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Zhu Y, Chen S, Lurong Q, Qi Z. Recent Advances in Antivirals for Japanese Encephalitis Virus. Viruses 2023; 15:v15051033. [PMID: 37243122 DOI: 10.3390/v15051033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 04/19/2023] [Accepted: 04/20/2023] [Indexed: 05/28/2023] Open
Abstract
Culex mosquitoes are the primary vectors of the Japanese encephalitis virus (JEV). Since its discovery in 1935, Japanese encephalitis (JE), caused by JEV, has posed a significant threat to human health. Despite the widespread implementation of several JEV vaccines, the transmission chain of JEV in the natural ecosystem has not changed, and the vector of transmission cannot be eradicated. Therefore, JEV is still the focus of attention for flaviviruses. At present, there is no clinically specific drug for JE treatment. JEV infection is a complex interaction between the virus and the host cell, which is the focus of drug design and development. An overview of antivirals that target JEV elements and host factors is presented in this review. In addition, drugs that balance antiviral effects and host protection by regulating innate immunity, inflammation, apoptosis, or necrosis are reviewed to treat JE effectively.
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Affiliation(s)
- Yongzhe Zhu
- Department of Microbiology, Faculty of Naval Medicine, Naval Medical University, Shanghai 200433, China
| | - Shenglin Chen
- Department of Clinic Laboratory Diagnostics, General Hospital of Tibet Military Area Command of PLA, Lhasa 850007, China
| | - Qilin Lurong
- Department of Geriatrics, General Hospital of Tibet Military Area Command of PLA, Lhasa 850007, China
| | - Zhongtian Qi
- Department of Microbiology, Faculty of Naval Medicine, Naval Medical University, Shanghai 200433, China
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Srivastava KS, Jeswani V, Pal N, Bohra B, Vishwakarma V, Bapat AA, Patnaik YP, Khanna N, Shukla R. Japanese Encephalitis Virus: An Update on the Potential Antivirals and Vaccines. Vaccines (Basel) 2023; 11:vaccines11040742. [PMID: 37112654 PMCID: PMC10146181 DOI: 10.3390/vaccines11040742] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/17/2023] [Accepted: 02/24/2023] [Indexed: 03/29/2023] Open
Abstract
Japanese encephalitis virus (JEV) is the causal agent behind Japanese encephalitis (JE), a potentially severe brain infection that spreads through mosquito bites. JE is predominant over the Asia-Pacific Region and has the potential to spread globally with a higher rate of morbidity and mortality. Efforts have been made to identify and select various target molecules essential in JEV’s progression, but until now, no licensed anti-JEV drug has been available. From a prophylactic point of view, a few licensed JE vaccines are available, but various factors, viz., the high cost and different side effects imposed by them, has narrowed their global use. With an average occurrence of >67,000 cases of JE annually, there is an urgent need to find a suitable antiviral drug to treat patients at the acute phase, as presently only supportive care is available to mitigate infection. This systematic review highlights the current status of efforts put in to develop antivirals against JE and the available vaccines, along with their effectiveness. It also summarizes epidemiology, structure, pathogenesis, and potential drug targets that can be explored to develop a new range of anti-JEV drugs to combat JEV infection globally.
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Antiviral drug research for Japanese encephalitis: an updated review. Pharmacol Rep 2022; 74:273-296. [PMID: 35182390 PMCID: PMC8964565 DOI: 10.1007/s43440-022-00355-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 01/21/2022] [Accepted: 01/28/2022] [Indexed: 12/23/2022]
Abstract
Japanese encephalitis (JE) caused by the Japanese encephalitis virus (JEV) is one of Asia's most common viral encephalitis. JEV is a flavivirus, common in rural and sub-urban regions of Asian countries. Although only 1% of JEV-infected individuals develop JE, there is a 20-30% chance of death among these individuals and possible neurological sequelae post-infection. No licensed anti-JE drugs are currently available, despite extensive efforts to develop them. Literature search was performed using databases such as PubMed Central, Google Scholar, Wiley Online Library, etc. using keywords such as Japanese encephalitis virus, antiviral drugs, antiviral drug screening, antiviral drug targets, etc. From around 230 papers/abstracts and research reviews retrieved and reviewed for this study, approximately 180 most relevant and important ones have been cited. Different approaches in drug testing and various antiviral drug targets explored so far have been thoroughly searched from the literature and compiled, besides addressing the future perspectives of the antiviral drug development strategies. Although the development of effective anti-JE drugs is an urgent issue, only supportive care is currently available. Recent advancements in understanding the biology of infection and new drug targets have been promising improvements. Despite hindrances such as the unavailability of a proper drug delivery system or a treatment regimen irrespective of the stage of infection, several promising anti-JE candidate molecules are in different phases of clinical trials. Nonetheless, efficient therapy against JEV is expected to be achieved with drug combinations and a highly targeted drug delivery system soon.
