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Nair N, Osterhaus ADME, Rimmelzwaan GF, Prajeeth CK. Rift Valley Fever Virus-Infection, Pathogenesis and Host Immune Responses. Pathogens 2023; 12:1174. [PMID: 37764982 PMCID: PMC10535968 DOI: 10.3390/pathogens12091174] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 09/09/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023] Open
Abstract
Rift Valley Fever Virus is a mosquito-borne phlebovirus causing febrile or haemorrhagic illness in ruminants and humans. The virus can prevent the induction of the antiviral interferon response through its NSs proteins. Mutations in the NSs gene may allow the induction of innate proinflammatory immune responses and lead to attenuation of the virus. Upon infection, virus-specific antibodies and T cells are induced that may afford protection against subsequent infections. Thus, all arms of the adaptive immune system contribute to prevention of disease progression. These findings will aid the design of vaccines using the currently available platforms. Vaccine candidates have shown promise in safety and efficacy trials in susceptible animal species and these may contribute to the control of RVFV infections and prevention of disease progression in humans and ruminants.
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Chen T, Ding Z, Lan J, Wong G. Advances and perspectives in the development of vaccines against highly pathogenic bunyaviruses. Front Cell Infect Microbiol 2023; 13:1174030. [PMID: 37274315 PMCID: PMC10234439 DOI: 10.3389/fcimb.2023.1174030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Accepted: 05/03/2023] [Indexed: 06/06/2023] Open
Abstract
Increased human activities around the globe and the rapid development of once rural regions have increased the probability of contact between humans and wild animals. A majority of bunyaviruses are of zoonotic origin, and outbreaks may result in the substantial loss of lives, economy contraction, and social instability. Many bunyaviruses require manipulation in the highest levels of biocontainment, such as Biosafety Level 4 (BSL-4) laboratories, and the scarcity of this resource has limited the development speed of vaccines for these pathogens. Meanwhile, new technologies have been created, and used to innovate vaccines, like the mRNA vaccine platform and bioinformatics-based antigen design. Here, we summarize current vaccine developments for three different bunyaviruses requiring work in the highest levels of biocontainment: Crimean-Congo Hemorrhagic Fever Virus (CCHFV), Rift Valley Fever Virus (RVFV), and Hantaan virus (HTNV), and provide perspectives and potential future directions that can be further explored to advance specific vaccines for humans and livestock.
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Affiliation(s)
- Tong Chen
- Viral Hemorrhagic Fevers Research Unit, Chinese Academy of Sciences (CAS) Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences (CAS), Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Zhe Ding
- Viral Hemorrhagic Fevers Research Unit, Chinese Academy of Sciences (CAS) Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences (CAS), Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jiaming Lan
- Viral Hemorrhagic Fevers Research Unit, Chinese Academy of Sciences (CAS) Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences (CAS), Shanghai, China
| | - Gary Wong
- Viral Hemorrhagic Fevers Research Unit, Chinese Academy of Sciences (CAS) Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences (CAS), Shanghai, China
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Morrill JC, Peters CJ, Bettinger GE, Palermo PM, Smith DR, Watts DM. Rift Valley fever MP-12 vaccine elicits an early protective immune response in mice. Vaccine 2022; 40:7255-7261. [PMID: 36333222 DOI: 10.1016/j.vaccine.2022.10.062] [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: 08/26/2022] [Revised: 10/20/2022] [Accepted: 10/24/2022] [Indexed: 11/13/2022]
Abstract
Rift Valley fever virus (RVFV) is an important mosquito-borne pathogen that causes outbreaks of severe disease in people and livestock throughout Africa and the Arabian Peninsula. The development of an effective veterinary and human vaccine to protect against Rift Valley fever (RVF) disease remains a high priority. The live attenuated RVFV MP-12 is a promising vaccine candidate for the prevention of RVF in both human and domestic ruminants. The aim of this study was to determine the onset of protective immunity elicted in mice by a single dose of this vaccine. Groups of CD-1 mice were vaccinated intraperitoneally with RVFV MP-12 vaccine and challenged on days 2, 5, 6 and 7 post-vaccination (PV) with a lethal dose of virulent RVFV. The mice were observed once daily for terminal morbidity and blood samples were obtained from the retro-orbital sinus complex on days 23 and 28 PV of surviving mice to determine RVFV neutralizing antibody titers. In one test, 2 of 3 mice challenged on day 2 PV survived and all 3 mice challenged at days 5 and 7 PV also survived. A second test of 10 mice per group was performed, and half (5) of those challenged at day 2 PV survived while all (10) survived challenge at day 4 and 6 PV. All surviving animals develop antibody that ranged from 1:80 to 1:1,280 PV. In a separate experiment, RVFV MP-12 vaccinated CD-1 mice, but not challenged developed a low viremia for the first 3 days PV and neutralzing antibody was detected on days 5 through day 28 PV. These findings demonstrated that the RVFV MP-12 vaccine elicited a rapid protective immune response in mice as early as 2 days PV, thus further supporting the effectiveness of this vaccine candidate for preventing RVF among humans and domestic ruminants.
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Affiliation(s)
- J C Morrill
- Departmentof Microbiology and Immunology, University of Texas Medical Branch at Galveston, TX 77555, United States.
| | - C J Peters
- Departments of Microbiology & Immunology and Pathology, University of Texas Medical Branch at Galveston, TX 77555, United States.
| | - G E Bettinger
- Dept. of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, United States
| | - P M Palermo
- Dept. of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, United States.
| | - D R Smith
- Department of Microbiology and Immunology, Naval Medical Research Center, Biological Defense Research Directorate, Fort Detrick, MD 21702, United States.
| | - D M Watts
- Dept. of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, United States.
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EGR1 Upregulation during Encephalitic Viral Infections Contributes to Inflammation and Cell Death. Viruses 2022; 14:v14061210. [PMID: 35746681 PMCID: PMC9227295 DOI: 10.3390/v14061210] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/24/2022] [Accepted: 05/30/2022] [Indexed: 02/07/2023] Open
Abstract
Early growth response 1 (EGR1) is an immediate early gene and transcription factor previously found to be significantly upregulated in human astrocytoma cells infected with Venezuelan equine encephalitis virus (VEEV). The loss of EGR1 resulted in decreased cell death but had no significant impact on viral replication. Here, we extend these studies to determine the impacts of EGR1 on gene expression following viral infection. Inflammatory genes CXCL3, CXCL8, CXCL10, TNF, and PTGS2 were upregulated in VEEV-infected cells, which was partially dependent on EGR1. Additionally, transcription factors, including EGR1 itself, as well as ATF3, FOS, JUN, KLF4, EGR2, and EGR4 were found to be partially transcriptionally dependent on EGR1. We also examined the role of EGR1 and the changes in gene expression in response to infection with other alphaviruses, including eastern equine encephalitis virus (EEEV), Sindbis virus (SINV), and chikungunya virus (CHIKV), as well as Zika virus (ZIKV) and Rift Valley fever virus (RVFV), members of the Flaviviridae and Phenuiviridae families, respectively. EGR1 was significantly upregulated to varying degrees in EEEV-, CHIKV-, RVFV-, SINV-, and ZIKV-infected astrocytoma cells. Genes that were identified as being partially transcriptionally dependent on EGR1 in infected cells included ATF3 (EEEV, CHIKV, ZIKV), JUN (EEEV), KLF4 (SINV, ZIKV, RVFV), CXCL3 (EEEV, CHIKV, ZIKV), CXCL8 (EEEV, CHIKV, ZIKV, RVFV), CXCL10 (EEEV, RVFV), TNF-α (EEEV, ZIKV, RVFV), and PTGS2 (EEEV, CHIKV, ZIKV). Additionally, inhibition of the inflammatory gene PTGS2 with Celecoxib, a small molecule inhibitor, rescued astrocytoma cells from VEEV-induced cell death but had no impact on viral titers. Collectively, these results suggest that EGR1 induction following viral infection stimulates multiple inflammatory mediators. Managing inflammation and cell death in response to viral infection is of utmost importance, especially during VEEV infection where survivors are at-risk for neurological sequalae.
