection NS3 behaves similarly to HIV protein Gag, an enveloped viral protein. Since Gag protein is known to interact with membrane lipid phosphatidylinositol (4,5) bisphosphate [PI(4,5)P2] and one of the known binding partners of NS3, cellular protein p11 also interacts with annexin a PI(4,5)P2 interacting protein, this study was designed to understand the role of this negatively charged membrane lipid in BTV assembly and maturation. Methods Over expression of cellular enzymes that either depleted cells of PI(4,5)P2 or altered the distribution of PI(4,5)P2, were used to analyze the effect of the lipid on BTV maturation at different times post-infection. The production of mature virus particles was monitored by plaque assay. Microscopic techniques such as confocal microscopy and electron microscopy (EM) were also undertaken to study localization of virus proteins and virus particles in cells, respectively. Results Initially, confocal microscopic analysis demonstrated that PI(4,5)P2 not only co-localized with NS3, but it also co-localized with VP5, one of the outer capsid proteins of BTV. Subsequently, experiments involving depletion of cellular PI(4,5)P2 or its relocation demonstrated an inhibitory effect on normal BTV maturation and it also led to a redistribution of BTV proteins within the cell. The data was supported further by EM visualization showing that modulation of PI(4,5)P2 in cells indeed resulted in less particle production. Conclusion This study to our knowledge, is the first report demonstrating involvement of PI(4,5)P2 in a non-enveloped virus assembly and release. As BTV does not have lipid envelope, this finding is unique for this group of viruses and it suggests that the maturation of capsid and enveloped viruses may be more closely related than previously thought.
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Affiliation(s)
- Bishnupriya Bhattacharya
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
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