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Somsoros W, Sangawa T, Takebe K, Attarataya J, Wongprasert K, Senapin S, Rattanarojpong T, Suzuki M, Khunrae P. Crystal structure of the C-terminal domain of envelope protein VP37 from white spot syndrome virus reveals sulphate binding sites responsible for heparin binding. J Gen Virol 2021; 102. [PMID: 34106826 DOI: 10.1099/jgv.0.001611] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
White spot syndrome virus (WSSV) is the most virulent pathogen causing high mortality and economic loss in shrimp aquaculture and various crustaceans. Therefore, the understanding of molecular mechanisms of WSSV infection is important to develop effective therapeutics to control the spread of this viral disease. In a previous study, we found that VP37 could bind with shrimp haemocytes through the interaction between its C-terminal domain and heparin-like molecules on the shrimp cells, and this interaction can also be inhibited by sulphated galactan. In this study, we present the crystal structure of C-terminal domain of VP37 from WSSV at a resolution of 2.51 Å. The crystal structure contains an eight-stranded β-barrel fold with an antiparallel arrangement and reveals a trimeric assembly. Moreover, there are two sulphate binding sites found in the position corresponding to R213 and K257. In order to determine whether these sulphate binding sites are involved in binding of VP37 to heparin, mutagenesis was performed to replace these residues with alanine (R213A and K257A), and the Surface Plasmon Resonance (SPR) system was used to study the interaction of each mutated VP37 with heparin. The results showed that mutants R213A and K257A exhibited a significant loss in heparin binding activity. These findings indicated that the sites of R213 and K257 on the C-terminal domain of envelope protein VP37 are essential for binding to sulphate molecules of heparin. This study provides further insight into the structure of C-terminal domain of VP37 and it is anticipated that the structure of VP37 might be used as a guideline for development of antivirus agent targeting on the VP37 protein.
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Affiliation(s)
- Wasusit Somsoros
- Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand
| | - Takeshi Sangawa
- Institute for Protein Research, Osaka University; 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Katsuki Takebe
- Department of Oral and Maxillofacial Surgery II, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Jakrada Attarataya
- Synchrotron Light Research Institute (Public Organization), Nakhon Ratchasima 30000, Thailand
| | - Kanokpan Wongprasert
- Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok 10400, Thailand
| | - Saengchan Senapin
- Center of Excellence for Shrimp Molecular Biology and Biotechnology, Faculty of Science, Mahidol University, 272 Rama VI Road, Bangkok, 10400, Thailand.,National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathum Thani 12120, Thailand
| | - Triwit Rattanarojpong
- Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand
| | - Mamoru Suzuki
- Institute for Protein Research, Osaka University; 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Pongsak Khunrae
- Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand
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Sotanon N, Saleeart A, Rattanarojpong T, Thanh Dong H, Senapin S, Wongprasert K, Sarikavanij S, Khunrae P. C-terminal domain of WSSV VP37 is responsible for shrimp haemocytes binding which can be inhibited by sulfated galactan. FISH & SHELLFISH IMMUNOLOGY 2018; 77:312-318. [PMID: 29601994 DOI: 10.1016/j.fsi.2018.03.043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 02/15/2018] [Accepted: 03/27/2018] [Indexed: 06/08/2023]
Abstract
Viral envelope proteins play an important role in facilitating the attachment of viruses to the surface of host cells. Here, we investigated the binding of White Spot Syndrome Virus (WSSV) VP37 to haemocytes of whiteleg shrimp, Litopenaeus vannamei. Three versions of recombinant VP37 proteins, including full length VP37 (VP37(1-281)), C-terminal domain VP37 (VP37(111-281)) and C-terminal domain disrupted VP37 (VP37(1-250)) were individually expressed and tested for their haemocytes binding ability. Through an ELISA-based binding assay, we found that VP37(111-281) bound to shrimp haemocytes in a similar way to VP37(1-281), while VP37(1-250) exhibited a significantly weaker binding. This suggests that the C-terminal domain of VP37 is required for the binding of VP37 to shrimp haemocytes. Furthermore, we found that the binding of VP37 to shrimp haemocytes was impaired by pre-incubation of VP37 with sulfated galactan (SG), a sulfated polysaccharide derived from red seaweed (Gracilaria fisheri). Previously, it has been shown that a type of sulfated polysaccharide, heparin, is also present in L. vannamei. To investigate the role of heparin as a receptor for VP37, the binding of VP37 to porcine heparin, whose structure is similar to that found in L.vannamei, was investigated in a Surface Plasmon Resonance (SPR) system. The results showed that VP37 bound strongly to heparin with binding affinity (KD) of 1.0 μM and the binding was significantly blocked by SG. These findings have lead us to propose that the attachment of WSSV might be mediated by the interaction between VP37 and a heparin-like molecule presented on the shrimp cells.