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More GK, Makola RT, Prinsloo G. In Vitro Evaluation of Anti-Rift Valley Fever Virus, Antioxidant and Anti-Inflammatory Activity of South African Medicinal Plant Extracts. Viruses 2021; 13:221. [PMID: 33572659 PMCID: PMC7912315 DOI: 10.3390/v13020221] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/02/2021] [Accepted: 01/26/2021] [Indexed: 02/06/2023] Open
Abstract
Rift valley fever virus (RVFV) is a mosquito-borne virus endemic to sub-Saharan African countries, and the first sporadic outbreaks outside Africa were reported in the Asia-Pacific region. There are no approved therapeutic agents available for RVFV; however, finding an effective antiviral agent against RVFV is important. This study aimed to evaluate the antiviral, antioxidant and anti-inflammatory activity of medicinal plant extracts. Twenty medicinal plants were screened for their anti-RVFV activity using the cytopathic effect (CPE) reduction method. The cytotoxicity assessment of the extracts was done before antiviral screening using the MTT assay. Antioxidant and reactive oxygen/nitrogen species' (ROS/RNS) inhibitory activity by the extracts was investigated using non-cell-based and cell-based assays. Out of twenty plant extracts tested, eight showed significant potency against RVFV indicated by a decrease in tissue culture infectious dose (TCID50) < 105. The cytotoxicity of extracts showed inhibitory concentrations values (IC50) > 200 µg/mL for most of the extracts. The antioxidant activity and anti-inflammatory results revealed that extracts scavenged free radicals exhibiting an IC50 range of 4.12-20.41 µg/mL and suppressed the production of pro-inflammatory mediators by 60-80% in Vero cells. This study demonstrated the ability of the extracts to lower RVFV viral load and their potency to reduce free radicals.
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Affiliation(s)
- Garland K. More
- College of Agriculture and Environmental Sciences, University of South Africa, Private Bag X6, Florida, Johannesburg 1710, South Africa;
| | - Raymond T. Makola
- Department of Biochemistry Microbiology and Biotechnology, School of Molecular and Life Science, University of Limpopo (Turfloop Campus) Sovenga, Polokwane 0727, South Africa;
- National institute of Communicable Diseases, Special Viral Pathogen/Arbovirus Unit, 1 Modderfontein Rd, Sandringham, Johannesburg 2192, South Africa
| | - Gerhard Prinsloo
- College of Agriculture and Environmental Sciences, University of South Africa, Private Bag X6, Florida, Johannesburg 1710, South Africa;
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Wright D, Allen ER, Clark MH, Gitonga JN, Karanja HK, Hulswit RJ, Taylor I, Biswas S, Marshall J, Mwololo D, Muriuki J, Bett B, Bowden TA, Warimwe GM. Naturally Acquired Rift Valley Fever Virus Neutralizing Antibodies Predominantly Target the Gn Glycoprotein. iScience 2020; 23:101669. [PMID: 33134899 PMCID: PMC7588868 DOI: 10.1016/j.isci.2020.101669] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/28/2020] [Accepted: 10/08/2020] [Indexed: 11/30/2022] Open
Abstract
Rift Valley fever (RVF) is a viral hemorrhagic disease first discovered in Kenya in 1930. Numerous animal studies have demonstrated that protective immunity is acquired following RVF virus (RVFV) infection and that this correlates with acquisition of virus-neutralizing antibodies (nAbs) that target the viral envelope glycoproteins. However, naturally acquired immunity to RVF in humans is poorly described. Here, we characterized the immune response to the viral envelope glycoproteins, Gn and Gc, in RVFV-exposed Kenyan adults. Long-lived IgG (dominated by IgG1 subclass) and T cell responses were detected against both Gn and Gc. However, antigen-specific antibody depletion experiments showed that Gn-specific antibodies dominate the RVFV nAb response. IgG avidity against Gn, but not Gc, correlated with nAb titers. These data are consistent with the greater level of immune accessibility of Gn on the viral envelope surface and confirm the importance of Gn as an integral component for RVF vaccine development.
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Affiliation(s)
- Daniel Wright
- KEMRI-Wellcome Trust Research Programme, CGMRC, PO Box 230-80108, Kilifi, Kenya
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Elizabeth R. Allen
- Wellcome Centre for Human Genetics, Division of Structural Biology, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | | | - John N. Gitonga
- KEMRI-Wellcome Trust Research Programme, CGMRC, PO Box 230-80108, Kilifi, Kenya
| | - Henry K. Karanja
- KEMRI-Wellcome Trust Research Programme, CGMRC, PO Box 230-80108, Kilifi, Kenya
| | - Ruben J.G. Hulswit
- Wellcome Centre for Human Genetics, Division of Structural Biology, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Iona Taylor
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Sumi Biswas
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | | | - Damaris Mwololo
- International Livestock Research Institute, PO Box 30709, Nairobi 00100, Kenya
| | - John Muriuki
- International Livestock Research Institute, PO Box 30709, Nairobi 00100, Kenya
| | - Bernard Bett
- International Livestock Research Institute, PO Box 30709, Nairobi 00100, Kenya
| | - Thomas A. Bowden
- Wellcome Centre for Human Genetics, Division of Structural Biology, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - George M. Warimwe
- KEMRI-Wellcome Trust Research Programme, CGMRC, PO Box 230-80108, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford OX3 7FZ, UK
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Ibrahim EH, Taha R, Ghramh HA, Kilany M. Development of Rift Valley fever (RVF) vaccine by genetic joining of the RVF-glycoprotein Gn with the strong adjuvant subunit B of cholera toxin (CTB) and expression in bacterial system. Saudi J Biol Sci 2019; 26:1676-1681. [PMID: 31762643 PMCID: PMC6864185 DOI: 10.1016/j.sjbs.2018.08.019] [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: 07/31/2018] [Revised: 08/19/2018] [Accepted: 08/20/2018] [Indexed: 12/31/2022] Open
Abstract
One of the mosquito-borne zoonotic diseases is the Rift Valley fever virus (RVFV). Currently, there is no completely licensed vaccine that can be used to vaccinate animals or humans outside endemic areas. The aim of this work was to use the RVFV glycoprotein (Gn) and the subunit B of cholera toxin (CTB) at gene level and build up fused recombinant vaccine. The gene of CTB was joined to the gene Gn to work as an adjuvant in the resulting fusion protein. The designed merged genes (CTB-Gn) was tested for restriction sites, open reading frames, expected fusion protein tertiary structure and antigenicity using computer software. The insert sequence was submitted to the BioProject (GenBank). The insert was subcloned into the pQE-31 expression plasmid. The target recombinant protein (rCTB-Gn) was expressed in M15 bacteria, purified and identified by protein gel electrophoresis. The insert got the accession No: PRJNA386723. Analysis of the designed rCTB-Gn protein revealed that it had the right 3D structure, immunogenic and at the correct molecular weight. The presence of the CTB in the proposed vaccine will augment its immunogenicity. Doses and protection levels of the vaccine need to be manipulated.
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Affiliation(s)
- Essam H. Ibrahim
- Biology Department, Faculty of Science, King Khalid University, P.O. Box 9004, Abha 61413, Saudi Arabia
- Blood Products Quality Control and Research Department, National Organization for Research and Control of Biologicals, Cairo, Egypt
| | - Ramadan Taha
- Biology Department, Faculty of Science, King Khalid University, P.O. Box 9004, Abha 61413, Saudi Arabia
- Department of Clinical Pathology, Faculty of Veterinary Medicine, Suez Canal University, Egypt
| | - Hamed A. Ghramh
- Biology Department, Faculty of Science, King Khalid University, P.O. Box 9004, Abha 61413, Saudi Arabia
- Research Center for Advanced Materials Science (RCAMS), King Khalid University, P.O. Box 9004, Abha 61413, Saudi Arabia
- Unit of Bee Research and Honey Production, Faculty of Science, King Khalid University, P.O. Box 9004, Abha 61413, Saudi Arabia
| | - Mona Kilany
- Biology Department, Faculty of Sciences and Arts, King Khalid University, Dhahran Al Janoub, Saudi Arabia
- Department of Microbiology, National Organization for Drug Control and Research (NODCAR), Cairo, Egypt
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Abstract
Rift Valley fever (RVF) is a mosquito-borne viral zoonosis that was first discovered in Kenya in 1930 and is now endemic throughout multiple African countries and the Arabian Peninsula. RVF virus primarily infects domestic livestock (sheep, goats, cattle) causing high rates of neonatal mortality and abortion, with human infection resulting in a wide variety of clinical outcomes, ranging from self-limiting febrile illness to life-threatening haemorrhagic diatheses, and miscarriage in pregnant women. Since its discovery, RVF has caused many outbreaks in Africa and the Arabian Peninsula with major impacts on human and animal health. However, options for the control of RVF outbreaks are limited by the lack of licensed human vaccines or therapeutics. For this reason, RVF is prioritized by the World Health Organization for urgent research and development of countermeasures for the prevention and control of future outbreaks. In this review, we highlight the current understanding of RVF, including its epidemiology, pathogenesis, clinical manifestations and status of vaccine development.
