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https://www.readbyqxmd.com/read/27738988/prophylactic-hepatitis-e-vaccine
#1
Jun Zhang, Qinjian Zhao, Ningshao Xia
Hepatitis E has been increasingly recognized as an underestimated global disease burden in recent years. Subpopulations with more serious infection-associated damage or death include pregnant women, patients with basic liver diseases, and elderly persons. Vaccine would be the most effective means for prevention of HEV infection. The lack of an efficient cell culture system for HEV makes the development of classic inactive or attenuated vaccine infeasible. Hence, the recombinant vaccine approaches are explored deeply...
2016: Advances in Experimental Medicine and Biology
https://www.readbyqxmd.com/read/26584510/role-of-asparagine-at-position-562-in-dimerization-and-immunogenicity-of-the-hepatitis-e-virus-capsid-protein
#2
Mingjie Xu, Nouredine Behloul, Jiyue Wen, Jianhua Zhang, Jihong Meng
The hepatitis E virus (HEV) capsid protein, pORF2, contains 2 potential N-glycosylation sites, N137 and N310, located in the S domain, and one site, N562, in the P domain. The last domain located at positions 454-606 aa forms a protruding spike from the shell, with N562 being located in the apical center of the spike, which is also a cell-attachment region and neutralizing antigenic site. Here, we expressed in Pichia pastoris a recombinant polypeptide p179 comprising the region of 439-617 aa of the HEV pORF2 as well as a set of 4 mutant proteins containing substitutions of Q, D, P and Y instead of N at position 562...
January 2016: Infection, Genetics and Evolution
https://www.readbyqxmd.com/read/26104584/recombinant-hepatitis-e-virus-like-particles-can-function-as-rna-nanocarriers
#3
Subrat Kumar Panda, Neeraj Kapur, Daizy Paliwal, Hemlata Durgapal
BACKGROUND: Assembled virus-like particles (VLPs) without genetic material, with structure similar to infectious virions, have been successfully used as vaccines. We earlier described in vitro assembly, characterisation and tissue specific receptor dependent Clathrin mediated entry of empty HEV VLPs, produced from Escherichia coli expressed HEV capsid protein (pORF2). Similar VLP's have been described as a potential candidate vaccine (Hecolin) against HEV. FINDINGS: We have attempted to use such recombinant assembled Hepatitis E virus (HEV) VLPs as a carrier for heterologous RNA with protein coding sequence fused in-frame with HEV 5' region (containing cap and encapsidation signal) and investigated, if the relevant protein could be expressed and elicit an immune response in vivo...
2015: Journal of Nanobiotechnology
https://www.readbyqxmd.com/read/26051517/a-novel-linear-neutralizing-epitope-of-hepatitis-e-virus
#4
Zi-Min Tang, Ming Tang, Min Zhao, Gui-Ping Wen, Fan Yang, Wei Cai, Si-Ling Wang, Zi-Zheng Zheng, Ning-Shao Xia
Hepatitis E virus (HEV) is a serious public health problem that causes acute hepatitis in humans and is primarily transmitted through fecal and oral routes. The major anti-HEV antibody responses are against conformational epitopes located in a.a. 459-606 of HEV pORF2. All reported neutralization epitopes are present on the dimer domain constructed by this peptide. While looking for a neutralizing monoclonal antibody (MAb)-recognized linear epitope, we found a novel neutralizing linear epitope (L2) located in a...
July 9, 2015: Vaccine
https://www.readbyqxmd.com/read/25714510/the-development-of-a-recombinant-hepatitis-e-vaccine-hev-239
#5
REVIEW
Shao-Wei Li, Qinjian Zhao, Ting Wu, Shu Chen, Jun Zhang, Ning-Shao Xia
Hepatitis E virus (HEV) infection is one of the main causes of acute hepatitis worldwide. A recombinant hepatitis E vaccine, HEV 239, has been licensed in China for immunizing adults of 16 y old and above. The vaccine antigen contains pORF2 aa 368 - 606 of the HEV genotype 1 expressed in E. coli. The quality of the vaccine is controlled through a combination of biophysical, biochemical and immunochemical methods. The vaccine is well tolerated in adults. The efficacy of the HEV 239 vaccine against symptomatic and asymptomatic infection had been proven to be high during a Phase III clinical trial and long-term follow up...
