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Howard-Jones AR, Pham D, Sparks R, Maddocks S, Dwyer DE, Kok J, Basile K. Arthropod-Borne Flaviviruses in Pregnancy. Microorganisms 2023; 11:433. [PMID: 36838398 PMCID: PMC9959669 DOI: 10.3390/microorganisms11020433] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 02/04/2023] [Accepted: 02/06/2023] [Indexed: 02/11/2023] Open
Abstract
Flaviviruses are a diverse group of enveloped RNA viruses that cause significant clinical manifestations in the pregnancy and postpartum periods. This review highlights the epidemiology, pathophysiology, clinical features, diagnosis, and prevention of the key arthropod-borne flaviviruses of concern in pregnancy and the neonatal period-Zika, Dengue, Japanese encephalitis, West Nile, and Yellow fever viruses. Increased disease severity during pregnancy, risk of congenital malformations, and manifestations of postnatal infection vary widely amongst this virus family and may be quite marked. Laboratory confirmation of infection is complex, especially due to the reliance on serology for which flavivirus cross-reactivity challenges diagnostic specificity. As such, a thorough clinical history including relevant geographic exposures and prior vaccinations is paramount for accurate diagnosis. Novel vaccines are eagerly anticipated to ameliorate the impact of these flaviviruses, particularly neuroinvasive disease manifestations and congenital infection, with consideration of vaccine safety in pregnant women and children pivotal. Moving forward, the geographical spread of flaviviruses, as for other zoonoses, will be heavily influenced by climate change due to the potential expansion of vector and reservoir host habitats. Ongoing 'One Health' engagement across the human-animal-environment interface is critical to detect and responding to emergent flavivirus epidemics.
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Affiliation(s)
- Annaleise R. Howard-Jones
- Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research—NSW Health Pathology, Westmead, NSW 2145, Australia
- Sydney Infectious Diseases Institute, The University of Sydney, Westmead, NSW 2145, Australia
- Faculty of Medicine and Health, University of Sydney, Camperdown, NSW 2006, Australia
| | - David Pham
- Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research—NSW Health Pathology, Westmead, NSW 2145, Australia
| | - Rebecca Sparks
- Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research—NSW Health Pathology, Westmead, NSW 2145, Australia
| | - Susan Maddocks
- Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research—NSW Health Pathology, Westmead, NSW 2145, Australia
| | - Dominic E. Dwyer
- Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research—NSW Health Pathology, Westmead, NSW 2145, Australia
- Sydney Infectious Diseases Institute, The University of Sydney, Westmead, NSW 2145, Australia
- Faculty of Medicine and Health, University of Sydney, Camperdown, NSW 2006, Australia
- Centre for Infectious Diseases and Microbiology-Public Health, Westmead, NSW 2145, Australia
| | - Jen Kok
- Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research—NSW Health Pathology, Westmead, NSW 2145, Australia
- Sydney Infectious Diseases Institute, The University of Sydney, Westmead, NSW 2145, Australia
- Centre for Infectious Diseases and Microbiology-Public Health, Westmead, NSW 2145, Australia
| | - Kerri Basile
- Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research—NSW Health Pathology, Westmead, NSW 2145, Australia
- Sydney Infectious Diseases Institute, The University of Sydney, Westmead, NSW 2145, Australia
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2
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Qi Z, Zhao J, Li Y, Zhang B, Hu S, Chen Y, Ma J, Shu Y, Wang Y, Cheng P. Live-attenuated Japanese encephalitis virus inhibits glioblastoma growth and elicits potent antitumor immunity. Front Immunol 2023; 14:982180. [PMID: 37114043 PMCID: PMC10126305 DOI: 10.3389/fimmu.2023.982180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 03/27/2023] [Indexed: 04/29/2023] Open
Abstract
Glioblastomas (GBMs) are highly aggressive brain tumors that have developed resistance to currently available conventional therapies, including surgery, radiation, and systemic chemotherapy. In this study, we investigated the safety of a live attenuated Japanese encephalitis vaccine strain (JEV-LAV) virus as an oncolytic virus for intracerebral injection in mice. We infected different GBM cell lines with JEV-LAV to investigate whether it had growth inhibitory effects on GBM cell lines in vitro. We used two models for evaluating the effect of JEV-LAV on GBM growth in mice. We investigated the antitumor immune mechanism of JEV-LAV through flow cytometry and immunohistochemistry. We explored the possibility of combining JEV-LAV with PD-L1 blocking therapy. This work suggested that JEV-LAV had oncolytic activity against GBM tumor cells in vitro and inhibited their growth in vivo. Mechanistically, JEV-LAV increased CD8+ T cell infiltration into tumor tissues and remodeled the immunosuppressive GBM microenvironment that is non-conducive to immunotherapy. Consequently, the results of combining JEV-LAV with immune checkpoint inhibitors indicated that JEV-LAV therapy improved the response of aPD-L1 blockade therapy against GBM. The safety of intracerebrally injected JEV-LAV in animals further supported the clinical use of JEV-LAV for GBM treatment.
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Affiliation(s)
- Zhongbing Qi
- State Key Laboratory of Biotherapy and Cancer Center/Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Jing Zhao
- Department of Biotherapy, Cancer Center, West China Hospital of Sichuan University, Chengdu, China
| | - Yuhua Li
- Department of Arboviruses Vaccine, National Institute for Food and Drug Control, Beijing, China
| | - Bin Zhang
- State Key Laboratory of Biotherapy and Cancer Center/Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Shichuan Hu
- State Key Laboratory of Biotherapy and Cancer Center/Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yanwei Chen
- State Key Laboratory of Biotherapy and Cancer Center/Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Jinhu Ma
- State Key Laboratory of Biotherapy and Cancer Center/Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yongheng Shu
- State Key Laboratory of Biotherapy and Cancer Center/Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yunmeng Wang
- State Key Laboratory of Biotherapy and Cancer Center/Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Ping Cheng
- State Key Laboratory of Biotherapy and Cancer Center/Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, China
- *Correspondence: Ping Cheng,
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3
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Khou C, Díaz-Salinas MA, da Costa A, Préhaud C, Jeannin P, Afonso PV, Vignuzzi M, Lafon M, Pardigon N. Comparative analysis of neuroinvasion by Japanese encephalitis virulent and vaccine viral strains in an in vitro model of human blood-brain barrier. PLoS One 2021; 16:e0252595. [PMID: 34086776 PMCID: PMC8177624 DOI: 10.1371/journal.pone.0252595] [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: 06/22/2020] [Accepted: 03/16/2021] [Indexed: 11/18/2022] Open
Abstract
Japanese encephalitis virus (JEV) is the major cause of viral encephalitis in South East Asia. It has been suggested that, as a consequence of the inflammatory process during JEV infection, there is disruption of the blood-brain barrier (BBB) tight junctions that in turn allows the virus access to the central nervous system (CNS). However, what happens at early times of JEV contact with the BBB is poorly understood. In the present work, we evaluated the ability of both a virulent and a vaccine strain of JEV (JEV RP9 and SA14-14-2, respectively) to cross an in vitro human BBB model. Using this system, we demonstrated that both JEV RP9 and SA14-14-2 are able to cross the BBB without disrupting it at early times post viral addition. Furthermore, we find that almost 10 times more RP9 infectious particles than SA14-14 cross the model BBB, indicating this BBB model discriminates between the virulent RP9 and the vaccine SA14-14-2 strains of JEV. Beyond contributing to the understanding of early events in JEV neuroinvasion, we demonstrate this in vitro BBB model can be used as a system to study the viral determinants of JEV neuroinvasiveness and the molecular mechanisms by which this flavivirus crosses the BBB during early times of neuroinvasion.
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Affiliation(s)
- Cécile Khou
- Unité de Recherche et d’Expertise Environnement et Risques Infectieux, Groupe Arbovirus, Institut Pasteur, Paris, France
| | - Marco Aurelio Díaz-Salinas
- Unité de Recherche et d’Expertise Environnement et Risques Infectieux, Groupe Arbovirus, Institut Pasteur, Paris, France
| | - Anaelle da Costa
- Unité de Neuro-Immunologie Virale, Institut Pasteur, Paris, France
| | | | - Patricia Jeannin
- Unité d’Epidémiologie et Physiopathologie des Virus Oncogènes, Institut Pasteur, CNRS UMR 3569, Paris, France
| | - Philippe V. Afonso
- Unité d’Epidémiologie et Physiopathologie des Virus Oncogènes, Institut Pasteur, CNRS UMR 3569, Paris, France
| | - Marco Vignuzzi
- Unité des Populations Virales et Pathogenèse, Institut Pasteur, Paris, France
| | - Monique Lafon
- Unité de Neuro-Immunologie Virale, Institut Pasteur, Paris, France
| | - Nathalie Pardigon
- Unité de Recherche et d’Expertise Environnement et Risques Infectieux, Groupe Arbovirus, Institut Pasteur, Paris, France
- * E-mail:
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4
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Leng SL, Huang R, Feng YN, Peng LJ, Yang J, Li YH. The pre membrane and envelope protein is the crucial virulence determinant of Japanese encephalitis virus. Microb Pathog 2020; 148:104492. [PMID: 32916243 DOI: 10.1016/j.micpath.2020.104492] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 08/11/2020] [Accepted: 09/06/2020] [Indexed: 01/23/2023]
Abstract
After sequence comparison, it was found that there are multiple amino acid mutations in pre-M and envelope (E) protein of Japanese encephalitis virus vaccine strain comparison with wild type (WT) strain SA14. It is generally acknowledged it is the mutations that have caused the virulence attenuation of vaccine strain, but lack of sufficient experimental evidences. For a better understanding of the mechanism of attenuation of Japanese encephalitis virus (JEV), in this study, we assessed whether prM/E is critical neurovirulence determinants of JEV with infectious cDNA clones technique. Substitutions prM/E of vaccine strain with that of WT SA14 did significantly increase the virulence of JEV to the similar level of wild type SA14, and simultaneously, replacement prM/E of JEV WT strain SA14 with that of vaccine strain SA14-14-2 decreased the virulence of JEV significantly to the similar level of vaccine stain. The results indicate that the prM/E protein is the crucial virulence determinant of Japanese encephalitis virus, although other proteins take part in the process to some extent.
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Affiliation(s)
- Sheng-Ling Leng
- School of Basic medical science, North Sichuan Medical College, Nanchong, 637000, China
| | - Rong Huang
- School of Basic medical science, North Sichuan Medical College, Nanchong, 637000, China
| | - Ya-Nan Feng
- School of Basic medical science, North Sichuan Medical College, Nanchong, 637000, China
| | - Li-Juan Peng
- School of Basic medical science, North Sichuan Medical College, Nanchong, 637000, China
| | - Jian Yang
- School of Basic medical science, North Sichuan Medical College, Nanchong, 637000, China.
| | - Yu-Hua Li
- Department of Arbovirus Vaccine, National Institutes for Food and Drug Control, Beijing, 100050, China.
