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Shayeghpour A, Kianfar R, Hosseini P, Ajorloo M, Aghajanian S, Hedayat Yaghoobi M, Hashempour T, Mozhgani SH. Hepatitis C virus DNA vaccines: a systematic review. Virol J 2021; 18:248. [PMID: 34903252 PMCID: PMC8667529 DOI: 10.1186/s12985-021-01716-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 11/26/2021] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Vaccination against HCV is an effective measure in reduction of virus-related public health burden and mortality. However, no prophylactic vaccine is available as of yet. DNA-based immunization is a promising modality to generate cellular and humoral immune responses. The objective of this study is to provide a systematic review of HCV DNA vaccines and investigate and discuss the strategies employed to optimize their efficacies. METHODS MEDLINE (PubMed), Web of Science, Scopus, ScienceDirect, and databases in persian language including the Regional Information Centre for Science & Technology (RICeST), the Scientific Information Database and the Iranian Research Institute for Information Science and Technology (IranDoc) were examined to identify studies pertaining to HCV nucleic acid vaccine development from 2000 to 2020. RESULTS Twenty-seven articles were included. Studies related to HCV RNA vaccines were yet to be published. A variety of strategies were identified with the potential to optimize HCV DNA vaccines such as incorporating multiple viral proteins and molecular tags such as HBsAg and Immunoglobulin Fc, multi-epitope expression, co-expression plasmid utilization, recombinant subunit immunogens, heterologous prime-boosting, incorporating NS3 mutants in DNA vaccines, utilization of adjuvants, employment of less explored methods such as Gene Electro Transfer, construction of multi- CTL epitopes, utilizing co/post translational modifications and polycistronic genes, among others. The effectiveness of the aforementioned strategies in boosting immune response and improving vaccine potency was assessed. CONCLUSIONS The recent progress on HCV vaccine development was examined in this systematic review to identify candidates with most promising prophylactic and therapeutic potential.
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Affiliation(s)
- Ali Shayeghpour
- Student Research Committee, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran
| | - Roya Kianfar
- Department of Medical Virology, Tarbiat Modares University, Tehran, Iran
| | - Parastoo Hosseini
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
- Research Center for Clinical Virology, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Ajorloo
- Hepatitis Research Center, Lorestan University of Medical Sciences, Khorramabad, Iran
- Department of Clinical Laboratory Sciences, School of Allied Medicine, Lorestan University of Medical Sciences, Khorramabad, Iran
| | - Sepehr Aghajanian
- Student Research Committee, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran
| | - Mojtaba Hedayat Yaghoobi
- Department of Infectious Disease, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran
| | - Tayebeh Hashempour
- Shiraz HIV/AIDS Research Center, Institute of Health, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Sayed-Hamidreza Mozhgani
- Non-Communicable Diseases Research Center, Alborz University of Medical Sciences, Karaj, Iran.
- Department of Microbiology, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran.
