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Benzarti E, Murray KO, Ronca SE. Interleukins, Chemokines, and Tumor Necrosis Factor Superfamily Ligands in the Pathogenesis of West Nile Virus Infection. Viruses 2023; 15:v15030806. [PMID: 36992514 PMCID: PMC10053297 DOI: 10.3390/v15030806] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/15/2023] [Accepted: 03/17/2023] [Indexed: 03/31/2023] Open
Abstract
West Nile virus (WNV) is a mosquito-borne pathogen that can lead to encephalitis and death in susceptible hosts. Cytokines play a critical role in inflammation and immunity in response to WNV infection. Murine models provide evidence that some cytokines offer protection against acute WNV infection and assist with viral clearance, while others play a multifaceted role WNV neuropathogenesis and immune-mediated tissue damage. This article aims to provide an up-to-date review of cytokine expression patterns in human and experimental animal models of WNV infections. Here, we outline the interleukins, chemokines, and tumor necrosis factor superfamily ligands associated with WNV infection and pathogenesis and describe the complex roles they play in mediating both protection and pathology of the central nervous system during or after virus clearance. By understanding of the role of these cytokines during WNV neuroinvasive infection, we can develop treatment options aimed at modulating these immune molecules in order to reduce neuroinflammation and improve patient outcomes.
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Affiliation(s)
- Emna Benzarti
- Department of Pediatrics, Division of Tropical Medicine, Baylor College of Medicine and Texas Children's Hospital, Houston, TX 77030, USA
- William T. Shearer Center for Human Immunobiology, Texas Children's Hospital, Houston, TX 77030, USA
| | - Kristy O Murray
- Department of Pediatrics, Division of Tropical Medicine, Baylor College of Medicine and Texas Children's Hospital, Houston, TX 77030, USA
- William T. Shearer Center for Human Immunobiology, Texas Children's Hospital, Houston, TX 77030, USA
- National School of Tropical Medicine, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Immunology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Shannon E Ronca
- Department of Pediatrics, Division of Tropical Medicine, Baylor College of Medicine and Texas Children's Hospital, Houston, TX 77030, USA
- William T. Shearer Center for Human Immunobiology, Texas Children's Hospital, Houston, TX 77030, USA
- National School of Tropical Medicine, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Immunology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
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2
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Flavivirus NS4B protein: Structure, function, and antiviral discovery. Antiviral Res 2022; 207:105423. [PMID: 36179934 DOI: 10.1016/j.antiviral.2022.105423] [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: 07/10/2022] [Revised: 09/16/2022] [Accepted: 09/18/2022] [Indexed: 11/02/2022]
Abstract
Infections with mosquito-borne flaviviruses, such as Dengue virus, ZIKV virus, and West Nile virus, pose significant threats to public health. Flaviviruses cause about 400 million infections each year, leading to many forms of diseases, including fatal hemorrhagic, encephalitis, congenital abnormalities, and deaths. Currently, there are no clinically approved antiviral drugs for the treatment of flavivirus infections. The non-structural protein NS4B is an emerging target for drug discovery due to its multiple roles in the flaviviral life cycle. In this review, we summarize the latest knowledge on the structure and function of flavivirus NS4B, as well as the progress on antiviral compounds that target NS4B.
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3
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Bhardwaj T, Kumar P, Giri R. Investigating the conformational dynamics of Zika virus NS4B protein. Virology 2022; 575:20-35. [PMID: 36037701 DOI: 10.1016/j.virol.2022.08.005] [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: 12/15/2021] [Revised: 08/14/2022] [Accepted: 08/16/2022] [Indexed: 11/27/2022]
Abstract
Zika virus (ZIKV) NS4B protein is a membranotropic multifunctional protein. Despite its versatile functioning, its topology and dynamics are not entirely understood. There is no X-ray or cryo-EM structure available for any flaviviral NS4B full-length protein. In this study, we have investigated the structural dynamics of full-length ZIKV NS4B protein through 3D structure models using molecular dynamics simulations and experimental techniques. Also, we employed a reductionist approach to understand the dynamics of NS4B protein where we studied its N-terminal (residues 1-38), C-terminal (residues 194-251), and cytosolic (residues 131-169) regions in isolation in addition to the full-length protein. Further, using a series of circular dichroism spectroscopic experiments, we validate the cytosolic region as an intrinsically disordered protein region. The microsecond-long all atoms molecular dynamics and replica-exchange simulations complement the experimental observations. Furthermore, we have also studied the NS4B proteins C-terminal regions of four other flaviviruses viz. DENV2, JEV, WNV, and YFV through microsecond simulations to characterize their behaviour in presence and absence of lipid membranes. There are significant differences observed in the conformations of other flavivirus NS4B C-terminal regions in comparison to ZIKV NS4B. Lastly, we have proposed a ZIKV NS4B protein model illustrating its putative topology consisting of various membrane-spanning and non-membranous regions.
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Affiliation(s)
- Taniya Bhardwaj
- School of Biosciences and Bioengineering, Indian Institute of Technology Mandi, VPO Kamand, Himachal Pradesh, 175005, India
| | - Prateek Kumar
- School of Biosciences and Bioengineering, Indian Institute of Technology Mandi, VPO Kamand, Himachal Pradesh, 175005, India
| | - Rajanish Giri
- School of Biosciences and Bioengineering, Indian Institute of Technology Mandi, VPO Kamand, Himachal Pradesh, 175005, India.
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INMI1 Zika Virus NS4B Antagonizes the Interferon Signaling by Suppressing STAT1 Phosphorylation. Viruses 2021; 13:v13122448. [PMID: 34960717 PMCID: PMC8705506 DOI: 10.3390/v13122448] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/22/2021] [Accepted: 12/02/2021] [Indexed: 12/17/2022] Open
Abstract
The evasion of the Interferon response has important implications in Zika virus (ZIKV) disease. Mutations in ZIKV viral protein NS4B, associated with modulation of the interferon (IFN) system, have been linked to increased pathogenicity in animal models. In this study, we unravel ZIKV NS4B as antagonist of the IFN signaling cascade. Firstly, we reported the genomic characterization of NS4B isolated from a strain of the 2016 outbreak, ZIKV Brazil/2016/INMI1, and we predicted its membrane topology. Secondly, we analyzed its phylogenetic correlation with other flaviviruses, finding a high similarity with dengue virus 2 (DEN2) strains; in particular, the highest conservation was found when NS4B was aligned with the IFN inhibitory domain of DEN2 NS4B. Hence, we asked whether ZIKV NS4B was also able to inhibit the IFN signaling cascade, as reported for DEN2 NS4B. Our results showed that ZIKV NS4B was able to strongly inhibit the IFN stimulated response element and the IFN-γ-activated site transcription, blocking IFN-I/-II responses. mRNA expression levels of the IFN stimulated genes ISG15 and OAS1 were also strongly reduced in presence of NS4B. We found that the viral protein was acting by suppressing the STAT1 phosphorylation and consequently blocking the nuclear transport of both STAT1 and STAT2.
