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Situ J, Hon-Yin Lo K, Cai JP, Li Z, Wu S, Hon-Kiu Shun E, Foo-Siong Chew N, Yiu-Hung Tsoi J, Sze-Man Chan G, Hei-Man Chan W, Chik-Yan Yip C, Sze KH, Chi-Chung Cheng V, Yuen KY, Sridhar S. An immunoassay system to investigate epidemiology of Rocahepevirus ratti (rat hepatitis E virus) infection in humans. JHEP Rep 2023; 5:100793. [PMID: 37575885 PMCID: PMC10415708 DOI: 10.1016/j.jhepr.2023.100793] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 03/23/2023] [Accepted: 04/14/2023] [Indexed: 08/15/2023] Open
Abstract
Background & Aims Rat hepatitis E virus (Rocahepevirus ratti; HEV-C1) is an emerging cause of hepatitis E that is divergent from conventional human-infecting HEV variants (Paslahepevirus balayani; HEV-A). Validated serological assays for HEV-C1 are lacking. We aimed to develop a parallel enzymatic immunoassay (EIA) system that identifies individuals with HEV-C1 exposure. We also aimed to conduct the first HEV-C1 seroprevalence study in humans using this validated EIA system. Methods Expressed HEV-A (HEV-A4 p239) and HEV-C1 (HEV-C1 p241) peptides were characterised. Blood samples were simultaneously tested in HEV-A4 p239 and HEV-C1 p241 IgG EIAs. An optical density (OD) cut-off-based interpretation algorithm for identifying samples seropositive for HEV-A or HEV-C1 was validated using RT-PCR-positive infection sera. This algorithm was used to measure HEV-C1 seroprevalence in 599 solid organ transplant recipients and 599 age-matched immunocompetent individuals. Results Both peptides formed virus-like particles. When run in HEV-A4 p239 and HEV-C1 p241 EIAs, HEV-A and HEV-C1 RT-PCR-positive samples formed distinct clusters with minimal overlap in a two-dimensional plot of optical density values. The final EIA interpretation algorithm showed high agreement with RT-PCR results (Cohen's κ = 0.959) and was able to differentiate HEV-A and HEV-C1 infection sera with an accuracy of 94.2% (95% CI: 85.8-98.4%). HEV-C1 IgG seroprevalence was 7/599 (1.2%) among solid organ transplant recipients and 4/599 (0.7%) among immunocompetent individuals. Five of 11 (45.5%) of these patients had history of transient hepatitis of unknown cause. Conclusions HEV-C1 exposure was identified in 11/1198 (0.92%) individuals in Hong Kong indicating endemic exposure. This is the first estimate of HEV-C1 seroprevalence in humans. The parallel IgG EIA algorithm is a valuable tool for investigating epidemiology and risk factors for HEV-C1 infection. Impact and Implications Rat hepatitis E virus has recently been discovered to infect humans, but antibody tests for this infection are lacking, making it difficult to gauge how common this infection is. We developed an antibody test algorithm that can identify individuals with past rat hepatitis E virus exposure. We used this algorithm to estimate rat hepatitis E exposure rates in humans in Hong Kong and found that approximately 1% of all tested people had been exposed to this virus previously.
