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Koutsoumpli G, Ip PP, Schepel I, Hoogeboom BN, Boerma A, Daemen T. Alphavirus-based hepatitis C virus therapeutic vaccines: can universal helper epitopes enhance HCV-specific cytotoxic T lymphocyte responses? Ther Adv Vaccines Immunother 2019; 7:2515135519874677. [PMID: 31620673 PMCID: PMC6777054 DOI: 10.1177/2515135519874677] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 07/31/2019] [Indexed: 12/28/2022] Open
Abstract
Background: Antigen-specific T cell immune responses play a pivotal role in resolving
acute and chronic hepatitis C virus (HCV) infections. Currently, no
prophylactic or therapeutic vaccines against HCV are available. We
previously demonstrated the preclinical potency of therapeutic HCV vaccines
based on recombinant Semliki Forest virus (SFV) replicon particles. However,
clinical trials do not always meet the high expectations of preclinical
studies, thus, optimization of vaccine strategies is crucial. In efforts to
further increase the frequency of HCV-specific immune responses in the
candidate SFV-based vaccines, the authors assessed whether inclusion of
three strong, so-called universal helper T cell epitopes, and an endoplasmic
reticulum localization, and retention signal (collectively termed
sigHELP-KDEL cassette) could enhance HCV-specific immune responses. Methods: We included the sigHELP-KDEL cassette in two of the candidate SFV-based HCV
vaccines, targeting NS3/4A and NS5A/B proteins. We characterized the new
constructs in vitro for the expression and stability of the
transgene-encoded proteins. Their immune efficacy with respect to
HCV-specific immune responses in vivo was compared with the
parental SFV vaccine expressing the corresponding HCV antigen. Further
characterization of the functionality of the HCV-specific CD8+ T
cells was assessed by surface and intracellular cytokine staining and flow
cytometry analysis. Results: Moderate, but significantly, enhanced frequencies of antigen-specific immune
responses were achieved upon lower/suboptimal dosage immunization. In
optimal dosage immunization, the inclusion of the cassette did not further
increase the frequencies of HCV-specific CD8+ T cells when
compared with the parental vaccines and the frequencies of effector and
memory populations were identical. Conclusion: We hypothesize that the additional effect of the sigHELP-KDEL cassette in
SFV-based vaccines depends on the immunogenicity, nature, and stability of
the target antigen expressed by the vaccine.
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Affiliation(s)
- Georgia Koutsoumpli
- Department of Medical Microbiology, Tumor Virology and Cancer Immunotherapy, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Peng Peng Ip
- Department of Medical Microbiology, Tumor Virology and Cancer Immunotherapy, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Ilona Schepel
- Department of Medical Microbiology, Tumor Virology and Cancer Immunotherapy, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Baukje Nynke Hoogeboom
- Department of Medical Microbiology, Tumor Virology and Cancer Immunotherapy, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Annemarie Boerma
- Department of Medical Microbiology, Tumor Virology and Cancer Immunotherapy, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Toos Daemen
- Department of Medical Microbiology, Tumor Virology and Cancer Immunotherapy, University of Groningen, University Medical Center Groningen, Antonius Deusinglaan 1, Groningen, 9713 AV, the Netherlands
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2
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Sun Y, Pan W, Zhang J, Cui Y, Wang H, Ru G, Chen L. Complex TNF-α B cell epitope MAP vaccine alleviates murine ulcerative colitis. Int J Mol Med 2019; 44:1106-1116. [PMID: 31524230 DOI: 10.3892/ijmm.2019.4271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 07/01/2019] [Indexed: 11/06/2022] Open
Abstract
The present study aimed to develop a tumor necrosis factor‑α (TNF‑α) B‑cell epitope/IL‑1β helper T lymphocyte epitope complex MAP vaccine for the alleviation of ulcerative colitis (UC) in mice. The B cell epitopes of murine TNF‑α (mTNF‑α) were predicted in silico and coupled with the universal interleukin 1β (IL‑1β) helper T‑cell epitope peptide VQGEESNDK to synthesize the eight‑branched MAP vaccine. Then, the immunological effects of the MAP vaccine were assessed in vitro and in vivo, as well as its impacts on DAI index, serum DAO levels, colon tissue tight junction protein amounts, ultrastructural changes, and MPO activity in BALB/c mice with UC. The amino acids LTLRSSSQNSSDKPV at positions 78‑92 of mTNF‑α may constitute the dominant B cell epitope. Based on this finding, an eight‑branched peptide structure, the TNF‑α B‑cell epitope/IL‑1β helper T‑cell epitope complex MAP vaccine, was synthesized. Indirect ELISA confirmed that MAP had a high affinity with commercialized mTNF‑α antibodies. Meanwhile, MAP induced high specific antibody titers in vivo, reduced the DAI score, serum MPO activity, colorectal lymph node colony count, ultrastructural injuries, colon tissue histological index score and MPO activity in UC mice, while increasing the expression levels of occludin, claudin1 and ZO1 in colon tissues. The synthetic complex MAP vaccine has good antigenicity and immunogenicity, and can alleviate UC in mouse models.