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5
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Yurayart N, Ninvilai P, Chareonviriyaphap T, Kaewamatawong T, Thontiravong A, Tiawsirisup S. Interactions of duck Tembusu virus with Aedes aegypti and Aedes albopictus mosquitoes: Vector competence and viral mutation. Acta Trop 2021; 222:106051. [PMID: 34273310 DOI: 10.1016/j.actatropica.2021.106051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 06/16/2021] [Accepted: 07/05/2021] [Indexed: 10/20/2022]
Abstract
Duck Tembusu virus (DTMUV) is an emerging flavivirus that causes severe disease in avian hosts, while also affecting mammalian hosts; however, information on viral interaction with mosquito vectors for mammalian hosts is limited. Vector competence of Aedes (Ae.) aegypti and Aedes albopictus mosquitoes for DTMUV were investigated. Both Aedes mosquito species were orally infected with DK/TH/CU-1 strain of Thai DTMUV and isolated DTMUV from BALB/c mouse. Genomes of the viruses isolated from hosts and vectors were analyzed and compared with the positive virus. Findings showed that both Aedes mosquito species could serve as vectors for DTMUV with minimum viral titer in blood meal of 106 TCID50/mL. After taking blood meal with viral titer at 107 TCID50/mL, vector competence of the mosquitoes was significantly different from the lower titer in both species. Both Aedes species did not support development of the isolated viruses from mouse. A point mutation of nucleotide and amino acid was found in all isolated DTMUV from Ae. aegypti saliva, while other viruses were similar to the positive virus. Our findings demonstrated that both Ae. aegypti and Ae. albopictus had potential to transmit the virus and play important roles in the viral transmission cycle in mammalian hosts, while viral mutation occurred in Ae. aegypti mosquitoes.
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Zhang YN, Li N, Zhang QY, Liu J, Zhan SL, Gao L, Zeng XY, Yu F, Zhang HQ, Li XD, Deng CL, Shi PY, Yuan ZM, Yuan SP, Ye HQ, Zhang B. Rational design of West Nile virus vaccine through large replacement of 3' UTR with internal poly(A). EMBO Mol Med 2021; 13:e14108. [PMID: 34351689 PMCID: PMC8422072 DOI: 10.15252/emmm.202114108] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 06/30/2021] [Accepted: 07/09/2021] [Indexed: 11/29/2022] Open
Abstract
The genus Flavivirus comprises numerous emerging and re-emerging arboviruses causing human illness. Vaccines are the best approach to prevent flavivirus diseases. But pathogen diversities are always one of the major hindrances for timely development of new vaccines when confronting unpredicted flavivirus outbreaks. We used West Nile virus (WNV) as a model to develop a new live-attenuated vaccine (LAV), WNV-poly(A), by replacing 5' portion (corresponding to SL and DB domains in WNV) of 3'-UTR with internal poly(A) tract. WNV-poly(A) not only propagated efficiently in Vero cells, but also was highly attenuated in mouse model. A single-dose vaccination elicited robust and long-lasting immune responses, conferring full protection against WNV challenge. Such "poly(A)" vaccine strategy may be promising for wide application in the development of flavivirus LAVs because of its general target regions in flaviviruses.
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Affiliation(s)
- Ya-Nan Zhang
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Na Li
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Qiu-Yan Zhang
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Jing Liu
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Shun-Li Zhan
- Beijing Shunlei Biotechnology Co. Ltd., Beijing, China
| | - Lei Gao
- Beijing Shunlei Biotechnology Co. Ltd., Beijing, China
| | - Xiang-Yue Zeng
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Fang Yu
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Hong-Qing Zhang
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Xiao-Dan Li
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Cheng-Lin Deng
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Pei-Yong Shi
- University of Texas Medical Branch, Galveston, TX, USA
| | - Zhi-Ming Yuan
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | | | - Han-Qing Ye
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Bo Zhang
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
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7
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Adam A, Fontes-Garfias CR, Sarathy VV, Liu Y, Luo H, Davis E, Li W, Muruato AE, Wang B, Ahatov R, Mahmoud Y, Shan C, Osman SR, Widen SG, Barrett ADT, Shi PY, Wang T. A genetically stable Zika virus vaccine candidate protects mice against virus infection and vertical transmission. NPJ Vaccines 2021; 6:27. [PMID: 33597526 PMCID: PMC7889622 DOI: 10.1038/s41541-021-00288-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Accepted: 01/15/2021] [Indexed: 12/20/2022] Open
Abstract
Although live attenuated vaccines (LAVs) have been effective in the control of flavivirus infections, to date they have been excluded from Zika virus (ZIKV) vaccine trials due to safety concerns. We have previously reported two ZIKV mutants, each of which has a single substitution in either envelope (E) glycosylation or nonstructural (NS) 4B P36 and displays a modest reduction in mouse neurovirulence and neuroinvasiveness, respectively. Here, we generated a ZIKV mutant, ZE4B-36, which combines mutations in both E glycosylation and NS4B P36. The ZE4B-36 mutant is stable and attenuated in viral replication. Next-generation sequence analysis showed that the attenuating mutations in the E and NS4B proteins are retained during serial cell culture passages. The mutant exhibits a significant reduction in neuroinvasiveness and neurovirulence and low infectivity in mosquitoes. It induces robust ZIKV-specific memory B cell, antibody, and T cell-mediated immune responses in type I interferon receptor (IFNR) deficient mice. ZIKV-specific T cell immunity remains strong months post-vaccination in wild-type C57BL/6 (B6) mice. Vaccination with ZE4B-36 protects mice from ZIKV-induced diseases and vertical transmission. Our results suggest that combination mutations in E glycosylation and NS4B P36 contribute to a candidate LAV with significantly increased safety but retain strong immunogenicity for prevention and control of ZIKV infection.