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Affiliation(s)
- Daniel Wright
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- The Jenner Institute, University of Oxford, Oxford OX1 2JD, UK
| | - Jeroen Kortekaas
- Wageningen Bioveterinary Research, Lelystad, The Netherlands
- Laboratory of Virology, Wageningen University, Wageningen, The Netherlands
| | - Thomas A. Bowden
- Wellcome Centre for Human Genetics, Division of Structural Biology, University of Oxford, Oxford OX1 2JD, UK
| | - George M. Warimwe
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford OX1 2JD, UK
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Wang G, Chang H, Jia B, Liu Y, Huang R, Wu W, Hao Y, Yan X, Xia J, Chen Y, Wu C. Nucleocapsid protein-specific IgM antibody responses in the disease progression of severe fever with thrombocytopenia syndrome. Ticks Tick Borne Dis 2019; 10:639-646. [PMID: 30824322 DOI: 10.1016/j.ttbdis.2019.02.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 12/23/2018] [Accepted: 02/06/2019] [Indexed: 01/10/2023]
Abstract
OBJECTIVES Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease that is caused by the SFTS virus (SFTSV) and has a high fatality rate. SFTSV-specific antibody profiles among patients with different clinical outcomes are yet to be described. The nucleocapsid protein (NP) is the most immunogenic viral antigen of the SFTSV. This study, therefore, sought to determine NP-specific antibody responses among SFTS patients with different disease progressions. METHODS In the present study, 43 patients with confirmed SFTS were enrolled in our cohort, and 9 of them deceased. The clinical presentations and key laboratory parameters associated with SFTS fatality were also recorded. Serum samples from each patient were collected every 2 days during their hospitalization. NP-specific IgM and IgG responses as well as Gn or Gc-specific IgM responses were examined by enzyme-linked immunosorbent assay (ELISA), whereas, the dynamic viral loads of SFTSV RNA were quantified via real-time reverse transcription polymerase chain reaction (RT-PCR). RESULTS First, 77% of patients generated positive NP-specific IgM antibody responses within two weeks since illness onset, defined as 'N-specific IgM-positive patients', while the rest of the patients were termed as 'N-specific IgM-delayed patients'. Only 17% of the patients generated NP-specific IgG responses. The absence of NP-specific humoral responses was strongly associated with a high risk of fatality and severity of SFTS. IgM-positive patients had significantly lower levels of viral loads, less disturbed coagulopathy, and hepatic and cardiac damage compared to IgM-delayed patients. Moreover, compared to severe or fatal SFTS patients, mild SFTS patients had significantly higher magnitudes of NP-specific IgM responses, but not NP-specific IgG, Gn-specific IgM, or Gc-specific IgM responses. The abundance of NP-specific IgM responses negatively correlated with viral loads, coagulation disturbances, and hepatic injuries among SFTS patients. CONCLUSIONS Our data highlight distinct humoral profiles of NP-specific IgM responses among SFTS patients with different disease progressions and clinical outcomes.
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Affiliation(s)
- Gai Wang
- Department of Infectious Diseases, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Haiyan Chang
- Department of Infectious Diseases, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Bei Jia
- Department of Infectious Diseases, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Yong Liu
- Department of Experimental Medicine, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Rui Huang
- Department of Infectious Diseases, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Weihua Wu
- Department of Infectious Diseases, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Yingying Hao
- Department of Intensive Care Unit, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Xiaomin Yan
- Department of Infectious Diseases, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Juan Xia
- Department of Infectious Diseases, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Yuxin Chen
- Department of Laboratory Medicine, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China.
| | - Chao Wu
- Department of Infectious Diseases, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China.
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Monteiro GER, Jansen van Vuren P, Wichgers Schreur PJ, Odendaal L, Clift SJ, Kortekaas J, Paweska JT. Mutation of adjacent cysteine residues in the NSs protein of Rift Valley fever virus results in loss of virulence in mice. Virus Res 2018. [PMID: 29530722 DOI: 10.1016/j.virusres.2018.03.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The NSs protein encoded by the S segment of Rift Valley fever virus (RVFV) is the major virulence factor, counteracting the host innate antiviral defence. It contains five highly conserved cysteine residues at positions 39, 40, 149, 178 and 194, which are thought to stabilize the tertiary and quaternary structure of the protein. Here, we report significant differences between clinical, virological, histopathological and host gene responses in BALB/c mice infected with wild-type RVFV (wtRVFV) or a genetic mutant having a double cysteine-to-serine substitution at residues 39 and 40 of the NSs protein (RVFV-C39S/C40S). Mice infected with the wtRVFV developed a fatal acute disease; characterized by high levels of viral replication, severe hepatocellular necrosis, and massive up-regulation of transcription of genes encoding type I and -II interferons (IFN) as well as pro-apoptotic and pro-inflammatory cytokines. The RVFV-C39S/C40S mutant did not cause clinical disease and its attenuated virulence was consistent with virological, histopathological and host gene expression findings in BALB/c mice. Clinical signs in mice infected with viruses containing cysteine-to-serine substitutions at positions 178 or 194 were similar to those occurring in mice infected with the wtRVFV, while a mutant containing a substitution at position 149 caused mild, non-fatal disease in mice. As mutant RVFV-C39S/C40S showed an attenuated phenotype in mice, the molecular mechanisms behind this attenuation were further investigated. The results show that two mechanisms are responsible for the attenuation; (1) loss of the IFN antagonistic propriety characteristic of the wtRVFV NSs and (2) the inability of the attenuated mutant to degrade Proteine Kinase R (PKR).
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Affiliation(s)
- Gaby E R Monteiro
- Department of Paraclinical Science, Veterinary Faculty, University Eduardo Mondlane, Maputo, Mozambique; Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, South Africa.
| | - Petrus Jansen van Vuren
- Center for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Sandringham, South Africa; Centre for Viral Zoonoses, Department of Medical Virology, School of Medicine, Faculty of Health Sciences, University of Pretoria, South Africa
| | | | - Lieza Odendaal
- Department of Paraclinical Science, Faculty of Veterinary Science, University of Pretoria, South Africa
| | - Sarah J Clift
- Department of Paraclinical Science, Faculty of Veterinary Science, University of Pretoria, South Africa
| | - Jeroen Kortekaas
- Department of Virology, Wageningen Bioveterinary Research, Lelystad, the Netherlands
| | - Janusz T Paweska
- Center for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Sandringham, South Africa; Centre for Viral Zoonoses, Department of Medical Virology, School of Medicine, Faculty of Health Sciences, University of Pretoria, South Africa; School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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11
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Wonderlich ER, Caroline AL, McMillen CM, Walters AW, Reed DS, Barratt-Boyes SM, Hartman AL. Peripheral Blood Biomarkers of Disease Outcome in a Monkey Model of Rift Valley Fever Encephalitis. J Virol 2018; 92:e01662-17. [PMID: 29118127 PMCID: PMC5774883 DOI: 10.1128/jvi.01662-17] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 11/01/2017] [Indexed: 12/31/2022] Open
Abstract
Rift Valley Fever (RVF) is an emerging arboviral disease of livestock and humans. Although the disease is caused by a mosquito-borne virus, humans are infected through contact with, or inhalation of, virus-laden particles from contaminated animal carcasses. Some individuals infected with RVF virus (RVFV) develop meningoencephalitis, resulting in morbidity and mortality. Little is known about the pathogenic mechanisms that lead to neurologic sequelae, and thus, animal models that represent human disease are needed. African green monkeys (AGM) exposed to aerosols containing RVFV develop a reproducibly lethal neurological disease that resembles human illness. To understand the disease process and identify biomarkers of lethality, two groups of 5 AGM were infected by inhalation with either a lethal or a sublethal dose of RVFV. Divergence between lethal and sublethal infections occurred as early as 2 days postinfection (dpi), at which point CD8+ T cells from lethally infected AGM expressed activated caspase-3 and simultaneously failed to increase levels of major histocompatibility complex (MHC) class II molecules, in contrast to surviving animals. At 4 dpi, lethally infected animals failed to demonstrate proliferation of total CD4+ and CD8+ T cells, in contrast to survivors. These marked changes in peripheral blood cells occur much earlier than more-established indicators of severe RVF disease, such as granulocytosis and fever. In addition, an early proinflammatory (gamma interferon [IFN-γ], interleukin 6 [IL-6], IL-8, monocyte chemoattractant protein 1 [MCP-1]) and antiviral (IFN-α) response was seen in survivors, while very late cytokine expression was found in animals with lethal infections. By characterizing immunological markers of lethal disease, this study furthers our understanding of RVF pathogenesis and will allow the testing of therapeutics and vaccines in the AGM model.IMPORTANCE Rift Valley Fever (RVF) is an important emerging viral disease for which we lack both an effective human vaccine and treatment. Encephalitis and neurological disease resulting from RVF lead to death or significant long-term disability for infected people. African green monkeys (AGM) develop lethal neurological disease when infected with RVF virus by inhalation. Here we report the similarities in disease course between infected AGM and humans. For the first time, we examine the peripheral immune response during the course of infection in AGM and show that there are very early differences in the immune response between animals that survive infection and those that succumb. We conclude that AGM are a novel and suitable monkey model for studying the neuropathogenesis of RVF and for testing vaccines and therapeutics against this emerging viral pathogen.