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Ansari N, Rafati S, Taheri T, Roohvand F, Farahmand M, Hajikhezri Z, Keshavarz A, Samimi-Rad K. A non-pathogenic Leishmania tarentolae vector based- HCV polytope DNA vaccine elicits potent and long lasting Th1 and CTL responses in BALB/c mice model. Mol Immunol 2019; 111:152-161. [PMID: 31054409 DOI: 10.1016/j.molimm.2019.04.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 04/11/2019] [Accepted: 04/23/2019] [Indexed: 02/06/2023]
Abstract
Despite successful anti-viral (DAAs) treatment of Hepatitis C virus (HCV) infection, recent data indicated the need for an effective vaccine. Preexisting anti-vector immunity is an obstacle for application of live vectors for antigen delivery and development of effective T-cell based HCV vaccines. Herein, we report construction of recombinant Leishmania tarentolae, a lizard (non-human) parasite, expressing an HCV polytope DNA, PT-NT(gp96), encoding for several immunogenic HCV epitopes and evaluation of its immunogenicity in three different prime/boost immunization groups (G) of BALB/c mice. Homologous prime/boost immunization by L.tarentolae-PT-NT(gp96) either with or without CpG (G1 and G2 respectively) and heterologous immunization with a PT-NT(gp96) encoding-pCDNA plasmid followed by L.tarentolae-PT-NT (G3) was undertaken. Immune responses were measured three and nine weeks (W) post immunization. Splenocytes (cultured with antigen-stimulant) of mice in G1 showed the highest percentage of specific CTL-cytolytic activity compared to G2 and G3 at both short (W3:70.98% versus 41.29% and 13.12%) and long (W9: 50% versus 24.5% and 20%) term periods, accompanied with high levels of secreted IFN-γ. Comparison of IFN-γ, IL-4, IL-17 and TNF-α cytokines levels obtained from the supernatant of antigen-stimulated splenocytes as well as antibodies level (as IgG1/IgG2a ratio; obtained from sera of immunized mice) indicated higher Th1 oriented responses for G1, G2 groups and balanced Th1-Th17 for G3. Results indicated the potential of L.tarentolae (+CpG), as a non-pathogenic live vaccine vector, for delivery and enhancement of immune responses against HCV-polytope antigens.
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Affiliation(s)
- Nastaran Ansari
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Sima Rafati
- Department of Immunotherapy and Leishmania Vaccine Research, Pasteur Institute of Iran, Tehran, Iran
| | - Tahereh Taheri
- Department of Immunotherapy and Leishmania Vaccine Research, Pasteur Institute of Iran, Tehran, Iran
| | - Farzin Roohvand
- Department of Virology, Pasteur Institute of Iran, Tehran, Iran
| | - Mohammad Farahmand
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Zamaneh Hajikhezri
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Abolfazl Keshavarz
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Katayoun Samimi-Rad
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
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Zhao D, Han K, Zhang L, Wang H, Tian Y, Huang X, Liu Q, Yang J, Liu Y, Li Y. Identification and immunogenic evaluation of T cell epitopes based on tembusu virus envelope protein in ducks. Virus Res 2018; 257:74-81. [DOI: 10.1016/j.virusres.2018.09.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 09/06/2018] [Accepted: 09/17/2018] [Indexed: 10/28/2022]
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Chen XY, Li DZ, Zhong XZ, Chen B, Duan ZL, Wen JS. Induction of multiple cytotoxic T lymphocyte responses in mice by a multiepitope DNA vaccine against dengue virus serotype 1. Microbiol Immunol 2017; 60:835-845. [PMID: 27981613 DOI: 10.1111/1348-0421.12457] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 11/14/2016] [Accepted: 12/02/2016] [Indexed: 12/20/2022]
Abstract
Dengue virus (DENV) is still a major threat to human health in most tropical and subtropical countries and regions. In the present study, a multi-epitope DNA vaccine that encodes 15 immunogenic and conserved HLA-A*0201-, HLA-A*1101-, HLA-A*2402-restricted CTL epitopes from DENV serotype 1 (DENV-1) was constructed based on the eukaryotic expressing plasmid pcDNATM 3.1/myc-His(-) A. Immunization of HLA-A*0201, HLA-A*1101 and HLA-A*2402 transgenic mice with the recombinant plasmid pcDNATM 3.1/myc-His(-) A-DENV-1-Meg resulted in significantly greater IFN-γ-secreting T-cell responses against most (14/15) CTL epitopes than occurred in mice immunized with the empty plasmid pcDNATM 3.1/myc-His(-) A. Additionally, the epitope-specific T cells directed to some epitopes secreted not only IFN-γ but also IL-6 and/or TNF-α. Finally, the induced epitope-specific T cells also efficiently lysed epitope-pulsed splenocytes and DENV-1-infected splenic monocytes. The present study confirms the immunogenicity of multi-epitope DENV vaccine, suggesting that it may contribute to the development of a universal DENV vaccine.