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Affiliation(s)
- Jianwen Situ
- Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Kelvin Hon-Yin Lo
- Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Jian-Piao Cai
- Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Zhiyu Li
- Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Shusheng Wu
- Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Estie Hon-Kiu Shun
- Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Nicholas Foo-Siong Chew
- Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - James Yiu-Hung Tsoi
- Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Gabriel Sze-Man Chan
- Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Winson Hei-Man Chan
- Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Cyril Chik-Yan Yip
- Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Kong Hung Sze
- Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Vincent Chi-Chung Cheng
- Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Kwok-Yung Yuen
- Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China
- The Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The University of Hong Kong, Hong Kong, China
- Centre for Virology, Vaccinology and Therapeutics, Hong Kong Science and Technology Park, Hong Kong Special Administrative Region, Hong Kong, China
| | - Siddharth Sridhar
- Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China
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Takahashi M, Kunita S, Nishizawa T, Ohnishi H, Primadharsini PP, Nagashima S, Murata K, Okamoto H. Infection Dynamics and Genomic Mutations of Hepatitis E Virus in Naturally Infected Pigs on a Farrow-to-Finish Farm in Japan: A Survey from 2012 to 2021. Viruses 2023; 15:1516. [PMID: 37515202 PMCID: PMC10385168 DOI: 10.3390/v15071516] [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: 06/23/2023] [Revised: 07/05/2023] [Accepted: 07/06/2023] [Indexed: 07/30/2023] Open
Abstract
Hepatitis E virus (HEV) causes acute or chronic hepatitis in humans. Pigs are the primary reservoir for zoonotic HEV genotypes 3 and 4 worldwide. This study investigated the infection dynamics and genomic mutations of HEV in domestic pigs on a farrow-to-finish pig farm in Japan between 2012 and 2021. A high prevalence of anti-HEV IgG antibodies was noted among pigs on this farm in 2012, when the survey started, and persisted for at least nine years. During 2012-2021, HEV RNA was detected in both serum and fecal samples, indicating active viral replication. Environmental samples, including slurry samples in manure pits, feces on the floor, floor and wall swabs in pens, and dust samples, also tested positive for HEV RNA, suggesting potential sources of infection within the farm environment. Indeed, pigs raised in HEV-contaminated houses had a higher rate of HEV infection than those in an HEV-free house. All 104 HEV strains belonged to subgenotype 3b, showing a gradual decrease in nucleotide identities over time. The 2012 (swEJM1201802S) and 2021 (swEJM2100729F) HEV strains shared 97.9% sequence identity over the entire genome. Importantly, the swEJM2100729F strain efficiently propagated in human hepatoma cells, demonstrating its infectivity. These findings contribute to our understanding of the prevalence, transmission dynamics, and genetic characteristics of HEV in domestic pigs, emphasizing the potential risks associated with HEV infections and are crucial for developing effective strategies to mitigate the risk of HEV infection in both animals and humans.
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Affiliation(s)
- Masaharu Takahashi
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Satoshi Kunita
- Center for Experimental Medicine, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Tsutomu Nishizawa
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Hiroshi Ohnishi
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Putu Prathiwi Primadharsini
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Shigeo Nagashima
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Kazumoto Murata
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Hiroaki Okamoto
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
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Takahashi M, Kunita S, Kawakami M, Kadosaka T, Fujita H, Takada N, Miyake M, Kobayashi T, Ohnishi H, Nagashima S, Murata K, Okamoto H. First Detection and Characterization of Rat Hepatitis E Virus (HEV-C1) in Japan. Virus Res 2022; 314:198766. [DOI: 10.1016/j.virusres.2022.198766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/27/2022] [Accepted: 03/28/2022] [Indexed: 10/18/2022]
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The Capsid (ORF2) Protein of Hepatitis E Virus in Feces Is C-Terminally Truncated. Pathogens 2021; 11:pathogens11010024. [PMID: 35055972 PMCID: PMC8779013 DOI: 10.3390/pathogens11010024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 12/21/2021] [Accepted: 12/24/2021] [Indexed: 11/17/2022] Open
Abstract
The hepatitis E virus (HEV) is a causative agent of hepatitis E. HEV virions in circulating blood and culture media are quasi-enveloped, while those in feces are nonenveloped. The capsid (ORF2) protein associated with an enveloped HEV virion is reported to comprise the translation product of leucine 14/methionine 16 to 660 (C-terminal end). However, the nature of the ORF2 protein associated with fecal HEV remains unclear. In the present study, we compared the molecular size of the ORF2 protein among fecal HEV, cell-culture-generated HEV (HEVcc), and detergent-treated protease-digested HEVcc. The ORF2 proteins associated with fecal HEV were C-terminally truncated and showed the same size as those of the detergent-treated protease-digested HEVcc virions (60 kDa), in contrast to those of the HEVcc (68 kDa). The structure prediction of the ORF2 protein (in line with previous studies) demonstrated that the C-terminal region (54 amino acids) of an ORF2 protein is in flux, suggesting that proteases target this region. The nonenveloped nondigested HEV structure prediction indicates that the C-terminal region of the ORF2 protein moves to the surface of the virion and is unnecessary for HEV infection. Our findings clarify the maturation of nonenveloped HEV and will be useful for studies on the HEV lifecycle.