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Affiliation(s)
- Elizabeth R Wonderlich
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Amy L Caroline
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Cynthia M McMillen
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Aaron W Walters
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Douglas S Reed
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Immunology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Simon M Barratt-Boyes
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Immunology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Amy L Hartman
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Goedhals D, Paweska JT, Burt FJ. Long-lived CD8+ T cell responses following Crimean-Congo haemorrhagic fever virus infection. PLoS Negl Trop Dis 2017; 11:e0006149. [PMID: 29261651 PMCID: PMC5752039 DOI: 10.1371/journal.pntd.0006149] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 01/03/2018] [Accepted: 12/02/2017] [Indexed: 12/11/2022] Open
Abstract
Crimean-Congo haemorrhagic fever virus (CCHFV) is a member of the Orthonairovirus genus of the Nairoviridae family and is associated with haemorrhagic fever in humans. Although T lymphocyte responses are known to play a role in protection from and clearance of viral infections, specific T cell epitopes have yet to be identified for CCHFV following infection. A panel of overlapping peptides covering the CCHFV nucleoprotein and the structural glycoproteins, GN and GC, were screened by ELISpot assay to detect interferon gamma (IFN-γ) production in vitro by peripheral blood mononuclear cells from eleven survivors with previous laboratory confirmed CCHFV infection. Reactive peptides were located predominantly on the nucleoprotein, with only one survivor reacting to two peptides from the glycoprotein GC. No single epitope was immunodominant, however all but one survivor showed reactivity to at least one T cell epitope. The responses were present at high frequency and detectable several years after the acute infection despite the absence of continued antigenic stimulation. T cell depletion studies confirmed that IFN-γ production as detected using the ELISpot assay was mediated chiefly by CD8+ T cells. This is the first description of CD8+ T cell epitopic regions for CCHFV and provides confirmation of long-lived T cell responses in survivors of CCHFV infection.
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Affiliation(s)
- Dominique Goedhals
- Division of Virology, National Health Laboratory Service/University of the Free State, Bloemfontein, South Africa
| | - Janusz T. Paweska
- Center for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
- School of Pathology, Faculty of Health Sciences, University of the Witswatersrand, Johannesburg, South Africa
| | - Felicity J. Burt
- Division of Virology, National Health Laboratory Service/University of the Free State, Bloemfontein, South Africa
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Current Status of Rift Valley Fever Vaccine Development. Vaccines (Basel) 2017; 5:vaccines5030029. [PMID: 28925970 PMCID: PMC5620560 DOI: 10.3390/vaccines5030029] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 09/16/2017] [Accepted: 09/18/2017] [Indexed: 01/08/2023] Open
Abstract
Rift Valley Fever (RVF) is a mosquito-borne zoonotic disease that presents a substantial threat to human and public health. It is caused by Rift Valley fever phlebovirus (RVFV), which belongs to the genus Phlebovirus and the family Phenuiviridae within the order Bunyavirales. The wide distribution of competent vectors in non-endemic areas coupled with global climate change poses a significant threat of the transboundary spread of RVFV. In the last decade, an improved understanding of the molecular biology of RVFV has facilitated significant progress in the development of novel vaccines, including DIVA (differentiating infected from vaccinated animals) vaccines. Despite these advances, there is no fully licensed vaccine for veterinary or human use available in non-endemic countries, whereas in endemic countries, there is no clear policy or practice of routine/strategic livestock vaccinations as a preventive or mitigating strategy against potential RVF disease outbreaks. The purpose of this review was to provide an update on the status of RVF vaccine development and provide perspectives on the best strategies for disease control. Herein, we argue that the routine or strategic vaccination of livestock could be the best control approach for preventing the outbreak and spread of future disease.
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Innate Immune Basis for Rift Valley Fever Susceptibility in Mouse Models. Sci Rep 2017; 7:7096. [PMID: 28769107 PMCID: PMC5541133 DOI: 10.1038/s41598-017-07543-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 06/29/2017] [Indexed: 12/20/2022] Open
Abstract
Rift Valley fever virus (RVFV) leads to varied clinical manifestations in animals and in humans that range from moderate fever to fatal illness, suggesting that host immune responses are important determinants of the disease severity. We investigated the immune basis for the extreme susceptibility of MBT/Pas mice that die with mild to acute hepatitis by day 3 post-infection compared to more resistant BALB/cByJ mice that survive up to a week longer. Lower levels of neutrophils observed in the bone marrow and blood of infected MBT/Pas mice are unlikely to be causative of increased RVFV susceptibility as constitutive neutropenia in specific mutant mice did not change survival outcome. However, whereas MBT/Pas mice mounted an earlier inflammatory response accompanied by higher amounts of interferon (IFN)-α in the serum compared to BALB/cByJ mice, they failed to prevent high viral antigen load. Several immunological alterations were uncovered in infected MBT/Pas mice compared to BALB/cByJ mice, including low levels of leukocytes that expressed type I IFN receptor subunit 1 (IFNAR1) in the blood, spleen and liver, delayed leukocyte activation and decreased percentage of IFN-γ-producing leukocytes in the blood. These observations are consistent with the complex mode of inheritance of RVFV susceptibility in genetic studies.
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15
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Calvert AE, Brault AC. Development and Characterization of Monoclonal Antibodies Directed Against the Nucleoprotein of Heartland Virus. Am J Trop Med Hyg 2015; 93:1338-40. [PMID: 26503274 DOI: 10.4269/ajtmh.15-0473] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 08/08/2015] [Indexed: 11/07/2022] Open
Abstract
Heartland virus (HRTV), a phlebovirus first isolated from two Missouri farmers in 2009, has been proposed to be transmitted to humans by the bite of infected Amblyomma americanum ticks. It is closely related to severe fever with thrombocytopenia syndrome virus (SFTSV) from China, another previously unrecognized phlebovirus that has subsequently been associated with hundreds of cases of severe disease in humans. To expand diagnostic capacity to detect HRTV infections, 20 hybridoma clones secreting anti-HRTV murine monoclonal antibodies (MAbs) were developed using splenocytes from HRTV-inoculated AG129 alpha/beta and gamma interferon receptor-deficient mice. Nine of these MAbs were characterized herein for inclusion in future HRTV diagnostic assay development. All of the MAbs developed were found to be non-neutralizing and reactive to linear epitopes on HRTV nucleocapsid protein. MAb 2AF11 was found to be cross-reactive with SFTSV.