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Affiliation(s)
- Yan Sun
- The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Wensheng Pan
- Department of Gastroenterology, People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang 310014, P.R. China
| | - Jun Zhang
- Department of Gastroenterology, People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang 310014, P.R. China
| | - Ying Cui
- Department of Nuclear Medicine, People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang 310014, P.R. China
| | - Huiju Wang
- Key Laboratory of Gastroenterology of Zhejiang Province, People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang 310014, P.R. China
| | - Guoqing Ru
- Department of Pathology, People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang 310014, P.R. China
| | - Legao Chen
- Department of Vascular Surgery, People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang 310014, P.R. China
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3
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Antigenicity Identification of a Novel Recombinant Multi-Epitope Antigen Based on FlaA and UreB Antigens of Helicobacter pylori. Jundishapur J Microbiol 2019. [DOI: 10.5812/jjm.66502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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4
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Wang Y, Alahdal M, Ye J, Jing L, Liu X, Chen H, Jin L, Cao R. Inhibition of RM-1 prostate carcinoma and eliciting robust immune responses in the mouse model by using VEGF-M 2-GnRH 3-hinge-MVP vaccine. Genes Immun 2018; 20:245-254. [PMID: 29362508 DOI: 10.1038/s41435-017-0005-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Revised: 07/25/2017] [Accepted: 08/08/2017] [Indexed: 12/27/2022]
Abstract
GnRH and VEGF have been investigated as prostate carcinoma enhancers that support tumor spread and progression. Although both have documented roles in prostate carcinoma and many cancer types, the weak immunogenicity of these peptides has remained a major challenge for use in immunotherapy. Here, we describe a novel strategy to inhibit GnRH and VEGF production and assess the effect on the immune responses against these hormones using the RM-1 prostate cancer model. We designed a novel recombinant fusion protein which combined GnRH and VEGF as a vaccine against this tumor. The newly constructed fusion protein hVEGF121-M2-GnRH3-hinge-MVP contains the human vascular endothelial growth factor (hVEGF121) and three copies of GnRH in sequential linear alignment and T helper epitope MVP as an immunogenic vaccine. The effectiveness of the vaccine in eliciting an immune response and attenuating the prostate tumor growth was evaluated. Results showed that administration of a new vaccine effectively elicited humoral and cellular immune responses. We found that, a novel fusion protein, hVEGF121-M2-GnRH3-hinge-MVP, effectively inhibited growth of RM-1 prostate model and effectively promoted immune response. In conclusion, hVEGF121-M2-GnRH3-hinge-MVP is an effective dual mechanism tumor vaccine that limits RM-1 prostate growth. This vaccine may be a promising strategy for the treatment of hormone refractory prostate malignancies.