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5
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Li N, Zhang ZR, Zhang YN, Liu J, Deng CL, Shi PY, Yuan ZM, Ye HQ, Zhang B. A replication-defective Japanese encephalitis virus (JEV) vaccine candidate with NS1 deletion confers dual protection against JEV and West Nile virus in mice. NPJ Vaccines 2020; 5:73. [PMID: 32802412 PMCID: PMC7406499 DOI: 10.1038/s41541-020-00220-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 07/14/2020] [Indexed: 11/09/2022] Open
Abstract
In our previous study, we have demonstrated in the context of WNV-ΔNS1 vaccine (a replication-defective West Nile virus (WNV) lacking NS1) that the NS1 trans-complementation system may offer a promising platform for the development of safe and efficient flavivirus vaccines only requiring one dose. Here, we produced high titer (107 IU/ml) replication-defective Japanese encephalitis virus (JEV) with NS1 deletion (JEV-ΔNS1) in the BHK-21 cell line stably expressing NS1 (BHKNS1) using the same strategy. JEV-ΔNS1 appeared safe with a remarkable genetic stability and high degrees of attenuation of in vivo neuroinvasiveness and neurovirulence. Meanwhile, it was demonstrated to be highly immunogenic in mice after a single dose, providing similar degrees of protection to SA14-14-2 vaccine (a most widely used live attenuated JEV vaccine), with healthy condition, undetectable viremia and gradually rising body weight. Importantly, we also found JEV-ΔNS1 induced robust cross-protective immune responses against the challenge of heterologous West Nile virus (WNV), another important member in the same JEV serocomplex, accounting for up to 80% survival rate following a single dose of immunization relative to mock-vaccinated mice. These results not only support the identification of the NS1-deleted flavivirus vaccines with a satisfied balance between safety and efficacy, but also demonstrate the potential of the JEV-ΔNS1 as an alternative vaccine candidate against both JEV and WNV challenge.
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Affiliation(s)
- Na Li
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Zhe-Rui Zhang
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, 100049 Beijing, China
| | - 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.,University of Chinese Academy of Sciences, 100049 Beijing, 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.,University of Chinese Academy of Sciences, 100049 Beijing, 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
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555 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.,Drug Discovery Center for Infectious Disease, Nankai University, 300350 Tianjin, China
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6
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Immunopathology of Zika virus infection. Adv Virus Res 2020; 107:223-246. [PMID: 32711730 DOI: 10.1016/bs.aivir.2020.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Zika virus (ZIKV) is a mosquito-borne virus of the flavivirus genus in the Flaviviridae family. Flaviviruses are single-stranded, positive-sense RNA viruses that have been responsible for numerous human epidemics. Notable flaviviruses include mosquito-borne viruses such as yellow fever virus (YFV), Dengue virus (DENV), West Nile virus (WNV), Japanese encephalitis virus (JEV), as well as tick-borne viruses including Powassan virus (POWV) and tick-borne encephalitis virus (TBEV). Despite having been relatively obscure until the past decade, ZIKV has become a major global health concern, and is a topic of active research following multiple outbreaks across the globe. Here, we discuss ZIKV pathogenesis and the associated immunopathology, as well as advances in research, therapies, and vaccines developed using models of ZIKV pathogenesis.
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7
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Liu X, Zhao D, Jia L, Xu H, Na R, Ge Y, Liu S, Yu Y, Li Y. Genetic and neuroattenuation phenotypic characteristics and their stabilities of SA14-14-2 vaccine seed virus. Vaccine 2018; 36:4650-4656. [PMID: 29954631 DOI: 10.1016/j.vaccine.2018.06.040] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 06/11/2018] [Accepted: 06/16/2018] [Indexed: 02/05/2023]
Abstract
Japanese encephalitis (JE) live attenuated vaccine SA14-14-2 is the most widely used JE vaccine in the world. Large-scale clinical trials have demonstrated satisfactory safety and efficacy profiles. The establishment of genetic and attenuated neurovirulence characteristics and their stabilities of SA14-14-2 virus are important in relation to vaccine safety in humans. Therefore, several researchers have studied and analyzed the full-length gene sequences of the SA14-14-2 virus strain. However, sequencing results have shown a significant difference. Here, we further studied the full-length sequence of three class seed virus banks of the vaccine as well as two vaccine viruses with different passages in primary hamster kidney cells, and compared them with our original stored SA14 parent virus (low passage in mouse brain). The full-length gene sequence determined in this study indicates there were 57 nucleotide and 25 amino acid substitutions of the SA14-14-2 strain compared to its parental SA14 virus strain. The full-length sequences of the three class seed bank viruses and the vaccine virus PHKC8 were completely identical among them, but the working seed virus passaged in primary hamster kidney cells for 17 generations (PHKC17) had a single nucleotide change at the 5' NCR. Both KM and ICR mice tested by intracerebral (i.c.) or subcutaneous (s.c.) routes with the three class seed viruses and vaccine viruses with ≥5.7 lgpfu/mL remained healthy, but all the mice inoculated with the SA14 parental virus strain died as early as day 5 post-inoculation. The present study provided new information on the full-length gene sequence and attenuated neurovirulence of SA14-14-2. They can be used as a reference sequence for vaccine quality control and surveillance of neurovirulence reversion following vaccination. Moreover, the present results further demonstrated the high genetic and phenotypic stabilities of the SA14-14-2 virus, suggesting the neurovirulence reversion of the vaccine strain will be highly unlikely.
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MESH Headings
- Amino Acid Substitution
- Animals
- Cells, Cultured
- Cricetinae
- DNA Mutational Analysis
- Drug Stability
- Encephalitis Virus, Japanese/genetics
- Encephalitis Virus, Japanese/growth & development
- Encephalitis Virus, Japanese/pathogenicity
- Genetic Variation
- Genomic Instability
- Japanese Encephalitis Vaccines/adverse effects
- Japanese Encephalitis Vaccines/genetics
- Japanese Encephalitis Vaccines/immunology
- Japanese Encephalitis Vaccines/isolation & purification
- Mice, Inbred ICR
- Point Mutation
- Sequence Analysis, DNA
- Serial Passage
- Survival Analysis
- Vaccines, Attenuated/adverse effects
- Vaccines, Attenuated/genetics
- Vaccines, Attenuated/immunology
- Vaccines, Attenuated/isolation & purification
- Virulence
- Virus Cultivation
- Whole Genome Sequencing
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Affiliation(s)
- Xinyu Liu
- Department of Arboviral Vaccine, National Institutes for Food and Drug Control, Beijing 102629, China
| | - Danhua Zhao
- Department of Arboviral Vaccine, National Institutes for Food and Drug Control, Beijing 102629, China
| | - Lili Jia
- Department of Arboviral Vaccine, National Institutes for Food and Drug Control, Beijing 102629, China
| | - Hongshan Xu
- Department of Arboviral Vaccine, National Institutes for Food and Drug Control, Beijing 102629, China
| | - Rui Na
- Department of Arboviral Vaccine, National Institutes for Food and Drug Control, Beijing 102629, China
| | - Yonghong Ge
- Chengdu Institutes for Biological Products, Chengdu 610023, China
| | - Shaoxiang Liu
- Chengdu Institutes for Biological Products, Chengdu 610023, China
| | - Yongxin Yu
- Department of Arboviral Vaccine, National Institutes for Food and Drug Control, Beijing 102629, China.
| | - Yuhua Li
- Department of Arboviral Vaccine, National Institutes for Food and Drug Control, Beijing 102629, China; State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu 610041, China.
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8
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Amicizia D, Zangrillo F, Lai PL, Iovine M, Panatto D. Overview of Japanese encephalitis disease and its prevention. Focus on IC51 vaccine (IXIARO ®). JOURNAL OF PREVENTIVE MEDICINE AND HYGIENE 2018; 59:E99-E107. [PMID: 29938245 DOI: 10.15167/2421-4248/jpmh2018.59.1.962] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 02/24/2018] [Indexed: 01/30/2023]
Abstract
Japanese encephalitis (JE) is a vector-borne disease caused by the Japanese encephalitis virus (JEV). JEV is transmitted by mosquitoes to a wide range of vertebrate hosts, including birds and mammals. Domestic animals, especially pigs, are generally implicated as reservoirs of the virus, while humans are not part of the natural transmission cycle and cannot pass the virus to other hosts. Although JEV infection is very common in endemic areas (many countries in Asia), less than 1% of people affected develop clinical disease, and severe disease affects about 1 case per 250 JEV infections. Although rare, severe disease can be devastating; among the 30,000-50,000 global cases per year, approximately 20-30% of patients die and 30-50% of survivors develop significant neurological sequelae. JE is a significant public health problem for residents in endemic areas and may constitute a substantial risk for travelers to these areas. The epidemiology of JE and its risk to travelers have changed, and continue to evolve. The rapid economic growth of Asian countries has led to a surge in both inbound and outbound travel, making Asia the second most-visited region in the world after Europe, with 279 million international travelers in 2015. The top destination is China, followed by Thailand, Hong Kong, Malaysia and Japan, and the number of travelers is forecast to reach 535 million by 2030 (+ 4.9% per year). Because of the lack of treatment and the infeasibility of eliminating the vector, vaccination is recognized as the most efficacious means of preventing JE. The IC51 vaccine (IXIARO®) is a purified, inactivated, whole virus vaccine against JE. It is safe, well tolerated, efficacious and can be administered to children, adults and the elderly. The vaccination schedule involves administering 2 doses four weeks apart. For adults, a rapid schedule (0-7 days) is available, which could greatly enhance the feasibility of its use. Healthcare workers should inform both short- and long-term travelers of the risk of JE in each period of the year and recommend vaccination. Indeed, it has been shown that short-term travelers are also at risk, not only in rural environments, but also in cities and coastal towns, especially in tourist localities where excursions to country areas are organized.
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Affiliation(s)
- D Amicizia
- Department of Health Sciences, University of Genoa, Italy
| | - F Zangrillo
- Department of Health Sciences, University of Genoa, Italy
| | - P L Lai
- Department of Health Sciences, University of Genoa, Italy
| | - M Iovine
- Department of Health Sciences, University of Genoa, Italy
| | - D Panatto
- Department of Health Sciences, University of Genoa, Italy
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9
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Development of a chimeric Zika vaccine using a licensed live-attenuated flavivirus vaccine as backbone. Nat Commun 2018; 9:673. [PMID: 29445153 PMCID: PMC5813210 DOI: 10.1038/s41467-018-02975-w] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 01/10/2018] [Indexed: 01/07/2023] Open
Abstract
The global spread of Zika virus (ZIKV) and its unexpected association with congenital defects necessitates the rapid development of a safe and effective vaccine. Here we report the development and characterization of a recombinant chimeric ZIKV vaccine candidate (termed ChinZIKV) that expresses the prM-E proteins of ZIKV using the licensed Japanese encephalitis live-attenuated vaccine SA14-14-2 as the genetic backbone. ChinZIKV retains its replication activity and genetic stability in vitro, while exhibiting an attenuation phenotype in multiple animal models. Remarkably, immunization of mice and rhesus macaques with a single dose of ChinZIKV elicits robust and long-lasting immune responses, and confers complete protection against ZIKV challenge. Significantly, female mice immunized with ChinZIKV are protected against placental and fetal damage upon ZIKV challenge during pregnancy. Overall, our study provides an alternative vaccine platform in response to the ZIKV emergency, and the safety, immunogenicity, and protection profiles of ChinZIKV warrant further clinical development.