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Production of capsid proteins of rat hepatitis E virus in Escherichia coli and characterization of self-assembled virus-like particles. Virus Res 2021; 302:198483. [PMID: 34146611 DOI: 10.1016/j.virusres.2021.198483] [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] [Received: 05/11/2021] [Revised: 06/09/2021] [Accepted: 06/10/2021] [Indexed: 12/19/2022]
Abstract
Rat hepatitis E virus (HEV) has been isolated from wild rats worldwide and the potential of zoonotic transmission has been documented. Escherichia coli (E. coli) is utilized as an effective system for producing HEV-like particles. However, the production of rat HEV ORF2 proteins in E. coli forming virus-like particles (VLPs) has not yet been reported. In this study, nine rat HEV ORF2 proteins of the ratELOMB-131L strain with truncated N- and C-termini (amino acids 339-594, 349-594, 351-594, 354-594, 357-594, 357-599, 357-604, 357-609, and 357-614 of ORF2 protein) were expressed in E. coli and the 357-614 protein self-assembled most efficiently. A bioanalyzer showed that the purified 357-614 protein has a molecular weight of 33.5 kDa and a purity of 93.2%. Electron microscopy revealed that the purified 33.5 kDa protein formed VLPs with a diameter of 21-52 (average 32) nm, and immunoelectron microscopy using an anti-rat HEV ORF2 monoclonal antibody (TA7014) indicated that the observed VLPs were derived from rat HEV ORF2. The VLPs attached to and entered the PLC/PRF/5 cells and blocked the neutralization of rat HEV by TA7014, suggesting that the VLPs possess the antigenic structure of infectious rat HEV particles. In addition, rat HEV VLPs showed high immunogenicity in mice. The present results would be useful for future studies on the development of VLP-based vaccines for HEV prevention in a rat model and for the prevention of rat HEV infection in humans.
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A broadly cross-reactive monoclonal antibody against hepatitis E virus capsid antigen. Appl Microbiol Biotechnol 2021; 105:4957-4973. [PMID: 34129082 PMCID: PMC8236046 DOI: 10.1007/s00253-021-11342-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 04/28/2021] [Accepted: 05/09/2021] [Indexed: 12/27/2022]
Abstract
Abstract To generate a hepatitis E virus (HEV) genotype 3 (HEV-3)–specific monoclonal antibody (mAb), the Escherichia coli–expressed carboxy-terminal part of its capsid protein was used to immunise BALB/c mice. The immunisation resulted in the induction of HEV-specific antibodies of high titre. The mAb G117-AA4 of IgG1 isotype was obtained showing a strong reactivity with the homologous E. coli, but also yeast-expressed capsid protein of HEV-3. The mAb strongly cross-reacted with ratHEV capsid protein derivatives produced in both expression systems and weaker with an E. coli–expressed batHEV capsid protein fragment. In addition, the mAb reacted with capsid protein derivatives of genotypes HEV-2 and HEV-4 and common vole hepatitis E virus (cvHEV), produced by the cell-free synthesis in Chinese hamster ovary (CHO) and Spodoptera frugiperda (Sf21) cell lysates. Western blot and line blot reactivity of the mAb with capsid protein derivatives of HEV-1 to HEV-4, cvHEV, ratHEV and batHEV suggested a linear epitope. Use of truncated derivatives of ratHEV capsid protein in ELISA, Western blot, and a Pepscan analysis allowed to map the epitope within a partially surface-exposed region with the amino acid sequence LYTSV. The mAb was also shown to bind to human patient–derived HEV-3 from infected cell culture and to hare HEV-3 and camel HEV-7 capsid proteins from transfected cells by immunofluorescence assay. The novel mAb may serve as a useful tool for further investigations on the pathogenesis of HEV infections and might be used for diagnostic purposes. Key points • The antibody showed cross-reactivity with capsid proteins of different hepeviruses. • The linear epitope of the antibody was mapped in a partially surface-exposed region. • The antibody detected native HEV-3 antigen in infected mammalian cells. Supplementary Information The online version contains supplementary material available at 10.1007/s00253-021-11342-7.