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Affiliation(s)
- Awadalkareem Adam
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, USA
| | - Camila R Fontes-Garfias
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
| | - Vanessa V Sarathy
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX, USA
| | - Yang Liu
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
| | - Huanle Luo
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, USA
| | - Emily Davis
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA
| | - Wenqian Li
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, USA
| | - Antonio E Muruato
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, USA
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
| | - Binbin Wang
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, USA
| | - Renat Ahatov
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, USA
| | - Yoseph Mahmoud
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, USA
| | - Chao Shan
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
| | - Samantha R Osman
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, USA
| | - Steven G Widen
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
- Molecular Genomics Core Facility, University of Texas Medical Branch, Galveston, TX, USA
| | - Alan D T Barrett
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, USA
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX, USA
| | - Pei-Yong Shi
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA.
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX, USA.
- Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA.
| | - Tian Wang
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, USA.
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA.
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX, USA.
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8
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O’Ketch M, Williams S, Larson C, Uhrlaub JL, Wong R, Hall B, Deshpande NR, Schenten D. MAVS regulates the quality of the antibody response to West-Nile Virus. PLoS Pathog 2020; 16:e1009009. [PMID: 33104760 PMCID: PMC7644103 DOI: 10.1371/journal.ppat.1009009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 11/05/2020] [Accepted: 09/28/2020] [Indexed: 01/01/2023] Open
Abstract
A key difference that distinguishes viral infections from protein immunizations is the recognition of viral nucleic acids by cytosolic pattern recognition receptors (PRRs). Insights into the functions of cytosolic PRRs such as the RNA-sensing Rig-I-like receptors (RLRs) in the instruction of adaptive immunity are therefore critical to understand protective immunity to infections. West Nile virus (WNV) infection of mice deficent of RLR-signaling adaptor MAVS results in a defective adaptive immune response. While this finding suggests a role for RLRs in the instruction of adaptive immunity to WNV, it is difficult to interpret due to the high WNV viremia, associated exessive antigen loads, and pathology in the absence of a MAVS-dependent innate immune response. To overcome these limitations, we have infected MAVS-deficient (MAVSKO) mice with a single-round-of-infection mutant of West Nile virus. We show that MAVSKO mice failed to produce an effective neutralizing antibody response to WNV despite normal antibody titers against the viral WNV-E protein. This defect occurred independently of antigen loads or overt pathology. The specificity of the antibody response in infected MAVSKO mice remained unchanged and was still dominated by antibodies that bound the neutralizing lateral ridge (LR) epitope in the DIII domain of WNV-E. Instead, MAVSKO mice produced IgM antibodies, the dominant isotype controlling primary WNV infection, with lower affinity for the DIII domain. Our findings suggest that RLR-dependent signals are important for the quality of the humoral immune response to WNV.
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MESH Headings
- Adaptive Immunity/immunology
- Adaptor Proteins, Signal Transducing/genetics
- Adaptor Proteins, Signal Transducing/immunology
- Adaptor Proteins, Signal Transducing/metabolism
- Animals
- Antibodies, Neutralizing/immunology
- Antibodies, Viral/immunology
- Antibody Formation
- DEAD Box Protein 58/immunology
- DEAD Box Protein 58/metabolism
- Female
- Immunity, Humoral
- Immunity, Innate/immunology
- Immunoglobulin M
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Receptors, Pattern Recognition/immunology
- Receptors, Pattern Recognition/metabolism
- Signal Transduction/immunology
- West Nile Fever/immunology
- West Nile Fever/virology
- West Nile virus/pathogenicity
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Affiliation(s)
- Marvin O’Ketch
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
| | - Spencer Williams
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
| | - Cameron Larson
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
| | - Jennifer L. Uhrlaub
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
| | - Rachel Wong
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
- Division of Biological and Biomedical Sciences, Washington University in St. Louis, Saint Louis, Missouri, United States of America
| | - Brenna Hall
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
| | - Neha R. Deshpande
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
| | - Dominik Schenten
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
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9
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West Nile Virus: An Update on Pathobiology, Epidemiology, Diagnostics, Control and "One Health" Implications. Pathogens 2020; 9:pathogens9070589. [PMID: 32707644 PMCID: PMC7400489 DOI: 10.3390/pathogens9070589] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 07/16/2020] [Accepted: 07/16/2020] [Indexed: 02/06/2023] Open
Abstract
West Nile virus (WNV) is an important zoonotic flavivirus responsible for mild fever to severe, lethal neuroinvasive disease in humans, horses, birds, and other wildlife species. Since its discovery, WNV has caused multiple human and animal disease outbreaks in all continents, except Antarctica. Infections are associated with economic losses, mainly due to the cost of treatment of infected patients, control programmes, and loss of animals and animal products. The pathogenesis of WNV has been extensively investigated in natural hosts as well as in several animal models, including rodents, lagomorphs, birds, and reptiles. However, most of the proposed pathogenesis hypotheses remain contentious, and much remains to be elucidated. At the same time, the unavailability of specific antiviral treatment or effective and safe vaccines contribute to the perpetuation of the disease and regular occurrence of outbreaks in both endemic and non-endemic areas. Moreover, globalisation and climate change are also important drivers of the emergence and re-emergence of the virus and disease. Here, we give an update of the pathobiology, epidemiology, diagnostics, control, and “One Health” implications of WNV infection and disease.