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10
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Yun SI, Song BH, Polejaeva IA, Davies CJ, White KL, Lee YM. Comparison of the live-attenuated Japanese encephalitis vaccine SA14-14-2 strain with its pre-attenuated virulent parent SA14 strain: similarities and differences in vitro and in vivo. J Gen Virol 2016; 97:2575-2591. [PMID: 27498826 DOI: 10.1099/jgv.0.000574] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Japanese encephalitis virus (JEV) is the main cause of acute viral encephalitis, primarily affecting children and young adults in the Asia-Pacific region. JEV is a vaccine-preventable pathogen, with four types of JE vaccine licensed in different regions of the world. To date, the most common JEV strain used in vaccine development and production is SA14-14-2, an attenuated strain derived from its wild-type parental strain SA14. In this study, we directly compared the phenotypic and genotypic characteristics of SA14 and SA14-14-2 to determine the biological and genetic properties associated with their differential virulence. In susceptible BHK-21 cells, SA14-14-2 grew slightly more slowly and formed smaller plaques than SA14, but unlike SA14, it showed almost no expression of the viral protein NS1', the product of a conserved predicted RNA pseudoknot-mediated ribosomal frameshift. In weanling ICR mice, SA14-14-2 was highly attenuated in terms of both neuroinvasiveness and neurovirulence, with its median lethal doses invariably over five logs higher than those of SA14 when inoculated intramuscularly and intracerebrally. Interestingly, the neurovirulence of SA14-14-2 was dependent on mouse age, with the 1- to 7-day-old mice being highly susceptible and the 14- to 21-day-old mice becoming resistant to intracerebral inoculation. At the genome level, SA14-14-2 differed from SA14 by 57 nucleotides, including one silent G-to-A substitution at position 3599 within the predicted RNA pseudoknot for NS1' synthesis; of the 57 differences, 25 resulted in amino acid substitutions. Our data pave the way for the development of new genetically modified JE vaccines.
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Affiliation(s)
- Sang-Im Yun
- Department of Animal, Dairy, and Veterinary Sciences, Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, 4815 Old Main Hill, Logan, UT 84322, USA
| | - Byung-Hak Song
- Department of Animal, Dairy, and Veterinary Sciences, Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, 4815 Old Main Hill, Logan, UT 84322, USA
| | - Irina A Polejaeva
- Department of Animal, Dairy, and Veterinary Sciences, Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, 4815 Old Main Hill, Logan, UT 84322, USA
| | - Christopher J Davies
- Department of Animal, Dairy, and Veterinary Sciences, Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, 4815 Old Main Hill, Logan, UT 84322, USA
| | - Kenneth L White
- Department of Animal, Dairy, and Veterinary Sciences, Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, 4815 Old Main Hill, Logan, UT 84322, USA
| | - Young-Min Lee
- Department of Animal, Dairy, and Veterinary Sciences, Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, 4815 Old Main Hill, Logan, UT 84322, USA
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11
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Abstract
Japanese encephalitis virus, as the most important vaccine-preventable cause of viral encephalitis in Asia, is estimated to cause over 68,000 clinical cases yearly. In endemic areas, most Japanese encephalitis infections occur in children younger than 10 y and clinical manifestation of this disease is critical, because there is no effective treatment available. As JEV infections are regarded as one of the most serious viral causes of encephalitis and mass immunization programmes are generally recommended for residents in endemic areas, a safe and effective JEV vaccine was needed to protect them as well as others at risk. Due to the safety concerns with the mouse brain derived vaccine, second generation vaccines against JE produced in cell culture like Vero cells were developed. IXIARO® is a purified, inactivated aluminum-adjuvanted JE vaccine, based on the SA14-14-2 virus strain, and is available in North America, Europe, Canada, Switzerland, Singapore, Hong Kong and Israel as well as in Australia & New Zealand (as JESPECT®).The safety, tolerability and immunogenicity profile of IXIARO® is well established through a number of clinical studies comparing IXIARO® with placebo as well as mouse brain derived vaccine. Recent data show that the global incidence of JE remains substantial, especially young children in endemic areas are most susceptible. As vaccination is the most feasible, reliable and cost effective tool for JE control, IXIARO® with confirmed excellent safety profile is highly recommendable, in particular for vaccination of children at risk. The European Commission as well as the FDA approved the extension of indication of IXIARO® to the pediatric segment (2 months of age and older) based on these data.
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Affiliation(s)
- Christa Firbas
- a Department of Clinical Pharmacology; Medical University of Vienna ; Vienna , Austria
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12
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Erra EO, Kantele A. The Vero cell-derived, inactivated, SA14-14-2 strain-based vaccine (Ixiaro) for prevention of Japanese encephalitis. Expert Rev Vaccines 2015; 14:1167-79. [PMID: 26162529 DOI: 10.1586/14760584.2015.1061939] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
With an estimated 68,000 cases each year, Japanese encephalitis (JE) is the leading cause of viral encephalitis in Asia. Vaccination against the disease is recommended for endemic populations and also for travelers at risk. Recently, a Vero cell-derived, inactivated, SA14-14-2 strain-based JE vaccine (JE-VC) became available for travelers from non-endemic regions, replacing the traditional mouse brain-derived vaccines. First licensed in 2009, JE-VC is currently available in Europe, the USA, Canada, Australia and several other countries. In 2013, the vaccine was approved by the European Medicines Agency and the US Food and Drug Administration for use in children. This review summarizes current data on the immunogenicity, safety and clinical use of JE-VC.
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Affiliation(s)
- Elina O Erra
- Haartman Institute, University of Helsinki, Helsinki, Finland
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13
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Genetic Determinants of Japanese Encephalitis Virus Vaccine Strain SA14-14-2 That Govern Attenuation of Virulence in Mice. J Virol 2015; 89:6328-37. [PMID: 25855730 DOI: 10.1128/jvi.00219-15] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 03/30/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The safety and efficacy of the live-attenuated Japanese encephalitis virus (JEV) SA14-14-2 vaccine are attributed to mutations that accumulated in the viral genome during its derivation. However, little is known about the contribution that is made by most of these mutations to virulence attenuation and vaccine immunogenicity. Here, we generated recombinant JEV (rJEV) strains containing JEV SA14-14-2 vaccine-specific mutations that are located in the untranslated regions (UTRs) and seven protein genes or are introduced from PCR-amplified regions of the JEV SA14-14-2 genome. The resulting mutant viruses were evaluated in tissue culture and in mice. The authentic JEV SA14-14-2 (E) protein, with amino acid substitutions L107F, E138K, I176V, T177A, E244G, Q264H, K279M, A315V, S366A, and K439R relative to the wild-type rJEV clone, was essential and sufficient for complete attenuation of neurovirulence. Individually, the nucleotide substitution T39A in the 5' UTR (5'-UTR-T39A), the capsid (C) protein amino acid substitution L66S (C-L66S), and the complete NS1/2A genome region containing 10 mutations each significantly reduced virus neuroinvasion but not neurovirulence. The levels of peripheral virulence attenuation imposed by the 5'-UTR-T39A and C-L66S mutations, individually, were somewhat mitigated in combination with other vaccine strain-specific mutations, which might be compensatory, and together did not affect immunogenicity. However, a marked reduction in immunogenicity was observed with the addition of the NS1/2A and NS5 vaccine virus genome regions. These results suggest that a second-generation recombinant vaccine can be rationally engineered to maximize levels of immunogenicity without compromising safety. IMPORTANCE The live-attenuated JEV SA14-14-2 vaccine has been vital for controlling the incidence of disease caused by JEV, particularly in rural areas of Asia where it is endemic. The vaccine was developed >25 years ago by passaging wild-type JEV strain SA14 in tissue cultures and rodents, with intermittent tissue culture plaque purifications, to produce a virus clone that had adequate levels of attenuation and immunogenicity. The vaccine and parent virus sequences were later compared, and mutations were identified throughout the vaccine virus genome, but their contributions to attenuation were never fully elucidated. Here, using reverse genetics, we comprehensively defined the impact of JEV SA14-14-2 mutations on attenuation of virulence and immunogenicity in mice. These results are relevant for quality control of new lots of the current live-attenuated vaccine and provide insight for the rational design of second-generation, live-attenuated, recombinant JEV vaccine candidates.
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Gromowski GD, Firestone CY, Bustos-Arriaga J, Whitehead SS. Genetic and phenotypic properties of vero cell-adapted Japanese encephalitis virus SA14-14-2 vaccine strain variants and a recombinant clone, which demonstrates attenuation and immunogenicity in mice. Am J Trop Med Hyg 2014; 92:98-107. [PMID: 25311701 DOI: 10.4269/ajtmh.14-0427] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The live-attenuated Japanese encephalitis virus (JEV) SA14-14-2 vaccine, produced in primary hamster kidney cells, is safe and effective. Past attempts to adapt this virus to replicate in cells that are more favorable for vaccine production resulted in mutations that significantly reduced immunogenicity. In this study, 10 genetically distinct Vero cell-adapted JEV SA14-14-2 variants were isolated and a recombinant wild-type JEV clone, modified to contain the JEV SA14-14-2 polyprotein amino acid sequence, was recovered in Vero cells. A single capsid protein mutation (S66L) was important for Vero cell-adaptation. Mutations were also identified that modulated virus sensitivity to type I interferon-stimulation in Vero cells. A subset of JEV SA14-14-2 variants and the recombinant clone were evaluated in vivo and exhibited levels of attenuation that varied significantly in suckling mice, but were avirulent and highly immunogenic in weanling mice and are promising candidates for the development of a second-generation, recombinant vaccine.
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Affiliation(s)
- Gregory D Gromowski
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Cai-Yen Firestone
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - José Bustos-Arriaga
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Stephen S Whitehead
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
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15
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Yun SI, Song BH, Kim JK, Yun GN, Lee EY, Li L, Kuhn RJ, Rossmann MG, Morrey JD, Lee YM. A molecularly cloned, live-attenuated japanese encephalitis vaccine SA14-14-2 virus: a conserved single amino acid in the ij Hairpin of the Viral E glycoprotein determines neurovirulence in mice. PLoS Pathog 2014; 10:e1004290. [PMID: 25077483 PMCID: PMC4117607 DOI: 10.1371/journal.ppat.1004290] [Citation(s) in RCA: 29] [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: 08/20/2013] [Accepted: 06/18/2014] [Indexed: 01/12/2023] Open
Abstract
Japanese encephalitis virus (JEV), a mosquito-borne flavivirus that causes fatal neurological disease in humans, is one of the most important emerging pathogens of public health significance. JEV represents the JE serogroup, which also includes West Nile, Murray Valley encephalitis, and St. Louis encephalitis viruses. Within this serogroup, JEV is a vaccine-preventable pathogen, but the molecular basis of its neurovirulence remains unknown. Here, we constructed an infectious cDNA of the most widely used live-attenuated JE vaccine, SA14-14-2, and rescued from the cDNA a molecularly cloned virus, SA14-14-2MCV, which displayed in vitro growth properties and in vivo attenuation phenotypes identical to those of its parent, SA14-14-2. To elucidate the molecular mechanism of neurovirulence, we selected three independent, highly neurovirulent variants (LD50, <1.5 PFU) from SA14-14-2MCV (LD50, >1.5×105 PFU) by serial intracerebral passage in mice. Complete genome sequence comparison revealed a total of eight point mutations, with a common single G1708→A substitution replacing a Gly with Glu at position 244 of the viral E glycoprotein. Using our infectious SA14-14-2 cDNA technology, we showed that this single Gly-to-Glu change at E-244 is sufficient to confer lethal neurovirulence in mice, including rapid development of viral spread and tissue inflammation in the central nervous system. Comprehensive site-directed mutagenesis of E-244, coupled with homology-based structure modeling, demonstrated a novel essential regulatory role in JEV neurovirulence for E-244, within the ij hairpin of the E dimerization domain. In both mouse and human neuronal cells, we further showed that the E-244 mutation altered JEV infectivity in vitro, in direct correlation with the level of neurovirulence in vivo, but had no significant impact on viral RNA replication. Our results provide a crucial step toward developing novel therapeutic and preventive strategies against JEV and possibly other encephalitic flaviviruses.