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Multimodal investigation of rat hepatitis E virus antigenicity: Implications for infection, diagnostics, and vaccine efficacy. J Hepatol 2021; 74:1315-1324. [PMID: 33845058 DOI: 10.1016/j.jhep.2020.12.028] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 11/30/2020] [Accepted: 12/17/2020] [Indexed: 01/20/2023]
Abstract
BACKGROUND & AIMS Rat hepatitis E virus (Orthohepevirus species C; HEV-C1) is an emerging cause of viral hepatitis in humans. HEV-C1 is divergent from other HEV variants infecting humans that belong to Orthohepevirus species A (HEV-A). This study assessed HEV-C1 antigenic divergence from HEV-A and investigated the impact of this divergence on infection susceptibility, serological test sensitivity, and vaccine efficacy. METHODS Immunodominant E2s peptide sequences of HEV-A and HEV-C1 were aligned. Interactions of HEV-C1 E2s and anti-HEV-A monoclonal antibodies (mAbs) were modeled. Recombinant peptides incorporating E2s of HEV-A (HEV-A4 p239) and HEV-C1 (HEV-C1 p241) were expressed. HEV-A and HEV-C1 patient sera were tested using antibody enzymatic immunoassays (EIA), antigen EIAs, and HEV-A4 p239/HEV-C1 p241 immunoblots. Rats immunized with HEV-A1 p239 vaccine (Hecolin), HEV-A4 p239 or HEV-C1 p241 peptides were challenged with a HEV-C1 strain. RESULTS E2s sequence identity between HEV-A and HEV-C1 was only 48%. There was low conservation at E2s residues (23/53; 43.4%) involved in mAb binding. Anti-HEV-A mAbs bound HEV-C1 poorly in homology modeling and antigen EIAs. Divergence resulted in low sensitivity of commercial antigen (0%) and antibody EIAs (10-70%) for HEV-C1 diagnosis. Species-specific HEV-A4 p239/HEV-C1 p241 immunoblots accurately differentiated HEV-A and HEV-C1 serological profiles in immunized rats (18/18; 100%) and infected-patient sera (32/36; 88.9%). Immunization with Hecolin and HEV-A4 p239 was partially protective while HEV-C1 p241 was fully protective against HEV-C1 infection in rats. CONCLUSIONS Antigenic divergence significantly decreases sensitivity of hepatitis E serodiagnostic assays for HEV-C1 infection. Species-specific immunoblots are useful for diagnosing HEV-C1 and for differentiating the serological profiles of HEV-A and HEV-C1. Prior HEV-A exposure is not protective against HEV-C1. HEV-C1 p241 is an immunogenic vaccine candidate against HEV-C1. LAY SUMMARY Rat hepatitis E virus (HEV-C1) is a new cause of hepatitis in humans. Using a combination of methods, we showed that HEV-C1 is highly divergent from the usual cause of human hepatitis (HEV-A). This divergence reduces the capacity of existing tests to diagnose HEV-C1 and also indicates that prior exposure to HEV-A (via infection or vaccination) is not protective against HEV-C1.
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Multivesicular body sorting and the exosomal pathway are required for the release of rat hepatitis E virus from infected cells. Virus Res 2020; 278:197868. [PMID: 31962066 DOI: 10.1016/j.virusres.2020.197868] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 01/17/2020] [Accepted: 01/17/2020] [Indexed: 01/14/2023]
Abstract
Recent reports have shown that rat hepatitis E virus (HEV) is capable of infecting humans. We also successfully propagated rat HEV into human PLC/PRF/5 cells, raising the possibility of a similar mechanism shared by human HEV and rat HEV. Rat HEV has the proline-rich sequence, PxYPMP, in the open reading frame 3 (ORF3) protein that is indispensable for its release. However, the release mechanism remains unclear. The overexpression of dominant-negative (DN) mutant of vacuolar protein sorting (Vps)4A or Vps4B decreased rat HEV release to 23.9 % and 18.0 %, respectively. The release of rat HEV was decreased to 8.3 % in tumor susceptibility gene 101 (Tsg101)-depleted cells and to 31.5 % in apoptosis-linked gene 2-interacting protein X (Alix)-depleted cells. Although rat HEV ORF3 protein did not bind to Tsg101, we found a 90-kDa protein capable of binding to wild-type rat HEV ORF3 protein but not to ORF3 mutant with proline to leucine mutations in the PxYPMP motif. Rat HEV release was also decreased in Ras-associated binding 27A (Rab27A)- or hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs)-depleted cells (to 20.1 % and 18.5 %, respectively). In addition, the extracellular rat HEV levels in the infected PLC/PRF/5 cells were increased after treatment with Bafilomycin A1 and decreased after treatment with GW4869. These results indicate that rat HEV utilizes multivesicular body (MVB) sorting for its release and that the exosomal pathway is required for rat HEV egress. A host protein alternative to Tsg101 that can bind to rat HEV ORF3 should be explored in further study.