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10
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Li G, Adam A, Luo H, Shan C, Cao Z, Fontes-Garfias CR, Sarathy VV, Teleki C, Winkelmann ER, Liang Y, Sun J, Bourne N, Barrett ADT, Shi PY, Wang T. An attenuated Zika virus NS4B protein mutant is a potent inducer of antiviral immune responses. NPJ Vaccines 2019; 4:48. [PMID: 31815005 PMCID: PMC6883050 DOI: 10.1038/s41541-019-0143-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 10/28/2019] [Indexed: 12/20/2022] Open
Abstract
Live attenuated vaccines (LAVs) are one of the most important strategies to control flavivirus diseases. The flavivirus nonstructural (NS) 4B proteins are a critical component of both the virus replication complex and evasion of host innate immunity. Here we have used site-directed mutagenesis of residues in the highly conserved N-terminal and central hydrophobic regions of Zika virus (ZIKV) NS4B protein to identify candidate attenuating mutations. Three single-site mutants were generated, of which the NS4B-C100S mutant was more attenuated than the other two mutants (NS4B-C100A and NS4B-P36A) in two immunocompromised mouse models of fatal ZIKV disease. The ZIKV NS4B-C100S mutant triggered stronger type 1 interferons and interleukin-6 production, and higher ZIKV-specific CD4+ and CD8+ T-cell responses, but induced similar titers of neutralization antibodies compared with the parent wild-type ZIKV strain and a previously reported candidate ZIKV LAV with a 10-nucleotide deletion in 3'-UTR (ZIKV-3'UTR-Δ10). Vaccination with ZIKV NS4B-C100S protected mice from subsequent WT ZIKV challenge. Furthermore, either passive immunization with ZIKV NS4B-C100S immune sera or active immunization with ZIKV NS4B-C100S followed by the depletion of T cells affords full protection from lethal WT ZIKV challenge. In summary, our results suggest that the ZIKV NS4B-C100S mutant may serve as a candidate ZIKV LAV due to its attenuated phenotype and high immunogenicity.
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Affiliation(s)
- Guangyu Li
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Awadalkareem Adam
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Huanle Luo
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Chao Shan
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Zengguo Cao
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Camila R. Fontes-Garfias
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Vanessa V. Sarathy
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555 USA
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Cody Teleki
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Evandro R. Winkelmann
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Yuejin Liang
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Jiaren Sun
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Nigel Bourne
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555 USA
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX 77555 USA
- Department of Pediatrics, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Alan D. T. Barrett
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555 USA
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555 USA
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Pei-Yong Shi
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555 USA
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX 77555 USA
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Tian Wang
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555 USA
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555 USA
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX 77555 USA
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Replication-Defective West Nile Virus with NS1 Deletion as a New Vaccine Platform for Flavivirus. J Virol 2019; 93:JVI.00720-19. [PMID: 31189715 DOI: 10.1128/jvi.00720-19] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 06/10/2019] [Indexed: 02/03/2023] Open
Abstract
We previously produced a replication-defective West Nile virus (WNV) lacking NS1 (WNV-ΔNS1) that could propagate at low levels (105 infectious units [IU]/ml) in a 293T cell line expressing wild-type (WT) NS1. This finding indicates the potential of developing WNV-ΔNS1 as a noninfectious vaccine. To explore this idea, we developed an NS1-expressing Vero cell line (VeroNS1) that significantly improved the yield of WNV-ΔNS1 (108 IU/ml). We evaluated the safety and efficacy of WNV-ΔNS1 in mice. WNV-ΔNS1 appeared to be safe, as no replicative virus was found in naive Vero cells after continuous culturing of WNV-ΔNS1 in VeroNS1 cells for 15 rounds. WNV-ΔNS1 was noninfectious in mice, even when IFNAR-/- mice were administered a high dose of WNV-ΔNS1. Vaccination with a single dose of WNV-ΔNS1 protected mice from a highly lethal challenge with WT WNV. The antibody response against WNV correlated well with the protection of vaccinated mice. Our study demonstrates the potential of the NS1 trans complementation system as a new platform for flavivirus vaccine development.IMPORTANCE Many flaviviruses are significant human pathogens that frequently cause outbreaks and epidemics around the world. Development of novel vaccine platforms against these pathogens is a public health priority. Using WNV as a model, we developed a new vaccine platform for flaviviruses. WNV containing a NS1 deletion (WNV-ΔNS1) could be efficiently trans complemented in Vero cells that constitutively expressed WT NS1 protein. A single-dose immunization with WNV-ΔNS1 elicited robust immune responses in mice. The immunized animals were fully protected against pathogenic WNV infection. No adverse effects related to the WNV-ΔNS1 vaccination were observed. The results have demonstrated the potential of the NS1 complementation system as an alternative platform for flavivirus vaccine development, especially for highly pathogenic flaviviruses.
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Abstract
The persistence of West Nile virus (WNV) infections throughout the USA since its inception in 1999 and its continuous spread throughout the globe calls for an urgent need of effective treatments and prevention measures. Although the licensing of several WNV vaccines for veterinary use provides a proof of concept, similar efforts on the development of an effective vaccine for humans remain still unsuccessful. Increased understanding of biology and pathogenesis of WNV together with recent technological advancements have raised hope that an effective WNV vaccine may be available in the near future. In addition, rapid progress in the structural and functional characterization of WNV and other flaviviral proteins have provided a solid base for the design and development of several classes of inhibitors as potential WNV therapeutics. Moreover, the therapeutic monoclonal antibodies demonstrate an excellent efficacy against WNV in animal models and represent a promising class of WNV therapeutics. However, there are some challenges as to the design and development of a safe and efficient WNV vaccine or therapeutic. In this chapter, we discuss the current approaches, progress, and challenges toward the development of WNV vaccines, therapeutic antibodies, and antiviral drugs.
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Kaiser JA, Wang T, Barrett AD. Virulence determinants of West Nile virus: how can these be used for vaccine design? Future Virol 2017; 12:283-295. [PMID: 28919920 DOI: 10.2217/fvl-2016-0141] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 02/14/2017] [Indexed: 12/12/2022]
Abstract
West Nile virus (WNV), a neurotropic mosquito-borne flavivirus, has become endemic in the USA and parts of Europe since 1999. There is no licensed WNV vaccine for humans. Considering the robust immunity from immunization with live, attenuated vaccines, a live WNV vaccine is an ideal platform for disease control. Animal and mosquito studies have identified a number of candidate attenuating mutations, including the structural proteins premembrane/membrane and envelope, and the nonstructural proteins NS1, NS2A, NS3, NS4A, NS4B and NS5, and the 3' UTR. Many of the mutations that have been examined attenuate WNV using different mechanisms, thus providing a greater understanding of WNV virulence while also identifying specific mutations as candidates to include in a WNV live vaccine.