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Affiliation(s)
- Amanda E Calvert
- Division of Vector-Borne Diseases, U.S. Centers for Disease Control and Prevention, Fort Collins, Colorado
| | - Aaron C Brault
- Division of Vector-Borne Diseases, U.S. Centers for Disease Control and Prevention, Fort Collins, Colorado
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Jansen van Vuren P, Shalekoff S, Grobbelaar AA, Archer BN, Thomas J, Tiemessen CT, Paweska JT. Serum levels of inflammatory cytokines in Rift Valley fever patients are indicative of severe disease. Virol J 2015; 12:159. [PMID: 26437779 PMCID: PMC4595326 DOI: 10.1186/s12985-015-0392-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 09/23/2015] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Rift Valley fever (RVF) is a mosquito-borne viral zoonosis affecting domestic and wild ruminants, camels and humans. Outbreaks of RVF are characterized by a sudden onset of abortions and high mortality amongst domestic ruminants. Humans develop disease ranging from a mild flu-like illness to more severe complications including hemorrhagic syndrome, ocular and neurological lesions and death. During the RVF outbreak in South Africa in 2010/11, a total of 278 human cases were laboratory confirmed, including 25 deaths. The role of the host inflammatory response to RVF pathogenesis is not completely understood. METHODS Virus load in serum from human fatal and non-fatal cases was determined by standard tissue culture infective dose 50 (TCID50) titration on Vero cells. Patient serum concentration of chemokines and cytokines involved in inflammatory responses (IL-8, RANTES, CXCL9, MCP-1, IP-10, IL-1β, IL-6, IL-10, TNF and IL-12p70) was determined using cytometric bead assays and flow cytometry. RESULTS Fatal cases had a 1-log10 higher TCID50/ml serum concentration of RVF virus (RVFV) than survivors (p < 0.05). There were no significant sequence differences between isolates recovered from fatal and non-fatal cases. Chemokines and pro- and anti-inflammatory cytokines were detected at significantly increased (IL-8, CXCL9, MCP-1, IP-10, IL-10) or decreased (RANTES) levels when comparing fatal cases to infected survivors and uninfected controls, or when comparing combined infected patients to uninfected controls. CONCLUSIONS The results suggest that regulation of the host inflammatory responses plays an important role in the outcome of RVFV infection in humans. Dysregulation of the inflammatory response contributes to a fatal outcome. The cytokines and chemokines identified in this study that correlate with fatal outcomes warrant further investigation as markers for disease severity.
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Affiliation(s)
- Petrus Jansen van Vuren
- Centre for Emerging and Zoonotic Diseases, National Institute for Communicable Diseases division of the National Health Laboratory Service, Sandringham, South Africa. .,Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria, South Africa.
| | - Sharon Shalekoff
- Centre for HIV and STIs, National Institute for Communicable Diseases division of the National Health Laboratory Service, Sandringham, South Africa. .,Faculty of Health Sciences, School of Pathology, University of the Witwatersrand, Johannesburg, South Africa.
| | - Antoinette A Grobbelaar
- Centre for Emerging and Zoonotic Diseases, National Institute for Communicable Diseases division of the National Health Laboratory Service, Sandringham, South Africa.
| | - Brett N Archer
- Outbreak Response Unit, Division of Public Health, Surveillance and Response, National Institute for Communicable Diseases division of the National Health Laboratory Service, Sandringham, South Africa.
| | - Juno Thomas
- Outbreak Response Unit, Division of Public Health, Surveillance and Response, National Institute for Communicable Diseases division of the National Health Laboratory Service, Sandringham, South Africa.
| | - Caroline T Tiemessen
- Centre for HIV and STIs, National Institute for Communicable Diseases division of the National Health Laboratory Service, Sandringham, South Africa. .,Faculty of Health Sciences, School of Pathology, University of the Witwatersrand, Johannesburg, South Africa.
| | - Janusz T Paweska
- Centre for Emerging and Zoonotic Diseases, National Institute for Communicable Diseases division of the National Health Laboratory Service, Sandringham, South Africa. .,Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria, South Africa. .,Faculty of Health Sciences, School of Pathology, University of the Witwatersrand, Johannesburg, South Africa.
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Roberts KK, Hill TE, Davis MN, Holbrook MR, Freiberg AN. Cytokine response in mouse bone marrow derived macrophages after infection with pathogenic and non-pathogenic Rift Valley fever virus. J Gen Virol 2015; 96:1651-1663. [PMID: 25759029 PMCID: PMC4635452 DOI: 10.1099/vir.0.000119] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 03/09/2015] [Indexed: 12/23/2022] Open
Abstract
Rift Valley fever virus (RVFV) is the most pathogenic member of the genus Phlebovirus within the family Bunyaviridae, and can cause severe disease in humans and livestock. Until recently, limited information has been published on the cellular host response elicited by RVFV, particularly in macrophages and dendritic cells, which play critical roles in stimulating adaptive and innate immune responses to viral infection. In an effort to define the initial response of host immunomodulatory cells to infection, primary mouse bone marrow derived macrophages (BMDM) were infected with the pathogenic RVFV strain ZH501, or attenuated strains MP-12 or MP-12 based Clone13 type (rMP12-C13 type), and cytokine secretion profiles examined. The secretion of T helper (Th)1-associated antiviral cytokines, chemokines and various interleukins increased rapidly after infection with the attenuated rMP12-C13 type RVFV, which lacks a functional NSs virulence gene. In comparison, infection with live-attenuated MP-12 encoding a functional NSs gene appeared to cause a delayed immune response, while pathogenic ZH501 ablates the immune response almost entirely. These data demonstrate that NSs can inhibit components of the BMDM antiviral response and supports previous work indicating that NSs can specifically regulate the type I interferon response in macrophages. Furthermore, our data demonstrate that genetic differences between ZH501 and MP-12 reduce the ability of MP-12 to inhibit antiviral signalling and subsequently reduce virulence in BMDM, demonstrating that viral components other than NSs play a critical role in regulating the host response to RVFV infection.
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Affiliation(s)
- Kimberly K. Roberts
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA
| | - Terence E. Hill
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA
| | - Melissa N. Davis
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, USA
| | - Michael R. Holbrook
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, TX, USA
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, USA
- Center for Tropical Diseases, University of Texas Medical Branch, Galveston, TX, USA
- Integrated Research Facility, National Institute of Allergy and Infectious Disease, National Institutes of Health, Frederick, MD, USA
| | - Alexander N. Freiberg
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, TX, USA
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, USA
- Center for Tropical Diseases, University of Texas Medical Branch, Galveston, TX, USA
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Terasaki K, Makino S. Interplay between the Virus and Host in Rift Valley Fever Pathogenesis. J Innate Immun 2015; 7:450-8. [PMID: 25766761 DOI: 10.1159/000373924] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 01/08/2015] [Indexed: 12/22/2022] Open
Abstract
Rift Valley fever virus (RVFV) belongs to the genus Phlebovirus, family Bunyaviridae, and carries single-stranded tripartite RNA segments. The virus is transmitted by mosquitoes and has caused large outbreaks among ruminants and humans in sub-Saharan African and Middle East countries. The disease is characterized by a sudden onset of fever, headache, muscle pain, joint pain, photophobia, and weakness. In most cases, patients recover from the disease after a period of weeks, but some also develop retinal or macular changes, which result in vision impairment that lasts for an undefined period of time, and severe disease, characterized by hemorrhagic fever or encephalitis. The virus also causes febrile illness resulting in a high rate of spontaneous abortions in ruminants. The handling of wild-type RVFV requires high-containment facilities, including biosafety level 4 or enhanced biosafety level 3 laboratories. Nonetheless, studies clarifying the mechanisms of the RVFV-induced diseases and preventing them are areas of active research throughout the world. By primarily referring to recent studies using several animal model systems, protein expression systems, and specific mutant viruses, this review describes the current knowledge about the mechanisms of pathogenesis of RVF and biological functions of various viral proteins that affect RVFV pathogenicity.
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Affiliation(s)
- Kaori Terasaki
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Tex., USA
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Lorenzo G, López-Gil E, Warimwe GM, Brun A. Understanding Rift Valley fever: contributions of animal models to disease characterization and control. Mol Immunol 2015; 66:78-88. [PMID: 25725948 DOI: 10.1016/j.molimm.2015.02.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 12/26/2014] [Accepted: 02/03/2015] [Indexed: 11/30/2022]
Abstract
Rift Valley fever (RVF) is a mosquito-borne viral zoonosis with devastating health impacts in domestic ruminants and humans. Effective vaccines and accurate disease diagnostic tools are key components in the control of RVF. Animal models reproducing infection with RVF virus are of upmost importance in the development of these disease control tools. Rodent infection models are currently used in the initial steps of vaccine development and for the study of virus induced pathology. Translation of data obtained in these animal models to target species (ruminants and humans) is highly desirable but does not always occur. Small ruminants and non-human primates have been used for pathogenesis and transmission studies, and for testing the efficacy of vaccines and therapeutic antiviral compounds. However, the molecular mechanisms of the immune response elicited by RVF virus infection or vaccination are still poorly understood. The paucity of data in this area offers opportunities for new research activities and programs. This review summarizes our current understanding with respect to immunity and pathogenesis of RVF in animal models with a particular emphasis on small ruminants and non-human primates, including recent experimental infection data in sheep.