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Affiliation(s)
- Nantharat Sotanon
- Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok 10140, Thailand
| | - Anchulee Saleeart
- Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok 10140, Thailand
| | - Triwit Rattanarojpong
- Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok 10140, Thailand
| | - Ha Thanh Dong
- Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok 10140, Thailand
| | - Saengchan Senapin
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani 12120, Thailand; Center of Excellence for Shrimp Molecular Biology and Biotechnology, Faculty of Science, Mahidol University, 272 Rama VI Road, Bangkok, 10400, Thailand
| | - Kanokpan Wongprasert
- Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Rd, Rajdhevi, Bangkok 10400, Thailand
| | - Sukuman Sarikavanij
- Department of Mathematics, Faculty of Science, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok 10140, Thailand
| | - Pongsak Khunrae
- Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok 10140, Thailand.
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Sakuragi M, Suzuki R, Hidari KI, Yamanaka T, Nakano H. Synthesis of p-methoxyphenyl sulfated β-GalNAc derivatives with inhibitory activity against Japanese encephalitis virus. PURE APPL CHEM 2017. [DOI: 10.1515/pac-2016-0921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The N-acetylgalactosamine (GalNAc) residue is one of the units of chondroitin sulfate E (CS-E) which has been reported to have inhibitory activity against Japanese encephalitis virus (JEV). Herein, we describe the synthesis of a series of p-methoxyphenyl β-GalNAc derivatives with a sulfate group at 3-, 4-, and/or 6-positions using an efficient route through a common synthetic intermediate. By measuring the inhibition activity of these compounds that bear different numbers and positions of sulfate groups, the effect of position specificity for interaction with the virus was determined. From these results, GalNAc6S and GalNAc4S6S derivatives inhibited JEV infections well; we suggest the 6-O-sulfate group is necessary for selective recognition by the virus.
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Affiliation(s)
- Miho Sakuragi
- Department of Chemistry , Aichi University of Education , Igaya, Kariya, Aichi 448-8542 , Japan
| | - Ryoko Suzuki
- Department of Chemistry , Aichi University of Education , Igaya, Kariya, Aichi 448-8542 , Japan
| | - Kazuya I.P.J. Hidari
- Junior College Division , University of Aizu, Ikki-machi , Aizuwakamatsu, Fukushima 965-8570 , Japan
| | - Takashi Yamanaka
- Epizootic Research Center, Equine Research Institute, Japan Racing Association , 1400-4 Shiba, Shimotsuke , Tochigi 329-0412 , Japan
| | - Hirofumi Nakano
- Department of Chemistry , Aichi University of Education , Igaya, Kariya, Aichi 448-8542 , Japan
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Ishikawa T, Konishi E. Potential chemotherapeutic targets for Japanese encephalitis: current status of antiviral drug development and future challenges. Expert Opin Ther Targets 2015; 19:1379-95. [PMID: 26156208 DOI: 10.1517/14728222.2015.1065817] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Japanese encephalitis (JE) remains a public health threat in Asia. Although several vaccines have been licensed, ∼ 67,900 cases of the disease are estimated to occur annually, probably because the vaccine coverage is low. Therefore, effective antiviral drugs are required to control JE. However, no licensed anti-JE drugs are available, despite extensive efforts to develop them. AREAS COVERED We provide a general overview of JE and JE virus, including its transmission cycle, distribution, structure, replication machinery, immune evasion mechanisms and vaccines. The current situation in antiviral drug development is then reviewed and future perspectives are discussed. EXPERT OPINION Although the development of effective anti-JE drugs is an urgent issue, only supportive care is currently available. Recent progress in our understanding of the viral replication machinery and immune evasion strategies has identified new targets for anti-JE drug development. To date, most candidate drugs have only been evaluated in single-drug formulations, and efficient drug delivery to the CNS has virtually not been considered. However, an effective anti-JE treatment is expected to be achieved with multiple-drug formulations and a targeted drug delivery system in the near future.
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Affiliation(s)
- Tomohiro Ishikawa
- a 1 Dokkyo Medical University, School of Medicine, Department of Microbiology , 880 Kitakobayashi, Mibu-machi, Shimotsuga-gun, Tochigi 321-0293, Japan
| | - Eiji Konishi
- b 2 Mahidol University, BIKEN Endowed Department of Dengue Vaccine Development, Faculty of Tropical Medicine , 420/6 Ratchawithi Road, Ratchathewi, Bangkok 10400, Thailand.,c 3 Osaka University, Research Institute for Microbial Diseases, BIKEN Endowed Department of Dengue Vaccine Development , 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan +66 2 354 5981 ;
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Ishikawa T, Konishi E. Japanese encephalitis: epidemiology, prevention and current status of antiviral drug development. Expert Opin Orphan Drugs 2014. [DOI: 10.1517/21678707.2014.934222] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Current world literature. Curr Opin Allergy Clin Immunol 2012; 12:211-7. [PMID: 22382450 DOI: 10.1097/aci.0b013e3283520fda] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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