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Affiliation(s)
- Jaclyn A Kaiser
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA.,Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Tian Wang
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA.,Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA.,Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX 77555, USA.,Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA.,Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA.,Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Alan Dt Barrett
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA.,Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA.,Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX 77555, USA.,Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA.,Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA.,Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX 77555, USA
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MAVS Is Essential for Primary CD4 + T Cell Immunity but Not for Recall T Cell Responses following an Attenuated West Nile Virus Infection. J Virol 2017; 91:JVI.02097-16. [PMID: 28077630 DOI: 10.1128/jvi.02097-16] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 12/30/2016] [Indexed: 12/20/2022] Open
Abstract
The use of pathogen recognition receptor (PRR) agonists and the molecular mechanisms involved have been the major focus of research in individual vaccine development. West Nile virus (WNV) nonstructural (NS) 4B-P38G mutant has several features for an ideal vaccine candidate, including significantly reduced neuroinvasiveness, induction of strong adaptive immunity, and protection of mice from wild-type (WT) WNV infection. Here, we determined the role of mitochondrial antiviral signaling protein (MAVS), the adaptor protein for RIG-I-like receptor in regulating host immunity against the NS4B-P38G vaccine. We found that Mavs-/- mice were more susceptible to NS4B-P38G priming than WT mice. Mavs-/- mice had a transiently reduced production of antiviral cytokines and an impaired CD4+ T cell response in peripheral organs. However, antibody and CD8+ T cell responses were minimally affected. NS4B-P38G induced lower type I interferon (IFN), IFN-stimulating gene, and proinflammatory cytokine responses in Mavs-/- dendritic cells and subsequently compromised the antigen-presenting capacity for CD4+ T cells. Interestingly, Mavs-/- mice surviving NS4B-P38G priming were all protected from a lethal WT WNV challenge. NS4B-P38G-primed Mavs-/- mice exhibited equivalent levels of protective CD4+ T cell recall response, a modestly reduced WNV-specific IgM production, but more robust CD8+ T cell recall response. Taken together, our results suggest that MAVS is essential for boosting optimal primary CD4+ T cell responses upon NS4B-P38G vaccination and yet is dispensable for host protection and recall T cell responses during secondary WT WNV infection.IMPORTANCE The production of innate cytokines induced by the recognition of pathogen recognition receptors (PRRs) via their cognate ligands are critical for enhancing antigen-presenting cell functions and influencing T cell responses during microbial infection. The use of PRR agonists and the underlying molecular mechanisms have been the major focus in individual vaccine development. Here, we determined the role of mitochondrial antiviral-signaling protein (MAVS), the adaptor protein for RIG-I like receptor in regulating host immunity against the live attenuated West Nile virus (WNV) vaccine strain, the nonstructural (NS) 4B-P38G mutant. We found that MAVS is important for boosting optimal primary CD4+ T cell response during NS4B-P38G vaccination. However, MAVS is dispensable for memory T cell development and host protection during secondary wild-type WNV infection. Overall, these results may be utilized as a paradigm to aid in the rational development of other efficacious live attenuated flavivirus vaccines.
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Abstract
West Nile virus (WNV) is a neurotropic mosquito-borne flavivirus responsible for recurrent outbreaks of meningitis and encephalitis. Several studies analyzing the interactions of this pathogen with the autophagic pathway have reported opposite results with evidence for and against the upregulation of autophagy in infected cells. In this regard, we have recently reported that minimal genetic changes (single amino acid substitutions) in nonstructural proteins of WNV can modify the ability of the virus to induce autophagic features such as LC3 modification and aggregation in infected cells. We think that these results could help explain some of the previously reported discrepancies. These findings could also aid in deciphering the interactions of this pathogen with the autophagic pathway at the molecular level aimed to develop feasible antiviral strategies to combat this pathogen, and other related flaviviruses.
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Affiliation(s)
- Miguel A Martín-Acebes
- a Department of Virology and Microbiology; Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM) ; Madrid , Spain
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16
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Szentpáli-Gavallér K, Lim SM, Dencső L, Bányai K, Koraka P, Osterhaus ADME, Martina BEE, Bakonyi T, Bálint Á. In Vitro and in Vivo Evaluation of Mutations in the NS Region of Lineage 2 West Nile Virus Associated with Neuroinvasiveness in a Mammalian Model. Viruses 2016; 8:v8020049. [PMID: 26907325 PMCID: PMC4776204 DOI: 10.3390/v8020049] [Citation(s) in RCA: 8] [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: 09/30/2015] [Revised: 01/19/2016] [Accepted: 02/09/2016] [Indexed: 12/25/2022] Open
Abstract
West Nile virus (WNV) strains may differ significantly in neuroinvasiveness in vertebrate hosts. In contrast to genetic lineage 1 WNVs, molecular determinants of pathogenic lineage 2 strains have not been experimentally confirmed so far. A full-length infectious clone of a neurovirulent WNV lineage 2 strain (578/10; Central Europe) was generated and amino acid substitutions that have been shown to attenuate lineage 1 WNVs were introduced into the nonstructural proteins (NS1 (P250L), NS2A (A30P), NS3 (P249H) NS4B (P38G, C102S, E249G)). The mouse neuroinvasive phenotype of each mutant virus was examined following intraperitoneal inoculation of C57BL/6 mice. Only the NS1-P250L mutation was associated with a significant attenuation of virulence in mice compared to the wild-type. Multiplication kinetics in cell culture revealed significantly lower infectious virus titres for the NS1 mutant compared to the wild-type, as well as significantly lower amounts of positive and negative stranded RNA.
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Affiliation(s)
| | - Stephanie M Lim
- Viroscience Laboratory, Erasmus Medical Centre, 3015CN, Rotterdam, The Netherlands.
| | - László Dencső
- Veterinary Diagnostic Directorate, National Food Chain Safety Office, H-1143, Budapest, Hungary.
| | - Krisztián Bányai
- Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, H-1143, Budapest, Hungary.
| | - Penelope Koraka
- Viroscience Laboratory, Erasmus Medical Centre, 3015CN, Rotterdam, The Netherlands.
| | | | - Byron E E Martina
- Viroscience Laboratory, Erasmus Medical Centre, 3015CN, Rotterdam, The Netherlands.
| | - Tamás Bakonyi
- Department of Microbiology and Infectious Diseases, Faculty of Veterinary Science, Szent István University, H-1143, Budapest, Hungary.
- Viral Zoonoses, Emerging and Vector-Borne Infections Group, Institute of Virology, University of Veterinary Medicine, A-1210, Vienna, Austria.
| | - Ádám Bálint
- Veterinary Diagnostic Directorate, National Food Chain Safety Office, H-1143, Budapest, Hungary.