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Affiliation(s)
- Gema Lorenzo
- Centro de Investigación en Sanidad Animal, Instituto Nacional de Investigación Agraria y Alimentaria (INIA-CISA), Valdeolmos, Madrid, Spain
| | - Elena López-Gil
- Centro de Investigación en Sanidad Animal, Instituto Nacional de Investigación Agraria y Alimentaria (INIA-CISA), Valdeolmos, Madrid, Spain
| | - George M Warimwe
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Alejandro Brun
- Centro de Investigación en Sanidad Animal, Instituto Nacional de Investigación Agraria y Alimentaria (INIA-CISA), Valdeolmos, Madrid, Spain.
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Shafagati N, Patanarut A, Luchini A, Lundberg L, Bailey C, Petricoin E, Liotta L, Narayanan A, Lepene B, Kehn-Hall K. The use of Nanotrap particles for biodefense and emerging infectious disease diagnostics. Pathog Dis 2014; 71:164-76. [PMID: 24449537 PMCID: PMC7108521 DOI: 10.1111/2049-632x.12136] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Revised: 01/07/2014] [Accepted: 01/07/2014] [Indexed: 11/28/2022] Open
Abstract
Detection of early infectious disease may be challenging due to the low copy number of organisms present. To overcome this limitation and rapidly measure low concentrations of the pathogen, we developed a novel technology: Nanotrap particles, which are designed to capture, concentrate, and protect biomarkers from complex biofluids. Nanotrap particles are thermoresponsive hydrogels that are capable of antigen capture through the coupling of affinity baits to the particles. Here, we describe recent findings demonstrating that Nanotrap particles are able to capture live infectious virus, viral RNA, and viral proteins. Capture is possible even in complex mixtures such as serum and allows the concentration and protection of these analytes, providing increased performance of downstream assays. The Nanotrap particles are a versatile sample preparation technology that has far reaching implications for biomarker discovery and diagnostic assays.
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Affiliation(s)
- Nazly Shafagati
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
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Reactive oxygen species activate NFκB (p65) and p53 and induce apoptosis in RVFV infected liver cells. Virology 2014; 449:270-86. [DOI: 10.1016/j.virol.2013.11.023] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 08/02/2013] [Accepted: 11/17/2013] [Indexed: 12/30/2022]
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Paweska JT. Rift Valley Fever. Emerg Infect Dis 2014. [DOI: 10.1016/b978-0-12-416975-3.00006-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Lihoradova O, Ikegami T. Countermeasure development for Rift Valley fever: deletion, modification or targeting of major virulence factor NSs.. Future Virol 2014; 9:27-39. [PMID: 24910709 DOI: 10.2217/fvl.13.117] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Rift Valley fever (RVF) is a mosquito-borne zoonotic disease characterized by a high rate of abortion in ruminants, and febrile illness, hemorrhagic fever, retinitis and encephalitis in humans. RVF is caused by the RVF virus (RVFV), belonging to the genus Phlebovirus of the family Bunyaviridae. RVFV encodes a major virulence factor, NSs, which is dispensable for viral replication, yet required for evasion of host innate immune responses. RVFV NSs inhibits host gene upregulation at the transcriptional level, while promoting viral translation in the cytoplasm. In this article, we summarize the virology and pathology of RVF, and countermeasure development for RVF, with emphasis on NSs function and applications.
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Affiliation(s)
- Olga Lihoradova
- Department of Pathology, University of Texas Medical Branch, MMNP3.206D, 301 University Blvd. Galveston, TX 77555-0436, USA
| | - Tetsuro Ikegami
- Department of Pathology, University of Texas Medical Branch, MMNP3.206D, 301 University Blvd. Galveston, TX 77555-0436, USA ; Sealy Center for Vaccine Development, The University of Texas Medical Branch, Galveston, TX, USA ; Center for Biodefense & Emerging Infectious Diseases, The University of Texas Medical Branch, Galveston, TX, USA
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Jäckel S, Eiden M, Dauber M, Balkema-Buschmann A, Brun A, Groschup MH. Generation and application of monoclonal antibodies against Rift Valley fever virus nucleocapsid protein NP and glycoproteins Gn and Gc. Arch Virol 2013; 159:535-46. [PMID: 24100475 DOI: 10.1007/s00705-013-1867-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 09/15/2013] [Indexed: 12/11/2022]
Abstract
Rift Valley fever virus (RVFV) is a vector-borne virus that causes high neonatal mortality in livestock and deadly haemorrhagic fever in humans. In this paper, we describe the generation of monoclonal antibodies (mabs) against all three structural proteins of RVFV (glycoproteins Gn and Gc and nucleocapsid protein NP). After immunization of BALB/c mice with individual recombinant proteins, a total of 45 clones secreting ELISA-reactive monoclonal antibodies against NP, Gn and Gc epitopes were obtained. Twelve clones were directed to NP, 28 to Gn, and 5 to Gc. Western blot analysis revealed that most of the mabs were reactive to linearized epitopes on recombinant as well as native virus proteins. Six mabs against NP, 21 against Gn and all mabs against Gc also detected conformational epitopes, as shown by indirect immunofluorescence on RVFV-infected cells. All of the mabs were evaluated for their use in a competition enzyme-linked immunosorbent assay (ELISA) for the detection of a RVFV infection. Several mabs were identified that competed with polyclonal rabbit serum, and one of them - mab Gn123, raised against Gn protein - was selected for a proof-of-principle study with field sera from a recent Rift Valley fever outbreak. The novel Gn-based competition ELISA demonstrated high performance, offering a promising alternative and addition to serological assays based on nucleocapsid protein.
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Affiliation(s)
- Susanne Jäckel
- Institute for Novel and Emerging Infectious Diseases at the Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, 17493, Greifswald-Insel Riems, Germany
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Jäckel S, Eiden M, Balkema-Buschmann A, Ziller M, Jansen van Vuren P, Paweska J, Groschup M. A novel indirect ELISA based on glycoprotein Gn for the detection of IgG antibodies against Rift Valley fever virus in small ruminants. Res Vet Sci 2013; 95:725-30. [DOI: 10.1016/j.rvsc.2013.04.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Revised: 04/08/2013] [Accepted: 04/14/2013] [Indexed: 12/21/2022]
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A single immunization with MVA expressing GnGc glycoproteins promotes epitope-specific CD8+-T cell activation and protects immune-competent mice against a lethal RVFV infection. PLoS Negl Trop Dis 2013; 7:e2309. [PMID: 23875044 PMCID: PMC3708870 DOI: 10.1371/journal.pntd.0002309] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 05/30/2013] [Indexed: 11/22/2022] Open
Abstract
Background Rift Valley fever virus (RVFV) is a mosquito-borne pathogen causing an important disease in ruminants often transmitted to humans after epizootic outbreaks in African and Arabian countries. To help combat the spread of the disease, prophylactic measures need to be developed and/or improved. Methodology/Principal Findings In this work, we evaluated the immunogenicity and protective efficacy of recombinant plasmid DNA and modified vaccinia virus Ankara (rMVA) vectored vaccines against Rift Valley fever in mice. These recombinant vaccines encoded either of two components of the Rift Valley fever virus: the viral glycoproteins (Gn/Gc) or the nucleoprotein (N). Following lethal challenge with live RVFV, mice immunized with a single dose of the rMVA-Gn/Gc vaccine showed no viraemia or clinical manifestation of disease, but mounted RVFV neutralizing antibodies and glycoprotein specific CD8+ T-cell responses. Neither DNA-Gn/Gc alone nor a heterologous prime-boost immunization schedule (DNA-Gn/Gc followed by rMVAGn/Gc) was better than the single rMVA-Gn/Gc immunization schedule with regards to protective efficacy. However, the rMVA-Gn/Gc vaccine failed to protect IFNAR−/− mice upon lethal RVFV challenge suggesting a role for innate responses in protection against RVFV. Despite induction of high titer antibodies against the RVFV nucleoprotein, the rMVA-N vaccine, whether in homologous or heterologous prime-boost schedules with the corresponding recombinant DNA vaccine, only conferred partial protection to RVFV challenge. Conclusions/Significance Given the excellent safety profile of rMVA based vaccines in humans and animals, our data supports further development of rMVA-Gn/Gc as a vaccine strategy that can be used for the prevention of Rift Valley fever in both humans and livestock. Rift Valley fever (RVF) is an important disease of ruminants that affects most African and Arabian Peninsula countries where domestic livestock is the basis for subsistence in rural areas. The disease is caused by a bunyavirus that can be transmitted by close contact with infected animals or through the bite of infected mosquitoes thus facilitating the spread of the virus. Safer and practical methods to control virus spread are demanded in order to prevent both human and animal disease after disease outbreaks. The efficacy of a recombinant modified poxvirus vector (the vaccinia modified Ankara virus (rMVA)) and/or DNA-based vaccines in a mouse infection model has been investigated. A single immunization with a rMVA encoding the virus envelope glycoproteins provided sufficient immunity to protect mice against a lethal dose of RVFV. The immune mechanisms underlying the protection were also investigated. A number of specific immune CD8+-T cells could be activated in the presence of at least three different glycoprotein epitopes. On the other hand, the protective effect of the vaccine was found only in immune competent mice since in mice lacking IFN-type-I responses the vaccine was not efficient.