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Affiliation(s)
- Xin Yu Chen
- Department of Clinical Laboratory, Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Xueyuan West Road, Wenzhou 325000
| | - De Zhou Li
- Department of Liver, The Second Hospital of Ningbo, Ningbo 315010, China
| | - Xiao Zhi Zhong
- Institute of Arboviruses, School of Basic Medical Sciences, Wenzhou Medical University, Chashan, Wenzhou 32500
| | - Bokun Chen
- Institute of Arboviruses, School of Basic Medical Sciences, Wenzhou Medical University, Chashan, Wenzhou 32500
| | - Zhi Liang Duan
- Department of Clinical Laboratory, Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Xueyuan West Road, Wenzhou 325000
| | - Jin Sheng Wen
- Institute of Arboviruses, School of Basic Medical Sciences, Wenzhou Medical University, Chashan, Wenzhou 32500
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Gholizadeh M, Khanahmad H, Memarnejadian A, Aghasadeghi MR, Roohvand F, Sadat SM, Cohan RA, Nazemi A, Motevalli F, Asgary V, Arezumand R. Design and expression of fusion protein consists of HBsAg and Polyepitope of HCV as an HCV potential vaccine. Adv Biomed Res 2015; 4:243. [PMID: 26682209 PMCID: PMC4673707 DOI: 10.4103/2277-9175.168610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 03/16/2015] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Hepatitis C virus (HCV) infection is a serious public health threat worldwide. Cellular immune responses, especially cytotoxic T-lymphocytes (CTLs), play a critical role in immune response toward the HCV clearance. Since polytope vaccines have the ability to stimulate the cellular immunity, a recombinant fusion protein was developed in this study. MATERIALS AND METHODS The designed fusion protein is composed of hepatitis B surface antigen (HBsAg), as an immunocarrier, fused to an HCV polytope sequence. The polytope containing five immunogenic epitopes of HCV was designed to induce specific CTL responses. The construct was cloned into the pET-28a, and its expression was investigated in BL21 (DE3), BL21 pLysS, BL21 pLysE, and BL21 AI Escherichia coli strains using 12% gel sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Finally, the identity of expressed fusion protein was confirmed by Western blotting using anti-His monoclonal antibody and affinity chromatography was applied to purify the expressed protein. RESULTS The accuracy of the construct was confirmed by restriction map analysis and sequencing. The transformation of the construct into the BL21 (DE3), pLysS, and pLysE E. coli strains did not lead to any expression. The fusion protein was found to be toxic for E. coli DE3. By applying two steps inhibition, the fusion protein was successfully expressed in BL21 (AI) E. coli strain. CONCLUSION The HBsAg-polytope fusion protein expressed in this study can be further evaluated for its immunogenicity in animal models.
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Affiliation(s)
- Monireh Gholizadeh
- Department of Biology, Islamic Azad University, Tonekabon Branch, Tonekabon, Iran
| | - Hossein Khanahmad
- Department of Genetics, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | | | | | - Farzin Roohvand
- Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran
| | - Seyed Mehdi Sadat
- Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran
| | | | - Ali Nazemi
- Department of Biology, Islamic Azad University, Tonekabon Branch, Tonekabon, Iran
| | - Fatemeh Motevalli
- Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran
| | - Vahid Asgary
- Department Of Rabies, Pasteur Institute of Iran, Tehran, Iran ; Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Roghaye Arezumand
- Department of Molecular Medicine, Pasteur Institute of Iran, Tehran, Iran
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Pishraft Sabet L, Taheri T, Memarnejadian A, Mokhtari Azad T, Asgari F, Rahimnia R, Alavian SM, Rafati S, Samimi Rad K. Immunogenicity of Multi-Epitope DNA and Peptide Vaccine Candidates Based on Core, E2, NS3 and NS5B HCV Epitopes in BALB/c Mice. HEPATITIS MONTHLY 2014; 14:e22215. [PMID: 25419219 PMCID: PMC4238154 DOI: 10.5812/hepatmon.22215] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 09/10/2014] [Accepted: 09/21/2014] [Indexed: 12/11/2022]