2015: Human Vaccines & Immunotherapeutics
https://www.readbyqxmd.com/read/24795447/hepatitis-e-virus-hev-protease-a-chymotrypsin-like-enzyme-that-processes-both-non-structural-porf1-and-capsid-porf2-protein
#6
Daizy Paliwal, Subrat Kumar Panda, Neeraj Kapur, Satya Pavan Kumar Varma, Hemlata Durgapal
Hepatitis E virus (HEV), a major cause of acute viral hepatitis across the world, is a non-enveloped, plus-strand RNA virus. Its genome codes three proteins, pORF1 (multifunctional polyprotein), pORF2 (capsid protein) and pORF3 (multi-regulatory protein). pORF1 encodes methyltransferase, putative papain-like cysteine protease, helicase and replicase enzymes. Of these, the protease domain has not been characterized. On the basis of sequence analysis, we cloned and expressed a protein covering aa 440-610 of pORF1, expression of which led to cell death in Escherichia coli BL-21 and Huh7 hepatoma cells...
August 2014: Journal of General Virology
https://www.readbyqxmd.com/read/24662711/bacteria-expressed-hepatitis-e-virus-capsid-proteins-maintain-virion-like-epitopes
#7
Minxi Wei, Xiao Zhang, Hai Yu, Zi-Min Tang, Kaihang Wang, Zhongyi Li, Zizheng Zheng, Shaowei Li, Jun Zhang, Ningshao Xia, Qinjian Zhao
The protein encoded by ORF2 in hepatitis E virus (HEV) is the only capsid protein for this single-stranded RNA virus. It was previously shown that 148 aa (aa 459-606) was needed for dimer formation, whereas 239 aa (aa 368-606) was necessary to form virus-like particles (VLPs). The self-assembled VLPs of p239 were characterized with a series of methods including high performance size-exclusion chromatography to demonstrate the particulate nature of purified and properly refolded p239. A neutralizing and protective mouse monoclonal antibody (mAb) 8C11 was previously shown to bind three discontinuous peptide segments in the dimer...
May 19, 2014: Vaccine
https://www.readbyqxmd.com/read/23508432/evaluation-of-antigenicity-and-cell-mediated-immunity-of-hepatitis-e-virus-patients-using-non-radioactive-mtt-assay
#8
M Majumdar, R Ratho, Y Chawla, M P Singh
Hepatitis E virus (HEV) is an important cause of hepatitis in developing nations. Disease spans from asymptomatic infection to acute viral hepatitis (AVH) and acute liver failure (ALF). Cell-mediated immunity (CMI) is less studied. Studies document CMI in HEV patients using [3 H]-thymidine incorporation (radioactive in nature). The aim of this study was to evaluate the antigenicity of recombinant HEV ORF 2 peptide (452-617 a.a) (pORF2) by non-radioactive MTT assay and detecting the proliferation indices of primary PBMC culture...
January 2013: Indian Journal of Medical Microbiology
https://www.readbyqxmd.com/read/22571906/hepatitis-e-virus-enters-liver-cells-through-receptor-dependent-clathrin-mediated-endocytosis
#9
N Kapur, D Thakral, H Durgapal, S K Panda
We investigated the virus-host interaction for hepatitis E virus (HEV) by performing competitive binding assays using in vitro assembled virus-like particles (VLPs). We used Escherichia coli expressed native capsid protein (pORF2) and its mutants with an attached Gly((5))-Ala (linker) reporter [enhanced green fluorescent protein (EGFP)/firefly luciferase (Fluc)]. Transmission electron microscopy and nanoparticle tracking showed near uniform particles of approximately 30-35 nm in diameter for pORF2 VLPs and 60-100 nm for reporter-linked VLPs...
June 2012: Journal of Viral Hepatitis
https://www.readbyqxmd.com/read/22239516/immunohistochemistry-for-the-diagnosis-of-hepatitis-e-virus-infection
#10
COMPARATIVE STUDY
P Gupta, N Jagya, S B Pabhu, H Durgapal, S K Acharya, S K Panda
Hepatitis E virus (HEV) is an emerging pathogen and the most common cause of acute viral hepatitis all over the world. We describe here an immunohistochemical method for the detection of HEV antigens (pORF2 and pORF3) in formalin-fixed, paraffin-embedded liver tissues using monoclonal antibodies raised against two of the virus proteins (pORF2 and pORF3). We analysed their specificity and sensitivity in comparison with serology and nucleic acid detection in cases of acute liver failure (ALF). We used this test on 30 liver biopsies collected post-mortem from the patients of ALF caused by HEV infection...