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Affiliation(s)
- Yiqin Wang
- Department of Biochemistry, Minigene Pharmacy Laboratory, School of Life Science and Technology, China Pharmaceutical University, TongjiaXiang 24, Nanjing, 210009, China
| | - Murad Alahdal
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Screening, School of Life Science and Technology, China Pharmaceutical University, Tongjia Xiang 24, Nanjing, 210009, China
| | - Jia Ye
- Department of Biochemistry, Minigene Pharmacy Laboratory, School of Life Science and Technology, China Pharmaceutical University, TongjiaXiang 24, Nanjing, 210009, China
| | - Liangliang Jing
- Department of Biochemistry, Minigene Pharmacy Laboratory, School of Life Science and Technology, China Pharmaceutical University, TongjiaXiang 24, Nanjing, 210009, China
| | - Xiaoxin Liu
- Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Tongjia Xiang 24, Nanjing, 210009, China
| | - Huan Chen
- Department of Biochemistry, Minigene Pharmacy Laboratory, School of Life Science and Technology, China Pharmaceutical University, TongjiaXiang 24, Nanjing, 210009, China
| | - Liang Jin
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Screening, School of Life Science and Technology, China Pharmaceutical University, Tongjia Xiang 24, Nanjing, 210009, China.
| | - Rongyue Cao
- Department of Biochemistry, Minigene Pharmacy Laboratory, School of Life Science and Technology, China Pharmaceutical University, TongjiaXiang 24, Nanjing, 210009, China.
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5
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Lambricht L, Vanvarenberg K, De Beuckelaer A, Van Hoecke L, Grooten J, Ucakar B, Lipnik P, Sanders NN, Lienenklaus S, Préat V, Vandermeulen G. Coadministration of a Plasmid Encoding HIV-1 Gag Enhances the Efficacy of Cancer DNA Vaccines. Mol Ther 2016; 24:1686-96. [PMID: 27434590 DOI: 10.1038/mt.2016.122] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 06/09/2016] [Indexed: 02/07/2023] Open
Abstract
DNA vaccination holds great promise for the prevention and treatment of cancer and infectious diseases. However, the clinical ability of DNA vaccines is still controversial due to the limited immune response initially observed in humans. We hypothesized that electroporation of a plasmid encoding the HIV-1 Gag viral capsid protein would enhance cancer DNA vaccine potency. DNA electroporation used to deliver plasmids in vivo, induced type I interferons, thereby supporting the activation of innate immunity. The coadministration of ovalbumin (OVA) and HIV-1 Gag encoding plasmids modulated the adaptive immune response. This strategy favored antigen-specific Th1 immunity, delayed B16F10-OVA tumor growth and improved mouse survival in both prophylactic and therapeutic vaccination approaches. Similarly, a prophylactic DNA immunization against the melanoma-associated antigen gp100 was enhanced by the codelivery of the HIV-1 Gag plasmid. The adjuvant effect was not driven by the formation of HIV-1 Gag virus-like particles. This work highlights the ability of both electroporation and the HIV-1 Gag plasmid to stimulate innate immunity for enhancing cancer DNA vaccine immunogenicity and demonstrates interesting tracks for the design of new translational genetic adjuvants to overcome the current limitations of DNA vaccines in humans.