Abstract
BACKGROUND Hypervariability of HCV proteins is an important obstacle to design an efficient vaccine for HCV infection. Multi-epitope vaccines containing conserved epitopes of the virus could be a promising approach for protection against HCV. OBJECTIVES Cellular and humoral immune responses against multi-epitope DNA and peptide vaccines were evaluated in BALB/c mice. MATERIALS AND METHODS In this experimental study, multi-epitope DNA- and peptide-based vaccines for HCV infection harboring immunodominant CD8+ T cell epitopes (HLA-A2 and H2-Dd) from Core (132-142), NS3 (1073-1081) and NS5B (2727-2735), a Th CD4+ epitope from NS3 (1248-1262) and a B-cell epitope from E2 (412-426) were designed. Multi-epitope DNA and peptide vaccines were tested in two regimens as heterologous DNA/peptide (group 1) and homologous peptide/peptide (group 2) prime/boost vaccine in BALB/c mice model. Electroporation was used for delivery of the DNA vaccine. Peptide vaccine was formulated with Montanide ISA 720 (M720) as adjuvant. Cytokine assay and antibody detection were performed to analyze the immune responses. RESULTS Mice immunized with multi-epitope peptide formulated with M720 developed higher HCV-specific levels of total IgG, IgG1 and IgG2a than those immunized with multi-epitope DNA vaccine. IFN-γ levels in group 2 were significantly higher than group 1 (i.e. 3 weeks after the last immunization; 37.61 ± 2.39 vs. 14.43 ± 0.43, P < 0.05). Moreover, group 2 had a higher IFN-γ/IL-4 ratio compared to group 1, suggesting a shift toward Th1 response. In addition, in the present study, induced immune responses were long lasting and stable after 9 weeks of the last immunization. CONCLUSIONS Evaluation of multi-epitope DNA and peptide-vaccines confirmed their specific immunogenicity in BALB/c mice. However, lower Th1 immune responses in mice immunized with DNA vaccine suggests further investigations to improve the immunogenicity of the multi-epitope DNA vaccine through immune enhancers.
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Affiliation(s)
- Leila Pishraft Sabet
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, IR Iran
- Razi Vaccine and Serum Research Institute, Karaj, IR Iran
| | - Tahereh Taheri
- Molecular Immunology and Vaccine Research Laboratory, Pasteur Institute of Iran, Tehran, IR Iran
| | | | - Talat Mokhtari Azad
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, IR Iran
| | - Fatemeh Asgari
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, IR Iran
| | - Ramin Rahimnia
- Department of Nano Medicine, School of Advanced Technologies in Medicine, Tehran, IR Iran
| | - Seyed Moayed Alavian
- Research Center for Gastroenterology and Liver Disease, Baqiyatallah University of Medical Sciences, Tehran, IR Iran
- Middle East Liver Disease Center (MELD), Tehran, IR Iran
| | - Sima Rafati
- Molecular Immunology and Vaccine Research Laboratory, Pasteur Institute of Iran, Tehran, IR Iran
| | - Katayoun Samimi Rad
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, IR Iran
- Corresponding Author: Katayoun Samimi Rad, Department of Virology, School of Public Health, Tehran University of Medical Sciences, P. O. Box: 6446, Tehran, IR Iran. Tel +98-2188950595; Fax: +98-2166462267, E-mail:
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Long-term functional duration of immune responses to HCV NS3/4A induced by DNA vaccination. Gene Ther 2014; 21:739-50. [PMID: 24871581 PMCID: PMC4126484 DOI: 10.1038/gt.2014.48] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Revised: 03/18/2014] [Accepted: 04/14/2014] [Indexed: 12/26/2022]
Abstract