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MESH Headings
- Amino Acid Sequence
- Animals
- Blotting, Northern
- Blotting, Western
- Cloning, Molecular
- Encephalitis Virus, Japanese/genetics
- Encephalitis Virus, Japanese/immunology
- Encephalitis, Japanese/genetics
- Encephalitis, Japanese/immunology
- Encephalitis, Japanese/virology
- Female
- Flow Cytometry
- Humans
- Immunoenzyme Techniques
- Japanese Encephalitis Vaccines/genetics
- Japanese Encephalitis Vaccines/immunology
- Membrane Glycoproteins/chemistry
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/metabolism
- Mice
- Mice, Inbred ICR
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Mutation/genetics
- Nervous System/virology
- Protein Conformation
- Sequence Homology, Amino Acid
- Vaccines, Attenuated/genetics
- Vaccines, Attenuated/immunology
- Viral Envelope Proteins/chemistry
- Viral Envelope Proteins/genetics
- Viral Envelope Proteins/metabolism
- Virulence/genetics
- Virus Replication
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Affiliation(s)
- Sang-Im Yun
- Department of Animal, Dairy, and Veterinary Sciences; Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, Logan, Utah, United States of America
| | - Byung-Hak Song
- Department of Animal, Dairy, and Veterinary Sciences; Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, Logan, Utah, United States of America
| | - Jin-Kyoung Kim
- Department of Animal, Dairy, and Veterinary Sciences; Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, Logan, Utah, United States of America
| | - Gil-Nam Yun
- Department of Microbiology, College of Medicine, Chungbuk National University, Cheongju, Republic of Korea
| | - Eun-Young Lee
- Department of Anatomy, College of Medicine, Chungbuk National University, Cheongju, Republic of Korea
| | - Long Li
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - Richard J. Kuhn
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - Michael G. Rossmann
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - John D. Morrey
- Department of Animal, Dairy, and Veterinary Sciences; Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, Logan, Utah, United States of America
| | - Young-Min Lee
- Department of Animal, Dairy, and Veterinary Sciences; Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, Logan, Utah, United States of America
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16
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Yang D, Li XF, Ye Q, Wang HJ, Deng YQ, Zhu SY, Zhang Y, Li SH, Qin CF. Characterization of live-attenuated Japanese encephalitis vaccine virus SA14-14-2. Vaccine 2014; 32:2675-81. [DOI: 10.1016/j.vaccine.2014.03.074] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 03/14/2014] [Accepted: 03/25/2014] [Indexed: 12/17/2022]
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17
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Gromowski GD, Firestone CY, Hanson CT, Whitehead SS. Japanese encephalitis virus vaccine candidates generated by chimerization with dengue virus type 4. Vaccine 2014; 32:3010-8. [PMID: 24699473 DOI: 10.1016/j.vaccine.2014.03.062] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/10/2014] [Accepted: 03/17/2014] [Indexed: 10/25/2022]
Abstract
Japanese encephalitis virus (JEV) is a leading cause of viral encephalitis worldwide and vaccination is one of the most effective ways to prevent disease. A suitable live-attenuated JEV vaccine could be formulated with a live-attenuated tetravalent dengue vaccine for the control of these viruses in endemic areas. Toward this goal, we generated chimeric virus vaccine candidates by replacing the precursor membrane (prM) and envelope (E) protein structural genes of recombinant dengue virus type 4 (rDEN4) or attenuated vaccine candidate rDEN4Δ30 with those of wild-type JEV strain India/78. Mutations were engineered in E, NS3 and NS4B protein genes to improve replication in Vero cells. The chimeric viruses were attenuated in mice and some elicited modest but protective levels of immunity after a single dose. One particular chimeric virus, bearing E protein mutation Q264H, replicated to higher titer in tissue culture and was significantly more immunogenic in mice. The results are compared with live-attenuated JEV vaccine strain SA14-14-2.
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Affiliation(s)
- Gregory D Gromowski
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States.
| | - Cai-Yen Firestone
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Christopher T Hanson
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Stephen S Whitehead
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
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18
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Halstead SB, Thomas SJ. New Japanese encephalitis vaccines: alternatives to production in mouse brain. Expert Rev Vaccines 2014; 10:355-64. [DOI: 10.1586/erv.11.7] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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19
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Li X, Ma SJ, Liu X, Jiang LN, Zhou JH, Xiong YQ, Ding H, Chen Q. Immunogenicity and safety of currently available Japanese encephalitis vaccines: a systematic review. Hum Vaccin Immunother 2014; 10:3579-93. [PMID: 25668666 PMCID: PMC4514081 DOI: 10.4161/21645515.2014.980197] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 08/26/2014] [Accepted: 09/05/2014] [Indexed: 11/19/2022] Open
Abstract
A number of Japanese encephalitis (JE) vaccines have been used for preventing Japanese encephalitis around the world. We here reviewed the immunogenicity and safety of the currently available Japanese encephalitis vaccines. We searched Pubmed, Embase, Web of Science, the Cochrane Library and other online databases up to March 25, 2014 for studies focusing on currently used JE vaccines in any language. The primary outcomes were the seroconversion rate against JEV and adverse events. Meta-analysis was performed for the primary outcome when available. A total of 51 articles were included. Studies were grouped on the basic types of vaccines. This systematic review led to 2 aspects of the conclusions. On one hand, all the currently available JE vaccines are safe and effective. On the other hand, the overall of JE vaccine evaluation is disorganized, the large variation in study designs, vaccine types, schedules, doses, population and few hand-to-hand trails, make direct comparisons difficult. In order to make a more evidence-based decision on optimizing the JE vaccine, it is warranted to standardize the JE vaccine evaluation research.
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Key Words
- ACIP, The Advisory Committee on Immunization Practices
- AEs, Adverse events
- CENTRAL, Cochrane Central Register of Controlled Trials
- CIs, Confidence intervals
- DARE, Database of Abstracts of Reviews of Effects
- GMTs, Geometric mean titers
- HAART, Highly active antiretroviral therapy
- JE, Japanese encephalitis
- JE-CV, Chimeric live-attenuated JE vaccine
- JEV, Japanese encephalitis virus
- Japanese encephalitis vaccine
- LILACS, Latin American and Caribbean Health Sciences Literature
- MBJEV, Mouse brain–derived inactivated vaccines
- MMR, Measles mumps rubella vaccine
- NIP, National Immunization Program
- NOS, Newcastle–Ottawa scale
- ORs, Odd ratios
- PHK, Primary hamster kidney cells
- PRNT50, Plaque-reduction neutralization tests
- RCTs, Randomized controlled trials
- TBE, Tick-borne encephalitis vaccine
- TGPO, Thai Governmental Pharmaceutical Organization
- WHO, World Health Organization
- YF-VAX, Yellow fever vaccine
- YFV, Yellow fever virus
- YFV17D, Yellow fever virus 17D vaccine strain
- immunogenicity
- meta-analysis
- safety
- systematic review
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Affiliation(s)
- Xing Li
- Department of Epidemiology; School of Public Health and Tropical Medicine; Southern Medical University; Guangzhou, China
| | - Shu-Juan Ma
- Department of Epidemiology; School of Public Health and Tropical Medicine; Southern Medical University; Guangzhou, China
| | - Xie Liu
- Department of Epidemiology; School of Public Health and Tropical Medicine; Southern Medical University; Guangzhou, China
| | - Li-Na Jiang
- Department of Epidemiology; School of Public Health and Tropical Medicine; Southern Medical University; Guangzhou, China
| | - Jun-Hua Zhou
- Department of Epidemiology; School of Public Health and Tropical Medicine; Southern Medical University; Guangzhou, China
| | - Yi-Quan Xiong
- Department of Epidemiology; School of Public Health and Tropical Medicine; Southern Medical University; Guangzhou, China
| | - Hong Ding
- Department of Epidemiology; School of Public Health and Tropical Medicine; Southern Medical University; Guangzhou, China
| | - Qing Chen
- Department of Epidemiology; School of Public Health and Tropical Medicine; Southern Medical University; Guangzhou, China
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20
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Development of a small animal peripheral challenge model of Japanese encephalitis virus using interferon deficient AG129 mice and the SA14-14-2 vaccine virus strain. Vaccine 2013; 32:258-64. [PMID: 24252694 DOI: 10.1016/j.vaccine.2013.11.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 10/28/2013] [Accepted: 11/06/2013] [Indexed: 12/25/2022]
Abstract
Japanese encephalitis virus (JEV) is the most common cause of viral encephalitis in Asia, and it is increasingly a global public health concern due to its recent geographic expansion. While commercial vaccines are available and used in some endemic countries, JEV continues to be a public health problem, with 50,000 cases reported annually. Research with virulent JEV in mouse models to develop new methods of prevention and treatment is restricted to BSL-3 containment facilities, confining these studies to investigators with access to these facilities. We have developed an adult small animal peripheral challenge model using interferon-deficient AG129 mice and the JEV live-attenuated vaccine SA14-14-2, thus requiring only BSL-2 containment. A low dose of virus (10PFU/0.1ml) induced 100% morbidity in infected mice. Increased body temperatures measured by implantable temperature transponders correlated with an increase in infectious virus and viral RNA in serum, spleen and brain as well as an increase in pro-inflammatory markers measured by a 58-biomarker multi-analyte profile (MAP) constructed during the course of infection. In the future, the MAP measurements can be used as a baseline for comparison in order to better assess the inhibition of disease progression by other prophylactic and therapeutic agents. The use of the AG129/JEV SA14-14-2 animal model makes vaccine and therapeutic studies feasible for laboratories with limited biocontainment facilities.
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21
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Kant Upadhyay R. Japanese Encephalitis Virus Generated Neurovirulence, Antigenicity, and Host Immune Responses. ACTA ACUST UNITED AC 2013. [DOI: 10.5402/2013/830396] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In response to a JE virus attack, infected body cells start secretion of different cytokines and activate innate immune response. Virus starts neuronal invasion by entering into nerve cells and inflecting the central nervous system. It avoids exposure of body’s natural immunity and generates neurotrophic effects. Virus causes acute susceptibility to CNS and establishes encephalitis syndrome that results in very high fatality in children. In survivors, JEV inhibits the growth and proliferation of NCPs and imposes permanent neuronal disorders like cognitive, motor, and behavioral impairments. However, body cells start TCR mediated interactions, to recognize viral antigens with class I MHC complex on specific target cells, and operate mass killing of virus infected cells by increased CTL activity. Thus, both cell mediated and antibody interactions plays a central role in protection against JEV. In the present review article virus generated neurovirulence, antigenicity, and host immune responses are described in detail. More emphasis is given on diagnosis, clinical care, and active immunization with well-designed potential antiflavivirus vaccines. Further, for achieving an elite success against JEV, global eradication strategies are to be needed for making vaccination program more responsible and effective in endemic areas.