February 2012: Journal of Viral Hepatitis
https://www.readbyqxmd.com/read/21931509/identification-and-characterization-of-two-critical-sequences-in-sv40polya-that-activate-the-green-fluorescent-protein-reporter-gene
#11
Honggang Wang, Wuzhuang Sun, Zhu Li, Xiufang Wang, Zhanjun Lv
Alu repeats or Line-1-ORF2 (ORF2) inhibit expression of the green fluorescent protein (GFP) gene when inserted downstream of this gene in the vector pEGFP-C1. In this work, we studied cis-acting elements that eliminated the repression of GFP gene expression induced by Alu and ORF2 and sequence characteristics of these elements. We found that sense and antisense PolyA of simian virus 40 (SV40PolyA, 240 bp) eliminated the repression of GFP gene expression when inserted between the GFP gene and the Alu (283 bp) repeats or ORF2 (3825 bp) in pAlu14 (14 tandem Alu repeats were inserted downstream of the GFP gene in the vector pEGFP-C1) or pORF2...
July 2011: Genetics and Molecular Biology
https://www.readbyqxmd.com/read/21123540/hepatitis-e-virus-replication-involves-alternating-negative-and-positive-sense-rna-synthesis
#12
Satya Pavan Kumar Varma, Amit Kumar, Neeraj Kapur, Hemlata Durgapal, Subrat Kumar Acharya, Subrat Kumar Panda
Hepatitis E virus (HEV) is the major cause of epidemic hepatitis and many outbreaks of sporadic hepatitis. The virus responsible has a single-stranded, positive-sense RNA. Its replication and the regulatory process involved therein are poorly understood. Much of the HEV biology studied has been done by using full-length capped RNA transcripts (replicons) and transient transfections in cell cultures. We investigated replicon replication using negative-sense strand-specific molecular beacons in live cell imaging, and quantifying intracellular viral RNA using strand-specific real-time PCR every 2 h until 24 h post-transfection...
March 2011: Journal of General Virology
https://www.readbyqxmd.com/read/21068233/spatial-configuration-of-hepatitis-e-virus-antigenic-domain
#13
Li Xing, Joseph C Wang, Tian-Cheng Li, Yasuhiro Yasutomi, James Lara, Yury Khudyakov, Darren Schofield, Suzanne U Emerson, Robert H Purcell, Naokazu Takeda, Tatsuo Miyamura, R Holland Cheng
Hepatitis E virus (HEV) is a human pathogen that causes acute hepatitis. When an HEV capsid protein containing a 52-amino-acid deletion at the C terminus and a 111-amino-acid deletion at the N terminus is expressed in insect cells, the recombinant HEV capsid protein can self-assemble into a T=1 virus-like particle (VLP) that retains the antigenicity of the native HEV virion. In this study, we used cryoelectron microscopy and image reconstruction to show that anti-HEV monoclonal antibodies bind to the protruding domain of the capsid protein at the lateral side of the spikes...
January 2011: Journal of Virology
https://www.readbyqxmd.com/read/20962536/evidence-of-hepatitis-e-virus-exposure-among-seronegative-healthy-residents-of-an-endemic-area
#14
Mohammad Mushtaq Husain, Ratika Srivastava, Rama Akondy, Rakesh Aggarwal, Shahid Jameel, Sita Naik
OBJECTIVE: Hepatitis E virus (HEV) infection is endemic in the Indian subcontinent. Detection of serum anti-HEV IgG has traditionally been used to determine prior exposure to this virus. We studied HEV-specific recall immune responses in healthy subjects with and without detectable anti-HEV IgG. METHODS: Memory B and T cells specific for HEV recombinant proteins pORF2 and pORF3 were estimated among healthy subjects residing in an HEV-endemic region using enzyme-linked immunospot (ELISPOT) assays...
2011: Intervirology
https://www.readbyqxmd.com/read/19812150/heparan-sulfate-proteoglycans-are-required-for-cellular-binding-of-the-hepatitis-e-virus-orf2-capsid-protein-and-for-viral-infection
#15
Manjula Kalia, Vivek Chandra, Sheikh Abdul Rahman, Deepak Sehgal, Shahid Jameel
The hepatitis E virus (HEV), a nonenveloped RNA virus, is the causative agent of hepatitis E. The mode by which HEV attaches to and enters into target cells for productive infection remains unidentified. Open reading frame 2 (ORF2) of HEV encodes its major capsid protein, pORF2, which is likely to have the determinants for virus attachment and entry. Using an approximately 56-kDa recombinant pORF2 that can self-assemble as virus-like particles, we demonstrated that cell surface heparan sulfate proteoglycans (HSPGs), specifically syndecans, play a crucial role in the binding of pORF2 to Huh-7 liver cells...