We have investigated the ability of hepatitis C virus non-structural (NS) 3/4A-DNA-based vaccines to activate long-term cell-mediated immune responses in mice. Wild-type and synthetic codon optimized (co) NS3/4A DNA vaccines have previously been shown to be immunogenic in mice, rabbits and humans, although we have very poor knowledge about the longevity of the immune responses primed. We therefore analyzed the functionality of primed NS3/4A-specific immune responses in BALB/c (H-2d) and/or C57BL/6J (H-2b) mice 1, 2, 3, 4, 6, 12 and 16 months after the last immunization. Mice were immunized one, two, three or four times using gene gun delivery to the skin or by intramuscular administration. Immunological responses after immunization were monitored by protection against in vivo challenge of NS3/4A-expressing syngeneic tumor cells. In addition, functionality of the NS3/4A-specific T cells was analyzed by a standard cytotoxicity assay. First, we identified a new unique murine H-2d-restricted NS3/4A cytotoxic T lymphocyte (CTL) epitope, which enabled us to study the epitope-specific immune responses. Our results show that the coNS3/4A vaccine was highly immunogenic by determination of interferon-γ/tumor necrosis factor-α production and lytic cytotoxic T cells, which could efficiently inhibit in vivo tumor growth. Importantly, we showed that one to four monthly immunizations protected mice from tumor development when challenged up to 16 months after the last immunization. When determining the functionality of NS3/4A-specific T cells in vitro, we showed detectable lytic activity up to 12 months after the last immunization. Thus, NS3/4A-based DNA vaccines activate potent cellular immune responses that are present and function in both BALB/c and C57BL/6J mice up to 12–16 months after the last immunization. The induction of long-term immunity after NS3/4A DNA immunization has not been shown previously and supports the use of NS3/4A in hepatitis C virus vaccine compositions.
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Ip PP, Nijman HW, Wilschut J, Daemen T. Therapeutic vaccination against chronic hepatitis C virus infection. Antiviral Res 2012; 96:36-50. [PMID: 22841700 DOI: 10.1016/j.antiviral.2012.07.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2012] [Revised: 06/25/2012] [Accepted: 07/13/2012] [Indexed: 12/12/2022]
Abstract
Approximately 170 million people worldwide are chronic carriers of Hepatitis C virus (HCV). To date, there is no prophylactic vaccine available against HCV. The standard-of-care therapy for HCV infection involves a combination of pegylated interferon-α and ribavirin. This therapy, which is commonly associated with side effects, has a curative rate varying from 43% (HCV genotype 1) to 80% (HCV genotype 2). In 2011, two direct-acting antiviral agents, telaprevir and boceprevir, were approved by the US Food and drug Administration and are now being used in combination with standard-of-care therapy in selected patients infected with HCV genotype 1. Although both drugs are promising, resulting in a shortening of therapy, these drugs also induce additional side effects and have reduced efficacy in patients who did not respond to standard-of-care previously. An alternative approach would be to treat HCV by stimulating the immune system with a therapeutic vaccine ideally aimed at (i) the eradication of HCV-infected cells and (ii) neutralization of infectious HCV particles. The challenge is to develop therapeutic vaccination strategies that are either at least as effective as antiviral drugs but with lower side effects, or vaccines that, when combined with antiviral drugs, can circumvent long-term use of these drugs thereby reducing their side effects. In this review, we summarize and discuss recent preclinical developments in the area of therapeutic vaccination against chronic HCV infection. Although neutralizing antibodies have been described to exert protective immunity, clinical studies on the induction of neutralizing antibodies in therapeutic settings are limited. Therefore, we will primarily discuss therapeutic vaccines which aim to induce effective cellular immune response against HCV.