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Affiliation(s)
- Ravi Kant Upadhyay
- Department of Zoology, D D U Gorakhpur University, Gorakhpur 273009, India
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22
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23
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Song BH, Yun GN, Kim JK, Yun SI, Lee YM. Biological and genetic properties of SA₁₄-14-2, a live-attenuated Japanese encephalitis vaccine that is currently available for humans. J Microbiol 2012; 50:698-706. [PMID: 22923123 DOI: 10.1007/s12275-012-2336-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 07/13/2012] [Indexed: 11/29/2022]
Abstract
Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, is a major cause of acute encephalitis, a disease of significance for global public health. In the absence of antiviral therapy to treat JEV infection, vaccination is the most effective method of preventing the disease. In JE-endemic areas, the most widely used vaccine to date is SA(14)-14-2, a live-attenuated virus derived from its virulent parent SA(14). In this study, we describe the biological properties of SA(14)-14-2, both in vitro and in vivo, and report the genetic characteristics of its genomic RNA. In BHK-21 (hamster kidney) cells, SA(14)-14-2 displayed a slight delay in plaque formation and growth kinetics when compared to a virulent JEV strain, CNU/LP2, with no decrease in maximum virus production. The delay in viral growth was also observed in two other cell lines, SH-SY5Y (human neuroblastoma) and C6/36 (mosquito larva), which are potentially relevant to JEV pathogenesis and transmission. In 3-week-old ICR mice, SA(14)-14-2 did not cause any symptoms or death after either intracerebral or peripheral inoculation with a maximum dose of up to 1.5×10(3) plaque-forming units (PFU) per mouse. The SA(14)-14-2 genome consisted of 10977 nucleotides, one nucleotide longer than all the previously reported genomes of SA(14)-14-2, SA(14) and two other SA(14)-derived attenuated viruses. This difference was due to an insertion of one G nucleotide at position 10701 in the 3 noncoding region. Also, we noted a significant number of nucleotide and/or amino acid substitutions throughout the genome of SA(14)-14-2, except for the prM protein-coding region, that differed from SA(14) and/or the other two attenuated viruses. Our results, together with others', provide a foundation not only for the study of JEV virulence but also for the development of new and improved vaccines for JEV.
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Affiliation(s)
- Byung-Hak Song
- Department of Microbiology, College of Medicine, Chungbuk National University, Cheongju 361-763, Republic of Korea
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24
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Pathogenic and vaccine strains of Japanese encephalitis virus elicit different levels of human macrophage effector functions. Arch Virol 2012; 157:1905-18. [PMID: 22729616 DOI: 10.1007/s00705-012-1386-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2011] [Accepted: 05/14/2012] [Indexed: 02/07/2023]
Abstract
In India, Japanese encephalitis virus (JEV) remains one of the major causative agents of pediatric encephalitis. Macrophages support various neurotropic viruses and influence the immune response. However, the functional status of human macrophages during JEV infection remains unidentified. In this study, we examined the cytokine response and co-stimulatory marker levels in primary human monocyte derived macrophages (MDMs) infected with JE057434 (neurovirulent, primary clinical isolate) or SA14-14-2 (non-neurovirulent, live-attenuated vaccine) JEV strains. We also examined the differential susceptibility of these JEV strains to antiviral effects of interferon and nitric oxide. The results indicate that both JEV strains are capable of inducing various cytokines (type-I IFN, TNFα, IL6 and IL8) and co-stimulatory molecules (CD86 and CD80) in MDMs. However, they varied in replication potential and corresponding interferon sensitivity. SA14-14-2 was highly susceptible to interferon and nitric oxide when compared to JE057434. Thus, reduction in infectious virion production and increased sensitivity of SA14-14-2 towards interferon in MDMs could potentially play a role in limiting viral spread to additional target tissues.
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25
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Sun J, Yu Y, Deubel V. Japanese encephalitis virus NS1' protein depends on pseudoknot secondary structure and is cleaved by caspase during virus infection and cell apoptosis. Microbes Infect 2012; 14:930-40. [PMID: 22504173 DOI: 10.1016/j.micinf.2012.03.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Revised: 03/15/2012] [Accepted: 03/19/2012] [Indexed: 02/06/2023]
Abstract
Japanese encephalitis virus (JEV) is a flavivirus with a complex life cycle involving mosquito vectors that mainly target birds and pigs, and causes severe encephalitis in children in Asia. Neurotropic flaviviruses of the JEV serogroup have a particular characteristic of expressing a unique nonstructural NS1' protein, which is a prolongation of NS1 at the C terminus by 52 amino acids derived from a pseudoknot-driven-1 translation frameshift. Protein NS1' is associated with virus neuro-invasiveness. In this study, the need of the pseudoknot structure for NS1' synthesis was confirmed. By using a specific antibody against the prolonged peptide, NS1' was found to be absent from the JEV SA14-14-2 vaccine strain, resulting from a single nucleotide silent mutation in the pseudoknot. A partial cleavage of NS1' at a specific site of its C-terminal appendix recognized by caspases and inhibited by caspase inhibitors suggests a unique feature of intracellular NS1'.
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Affiliation(s)
- Jin Sun
- Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200025, China
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26
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Trobaugh DW, Yang L, Ennis FA, Green S. Altered effector functions of virus-specific and virus cross-reactive CD8+ T cells in mice immunized with related flaviviruses. Eur J Immunol 2010; 40:1315-27. [PMID: 20213733 DOI: 10.1002/eji.200839108] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Memory cross-reactive CD8+ T-cell responses may induce protection or immunopathology upon secondary viral challenge. To elucidate the potential role of T cells in sequential flavivirus infection, we characterized cross-reactive CD4+ and CD8+ T-cell responses between attenuated and pathogenic Japanese encephalitis virus (JEV) and pathogenic West Nile virus (WNV). A previously reported WNV NS4b CD8+ T-cell epitope and its JEV variant elicited CD8+ T-cell responses in both JEV- and WNV-infected mice. The peptide variant homologous to the immunizing virus induced greater cytokine secretion and activated higher frequencies of epitope-specific CD8+ T cells. However, there was a virus-dependent, peptide variant-independent pattern of cytokine secretion; the IFNgamma+-to-IFNgamma+TNFalpha+ CD8+ T-cell ratio was greater in JEV- than in WNV-infected mice. Despite similarities in viral burden for pathogenic WNV and JEV viruses, CD8+ T cells from pathogenic JEV-immunized mice exhibited functional and phenotypic profiles similar to those seen for the attenuated JEV strain. Patterns of killer cell lectin-like receptor G1 (KLRG1) and CD127 expression differed by virus type, with a rapid expansion and contraction of short-lived effector cells in JEV infection and persistence of high levels of short-lived effector cells in WNV infection. Such cross-reactive T-cell responses to primary infection may affect the outcomes of sequential flavivirus infections.
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Affiliation(s)
- Derek W Trobaugh
- Center for Infectious Disease and Vaccine Research, University of Massachusetts Medical School, Worcester, MA 01655, USA
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Phenotypic and genotypic characteristics of Japanese encephalitis attenuated live vaccine virus SA14-14-2 and their stabilities. Vaccine 2010; 28:3635-41. [PMID: 20226891 DOI: 10.1016/j.vaccine.2010.02.105] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Revised: 02/05/2010] [Accepted: 02/24/2010] [Indexed: 10/19/2022]
Abstract
A novel Japanese encephalitis (JE) attenuated live vaccine virus SA14-14-2 was licensed for commercial application in China in 1989. Since then this vaccine has been widely used in China and other countries in Asia, and no vaccine associated encephalitis case was reported. The neurovirulence of the SA14-14-2 was tested in JE susceptible laboratory animals, such as mice, monkeys, hamsters and athymic nude mice. The results showed that the attenuated virus strain was avirulent to these animals by intracerebral inoculation (i.c.) or intraperitoneal inoculation (i.p.). Studies on the neuroattenuation stability revealed that no reversion after 17 times tissue culture passages or one i.c. sucking mice passage. Mosquito infection studies indicated that after one mosquito intrathoracical passage, the progeny viruses in the infected mosquitoes were unable to cause sucking mice or weanling mice disease. Molecules characteristics' studies of the SA14-14-2 virus strain showed that there are 57-61 nucleotide changes and 24-31 amino acid substitutions, eight substitutions in the E protein gene are the critical amino acid related to the virus attenuation. The E gene sequence studies have showed that the 8 critical amino acids were not changed after 22 passages in tissue cultures or one passage in mosquitoes. Comparison of the full-length sequence to the parental SA14 virus has revealed that after 22 passages in the tissue cultures, only 8 nucleotides changed leading to 4 amino acid substitutions. However they were not the reverse mutation and none of the 8 critical residues changed. The homology of the nucleotide and amino acid between the virus of passage 22 and the primary seed virus in Genbank was 99.93% and 99.88% respectively. The above results demonstrated that the SA14-14-2 virus is highly attenuated for the various JE susceptible animals. The attenuated phenotypes and the genetic characteristics of the SA14-14-2 strain are highly stable after multiple in vitro passages or mosquitoes infection. Therefore the safety of the live JE vaccine is due to a high degree of neuroattenuation and a number of stable phenotypically and genetically characteristics, suggesting that reversion to neurovirulence of the vaccine strain would be highly unlikely.
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Guy B, Guirakhoo F, Barban V, Higgs S, Monath TP, Lang J. Preclinical and clinical development of YFV 17D-based chimeric vaccines against dengue, West Nile and Japanese encephalitis viruses. Vaccine 2009; 28:632-49. [PMID: 19808029 DOI: 10.1016/j.vaccine.2009.09.098] [Citation(s) in RCA: 209] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2009] [Revised: 08/28/2009] [Accepted: 09/23/2009] [Indexed: 11/18/2022]
Abstract
Dengue viruses (DENV), West Nile virus (WNV) and Japanese encephalitis virus (JEV) are major global health and growing medical problems. While a live-attenuated vaccine exists since decades against the prototype flavivirus, yellow fever virus (YFV), there is an urgent need for vaccines against dengue or West Nile diseases, and for improved vaccines against Japanese encephalitis. Live-attenuated chimeric viruses were constructed by replacing the genes coding for Premembrane (prM) and Envelope (E) proteins from YFV 17D vaccine strain with those of heterologous flaviviruses (ChimeriVax technology). This technology has been used to produce vaccine candidates for humans, for construction of a horse vaccine for West Nile fever, and as diagnostic reagents for dengue, Japanese encephalitis, West Nile and St. Louis encephalitis infections. This review focuses on human vaccines and their characterization from the early stages of research through to clinical development. Phenotypic and genetic properties and stability were examined, preclinical evaluation through in vitro or animal models, and clinical testing were carried out. Theoretical environmental concerns linked to the live and genetically modified nature of these vaccines have been carefully addressed. Results of the extensive characterizations are in accordance with the immunogenicity and excellent safety profile of the ChimeriVax-based vaccine candidates, and support their development towards large-scale efficacy trials and registration.
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Affiliation(s)
- Bruno Guy
- Sanofi Pasteur, Research and Development, 1541 Av Marcel Merieux, 69280 Marcy l'Etoile, France.
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Kollaritsch H, Paulke-Korinek M, Dubischar-Kastner K. IC51 Japanese encephalitis vaccine. Expert Opin Biol Ther 2009; 9:921-31. [PMID: 19527110 DOI: 10.1517/14712590903042282] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Japanese encephalitis is the leading cause of viral encephalitis in Asia. Every year 30,000 - 50,000 cases and 10,000 deaths from Japanese encephalitis are reported, and underreporting has been suggested. No effective antiviral therapy exists to treat this mosquito-borne flavivirus infection. For active immunization vaccines are available. The manufacturing of the only vaccine that was internationally licensed, JE-VAX, was ceased in 2005. Therefore a shortage of Japanese encephalitis vaccines might occur before new generation vaccines based on cell culture technology will be available. A promising new vaccine candidate is the inactivated whole-virus vaccine IXIARO (Strain SA(14)-14-2), developed by Intercell AG. Which was licensed in Europe, the USA and Australia in spring 2009. Recently, successful Phase III immunogenicity and tolerability studies were published, indicating that this vaccine will be an acceptable approach to active immunization against Japanese encephalitis. Cell-culture-based vaccines will not only be used in the population living in endemic areas where the risk of infection is high, but also by travelers and military personnel.