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Acheampong DO. Bispecific Antibody (bsAb) Construct Formats and their Application in Cancer Therapy. Protein Pept Lett 2019; 26:479-493. [DOI: 10.2174/0929866526666190311163820] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 02/28/2019] [Accepted: 03/03/2019] [Indexed: 12/15/2022]
Abstract
Development of cancers mostly involves more than one signal pathways, because of the complicated nature of cancer cells. As such, the most effective treatment option is the one that stops the cancer cells in their tracks by targeting these signal pathways simultaneously. This explains why therapeutic monoclonal antibodies targeted at cancers exert utmost activity when two or more are used as combination therapy. This notwithstanding, studies elsewhere have proven that when bispecific antibody (bsAb) is engineered from two conventional monoclonal antibodies or their chains, it produces better activity than when used as combination therapy. This therefore presents bispecific antibody (bsAb) as the appropriate and best therapeutic agent for the treatment of such cancers. This review therefore discusses the various engineering formats for bispecific antibodies (bsAbs) and their applications.
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Affiliation(s)
- Desmond O. Acheampong
- Department of Biomedical Sciences, School of Allied Health Sciences, College of Health and Allied Science, University of Cape Coast, Cape Coast, Ghana
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Meister TL, Bruening J, Todt D, Steinmann E. Cell culture systems for the study of hepatitis E virus. Antiviral Res 2019; 163:34-49. [PMID: 30653997 DOI: 10.1016/j.antiviral.2019.01.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 01/08/2019] [Accepted: 01/13/2019] [Indexed: 12/26/2022]
Abstract
Hepatitis E virus (HEV) is the causative agent of hepatitis E in humans and is the leading cause of enterically-transmitted viral hepatitis worldwide. Increasing numbers of HEV infections, together with no available specific anti-HEV treatment, contributes to the pathogen's major health burden. A robust cell culture system is required for virologic studies and the development of new antiviral drugs. Unfortunately, like other hepatitis viruses, HEV is difficult to propagate in conventional cell lines. Many different cell culture systems have been tested using various HEV strains, but viral replication usually progresses very slowly, and infection with low virion counts results in non-productive HEV replication. However, recent progress involving generation of cDNA clones and passaging primary patient isolates in distinct cell lines has improved in vitro HEV propagation. This review describes various approaches to cultivate HEV in cellular and animal models and how these systems are used to study HEV infections and evaluate anti-HEV drug candidates.
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Affiliation(s)
- Toni L Meister
- Ruhr-University Bochum, Faculty of Medicine, Department of Molecular and Medical Virology, Bochum, Germany
| | - Janina Bruening
- Ruhr-University Bochum, Faculty of Medicine, Department of Molecular and Medical Virology, Bochum, Germany
| | - Daniel Todt
- Ruhr-University Bochum, Faculty of Medicine, Department of Molecular and Medical Virology, Bochum, Germany.
| | - Eike Steinmann
- Ruhr-University Bochum, Faculty of Medicine, Department of Molecular and Medical Virology, Bochum, Germany.