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Pavitrakar DV, Ayachit VM, Mundhra S, Bondre VP. Development and characterization of reverse genetics system for the Indian West Nile virus lineage 1 strain 68856. J Virol Methods 2015; 226:31-9. [DOI: 10.1016/j.jviromet.2015.09.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 09/09/2015] [Accepted: 09/15/2015] [Indexed: 12/14/2022]
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18
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Dysregulation of Toll-Like Receptor 7 Compromises Innate and Adaptive T Cell Responses and Host Resistance to an Attenuated West Nile Virus Infection in Old Mice. J Virol 2015; 90:1333-44. [PMID: 26581984 DOI: 10.1128/jvi.02488-15] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 11/06/2015] [Indexed: 12/24/2022] Open
Abstract
UNLABELLED The elderly are known to have enhanced susceptibility to infections and an impaired capacity to respond to vaccination. West Nile virus (WNV), a mosquito-borne flavivirus, has induced severe neurological symptoms, mostly in the elderly population. No vaccines are available for human use. Recent work showed that an attenuated WNV, a nonstructural (NS) 4B-P38G mutant, induced no lethality but strong immune responses in young (6- to 10-week-old) mice. While studying protective efficacy, we found unexpectedly that old (21- to 22-month) mice were susceptible to WNV NS4B-P38G mutant infection but were protected from subsequent lethal wild-type WNV challenge. Compared to responses in young mice, the NS4B-P38G mutant triggered higher inflammatory cytokine and interleukin-10 (IL-10) production, a delayed γδ T cell expansion, and lower antibody and WNV-specific T cell responses in old mice. Toll-like receptor 7 (TLR7) is expressed on multiple types of cells. Impaired TLR7 signaling in old mice led to dendritic cell (DC) antigen-presenting function compromise and a reduced γδ T cell and regulatory T cell (Treg) expansion during NS4B-P38G mutant infection. R848, a TLR7 agonist, decreased host vulnerability in NS4B-P38G-infected old mice by enhancing γδ T cell and Treg expansion and the antigen-presenting capacity of DCs, thereby promoting T cell responses. In summary, our results suggest that dysregulation of TLR7 partially contributes to impaired innate and adaptive T cell responses and an enhanced vulnerability in old mice during WNV NS4B-P38G mutant infection. R848 increases the safety and efficacy during immunization of old mice with the WNV NS4B-P38G mutant. IMPORTANCE The elderly are known to have enhanced susceptibility to infections and an impaired capacity to respond to vaccination. West Nile virus (WNV), an emerging mosquito-borne flavivirus, has induced severe neurological symptoms more frequently in the elderly population. No vaccines are available for human use. Here, we used an aged mouse model to investigate the protective efficacy of an attenuated WNV, the nonstructural 4B-P38G mutant, which was previously shown to induce no lethality but strong immune responses in young adult mice. Studies that contribute to a mechanistic understanding of immune defects in the elderly will allow the development of strategies to improve responses to infectious diseases and to increase vaccine efficacy and safety in aging individuals.
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19
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Xie G, Luo H, Tian B, Mann B, Bao X, McBride J, Tesh R, Barrett AD, Wang T. A West Nile virus NS4B-P38G mutant strain induces cell intrinsic innate cytokine responses in human monocytic and macrophage cells. Vaccine 2015; 33:869-78. [PMID: 25562791 DOI: 10.1016/j.vaccine.2014.12.056] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 12/17/2014] [Indexed: 11/25/2022]
Abstract
Previous studies have shown that an attenuated West Nile virus (WNV) nonstructural (NS) 4B-P38G mutant induces stronger innate and adaptive immune responses than wild-type WNV in mice, which has important applications to vaccine development. To investigate the mechanism of immunogenicity, we characterized WNV NS4B-P38G mutant infection in two human cell lines-THP-1 cells and THP-1 macrophages. Although the NS4B-P38G mutant produced more viral RNA than the parental WNV NY99 in both cell types, there was no detectable infectious virus in the supernatant of either cell type. Nonetheless, the attenuated mutant boosted higher innate cytokine responses than virulent parental WNV NY99 in these cells. The NS4B-P38G mutant infection of THP-1 cells led to more diverse and robust innate cytokine responses than that seen in THP-1 macrophages, which were mediated by toll-like receptor (TLR)7 and retinoic acid-inducible gene 1(RIG-I) signaling pathways. Overall, these results suggest that a defective viral life cycle during NS4B-P38G mutant infection in human monocytic and macrophage cells leads to more potent cell intrinsic innate cytokine responses.
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Affiliation(s)
- Guorui Xie
- Department of Microbiology & Immunology, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Huanle Luo
- Department of Microbiology & Immunology, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Bing Tian
- Department of Internal Medicine, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Brian Mann
- Department of Pathology, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Xiaoyong Bao
- Department of Pediatrics, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Jere McBride
- Department of Microbiology & Immunology, The University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Pathology, The University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center for Vaccine Development, The University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Robert Tesh
- Department of Microbiology & Immunology, The University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Pathology, The University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center for Vaccine Development, The University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Alan D Barrett
- Department of Microbiology & Immunology, The University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Pathology, The University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center for Vaccine Development, The University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Tian Wang
- Department of Microbiology & Immunology, The University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Pathology, The University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center for Vaccine Development, The University of Texas Medical Branch, Galveston, TX 77555 USA.
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20
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Xie G, Whiteman MC, Wicker JA, Barrett ADT, Wang T. In vitro analysis of MyD88-mediated cellular immune response to West Nile virus mutant strain infection. J Vis Exp 2014:e52121. [PMID: 25489855 DOI: 10.3791/52121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
An attenuated West Nile virus (WNV), a nonstructural (NS) 4B-P38G mutant, induced higher innate cytokine and T cell responses than the wild-type WNV in mice. Recently, myeloid differentiation factor 88 (MyD88) signaling was shown to be important for initial T cell priming and memory T cell development during WNV NS4B-P38G mutant infection. In this study, two flow cytometry-based methods - an in vitro T cell priming assay and an intracellular cytokine staining (ICS) - were utilized to assess dendritic cells (DCs) and T cell functions. In the T cell priming assay, cell proliferation was analyzed by flow cytometry following co-culture of DCs from both groups of mice with carboxyfluorescein succinimidyl ester (CFSE) - labeled CD4(+) T cells of OTII transgenic mice. This approach provided an accurate determination of the percentage of proliferating CD4(+) T cells with significantly improved overall sensitivity than the traditional assays with radioactive reagents. A microcentrifuge tube system was used in both cell culture and cytokine staining procedures of the ICS protocol. Compared to the traditional tissue culture plate-based system, this modified procedure was easier to perform at biosafety level (BL) 3 facilities. Moreover, WNV- infected cells were treated with paraformaldehyde in both assays, which enabled further analysis outside BL3 facilities. Overall, these in vitro immunological assays can be used to efficiently assess cell-mediated immune responses during WNV infection.