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Gowen BB, Bailey KW, Scharton D, Vest Z, Westover JB, Skirpstunas R, Ikegami T. Post-exposure vaccination with MP-12 lacking NSs protects mice against lethal Rift Valley fever virus challenge. Antiviral Res 2013; 98:135-43. [PMID: 23523764 DOI: 10.1016/j.antiviral.2013.03.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 02/19/2013] [Accepted: 03/01/2013] [Indexed: 11/17/2022]
Abstract
Rift Valley fever virus (RVFV) causes severe disease in humans and livestock. There are currently no approved antivirals or vaccines for the treatment or prevention of RVF disease in humans. A major virulence factor of RVFV is the NSs protein, which inhibits host transcription including the interferon (IFN)-β gene and promotes the degradation of dsRNA-dependent protein kinase, PKR. We analyzed the efficacy of the live-attenuated MP-12 vaccine strain and MP-12 variants that lack the NSs protein as post-exposure vaccinations. Although parental MP-12 failed to elicit a protective effect in mice challenged with wild-type (wt) RVFV by the intranasal route, significant protection was demonstrated by vaccination with MP-12 strains lacking NSs when they were administered at 20-30 min post-exposure. Viremia and virus replication in liver, spleen and brain were also inhibited by post-exposure vaccination with MP-12 lacking NSs. The protective effect was mostly lost when vaccination was delayed 6 or 24 h after intranasal RVFV challenge. When mice were challenged subcutaneously, efficacy of MP-12 lacking NSs was diminished, most likely due to more rapid dissemination of wt RVFV. Our findings suggest that post-exposure vaccination with MP-12 lacking NSs may be developed as a novel post-exposure treatment to prevent RVF.
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Affiliation(s)
- Brian B Gowen
- Department of Animal, Dairy, and Veterinary Sciences, Utah State University, Logan, UT, USA.
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28
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Xu W, Watts DM, Costanzo MC, Tang X, Venegas LA, Jiao F, Sette A, Sidney J, Sewell AK, Wooldridge L, Makino S, Morrill JC, Peters CJ, Kan-Mitchell J. The nucleocapsid protein of Rift Valley fever virus is a potent human CD8+ T cell antigen and elicits memory responses. PLoS One 2013; 8:e59210. [PMID: 23527138 PMCID: PMC3601065 DOI: 10.1371/journal.pone.0059210] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 02/12/2013] [Indexed: 01/10/2023] Open
Abstract
There is no licensed human vaccine currently available for Rift Valley Fever Virus (RVFV), a Category A high priority pathogen and a serious zoonotic threat. While neutralizing antibodies targeting the viral glycoproteins are protective, they appear late in the course of infection, and may not be induced in time to prevent a natural or bioterrorism-induced outbreak. Here we examined the immunogenicity of RVFV nucleocapsid (N) protein as a CD8(+) T cell antigen with the potential for inducing rapid protection after vaccination. HLA-A*0201 (A2)-restricted epitopic determinants were identified with N-specific CD8(+) T cells from eight healthy donors that were primed with dendritic cells transduced to express N, and subsequently expanded in vitro by weekly re-stimulations with monocytes pulsed with 59 15mer overlapping peptides (OLPs) across N. Two immunodominant epitopes, VT9 (VLSEWLPVT, N(121-129)) and IL9 (ILDAHSLYL, N165-173), were defined. VT9- and IL9-specific CD8(+) T cells identified by tetramer staining were cytotoxic and polyfunctional, characteristics deemed important for viral control in vivo. These peptides induced specific CD8(+) T cell responses in A2-transgenic mice, and more importantly, potent N-specific CD8(+) T cell reactivities, including VT9- and IL9-specific ones, were mounted by mice after a booster vaccination with the live attenuated RVF MP-12. Our data suggest that the RVFV N protein is a potent human T cell immunogen capable of eliciting broad, immunodominant CD8(+) T cell responses that are potentially protective. Understanding the immune responses to the nucleocapsid is central to the design of an effective RVFV vaccine irrespective of whether this viral protein is effective as a stand-alone immunogen or only in combination with other RVFV antigens.
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Affiliation(s)
- Weidong Xu
- Department of Biological Science and Border Biomedical Research Center, The University of Texas at El Paso, El Paso, Texas, United States of America
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29
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Large-scale chromatin immunoprecipitation with promoter sequence microarray analysis of the interaction of the NSs protein of Rift Valley fever virus with regulatory DNA regions of the host genome. J Virol 2012; 86:11333-44. [PMID: 22896612 DOI: 10.1128/jvi.01549-12] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Rift Valley fever virus (RVFV) is a highly pathogenic Phlebovirus that infects humans and ruminants. Initially confined to Africa, RVFV has spread outside Africa and presently represents a high risk to other geographic regions. It is responsible for high fatality rates in sheep and cattle. In humans, RVFV can induce hepatitis, encephalitis, retinitis, or fatal hemorrhagic fever. The nonstructural NSs protein that is the major virulence factor is found in the nuclei of infected cells where it associates with cellular transcription factors and cofactors. In previous work, we have shown that NSs interacts with the promoter region of the beta interferon gene abnormally maintaining the promoter in a repressed state. In this work, we performed a genome-wide analysis of the interactions between NSs and the host genome using a genome-wide chromatin immunoprecipitation combined with promoter sequence microarray, the ChIP-on-chip technique. Several cellular promoter regions were identified as significantly interacting with NSs, and the establishment of NSs interactions with these regions was often found linked to deregulation of expression of the corresponding genes. Among annotated NSs-interacting genes were present not only genes regulating innate immunity and inflammation but also genes regulating cellular pathways that have not yet been identified as targeted by RVFV. Several of these pathways, such as cell adhesion, axonal guidance, development, and coagulation were closely related to RVFV-induced disorders. In particular, we show in this work that NSs targeted and modified the expression of genes coding for coagulation factors, demonstrating for the first time that this hemorrhagic virus impairs the host coagulation cascade at the transcriptional level.
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Ayari-Fakhfakh E, do Valle TZ, Guillemot L, Panthier JJ, Bouloy M, Ghram A, Albina E, Cêtre-Sossah C. MBT/Pas mouse: a relevant model for the evaluation of Rift Valley fever vaccines. J Gen Virol 2012; 93:1456-1464. [DOI: 10.1099/vir.0.042754-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Currently, there are no worldwide licensed vaccines for Rift Valley fever (RVF) that are both safe and effective. Development and evaluation of vaccines, diagnostics and treatments depend on the availability of appropriate animal models. Animal models are also necessary to understand the basic pathobiology of infection. Here, we report the use of an inbred MBT/Pas mouse model that consistently reproduces RVF disease and serves our purpose for testing the efficacy of vaccine candidates; an attenuated Rift Valley fever virus (RVFV) and a recombinant RVFV–capripoxvirus. We show that this model is relevant for vaccine testing.