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Affiliation(s)
- Herwig Kollaritsch
- Medical University Vienna, Centre for Physiology and Pathophysiology, Institute of Specific Prophylaxis and Tropical Medicine, Kinderspitalgasse 15, A-1090 Vienna, Austria.
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Widman DG, Frolov I, Mason PW. Third-generation flavivirus vaccines based on single-cycle, encapsidation-defective viruses. Adv Virus Res 2009; 72:77-126. [PMID: 19081489 DOI: 10.1016/s0065-3527(08)00402-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Flaviviruses are arthropod-borne pathogens that cause significant disease on all continents of the world except Antarctica. Flavivirus diseases are particularly important in tropical regions where arthropod vectors are abundant. Live-attenuated virus vaccines (LAVs) and inactivated virus vaccines (INVs) exist for some of these diseases. LAVs are economical to produce and potent, but are not suitable for use in the immunocompromised. INVs are safer, but are more expensive to produce and less potent. Despite the success of both classes of these first-generation flavivirus vaccines, problems associated with their use indicate a need for improved products. Furthermore, there are no suitable vaccines available for important emerging flavivirus diseases, notably dengue and West Nile encephalitis (WNE). To address these needs, new products, including LAVs, INVs, viral-vectored, genetically engineered LAVs, naked DNA, and subunit vaccines are in various stages of development. Here we describe the current state of these first- and second-generation vaccine candidates, and compare these products to our recently described single-cycle, encapsidation defective flavivirus vaccine: RepliVAX. RepliVAX can be propagated in C-expressing cells (or as a unique two-component virus) using methods similar to those used to produce today's economical and potent LAVs. However, due to deletion of most of the gene for the C protein, RepliVAX cannot spread between normal cells, and is unable to cause disease in vaccinated animals. Nevertheless, RepliVAX is potent and efficacious in animal models for WNE and Japanese encephalitis, demonstrating its utility as a third-generation flavivirus vaccine that should be potent, economical to produce, and safe in the immunocompromised.
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Affiliation(s)
- Douglas G Widman
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas 77555, USA
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Schuller E, Klade CS, Heinz FX, Kollaritsch H, Rendi-Wagner P, Jilma B, Tauber E. Effect of pre-existing anti-tick-borne encephalitis virus immunity on neutralising antibody response to the Vero cell-derived, inactivated Japanese encephalitis virus vaccine candidate IC51. Vaccine 2008; 26:6151-6. [PMID: 18804132 DOI: 10.1016/j.vaccine.2008.08.056] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2008] [Revised: 08/01/2008] [Accepted: 08/31/2008] [Indexed: 12/30/2022]
Abstract
Japanese encephalitis virus (JEV) is the leading cause of viral encephalitis in Asia with a case fatality rate up to 35% and long-term sequelae up to 75%. This active-controlled, randomized, multi-centre, observer-blind, phase III trial investigated the neutralising antibody response to the new Japanese encephalitis (JE) vaccine IC51 in subjects with (N=81) and without (N=339) pre-existing tick-borne encephalitis (TBE) vaccine induced antibodies as determined by TBE enzyme-linked immunosorbent assay IgG (ELISA). Neutralising antibody response was statistically superior in TBE ELISA-positive subjects compared to TBE ELISA-negative subjects after the first (p<0.0001) but not after the second vaccination with IC51. Thus, pre-existing vaccine-induced TBE immunity enhances the neutralising JEV-specific antibody response after a single IC51 vaccination.
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Tauber E, Kollaritsch H, von Sonnenburg F, Lademann M, Jilma B, Firbas C, Jelinek T, Beckett C, Knobloch J, McBride W, Schuller E, Kaltenböck A, Sun W, Lyons A. Randomized, Double‐Blind, Placebo‐Controlled Phase 3 Trial of the Safety and Tolerability of IC51, an Inactivated Japanese Encephalitis Vaccine. J Infect Dis 2008; 198:493-9. [DOI: 10.1086/590116] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Schuller E, Jilma B, Voicu V, Golor G, Kollaritsch H, Kaltenböck A, Klade C, Tauber E. Long-term immunogenicity of the new Vero cell-derived, inactivated Japanese encephalitis virus vaccine IC51. Vaccine 2008; 26:4382-6. [DOI: 10.1016/j.vaccine.2008.05.081] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2007] [Revised: 05/05/2008] [Accepted: 05/28/2008] [Indexed: 10/21/2022]
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Beasley DWC, Lewthwaite P, Solomon T. Current use and development of vaccines for Japanese encephalitis. Expert Opin Biol Ther 2008; 8:95-106. [PMID: 18081539 DOI: 10.1517/14712598.8.1.95] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Japanese encephalitis (JE) is a significant cause of human morbidity and mortality throughout Asia. Vaccines for JE have been available for many years and their use has been effective in reducing the incidence of JE disease in several countries but, as disease incidence has decreased, concerns regarding adverse events following immunisation have increased. OBJECTIVE To review existing JE vaccines and new candidates in advanced preclinical or clinical evaluation. METHODS The review primarily covers published and some unpublished literature from the past decade describing current use of approved JE vaccines in various parts of the world, and advanced development and clinical testing of alternative vaccine candidates. RESULTS/CONCLUSION There is a clear need for additional licensing of existing or new JE vaccines. Several promising candidates are currently in use or completing clinical trials.
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Affiliation(s)
- David W C Beasley
- University of Texas Medical Branch, Department of Microbiology and Immunology, Galveston, TX 77555-0609, USA
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Chambers TJ, Droll DA, Jiang X, Wold WSM, Nickells JA. JE Nakayama/JE SA14-14-2 virus structural region intertypic viruses: biological properties in the mouse model of neuroinvasive disease. Virology 2007; 366:51-61. [PMID: 17521693 PMCID: PMC2266982 DOI: 10.1016/j.virol.2007.04.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Revised: 02/04/2007] [Accepted: 04/07/2007] [Indexed: 11/19/2022]
Abstract
A molecular clone of Japanese encephalitis (JE) virus Nakayama strain was used to create intertypic viruses containing either the 5'-C-prM-E or the prM-E region of the attenuated JE SA14-14-2 virus in the JE Nakayama background. These two intertypic JE viruses, JE-X/5'CprME(S) and JE-X/prME(S), respectively, generally resembled the parental JE virus in cell culture properties. Similar to virus derived from the JE Nakayama molecular clone (JE-XJN), JE-X/prME(S) was highly neuroinvasive and neurovirulent for young adult mice, whereas JE-X/5'CprME(S) was attenuated for neuroinvasiveness and only partially attenuated for neurovirulence. Immunization of young mice with JE-X/5'CprME(S) virus elicited neutralizing antibodies against JE Nakayama virus and conferred protection against encephalitis following challenge with JE Nakayama virus. The sequence of the JE-X/5'CprME(S) virus differed from that of JE-X/prME(S) virus at two nucleotides in the 5' UTR, 3 amino acid positions in the capsid protein, 4 positions in the prM protein and 1 in the envelope protein. For JE-X/prME(S) virus, the 4 differences in prM and the single substitution in the envelope represented reversions to the sequence of JE Nakayama virus. Overall, this study reveals that molecular determinants associated with the prM-E region of the attenuated JE SA14-14-2 virus are insufficient by themselves to confer an attenuation phenotype upon JE Nakayama virus. This suggests a role for determinants in the 5' UTR and/or the capsid protein of the JE SA 14-14-2 virus genome in influencing the virulence properties of the JE Nakayama virus in the mouse model.
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Affiliation(s)
- Thomas J Chambers
- Department of Molecular Microbiology and Immunology, St. Louis University School of Medicine, 1402 South Grand Ave. St. Louis, MO 63104, USA.
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Lyons A, Kanesa-thasan N, Kuschner RA, Eckels KH, Putnak R, Sun W, Burge R, Towle AC, Wilson P, Tauber E, Vaughn DW. A Phase 2 study of a purified, inactivated virus vaccine to prevent Japanese encephalitis. Vaccine 2007; 25:3445-53. [PMID: 17241714 DOI: 10.1016/j.vaccine.2006.12.046] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2006] [Revised: 12/01/2006] [Accepted: 12/20/2006] [Indexed: 11/15/2022]
Abstract
Japanese encephalitis (JE) is a serious disease caused by the JE virus. New generation JE vaccines are needed to prevent this disease. We conducted this Phase 2 randomized, open label, unblinded, single center study of a new, cell-culture derived, purified inactivated virus (JE-PIV) vaccine. The JE-PIV vaccine was administered in either two or three intramuscular (IM) doses (6.0 or 12.0 mcg each) with observation over 8 weeks. All volunteers completed the protocol without serious adverse reactions. Headache and transient tenderness at the injection site were the most common complaints. There were no laboratory abnormalities believed to be related to vaccine during the study. JE-PIV was well tolerated, resulted in high seroconversion rates [Day 56 (primary endpoint); 95-100%] and induced enduring immune responses up to 2 years after vaccination. Expanded Phase 3 trials are planned.
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Affiliation(s)
- Arthur Lyons
- Department of Virus Diseases, Division of Communicable Diseases and Immunology, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA.
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Chambers TJ, Jiang X, Droll DA, Liang Y, Wold WSM, Nickells J. Chimeric Japanese encephalitis virus/dengue 2 virus infectious clone: biological properties, immunogenicity and protection against dengue encephalitis in mice. J Gen Virol 2006; 87:3131-3140. [PMID: 17030845 DOI: 10.1099/vir.0.81909-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A molecular clone of Japanese encephalitis virus (JE virus) was derived from the JE virus Nakayama strain and used to produce infectious JE virus in cell culture. The engineered JE virus resembled the parental JE virus in cell-culture properties and was related closely to other JE virus strains based on nucleotide sequence analysis. The JE virus clone was used as a genetic background for construction of a chimeric virus containing the structural proteins prM and E of Dengue virus, serotype 2. The chimeric JE/dengue 2 virus generated authentic dengue 2 structural proteins as assessed by immunoassays for the dengue E protein. It exhibited a small plaque size and less efficient growth in various cell lines than the parental JE virus. JE/dengue 2 virus was non-neuroinvasive for young adult mice, but displayed partial neurovirulence at doses up to 4 log p.f.u. given intracerebrally. Immunization of 3-week-old mice with JE/dengue 2 virus yielded neutralizing-antibody titres against dengue 2 virus and conferred protection against dengue encephalitis caused by neuroadapted dengue 2 virus. A rise in post-challenge neutralizing-antibody titres against dengue 2 virus in surviving mice suggests that immunization is associated with establishment of a memory antibody response in this model. This study demonstrates the capacity of JE virus to serve as a vector for expression of heterologous flavivirus structural proteins. Similar to previous studies with other chimeric flaviviruses, this approach may be useful as a genetic system for engineering experimental vaccines against Dengue virus and other medically important flaviviruses.