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Affiliation(s)
- Guorui Xie
- Department of Microbiology & Immunology, The University of Texas Medical Branch
| | | | - Jason A Wicker
- Department of Pathology, The University of Texas Medical Branch
| | - Alan D T Barrett
- Department of Microbiology & Immunology, The University of Texas Medical Branch; Department of Pathology, The University of Texas Medical Branch; Center for Biodefense and Emerging Infectious Diseases, Sealy Center for Vaccine Development, The University of Texas Medical Branch
| | - Tian Wang
- Department of Microbiology & Immunology, The University of Texas Medical Branch; Department of Pathology, The University of Texas Medical Branch; Center for Biodefense and Emerging Infectious Diseases, Sealy Center for Vaccine Development, The University of Texas Medical Branch;
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Suen WW, Prow NA, Hall RA, Bielefeldt-Ohmann H. Mechanism of West Nile virus neuroinvasion: a critical appraisal. Viruses 2014; 6:2796-825. [PMID: 25046180 PMCID: PMC4113794 DOI: 10.3390/v6072796] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 07/09/2014] [Accepted: 07/10/2014] [Indexed: 12/11/2022] Open
Abstract
West Nile virus (WNV) is an important emerging neurotropic virus, responsible for increasingly severe encephalitis outbreaks in humans and horses worldwide. However, the mechanism by which the virus gains entry to the brain (neuroinvasion) remains poorly understood. Hypotheses of hematogenous and transneural entry have been proposed for WNV neuroinvasion, which revolve mainly around the concepts of blood-brain barrier (BBB) disruption and retrograde axonal transport, respectively. However, an over‑representation of in vitro studies without adequate in vivo validation continues to obscure our understanding of the mechanism(s). Furthermore, WNV infection in the current rodent models does not generate a similar viremia and character of CNS infection, as seen in the common target hosts, humans and horses. These differences ultimately question the applicability of rodent models for pathogenesis investigations. Finally, the role of several barriers against CNS insults, such as the blood-cerebrospinal fluid (CSF), the CSF-brain and the blood-spinal cord barriers, remain largely unexplored, highlighting the infancy of this field. In this review, a systematic and critical appraisal of the current evidence relevant to the possible mechanism(s) of WNV neuroinvasion is conducted.
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Affiliation(s)
- Willy W Suen
- School of Veterinary Science, University of Queensland, Gatton, QLD, 4343, Australia.
| | - Natalie A Prow
- Australian Infectious Diseases Research Centre, University of Queensland, St. Lucia, QLD, 4072, Australia.
| | - Roy A Hall
- Australian Infectious Diseases Research Centre, University of Queensland, St. Lucia, QLD, 4072, Australia.
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22
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Lim SP, Shi PY. West Nile virus drug discovery. Viruses 2013; 5:2977-3006. [PMID: 24300672 PMCID: PMC3967157 DOI: 10.3390/v5122977] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Revised: 11/25/2013] [Accepted: 11/25/2013] [Indexed: 02/08/2023] Open
Abstract
The outbreak of West Nile virus (WNV) in 1999 in the USA, and its continued spread throughout the Americas, parts of Europe, the Middle East and Africa, underscored the need for WNV antiviral development. Here, we review the current status of WNV drug discovery. A number of approaches have been used to search for inhibitors of WNV, including viral infection-based screening, enzyme-based screening, structure-based virtual screening, structure-based rationale design, and antibody-based therapy. These efforts have yielded inhibitors of viral or cellular factors that are critical for viral replication. For small molecule inhibitors, no promising preclinical candidate has been developed; most of the inhibitors could not even be advanced to the stage of hit-to-lead optimization due to their poor drug-like properties. However, several inhibitors developed for related members of the family Flaviviridae, such as dengue virus and hepatitis C virus, exhibited cross-inhibition of WNV, suggesting the possibility to re-purpose these antivirals for WNV treatment. Most promisingly, therapeutic antibodies have shown excellent efficacy in mouse model; one of such antibodies has been advanced into clinical trial. The knowledge accumulated during the past fifteen years has provided better rationale for the ongoing WNV and other flavivirus antiviral development.
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Affiliation(s)
- Siew Pheng Lim
- Novartis Institute for Tropical Diseases, 10 Biopolis Road, Chromos 05-01, Singapore 138670, Singapore.
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An inactivated cell culture Japanese encephalitis vaccine (JE-ADVAX) formulated with delta inulin adjuvant provides robust heterologous protection against West Nile encephalitis via cross-protective memory B cells and neutralizing antibody. J Virol 2013; 87:10324-33. [PMID: 23864620 DOI: 10.1128/jvi.00480-13] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
West Nile virus (WNV), currently the cause of a serious U.S. epidemic, is a mosquito-borne flavivirus and member of the Japanese encephalitis (JE) serocomplex. There is currently no approved human WNV vaccine, and treatment options remain limited, resulting in significant mortality and morbidity from human infection. Given the availability of approved human JE vaccines, this study asked whether the JE-ADVAX vaccine, which contains an inactivated cell culture JE virus antigen formulated with Advax delta inulin adjuvant, could provide heterologous protection against WNV infection in wild-type and β2-microglobulin-deficient (β2m(-/-)) murine models. Mice immunized twice or even once with JE-ADVAX were protected against lethal WNV challenge even when mice had low or absent serum cross-neutralizing WNV titers prior to challenge. Similarly, β2m(-/-) mice immunized with JE-ADVAX were protected against lethal WNV challenge in the absence of CD8(+) T cells and prechallenge WNV antibody titers. Protection against WNV could be adoptively transferred to naive mice by memory B cells from JE-ADVAX-immunized animals. Hence, in addition to increasing serum cross-neutralizing antibody titers, JE-ADVAX induced a memory B-cell population able to provide heterologous protection against WNV challenge. Heterologous protection was reduced when JE vaccine antigen was administered alone without Advax, confirming the importance of the adjuvant to induction of cross-protective immunity. In the absence of an approved human WNV vaccine, JE-ADVAX could provide an alternative approach for control of a major human WNV epidemic.