December 2009: Journal of Virology
https://www.readbyqxmd.com/read/19709712/interference-of-porcine-circovirus-type-2-orf2-immunogenicity-by-orf1-and-orf3-mixed-dna-immunizations-in-mice
#16
Hui-Gang Shen, Ji-Yong Zhou, Xin Zhang, Zhen-Yu Huang, Jia-Ling He, Yan Yan
Little is known about the influences of other porcine circovirus type 2 (PCV2) proteins on the immunogenicity of Cap protein. Here we constructed plasmids expressing the ORF1 (pORF1) and ORF3 (pORF3) of PCV2, and mixed either of them with the plasmid expressing ORF2 (pORF2) as combined DNA vaccines, to compare their immunogenicity and protective efficacy. Our data revealed that pORF1 reduced the Cap-specific CD8(+)cell frequency, and both pORF1 and pORF3 attenuated the Cap-specific Th1 and post-challenge-recall VN antibody responses induced by the pORF2 plasmid, despite successful induction of Rep and ORF3 antibodies by pORF1 and pORF3, respectively...
October 10, 2009: Virology
https://www.readbyqxmd.com/read/18632956/protective-immunity-against-porcine-circovirus-2-by-vaccination-with-orf2-based-dna-and-subunit-vaccines-in-mice
#17
Hui-Gang Shen, Ji-Yong Zhou, Zhen-Yu Huang, Jun-Qing Guo, Gang Xing, Jia-Ling He, Yan Yan, Li-Yang Gong
The protective immune response against porcine circovirus 2 (PCV2) infection in mice was characterized using flow cytometric analysis (FCM), assays of antibody (of different IgG isotypes) and viraemia, and histopathological examination. An open reading frame 2 plasmid (pORF2) and the capsid protein (Cap) of PCV2 were used as DNA and subunit vaccines, respectively. In FCM analysis, although pORF2 and Cap alone showed comparable efficacy in eliciting lymphoproliferative responses and Cap-specific CD4(+) T cells, pORF2 was superior to the Cap protein in triggering CD8(+) T cells...
August 2008: Journal of General Virology
https://www.readbyqxmd.com/read/16643795/-expression-purification-and-immunogenicity-of-a-novel-hepatitis-e-virus-like-particle
#18
Chen Dong, Ji-hong Meng
AIM: To express and characterize a novel hepatitis E virus (HEV) recombinant protein which contains HEV neutralization epitope(s). METHODS: The gene fragment encoding for amino acid 452-617 of HEV open reading frame 2 protein (pORF2) was inserted into the plasmid pET28a(+). The recombinant plasmid was used to transform the E. coli BL21(DE3) strain. The recombinant protein was expressed by IPTG induction, purified by Ni-NTA chromatography and analyzed by SDS-PAGE, Western blot and electronmicroscopy...
May 2006: Xi Bao Yu Fen Zi Mian Yi Xue za Zhi, Chinese Journal of Cellular and Molecular Immunology
https://www.readbyqxmd.com/read/16242219/the-effect-of-antigen-targeting-sequences-on-antibody-responses-to-hepatitis-e-virus-dna-vaccines-in-rats-and-sheep
#19
Fan Li, Paxton Loke, Anne Healy, Marshall W Lightowlers, Charles G Gauci, Damian F J Purcell, David A Anderson
Expression of the capsid (PORF2) protein of hepatitis E virus (HEV) in mammalian cells results in heterogeneous intracellular processing with a mixture of stable and rapidly degraded forms, which might be expected to influence immune responses to DNA immunisation. Plasmids encoding the N-terminal 22 or 50 amino acids of PORF2 (Sig1 or Sig3, respectively) fused at the N-terminus of the ORF2.1 antigen of HEV (amino acids 394-660 of PORF2) were examined for processing in vitro and antibody responses in vivo, in both rats and sheep...
February 27, 2006: Vaccine
https://www.readbyqxmd.com/read/16108497/-interface-domain-of-hepatitis-e-virus-capsid-protein-homodimer
#20
Shao-Wei Li, Zhi-Qiang He, Ying-Bin Wang, Yi-Xin Chen, Ru-Shi Liu, Jian Lin, Ying Gu, Jun Zhang, Ning-Shao Xia
Hepatitis E is a main cause of acute viral hepatitis in developing countries where it occurs as sporadic cases and in epidemics form. The causative agent, hepatitis E virus, is transmitted primarily by the fecal-oral route. The approximately 7.5 kb positive-sense single-strand RNA genome includes three open reading frames (ORFs), one of which (ORF2) is postulated to encode the major viral capsid protein (pORF2) of 660 amino acid residues. We earlier showed that a bacterially expressed peptide, designated as NE2, located from amino acid residues 394 to 606 of ORF2, was found to aggregate into homodimer to at least hexamer...
January 2004: Sheng Wu Gong Cheng Xue Bao, Chinese Journal of Biotechnology
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