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Affiliation(s)
- Thomas J Chambers
- Department of Molecular Microbiology and Immunology, St Louis University School of Medicine, 1402 South Grand Avenue, St Louis, MO 63104, USA
| | - Xiaoshan Jiang
- Department of Molecular Microbiology and Immunology, St Louis University School of Medicine, 1402 South Grand Avenue, St Louis, MO 63104, USA
| | - Deborah A Droll
- Department of Molecular Microbiology and Immunology, St Louis University School of Medicine, 1402 South Grand Avenue, St Louis, MO 63104, USA
| | - Yan Liang
- Department of Molecular Microbiology and Immunology, St Louis University School of Medicine, 1402 South Grand Avenue, St Louis, MO 63104, USA
| | - William S M Wold
- Department of Molecular Microbiology and Immunology, St Louis University School of Medicine, 1402 South Grand Avenue, St Louis, MO 63104, USA
| | - Janice Nickells
- Department of Molecular Microbiology and Immunology, St Louis University School of Medicine, 1402 South Grand Avenue, St Louis, MO 63104, USA
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Nemirov K, Lundkvist A, Vaheri A, Plyusnin A. Adaptation of Puumala hantavirus to cell culture is associated with point mutations in the coding region of the L segment and in the noncoding regions of the S segment. J Virol 2003; 77:8793-800. [PMID: 12885898 PMCID: PMC167242 DOI: 10.1128/jvi.77.16.8793-8800.2003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
We previously developed a model for studies on hantavirus host adaptation and initiated genetic analysis of Puumala virus variants passaged in colonized bank voles and in cultured Vero E6 cells. With the data presented in this paper, the sequence comparison of the wild-type and Vero E6-adapted variants of Puumala virus, strain Kazan, has been completed. The only amino acid substitution that distinguished the two virus variants was found in the L protein, Ser versus Phe at position 2053. Another mutation found in the L segment, the silent transition C1053U, could result from the selection of a variant with altered L RNA folding. Nucleotide substitutions observed in individual L cDNA clones, most of them A-->G and U-->C transitions, suggested that the population of L RNA molecules is represented by quasispecies. The mutation frequency in the L segment quasispecies appeared to be similar to the corresponding values for the S and M quasispecies. Analysis of the cDNA clones with the complete S segment sequences from passage 20 confirmed our earlier conclusion that the cell-adapted genotype of the virus is represented mostly by variants with mutated S segment noncoding regions. However, the spectrum of the S segment quasispecies appeared to be changing, suggesting that, after the initial adaptation (passages 1 to 11), the viral population is still being driven by selection for variants with higher fitness.
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Affiliation(s)
- Kirill Nemirov
- Department of Virology, Haartman Institute, FIN-00014 University of Helsinki, Finland
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Ramakrishna C, Ravi V, Desai A, Subbakrishna DK, Shankar SK, Chandramuki A. T helper responses to Japanese encephalitis virus infection are dependent on the route of inoculation and the strain of mouse used. J Gen Virol 2003; 84:1559-1567. [PMID: 12771426 DOI: 10.1099/vir.0.18676-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
T helper cytokine and IgG subtype responses were studied in three strains of mice (C57BL/6J, Swiss albino, BALB/c; n=90 per strain) immunized with live Japanese encephalitis virus (JEV) by intraperitoneal (IP), subcutaneous (SC) and peroral (PO) routes. Lymphocytes obtained from the spleens of immunized and control mice were stimulated in vitro with JEV for 48 h and the supernatants were assayed for the presence of the cytokines IL-4 and IFN-gamma. JEV-specific IgG isotypes were also measured in the sera of immunized mice. T helper cytokine responses in mice immunized with JEV were found to be strain- and route-specific in the three species tested. Moreover, they were also dependent on the type of immunogen used (live vs killed virus), as well as the number of doses administered. C57BL/6J and BALB/c mice were more uniform in their T helper responses compared with the outbred Swiss albino mice and induced a good Th1 response (P<0.001). Among the three routes evaluated, the IP and SC routes consistently elicited a Th1 response compared with the PO route (P<0.001), where an initial Th2-type response reverted to a Th1 response after repeated immunization. Live JEV induced a Th1 response while the commercial killed vaccine induced a predominant Th2 profile.
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MESH Headings
- Administration, Oral
- Animals
- Cytokines/biosynthesis
- Disease Models, Animal
- Dose-Response Relationship, Immunologic
- Encephalitis Virus, Japanese/immunology
- Encephalitis Virus, Japanese/pathogenicity
- Encephalitis, Japanese/etiology
- Encephalitis, Japanese/immunology
- Female
- Immunoglobulin G/biosynthesis
- Immunoglobulin G/classification
- In Vitro Techniques
- Injections, Intraperitoneal
- Injections, Subcutaneous
- Interferon-gamma/biosynthesis
- Interleukin-4/biosynthesis
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Species Specificity
- T-Lymphocytes, Helper-Inducer/immunology
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Affiliation(s)
- C Ramakrishna
- Departments of Neurovirology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - V Ravi
- Departments of Neurovirology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - A Desai
- Departments of Neurovirology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - D K Subbakrishna
- Departments of Biostatistics, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - S K Shankar
- Departments of Neuropathology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - A Chandramuki
- Departments of Neuromicrobiology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
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Pugachev KV, Guirakhoo F, Trent DW, Monath TP. Traditional and novel approaches to flavivirus vaccines. Int J Parasitol 2003; 33:567-82. [PMID: 12782056 DOI: 10.1016/s0020-7519(03)00063-8] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Yellow fever, dengue, Japanese encephalitis and tick-borne encephalitis viruses are the medically most important members of the Flavivirus genus composed primarily of arboviruses. In this paper, we review the commercially available traditional flavivirus vaccines against yellow fever, Japanese encephalitis, and tick-borne encephalitis, as well as modern approaches to flavivirus vaccines. Formalin inactivation technology has been employed to produce killed vaccines. Flaviviruses have been attenuated by multiple passages in animal tissues and cell cultures to produce empirical live attenuated vaccines. The use of traditional methods is being pursued to develop vaccines against other flavivirus diseases, such as dengue, and to improve existing vaccines, such as for Japanese encephalitis. With the recent development of infectious clones, rational approaches to attenuated flavivirus vaccines have employed the introduction of specific mutations into wild type viruses and chimerisation between different viruses. Novel methods for delivery of live vaccines, such as inoculation of infectious DNA or RNA, have been described. Other approaches, such as the construction of protein subunit, expression vector-based and naked DNA vaccines, have been proposed to create alternate vaccine candidates.
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Wu SC, Lin CW, Lee SC, Lian WC. Phenotypic and genotypic characterization of the neurovirulence and neuroinvasiveness of a large-plaque attenuated Japanese encephalitis virus isolate. Microbes Infect 2003; 5:475-80. [PMID: 12758275 DOI: 10.1016/s1286-4579(03)00064-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The virulent phenotypes of Japanese encephalitis virus (JEV) can be divided into neuroinvasiveness (NI) and neurovirulence (NV). In this study, two JEV antigenic variants, CH2195LA (large-plaque, attenuated) and CH2195SA (small-plaque, non-attenuated), were passaged in suckling mice by intracerebral inoculation. Viruses at passage two and four were characterized in terms of NV and NI in weaning mice, as well as their in vitro growth characteristics in six cell lines. Following two brain-brain passages in mice, the attenuated variant CH2195LA was found to significantly restore the NV and NI by approximately 90% and 20-40%, respectively. The increased titers in THP-1 monocytic cells but not IMR-32 and Neuro-2A neuroblastoma cells were more correlated with the phenotypic changes of NI and NV in mice. Entire genomic sequencing was further performed to demonstrate that 14 nucleotides were altered in the attenuated variant CH2195LA following four brain-brain passages in mice, giving 12 amino acid changes, in prM-73, prM-80, E-161, E-170, E-276, NS2A-136, NS2A-215, NS3-346, NS4A-128, NS4B-196, NS4B-197, NS4B-198. This study indicated a cluster of amino acids which is involved in NV and NI of the JEV for mice and, perhaps, for humans. Elucidating the molecular basis of virulence of flaviviruses can provide valuable information for live-attenuated vaccine development.
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Affiliation(s)
- Suh-Chin Wu
- Department of Life Science, Institute of Biotechnology, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC.
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44
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Kinney RM, Huang CY. Development of new vaccines against dengue fever and Japanese encephalitis. Intervirology 2002; 44:176-97. [PMID: 11509879 DOI: 10.1159/000050045] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Mosquito-borne dengue (DEN) and Japanese encephalitis (JE) viruses are the leading causes of arthropod-transmitted viral disease in humans. A licensed tetravalent vaccine that provides effective, long-term immunity against all four serotypes of DEN virus is needed, but is currently unavailable. Improvements to currently available JE vaccines are also needed. Past and recent strategies for the development of new DEN and JE vaccines include inactivated and live attenuated viruses, engineered viruses and chimeric viruses derived from infectious cDNA clones of DEN or JE virus, recombinant poxviruses, recombinant baculoviruses, protein expression in Escherichia coli, and naked DNA vaccines. This report summarizes some of the recent developments in DEN and JE vaccinology, particularly vaccine strategies that involve live attenuated viruses, engineered viruses derived from infectious cDNA clones, and naked DNA vaccines.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigens, Viral/chemistry
- Antigens, Viral/genetics
- Antigens, Viral/immunology
- Dengue/immunology
- Dengue/prevention & control
- Dengue/virology
- Dengue Virus/genetics
- Dengue Virus/immunology
- Encephalitis Virus, Japanese/genetics
- Encephalitis Virus, Japanese/immunology
- Encephalitis, Japanese/immunology
- Encephalitis, Japanese/prevention & control
- Encephalitis, Japanese/virology
- Humans
- Molecular Sequence Data
- Vaccines, Attenuated/immunology
- Vaccines, DNA/genetics
- Vaccines, DNA/immunology
- Vaccines, Subunit/genetics
- Vaccines, Subunit/immunology
- Viral Vaccines/genetics
- Viral Vaccines/immunology
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Affiliation(s)
- R M Kinney
- Division of Vector-Borne Infectious Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, US Department of Health and Human Services, Fort Collins, Colo 80522, USA.
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45
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Hong SP, Yoo WD, Putnak R, Eckels KH, Rho HM, Kim SO. Nucleotide sequence of envelope protein of Japanese encephalitis virus SA14-14-2 adapted to vero cells. DNA SEQUENCE : THE JOURNAL OF DNA SEQUENCING AND MAPPING 2001; 12:437-42. [PMID: 11913793 DOI: 10.3109/10425170109084471] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Live attenuated Japanese encephalitis (JE) virus SA(14)-14-2 produced in primary dog kidney cells (PDK) was adapted to Vero cells. In an effort to gain insight into the molecular basis of the biological characteristics of the SA14-14-2(Vero) strain, the 1500 nucleotide sequence encoding the envelope (E) gene which possesses major neutralizing epitopes was determined and compared with the sequences of two other attenuated JE virus strains, SA14-14-2(PHK) and SA14-14-2(PDK). The amino acid sequence of the C-terminal region (a.a. 280-500) was found to be identical for all three strains, while the N-terminal region (a.a. 1-279) shows sequence variation. The distribution of mutations in the N-terminal region was nearly the same among the three attenuated strains, suggesting that the N-terminal sequences might be related with virus-host cell specificity. However, it was found that Lys and Val (a.a. 138 and 176, respectively), known to be responsible for attenuation, are still conserved in SA(14)-14-2(Vero). Animal testing showed that SA(14)-14-2(Vero) has an attenuation phenotype similar to that of the parent SA(14)-14-2(PDK) strain in mice.