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Affiliation(s)
- Laure Lambricht
- Advanced Drug Delivery and Biomaterials, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Kevin Vanvarenberg
- Advanced Drug Delivery and Biomaterials, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Ans De Beuckelaer
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Lien Van Hoecke
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.,VIB Medical Biotechnology Center, Ghent University, Ghent, Belgium
| | - Johan Grooten
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Bernard Ucakar
- Advanced Drug Delivery and Biomaterials, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Pascale Lipnik
- Bio and Soft Matter, Université catholique de Louvain, Louvain-La-Neuve, Belgium
| | - Niek N Sanders
- Laboratory of Gene Therapy, Ghent University, Ghent, Belgium.,Cancer Research Institute Ghent, Ghent, Belgium
| | - Stefan Lienenklaus
- Institute for Laboratory Animal Science, Hannover Medical School, Hannover, Germany.,Institute for Experimental Infection Research, Centre for Experimental and Clinical Infection Research, TWINCORE, Hannover, Germany
| | - Véronique Préat
- Advanced Drug Delivery and Biomaterials, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Gaëlle Vandermeulen
- Advanced Drug Delivery and Biomaterials, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
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6
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Yang Y, Sun W, Guo J, Zhao G, Sun S, Yu H, Guo Y, Li J, Jin X, Du L, Jiang S, Kou Z, Zhou Y. In silico design of a DNA-based HIV-1 multi-epitope vaccine for Chinese populations. Hum Vaccin Immunother 2015; 11:795-805. [PMID: 25839222 DOI: 10.1080/21645515.2015.1012017] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The development of an HIV-1 vaccine that is capable of inducing effective and broadly cross-reactive humoral and cellular immune responses remains a challenging task because of the extensive diversity of HIV-1, the difference of virus subtypes (clades) in different geographical regions, and the polymorphism of human leukocyte antigens (HLA). We performed an in silico design of 3 DNA vaccines, designated pJW4303-MEG1, pJW4303-MEG2 and pJW4303-MEG3, encoding multi-epitopes that are highly conserved within the HIV-1 subtypes most prevalent in China and can be recognized through HLA alleles dominant in China. The pJW4303-MEG1-encoded protein consisted of one Th epitope in Env, and one, 2, and 6 epitopes in Pol, Env, and Gag proteins, respectively, with a GGGS linker sequence between epitopes. The pJW4303-MEG2-encoded protein contained similar epitopes in a different order, but with the same linker as pJW4303-MEG1. The pJW4303-MEG3-encoded protein contained the same epitopes in the same order as that of pJW4303-MEG2, but with a different linker sequence (AAY). To evaluate immunogenicity, mice were immunized intramuscularly with these DNA vaccines. Both pJW4303-MEG1 and pJW4303-MEG2 vaccines induced equally potent humoral and cellular immune responses in the vaccinated mice, while pJW4303-MEG3 did not induce immune responses. These results indicate that both epitope and linker sequences are important in designing effective epitope-based vaccines against HIV-1 and other viruses.
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Affiliation(s)
- Yi Yang
- a State Key Laboratory of Pathogen and Biosecurity ; Beijing Institute of Microbiology and Epidemiology ; Beijing , China
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7
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Epitope Prediction Assays Combined with Validation Assays Strongly Narrows down Putative Cytotoxic T Lymphocyte Epitopes. Vaccines (Basel) 2015; 3:203-20. [PMID: 26343185 PMCID: PMC4494349 DOI: 10.3390/vaccines3020203] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 03/16/2015] [Indexed: 02/07/2023] Open
Abstract
Tumor vaccine design requires prediction and validation of immunogenic MHC class I epitopes expressed by target cells as well as MHC class II epitopes expressed by antigen-presenting cells essential for the induction of optimal immune responses. Epitope prediction methods are based on different algorithms and are instrumental for a first screening of possible epitopes. However, their results do not reflect a one-to-one correlation with experimental data. We combined several in silico prediction methods to unravel the most promising C57BL/6 mouse-restricted Hepatitis C virus (HCV) MHC class I epitopes and validated these epitopes in vitro and in vivo. Cytotoxic T lymphocyte (CTL) epitopes within the HCV non-structural proteins were identified, and proteasomal cleavage sites and helper T cell (Th) epitopes at close proximity to these CTL epitopes were analyzed using multiple prediction algorithms. This combined in silico analysis enhances the precision of identification of functional HCV-specific CTL epitopes. This approach will be applicable to the design of human vaccines not only for HCV, but also for other antigens in which T-cell responses play a crucial role.