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Affiliation(s)
- Emna Ayari-Fakhfakh
- Institut Pasteur de Tunis, Université de Tunis El Manar, 1002 Tunis Belvédère, Tunisia
| | - Tânia Zaverucha do Valle
- Centre National de la Recherche Scientifique, Unité de Recherche Associée 2578, Paris, France
- Mouse Functional Genetics, Institut Pasteur, Paris, France
| | - Laurent Guillemot
- Centre National de la Recherche Scientifique, Unité de Recherche Associée 2578, Paris, France
- Mouse Functional Genetics, Institut Pasteur, Paris, France
| | - Jean-Jacques Panthier
- Centre National de la Recherche Scientifique, Unité de Recherche Associée 2578, Paris, France
- Mouse Functional Genetics, Institut Pasteur, Paris, France
| | - Michèle Bouloy
- Molecular Genetics of Bunyaviruses, Institut Pasteur, Paris, France
| | - Abdeljelil Ghram
- Institut Pasteur de Tunis, Université de Tunis El Manar, 1002 Tunis Belvédère, Tunisia
| | - Emmanuel Albina
- CIRAD, UMR Contrôle des Maladies, Montpellier, F-34398, France
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Yu L, Zhang L, Sun L, Lu J, Wu W, Li C, Zhang Q, Zhang F, Jin C, Wang X, Bi Z, Li D, Liang M. Critical epitopes in the nucleocapsid protein of SFTS virus recognized by a panel of SFTS patients derived human monoclonal antibodies. PLoS One 2012; 7:e38291. [PMID: 22719874 PMCID: PMC3373585 DOI: 10.1371/journal.pone.0038291] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 05/03/2012] [Indexed: 12/13/2022] Open
Abstract
Background SFTS virus (SFTSV) is a newly discovered pathogen to cause severe fever with thrombocytopenia syndrome (SFTS) in human. Successful control of SFTSV epidemic requires better understanding of the antigen target in humoral immune responses to the new bunyavirus infection. Methodology/Principal Findings We have generated a combinatorial Fab antibody phage library from two SFTS patients recovered from SFTSV infection. To date, 94 unique human antibodies have been generated and characterized from over 1200 Fab antibody clones obtained by screening the library with SFTS purified virions. All those monoclonal antibodies (MAbs) recognized the nucleocapsid (N) protein of SFTSV while none of them were reactive to the viral glycoproteins Gn or Gc. Furthermore, over screening 1000 mouse monoclonal antibody clones derived from SFTSV virions immunization, 462 clones reacted with N protein, while only 16 clones were reactive to glycoprotein. Furthermore, epitope mapping of SFTSV N protein was performed through molecular simulation, site mutation and competitive ELISA, and we found that at least 4 distinct antigenic epitopes within N protein were recognized by those human and mouse MAbs, in particular mutation of Glu10 to Ala10 abolished or significantly reduced the binding activity of nearly most SFTS patients derived MAbs. Conclusions/Significance The large number of human recombinant MAbs derived from SFTS patients recognized the viral N protein indicated the important role of the N protein in humoral responses to SFTSV infection, and the critical epitopes we defined in this study provided molecular basis for detection and diagnosis of SFTSV infection.
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Affiliation(s)
- Li Yu
- Laboratory Institute for Viral Disease Control and Prevention, China CDC, Beijing, China
| | - Li Zhang
- Laboratory Institute for Viral Disease Control and Prevention, China CDC, Beijing, China
| | - Lina Sun
- Laboratory Institute for Viral Disease Control and Prevention, China CDC, Beijing, China
| | - Jing Lu
- Laboratory Institute for Viral Disease Control and Prevention, China CDC, Beijing, China
| | - Wei Wu
- Laboratory Institute for Viral Disease Control and Prevention, China CDC, Beijing, China
| | - Chuan Li
- Laboratory Institute for Viral Disease Control and Prevention, China CDC, Beijing, China
| | - Quanfu Zhang
- Laboratory Institute for Viral Disease Control and Prevention, China CDC, Beijing, China
| | - Fushun Zhang
- Laboratory Institute for Viral Disease Control and Prevention, China CDC, Beijing, China
| | - Cong Jin
- Laboratory Institute for Viral Disease Control and Prevention, China CDC, Beijing, China
| | - Xianjun Wang
- Shandong Key Laboratory for Infectious Disease Prevention and Control, Shandong Province CDC, Jinan Shandong, China
| | - Zhenqiang Bi
- Shandong Key Laboratory for Infectious Disease Prevention and Control, Shandong Province CDC, Jinan Shandong, China
| | - Dexin Li
- Laboratory Institute for Viral Disease Control and Prevention, China CDC, Beijing, China
| | - Mifang Liang
- Laboratory Institute for Viral Disease Control and Prevention, China CDC, Beijing, China
- * E-mail:
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32
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The dominant-negative inhibition of double-stranded RNA-dependent protein kinase PKR increases the efficacy of Rift Valley fever virus MP-12 vaccine. J Virol 2012; 86:7650-61. [PMID: 22573861 DOI: 10.1128/jvi.00778-12] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Rift Valley fever virus (RVFV), belonging to the genus Phlebovirus, family Bunyaviridae, is endemic to sub-Saharan Africa and causes a high rate of abortion in ruminants and hemorrhagic fever, encephalitis, or blindness in humans. MP-12 is the only RVFV strain excluded from the select-agent rule and handled at a biosafety level 2 (BSL2) laboratory. MP-12 encodes a functional major virulence factor, the NSs protein, which contributes to its residual virulence in pregnant ewes. We found that 100% of mice subcutaneously vaccinated with recombinant MP-12 (rMP12)-murine PKRN167 (mPKRN167), which encodes a dominant-negative form of mouse double-stranded RNA (dsRNA)-dependent protein kinase (PKR) in place of NSs, were protected from wild-type (wt) RVFV challenge, while 72% of mice vaccinated with MP-12 were protected after challenge. rMP12-mPKRN167 induced alpha interferon (IFN-α) in sera, accumulated RVFV antigens in dendritic cells at the local draining lymph nodes, and developed high levels of neutralizing antibodies, while parental MP-12 induced neither IFN-α nor viral-antigen accumulation at the draining lymph node yet induced a high level of neutralizing antibodies. The present study suggests that the expression of a dominant-negative PKR increases the immunogenicity and efficacy of live-attenuated RVFV vaccine, which will lead to rational design of safe and highly immunogenic RVFV vaccines for livestock and humans.
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33
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Gray KK, Worthy MN, Juelich TL, Agar SL, Poussard A, Ragland D, Freiberg AN, Holbrook MR. Chemotactic and inflammatory responses in the liver and brain are associated with pathogenesis of Rift Valley fever virus infection in the mouse. PLoS Negl Trop Dis 2012; 6:e1529. [PMID: 22389738 PMCID: PMC3289610 DOI: 10.1371/journal.pntd.0001529] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 01/02/2012] [Indexed: 12/17/2022] Open
Abstract
Rift Valley fever virus (RVFV) is a major human and animal pathogen associated with severe disease including hemorrhagic fever or encephalitis. RVFV is endemic to parts of Africa and the Arabian Peninsula, but there is significant concern regarding its introduction into non-endemic regions and the potentially devastating effect to livestock populations with concurrent infections of humans. To date, there is little detailed data directly comparing the host response to infection with wild-type or vaccine strains of RVFV and correlation with viral pathogenesis. Here we characterized clinical and systemic immune responses to infection with wild-type strain ZH501 or IND vaccine strain MP-12 in the C57BL/6 mouse. Animals infected with live-attenuated MP-12 survived productive viral infection with little evidence of clinical disease and minimal cytokine response in evaluated tissues. In contrast, ZH501 infection was lethal, caused depletion of lymphocytes and platelets and elicited a strong, systemic cytokine response which correlated with high virus titers and significant tissue pathology. Lymphopenia and platelet depletion were indicators of disease onset with indications of lymphocyte recovery correlating with increases in G-CSF production. RVFV is hepatotropic and in these studies significant clinical and histological data supported these findings; however, significant evidence of a pro-inflammatory response in the liver was not apparent. Rather, viral infection resulted in a chemokine response indicating infiltration of immunoreactive cells, such as neutrophils, which was supported by histological data. In brains of ZH501 infected mice, a significant chemokine and pro-inflammatory cytokine response was evident, but with little pathology indicating meningoencephalitis. These data suggest that RVFV pathogenesis in mice is associated with a loss of liver function due to liver necrosis and hepatitis yet the long-term course of disease for those that might survive the initial hepatitis is neurologic in nature which is supported by observations of human disease and the BALB/c mouse model.
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Affiliation(s)
- Kimberly K. Gray
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Melissa N. Worthy
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Galveston National Laboratory, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Terry L. Juelich
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Stacy L. Agar
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, United States of America
| | - Allison Poussard
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Galveston National Laboratory, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Dan Ragland
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, United States of America
| | - Alexander N. Freiberg
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Galveston National Laboratory, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute for Human Infections and Immunity, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Center for Tropical Diseases, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Michael R. Holbrook
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Galveston National Laboratory, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, United States of America
- Institute for Human Infections and Immunity, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Center for Tropical Diseases, The University of Texas Medical Branch, Galveston, Texas, United States of America
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