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Affiliation(s)
- S P Hong
- Cheil Jedang Corporation, Research and Development Center, Ichon-Si, Kyeonggi-Do, South Korea
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46
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Chiou SS, Chen WJ. Mutations in the NS3 gene and 3'-NCR of Japanese encephalitis virus isolated from an unconventional ecosystem and implications for natural attenuation of the virus. Virology 2001; 289:129-36. [PMID: 11601924 DOI: 10.1006/viro.2001.1033] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The T1P1 strain of Japanese encephalitis (JE) virus was recently isolated from paddy-free Liu-Chiu Islet in which natural JE antibody has been prevalent. In mouse neuroblastoma-derived Neuro-2a cells, T1P1 appeared significantly lower in virus productivity than another local isolate, CH1392. It implied that this new isolate possesses a characteristic viral replication pattern other than that of CH1392. T1P1 has also shown lower neurovirulence, which was reflected by a significantly higher LD(50) (2.44 x 10(6) PFU) than CH1392 (2.87 x 10(2) PFU). In comparison of the full-length RNA sequences between T1P1 and CH1392, a total of 7 nucleotides, including 1 in preM/M and 2 each in NS3, NS5, and the 3'-end noncoding region (NCR), appeared different. Of them, only the changes in NS3 (position 325, T for CH1392, A for T1P1; and position 364, G for CH1392 and A for T1P1) resulted in substitutions of deduced amino acids. There were two additional nucleotide changes appearing in the 3'-NCR. The amino acids 109 Phe and 122 Glu in NS3 of CH1392 were substituted by Ile and Lys, respectively, in T1P1. The unique growth properties and low virulence of T1P1 presented in this report were likely related to abnormal enzymatic activity due to mutations of the NS3 gene (especially position 364) and possibly to the mutations in the 3'-NCR. The natural attenuation of T1P1 that has been circulating in paddy-free Liu-Chiu Islet may account for the absence of clinical JE cases in past years.
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MESH Headings
- 3' Untranslated Regions/genetics
- Amino Acid Substitution
- Animals
- Animals, Suckling
- Brain/virology
- Cell Line
- Culex/physiology
- Culex/virology
- Ecosystem
- Encephalitis Virus, Japanese/genetics
- Encephalitis Virus, Japanese/growth & development
- Encephalitis Virus, Japanese/isolation & purification
- Encephalitis Virus, Japanese/pathogenicity
- Encephalitis, Japanese/epidemiology
- Encephalitis, Japanese/virology
- Genome, Viral
- Mice
- Molecular Sequence Data
- Mutation
- RNA Helicases
- RNA, Viral/biosynthesis
- RNA, Viral/genetics
- Sequence Analysis, DNA
- Serine Endopeptidases
- Taiwan/epidemiology
- Tumor Cells, Cultured
- Viral Nonstructural Proteins/chemistry
- Viral Nonstructural Proteins/genetics
- Viral Plaque Assay
- Virulence
- Virus Replication
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Affiliation(s)
- S S Chiou
- Institute of Epidemiology, College of Public Health, National Taiwan University, Taipei 10018, Taiwan
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47
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Srivastava AK, Putnak JR, Lee SH, Hong SP, Moon SB, Barvir DA, Zhao B, Olson RA, Kim SO, Yoo WD, Towle AC, Vaughn DW, Innis BL, Eckels KH. A purified inactivated Japanese encephalitis virus vaccine made in Vero cells. Vaccine 2001; 19:4557-65. [PMID: 11483284 DOI: 10.1016/s0264-410x(01)00208-0] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A second generation, purified, inactivated vaccine (PIV) against Japanese encephalitis (JE) virus was produced and tested in mice where it was found to be highly immunogenic and protective. The JE-PIV was made from an attenuated strain of JE virus propagated in certified Vero cells, purified, and inactivated with formalin. Its manufacture followed current GMP guidelines for the production of biologicals. The manufacturing process was efficient in generating a high yield of virus, essentially free of contaminating host cell proteins and nucleic acids. The PIV was formulated with aluminum hydroxide and administered to mice by subcutaneous inoculation. Vaccinated animals developed high-titered JE virus neutralizing antibodies in a dose dependent fashion after two injections. The vaccine protected mice against morbidity and mortality after challenge with live, virulent, JE virus. Compared with the existing licensed mouse brain-derived vaccine, JE-Vax, the Vero cell-derived JE-PIV was more immunogenic and as effective as preventing encephalitis in mice. The JE-PIV is currently being tested for safety and immunogenicity in volunteers.
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Affiliation(s)
- A K Srivastava
- Walter Reed Army Institute of Research, Division of Communicable Diseases and Immunology, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
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48
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Arroyo J, Guirakhoo F, Fenner S, Zhang ZX, Monath TP, Chambers TJ. Molecular basis for attenuation of neurovirulence of a yellow fever Virus/Japanese encephalitis virus chimera vaccine (ChimeriVax-JE). J Virol 2001; 75:934-42. [PMID: 11134306 PMCID: PMC113989 DOI: 10.1128/jvi.75.2.934-942.2001] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A yellow fever virus (YFV)/Japanese encephalitis virus (JEV) chimera in which the structural proteins prM and E of YFV 17D are replaced with those of the JEV SA14-14-2 vaccine strain is under evaluation as a candidate vaccine against Japanese encephalitis. The chimera (YFV/JEV SA14-14-2, or ChimeriVax-JE) is less neurovirulent than is YFV 17D vaccine in mouse and nonhuman primate models (F. Guirakhoo et al., Virology 257:363-372, 1999; T. P. Monath et al., Vaccine 17:1869-1882, 1999). Attenuation depends on the presence of the JEV SA14-14-2 E protein, as shown by the high neurovirulence of an analogous YFV/JEV Nakayama chimera derived from the wild JEV Nakayama strain (T. J. Chambers, A. Nestorowicz, P. W. Mason, and C. M. Rice, J. Virol. 73:3095-3101, 1999). Ten amino acid differences exist between the E proteins of ChimeriVax-JE and the YFV/JEV Nakayama virus, four of which are predicted to be neurovirulence determinants based on various sequence comparisons. To identify residues that are involved in attenuation, a series of intratypic YFV/JEV chimeras containing either single or multiple amino acid substitutions were engineered and tested for mouse neurovirulence. Reversions in at least three distinct clusters were required to restore the neurovirulence typical of the YFV/JEV Nakayama virus. Different combinations of cluster-specific reversions could confer neurovirulence; however, residue 138 of the E protein (E(138)) exhibited a dominant effect. No single amino acid reversion produced a phenotype significantly different from that of the ChimeriVax-JE parent. Together with the known genetic stability of the virus during prolonged cell culture and mouse brain passage, these findings support the candidacy of this experimental vaccine as a novel live-attenuated viral vaccine against Japanese encephalitis.
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MESH Headings
- Amino Acid Sequence
- Animals
- Encephalitis Virus, Japanese/genetics
- Encephalitis Virus, Japanese/immunology
- Encephalitis Virus, Japanese/metabolism
- Encephalitis Virus, Japanese/pathogenicity
- Encephalitis, Japanese/virology
- Japanese Encephalitis Vaccines
- Membrane Glycoproteins/chemistry
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/metabolism
- Mice
- Mice, Inbred ICR
- Molecular Sequence Data
- Nervous System/virology
- Plasmids
- Recombinant Fusion Proteins
- Sequence Analysis, DNA
- Transcription, Genetic
- Transfection
- Vaccines, Attenuated
- Vaccines, Synthetic
- Viral Envelope Proteins/chemistry
- Viral Envelope Proteins/genetics
- Viral Envelope Proteins/metabolism
- Virulence/genetics
- Yellow fever virus/genetics
- Yellow fever virus/immunology
- Yellow fever virus/metabolism
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Affiliation(s)
- J Arroyo
- OraVax, Inc., Cambridge, Massachusetts 02139, USA
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49
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Wu SC, Lee SC. Complete nucleotide sequence and cell-line multiplication pattern of the attenuated variant CH2195LA of Japanese encephalitis virus. Virus Res 2001; 73:91-102. [PMID: 11163647 DOI: 10.1016/s0168-1702(00)00235-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Strain-specific determinant of Japanese encephalitis virus (JEV) can be different among each virulence phenotype. We reported previously that the attenuated variant CH2195LA compared with the non-attenuated variant CH2195SA had four amino acid differences in E protein (E-85, E-306, E-331, and E-387) (Wu, S.-C., Lian, W.-C., Hsu, L.-C., Liau, M., 1997. Japanese encephalitis virus antigenic variants with characteristic differences in neutralization resistance and mouse virulence. Virus Res. 51, 173-181). Our present study determined the complete nucleotide sequences of these two variants and found another five amino acid changes in the nonstructural gene regions, including NS2A-215, NS3-350, NS4B-196, NS4B-197, and NS4B-198. The complete nucleotide sequences of the attenuated variant CH2195LA were compared with the non-attenuated variant CH2195SA and other 13 JEV strains. CH2195LA was mostly close to CH2195SA and JaOArS982, and phylogenetically distant to SA14-14-2, SA14-2-8, and RP-2ms of the attenuated JEV strains. The multiplication patterns for CH2195LA compared with CH2195SA in other seven cell lines were different from Vero cells. Relative fitness vector analysis based on a mixture of both variants during cell passage indicated the attenuated variant CH2195LA showed increased viral fitness in Vero cell adaptation. These results revealed that the attenuated variant CH2195LA was unique to culture in Vero cells.
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Affiliation(s)
- S C Wu
- Department of Life Science, National Tsing Hua University, 30043, Hsinchu, Taiwan, ROC.
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50
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Ramakrishna C, Desai A, Shankar SK, Chandramuki A, Ravi V. Oral immunisation of mice with live Japanese encephalitis virus induces a protective immune response. Vaccine 1999; 17:3102-8. [PMID: 10462246 DOI: 10.1016/s0264-410x(99)00137-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study was undertaken to evaluate the efficacy of oral immunisation of mice with live Japanese encephalitis virus (JEV). Swiss albino mice were immunised with JEV by the peroral (p.o.), intraperitoneal (i.p.) and the subcutaneous (s.c.) routes on days 0, 7 and 14 using either mouse brain derived immunogen (MBDI) or cell culture derived immunogen (CCDI). Oral immunisation of mice evoked high anti-JEV antibody titres by ELISA (Geometric mean titres of 5065 with CCDI and 8854 with MBDI). Moreover, the orally immunised mice showed 76.7% protection with MBDI and 70% with CCDI against intracerebral challenge with a lethal dose of JEV. This study demonstrates for the first time that oral immunisation of mice with live JEV generates a brisk, protective immune response. The results of this study suggest that oral immunisation with JEV holds promise for the future.
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MESH Headings
- Administration, Oral
- Animals
- Antibodies, Viral/biosynthesis
- Antibodies, Viral/blood
- Encephalitis Virus, Japanese/immunology
- Encephalitis, Japanese/immunology
- Encephalitis, Japanese/prevention & control
- Enzyme-Linked Immunosorbent Assay
- Injections, Intraperitoneal
- Injections, Subcutaneous
- Mice
- Vaccines, Synthetic/administration & dosage
- Vaccines, Synthetic/immunology
- Viral Nonstructural Proteins/blood
- Viral Nonstructural Proteins/immunology
- Viral Vaccines/administration & dosage
- Viral Vaccines/immunology
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Affiliation(s)
- C Ramakrishna
- Department of Neurovirology, National Institute of Mental Health and Neuro Sciences, Bangalore, India
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