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Pan Q, Wang J, Gao Y, Cui H, Liu C, Qi X, Zhang Y, Wang Y, Wang X. Identification of two novel fowl adenovirus C-specific B cell epitopes using monoclonal antibodies against the capsid hexon protein. Appl Microbiol Biotechnol 2018; 102:9243-9253. [PMID: 30141086 DOI: 10.1007/s00253-018-9262-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 07/16/2018] [Accepted: 07/19/2018] [Indexed: 12/18/2022]
Abstract
The diseases associated with fowl adenovirus (FAdV) infection, such as inclusion body hepatitis (IBH), hepatitis-hydropericardium syndrome (HPS), and gizzard erosion (GE), were first reported in Pakistan in 1987, and subsequent outbreaks have been reported worldwide, especially in China, where severe outbreaks of HPS with high mortality from 30 to 100% were recently reported and resulted in significant economic losses to the poultry industry. The diagnosis methods of FAdVs were mostly limited to the nucleotide sequence of hexon by PCR and DNA sequencing. The aim of this study was to generate B cell epitope maps of the species- and serotype-specific hexon L1 using monoclonal antibodies (mAbs) and bioinformatics tools for the development of novel diagnostic methods. In this study, the hexon L1 (230 amino acids) was expressed and used to generate 10 mAb-expressing hybridoma cell lines against the relative protein peptide. Subsequently, we defined the linear peptide epitopes recognized by these mAbs using a series of partially overlapping peptides derived from the FAdV-C hexon protein amino acid sequence to map mAbs reactivity. Finally, a common B cell epitope (31PLAPKESMFN40) for all species FAdVs and two FAdV-C-specific epitopes (79KISGVFPNP87 and 181DYDDYNIGTT190) were identified. These mAbs and their defined epitopes may support the development of the universal or species-specific differential diagnostic methods of FAdVs.
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Affiliation(s)
- Qing Pan
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China
| | - Jing Wang
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China
| | - Yulong Gao
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China
| | - Hongyu Cui
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China
| | - Changjun Liu
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China
| | - Xiaole Qi
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China
| | - Yanping Zhang
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China
| | - Yongqiang Wang
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China
| | - Xiaomei Wang
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China.
- Jiangsu Co-innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonose, Yangzhou University, Yangzhou, 225009, China.
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Tanggis, Kobayashi T, Takahashi M, Jirintai S, Nishizawa T, Nagashima S, Nishiyama T, Kunita S, Hayama E, Tanaka T, Mulyanto, Okamoto H. An analysis of two open reading frames (ORF3 and ORF4) of rat hepatitis E virus genome using its infectious cDNA clones with mutations in ORF3 or ORF4. Virus Res 2018; 249:16-30. [DOI: 10.1016/j.virusres.2018.02.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 02/14/2018] [Accepted: 02/14/2018] [Indexed: 01/13/2023]
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Generation in yeast and antigenic characterization of hepatitis E virus capsid protein virus-like particles. Appl Microbiol Biotechnol 2017; 102:185-198. [PMID: 29143081 DOI: 10.1007/s00253-017-8622-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 10/29/2017] [Accepted: 10/31/2017] [Indexed: 12/30/2022]
Abstract
Hepatitis E is a globally distributed human disease caused by hepatitis E virus (HEV). In Europe, it spreads through undercooked pork meat or other products and with blood components through transfusions. There are no approved or golden standard serologic systems for HEV diagnostics. Commercially available HEV tests often provide inconsistent results which may differ among the assays. In this study, we describe generation in yeast and characterization of HEV genotype 3 (HEV-3) and rat HEV capsid proteins self-assembled into virus-like particles (VLPs) and the development of HEV-specific monoclonal antibodies (MAbs). Full-length HEV-3 and rat HEV capsid proteins and their truncated variants comprising amino acids (aa) 112-608 were produced in yeast S. cerevisiae. The yeast-expressed rat HEV capsid protein was found to be glycosylated. The full-length HEV-3 capsid protein and both full-length and truncated rat HEV capsid proteins were capable to self-assemble into VLPs. All recombinant proteins contained HEV genotype-specific linear epitopes and cross-reactive conformational epitopes recognized by serum antibodies from HEV-infected reservoir animals. Two panels of MAbs against HEV-3 and rat HEV capsid proteins were generated. Their cross-reactivity pattern was investigated by Western blot, ELISA, and immunofluorescence assay on HEV-3-infected cell cultures. The analysis revealed cross-reactive, genotype-specific, and virus-reactive MAbs. MAb epitopes were localized within S, M, and P domains of HEV-3 and rat HEV capsid proteins. Yeast-generated recombinant VLPs of HEV-3 and rat HEV capsid proteins and HEV-specific MAbs might be employed to develop novel HEV detection systems.