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8
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Schussek S, Trieu A, Doolan DL. Genome- and proteome-wide screening strategies for antigen discovery and immunogen design. Biotechnol Adv 2014; 32:403-14. [DOI: 10.1016/j.biotechadv.2013.12.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 11/04/2013] [Accepted: 12/16/2013] [Indexed: 01/17/2023]
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9
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Gu Y, Wei J, Yang J, Huang J, Yang X, Zhu X. Protective immunity against Trichinella spiralis infection induced by a multi-epitope vaccine in a murine model. PLoS One 2013; 8:e77238. [PMID: 24130862 PMCID: PMC3795051 DOI: 10.1371/journal.pone.0077238] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 08/30/2013] [Indexed: 12/13/2022] Open
Abstract
Trichinellosis is one of the most important food-borne parasitic zoonoses throughout the world. Because infected pigs are the major source of human infections, and China is becoming the largest international producer of pork, the development of a transmission-blocking vaccine to prevent swine from being infected is urgently needed for trichinellosis control in China. Our previous studies have demonstrated that specific Trichinella spiralis paramyosin (Ts-Pmy) and Ts-87 antigen could provide protective immunity against T. spiralis infection in immunized mice. Certain protective epitopes of Ts-Pmy and Ts-87 antigen have been identified. To identify more Ts-Pmy protective epitopes, a new monoclonal antibody, termed 8F12, was produced against the N-terminus of Ts-Pmy. This antibody elicited significant protective immunity in mice against T. spiralis infection by passive transfer and was subsequently used to screen a random phage display peptide library to identify recognized epitopes. Seven distinct positive phage clones were identified and their displayed peptides were sequenced. Synthesized epitope peptides conjugated to keyhole limpet hemocyanin were used to immunize mice, four of which exhibited larval reduction (from 18.7% to 26.3%, respectively) in vaccinated mice in comparison to the KLH control. To increase more effective protection, the epitope 8F7 that was found to induce the highest protection in this study was combined with two other previously identified epitopes (YX1 from Ts-Pmy and M7 from Ts-87) to formulate a multi-epitope vaccine. Mice immunized with this multi-epitope vaccine experienced a 35.0% reduction in muscle larvae burden after being challenged with T. spiralis larvae. This protection is significantly higher than that induced by individual-epitope peptides and is associated with high levels of subclasses IgG and IgG1. These results showed that a multi-epitope vaccine induced better protective immunity than an individual epitope and provided a feasible approach for developing a safer and more effective vaccine against trichinellosis.
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Affiliation(s)
- Yuan Gu
- Department of Parasitology, School of Basic Medical Sciences, Capital Medical University, Beijing, PR China
| | - Junfei Wei
- Department of Parasitology, School of Basic Medical Sciences, Capital Medical University, Beijing, PR China
| | - Jing Yang
- Department of Parasitology, School of Basic Medical Sciences, Capital Medical University, Beijing, PR China
| | - Jingjing Huang
- Department of Parasitology, School of Basic Medical Sciences, Capital Medical University, Beijing, PR China
| | - Xiaodi Yang
- Department of Parasitology, School of Basic Medical Sciences, Capital Medical University, Beijing, PR China
| | - Xinping Zhu
- Department of Parasitology, School of Basic Medical Sciences, Capital Medical University, Beijing, PR China
- * E-mail:
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10
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Recognition of higher order patterns in proteins: immunologic kernels. PLoS One 2013; 8:e70115. [PMID: 23922927 PMCID: PMC3726486 DOI: 10.1371/journal.pone.0070115] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 06/17/2013] [Indexed: 01/28/2023] Open
Abstract
By applying analysis of the principal components of amino acid physical properties we predicted cathepsin cleavage sites, MHC binding affinity, and probability of B-cell epitope binding of peptides in tetanus toxin and in ten diverse additional proteins. Cross-correlation of these metrics, for peptides of all possible amino acid index positions, each evaluated in the context of a ±25 amino acid flanking region, indicated that there is a strongly repetitive pattern of short peptides of approximately thirty amino acids each bounded by cathepsin cleavage sites and each comprising B-cell linear epitopes, MHC–I and MHC-II binding peptides. Such “immunologic kernel” peptides comprise all signals necessary for adaptive immunologic cognition, response and recall. The patterns described indicate a higher order spatial integration that forms a symbolic logic coordinating the adaptive immune system.