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A West Nile virus NS4B-P38G mutant strain induces adaptive immunity via TLR7-MyD88-dependent and independent signaling pathways. Vaccine 2013; 31:4143-51. [PMID: 23845800 DOI: 10.1016/j.vaccine.2013.06.093] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 06/20/2013] [Accepted: 06/25/2013] [Indexed: 12/13/2022]
Abstract
Prior work shows that an attenuated West Nile virus (WNV), the nonstructural (NS)4B-P38G mutant infection in mice induced strong immune responses and protected host from subsequent lethal wild-type WNV infection. Here, we investigated NS4B-P38G mutant infection in myeloid differentiation factor 88-deficient (MyD88(-/-)) and Toll-like receptor 7-deficient (TLR7(-/-)) mice and found they had enhanced susceptibility compared to wild-type mice. Both groups had lower WNV-specific IgM response and reduced effector T cell functions. Dendritic cells (DCs) also exhibited a reduced maturation and impaired antigen-presenting functions compared to wild-type DCs. Moreover, infection with NS4B-P38G mutant in TLR7(-/-) and MyD88(-/-) mice provided full and partial protection respectively from subsequent challenge with lethal wild-type WNV. There were reduced T cell responses in MyD88(-/-) and interleukin-1 receptor deficient (IL-1R(-/-)) mice during secondary challenge with wild-type WNV. In contrast, TLR7(-/-) mice displayed normal T cell functions. Collectively, these results suggest that TLR7-dependent MyD88 signaling is required for T cell priming during NS4B-P38G mutant infection, whereas the TLR7-independent MyD88 signaling pathways are involved in memory T cell development, which may contribute to host protection during secondary challenge with wild-type WNV.
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Van Slyke GA, Jia Y, Whiteman MC, Wicker JA, Barrett ADT, Kramer LD. Vertebrate attenuated West Nile virus mutants have differing effects on vector competence in Culex tarsalis mosquitoes. J Gen Virol 2013; 94:1069-1072. [PMID: 23303828 DOI: 10.1099/vir.0.049833-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Previous mutational analyses of naturally occurring West Nile virus (WNV) strains and engineered mutant WNV strains have identified locations in the viral genome that can have profound phenotypic effect on viral infectivity, temperature sensitivity and neuroinvasiveness. We chose six mutant WNV strains to evaluate for vector competence in the natural WNV vector Culex tarsalis, two of which contain multiple ablations of glycosylation sites in the envelope and NS1 proteins; three of which contain mutations in the NS4B protein and an attenuated natural bird isolate (Bird 1153) harbouring an NS4B mutation. Despite vertebrate attenuation, all NS4B mutant viruses displayed enhanced vector competence by Cx. tarsalis. Non-glycosylated mutant viruses displayed decreased vector competence in Cx. tarsalis mosquitoes, particularly when all three NS1 glycosylation sites were abolished. These results indicate the importance of both the NS4B protein and NS1 glycosylation in the transmission of WNV by a significant mosquito vector.
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Affiliation(s)
- Greta A Van Slyke
- The Arbovirus Laboratories, Wadsworth Center, New York State Dept. of Health, NY 12159, USA
| | - Yongqing Jia
- The Arbovirus Laboratories, Wadsworth Center, New York State Dept. of Health, NY 12159, USA
| | - Melissa C Whiteman
- Department of Pathology, Sealy Center for Vaccine Development, Center for Biodefense and Emerging Infectious Diseases, and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston TX 77555-0436, USA
| | - Jason A Wicker
- Department of Pathology, Sealy Center for Vaccine Development, Center for Biodefense and Emerging Infectious Diseases, and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston TX 77555-0436, USA
| | - Alan D T Barrett
- Department of Pathology, Sealy Center for Vaccine Development, Center for Biodefense and Emerging Infectious Diseases, and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston TX 77555-0436, USA
| | - Laura D Kramer
- School of Public Health, State University of New York, NY 12205, USA
- The Arbovirus Laboratories, Wadsworth Center, New York State Dept. of Health, NY 12159, USA
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Current World Literature. Curr Opin Allergy Clin Immunol 2012; 12:670-5. [DOI: 10.1097/aci.0b013e32835af232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Martín-Acebes MA, Saiz JC. West Nile virus: A re-emerging pathogen revisited. World J Virol 2012; 1:51-70. [PMID: 24175211 PMCID: PMC3782267 DOI: 10.5501/wjv.v1.i2.51] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Revised: 02/16/2012] [Accepted: 03/05/2012] [Indexed: 02/05/2023] Open
Abstract
West Nile virus (WNV), a flavivirus of the Flaviviridae family, is maintained in nature in an enzootic transmission cycle between avian hosts and ornithophilic mosquito vectors, although the virus occasionally infects other vertebrates. WNV causes sporadic disease outbreaks in horses and humans, which may result in febrile illness, meningitis, encephalitis and flaccid paralysis. Until recently, its medical and veterinary health concern was relatively low; however, the number, frequency and severity of outbreaks with neurological consequences in humans and horses have lately increased in Europe and the Mediterranean basin. Since its introduction in the Americas, the virus spread across the continent with worrisome consequences in bird mortality and a considerable number of outbreaks among humans and horses, which have resulted in the largest epidemics of neuroinvasive WNV disease ever documented. Surprisingly, its incidence in human and animal health is very different in Central and South America, and the reasons for it are not yet understood. Even though great advances have been obtained lately regarding WNV infection, and although efficient equine vaccines are available, no specific treatments or vaccines for human use are on the market. This review updates the most recent investigations in different aspects of WNV life cycle: molecular virology, transmission dynamics, host range, clinical presentations, epidemiology, ecology, diagnosis, control, and prevention, and highlights some aspects that certainly require further research.
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Affiliation(s)
- Miguel A Martín-Acebes
- Miguel A Martín-Acebes, Juan-Carlos Saiz, Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, 28040 Madrid, Spain
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