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Mykytczuk O, Harlow J, Bidawid S, Corneau N, Nasheri N. Prevalence and Molecular Characterization of the Hepatitis E Virus in Retail Pork Products Marketed in Canada. FOOD AND ENVIRONMENTAL VIROLOGY 2017; 9:208-218. [PMID: 28197972 PMCID: PMC5429394 DOI: 10.1007/s12560-017-9281-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 01/31/2017] [Indexed: 05/21/2023]
Abstract
Infection with the hepatitis E virus (HEV) is very common worldwide. HEV causes acute viral hepatitis with approximately 20 million cases per year. While HEV genotypes 1 and 2 cause large waterborne and foodborne outbreaks with a significant mortality in developing countries, genotypes 3 and 4 are more prevalent in developed countries with transmission being mostly zoonotic. In North America and Europe, HEV has been increasingly detected in swine, and exposure to pigs and pork products is considered to be the primary source of infection. Therefore we set out to investigate the prevalence of HEV in retail pork products available in Canada, by screening meal-size portions of pork pâtés, raw pork sausages, and raw pork livers. The presence of the HEV genomes was determined by RT-PCR and viral RNA was quantified by digital droplet PCR. Overall, HEV was detected in 47% of the sampled pork pâtés and 10.5% of the sampled raw pork livers, but not in the sampled pork sausages, and sequencing confirmed that all HEV strains belonged to genotype 3. Further phylogenetic analysis revealed that except for one isolate that clusters with subtype 3d, all isolates belong to subtype 3a. Amino acid variations between the isolates were also observed in the sequenced capsid region. In conclusion, the prevalence of HEV in pâtés and raw pork livers observed in this study is in agreement with the current HEV distribution in pork products reported in other developed countries.
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Affiliation(s)
- Oksana Mykytczuk
- National Food Virology Reference Centre, Bureau of Microbial Hazards, Food Directorate, Health Canada, 251 Sir Frederick Banting Driveway, Ottawa, ON, K1A 0K9, Canada
| | - Jennifer Harlow
- National Food Virology Reference Centre, Bureau of Microbial Hazards, Food Directorate, Health Canada, 251 Sir Frederick Banting Driveway, Ottawa, ON, K1A 0K9, Canada
| | - Sabah Bidawid
- National Food Virology Reference Centre, Bureau of Microbial Hazards, Food Directorate, Health Canada, 251 Sir Frederick Banting Driveway, Ottawa, ON, K1A 0K9, Canada
| | - Nathalie Corneau
- National Food Virology Reference Centre, Bureau of Microbial Hazards, Food Directorate, Health Canada, 251 Sir Frederick Banting Driveway, Ottawa, ON, K1A 0K9, Canada
| | - Neda Nasheri
- National Food Virology Reference Centre, Bureau of Microbial Hazards, Food Directorate, Health Canada, 251 Sir Frederick Banting Driveway, Ottawa, ON, K1A 0K9, Canada.
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Takahashi M, Kobayashi T, Tanggis, Jirintai S, Mulyanto, Nagashima S, Nishizawa T, Kunita S, Okamoto H. Production of monoclonal antibodies against the ORF3 protein of rat hepatitis E virus (HEV) and demonstration of the incorporation of the ORF3 protein into enveloped rat HEV particles. Arch Virol 2016; 161:3391-3404. [DOI: 10.1007/s00705-016-3047-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 09/01/2016] [Indexed: 02/07/2023]
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16
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Chingwaru W, Vidmar J. A novel porcine cell culture based protocol for the propagation of hepatitis E virus. ASIAN PACIFIC JOURNAL OF TROPICAL DISEASE 2016. [DOI: 10.1016/s2222-1808(16)61092-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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