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Affiliation(s)
- Peng Peng Ip
- Department of Medical Microbiology, Molecular Virology Section, University of Groningen, University Medical Center Groningen, The Netherlands
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Duan L, Lei P, Yumei X, Xiaoping X, Futao Z, Li M, Xin W, Jiuping W, Xuefan B, Zhansheng J. Prediction and identification-based prediction of Chinese hepatitis C viral-specific cytotoxic T lymphocyte epitopes. J Med Virol 2011; 83:1315-20. [DOI: 10.1002/jmv.22053] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/23/2010] [Indexed: 11/08/2022]
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Memarnejadian A, Roohvand F. Fusion of HBsAg and prime/boosting augment Th1 and CTL responses to HCV polytope DNA vaccine. Cell Immunol 2010; 261:93-8. [PMID: 20056196 DOI: 10.1016/j.cellimm.2009.11.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Revised: 11/01/2009] [Accepted: 11/13/2009] [Indexed: 12/19/2022]
Abstract
Correlation of hepatitis C virus (HCV) spontaneous resolution with Th1 and CD8(+)CTL responses during natural infection implies the potentiality of poly-CTL-epitopic HCV vaccines. We recently reported in silico design and construction of DNA vaccines (pcPOL-plasmids) harboring HCV CTL epitopes. Herein, we provide data of mice immunization by pcPOL, (encoding; core(132-142) [C], E2(405-414) [E(4)], E2(614-622) [E(6)] and NS3(1406-1415) [N] CD8(+)CTL epitopes as CE(4)E(6)N polytope) and its HBsAg-fused counterpart (pcHPOL), compared to the adjuvant-formulated (Montanide+CpG) CE(4)E(6)N synthetic-peptide immunization. All vaccinated groups developed different levels of cellular responses, however, only the pcHPOL-immunized mice elicited strong CTLs and IFN-gamma-secreting cells that were further augmented towards a Th1 response and partial tumor protection by DNA-prime/peptide-boosting regimen. Priming with HBsAg alone could not afford its augmenting effect indicating the importance of priming by polytope itself. Hence, fusion of immunocarriers like HBsAg conjoined with DNA-prime/peptide-boost immunization regimen seems a strategy to enhance the epitope-specific immune responses towards poly-CTL-epitopic vaccines.
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Affiliation(s)
- Arash Memarnejadian
- Hepatitis & AIDS Department-NRGB Laboratory, Pasteur institute of Iran, Tehran, Iran
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Construction of HCV-polytope vaccine candidates harbouring immune-enhancer sequences and primary evaluation of their immunogenicity in BALB/c mice. Virus Genes 2009; 40:44-52. [PMID: 19882243 DOI: 10.1007/s11262-009-0417-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Accepted: 10/15/2009] [Indexed: 01/30/2023]
Abstract
An efficient vaccine against hepatitis-C virus (HCV) infection requires vigorous and focused CD8(+) T-cell responses against viral antigens. Due to immunosuppressive effect of HCV antigens, polytope vaccines comprising the minimal CD8(+)CTL epitopes are of peculiar concern. Herein, to provide information for construction of efficient HCV polytope vaccine candidates, one H-2D(d) (E2(405-414):E(2)) and two HLA-A*0201 (E1(363-372):E(1) and Core(35-44):C)-restricted CD8(+) T-cell epitopes of HCV were selected. By employing number of in silico analyses, the E(2)E(1)C linear format was predicted as optimum epitope consecution and after amplification by SOEing-PCR, the corresponding DNA sequence was cloned in pcDNA3.1+ vector. To further evaluate the role of immune-enhancer elements, a universal T-helper epitope (PADRE), endoplasmic reticulum signal sequence (ERss) and hepatitis-B surface-antigen (HBsAg) gene were fused separately or in combination to the E(2)E(1)C minigene. In vitro analyses of polytopes by different DNA/protein-based assays demonstrated proper transcription/expression of constructs in transfected cells. Measurement of the HBsAg-mediated particle secretion by ELISA indicated lack of secretion in the related polytopes. Results of delayed-type hypersensitivity (DTH) as a preliminary in vivo analysis, and confirmatory ELISPOT assays showed the proper processing and presentation of H-2D(d)-restricted-E(2) epitope and approved the enhancing effect of PADRE and ERss sequences but not HBsAg for the immune responses against E(2) in immunized BALB/c mice. Our results pointed to the value of in silico predictions and application of immune-enhancer elements as well as DTH analysis for design and primary in vivo evaluation of HCV polytopes, prior to costly transgenic studies on immunogenicity of HLA-A*0201 epitopes.
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