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11
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Rahm N, Gfeller D, Snoeck J, Martinez R, McLaren PJ, Ortiz M, Ciuffi A, Telenti A. Susceptibility and adaptation to human TRIM5α alleles at positive selected sites in HIV-1 capsid. Virology 2013; 441:162-70. [PMID: 23601783 DOI: 10.1016/j.virol.2013.03.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 03/20/2013] [Accepted: 03/21/2013] [Indexed: 01/25/2023]
Abstract
Numerous in vitro studies attribute to human TRIM5α some modest anti-HIV-1 activity and human population studies suggest some differential effect of TRIM5α polymorphisms on disease progression. If the activity of TRIM5α were relevant in vivo, it could result in positive selection on the viral capsid. To address this issue, we identified 10 positively selected sites in HIV-1 capsid from multiple viral strains and generated 17 clade B viruses carrying a minor (i.e. low frequency) residue or an alanine at those positions. All recombinant viruses were susceptible to the modest effect of common human TRIM5α and allelic variants R136Q, and H419Y; H43Y and G249D TRIM5α were generally inactive. Increased sensitivity to TRIM5α was observed for some capsid variants, suggesting that minor residues are selected against in human populations. On the other hand, the modest potency of human TRIM5α does not translate in escape mutations in the viral capsid.
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Affiliation(s)
- Nadia Rahm
- Institute of Microbiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
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12
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Sanjuán R, Nebot MR, Peris JB, Alcamí J. Immune activation promotes evolutionary conservation of T-cell epitopes in HIV-1. PLoS Biol 2013; 11:e1001523. [PMID: 23565057 PMCID: PMC3614509 DOI: 10.1371/journal.pbio.1001523] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Accepted: 02/14/2013] [Indexed: 01/06/2023] Open
Abstract
HIV, unlike other viruses, may benefit from immune recognition by preserving the sequence of its T cell epitopes, thereby enhancing transmission between cells. The immune system should constitute a strong selective pressure promoting viral genetic diversity and evolution. However, HIV shows lower sequence variability at T-cell epitopes than elsewhere in the genome, in contrast with other human RNA viruses. Here, we propose that epitope conservation is a consequence of the particular interactions established between HIV and the immune system. On one hand, epitope recognition triggers an anti-HIV response mediated by cytotoxic T-lymphocytes (CTLs), but on the other hand, activation of CD4+ helper T lymphocytes (TH cells) promotes HIV replication. Mathematical modeling of these opposite selective forces revealed that selection at the intrapatient level can promote either T-cell epitope conservation or escape. We predict greater conservation for epitopes contributing significantly to total immune activation levels (immunodominance), and when TH cell infection is concomitant to epitope recognition (trans-infection). We suggest that HIV-driven immune activation in the lymph nodes during the chronic stage of the disease may offer a favorable scenario for epitope conservation. Our results also support the view that some pathogens draw benefits from the immune response and suggest that vaccination strategies based on conserved TH epitopes may be counterproductive. A key component of the immune response against viruses and other pathogens is the recognition of short foreign protein sequences called epitopes. However, viruses can escape the immune system by mutating, so epitopes should accumulate high levels of genetic variability. This has been documented in several human viruses, but in HIV, unexpectedly, epitopes tend to be relatively conserved. Here, we propose that this is a consequence of the peculiar interactions that occur between HIV and the immune system. As with other viruses, recognition of HIV epitopes promotes the activation of cytotoxic and helper T lymphocytes, which then orchestrate a cellular immune response. However, HIV infects helper T lymphocytes as their target cell in the body and does so more efficiently when these cells have been activated to participate in an immune response. Mathematical modeling showed that, in some cases, HIV may take advantage of immune activation, thus favoring epitope conservation. This should be more likely to occur with epitopes that trigger more vigorous T-cell responses, and during the process known as “trans-infection,” in which helper T lymphocytes are infected while being activated. Our results highlight the potential advantages of an HIV vaccination strategy based on epitopes that stimulate cytotoxic T lymphocytes without specifically stimulating helper T lymphocytes.
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Affiliation(s)
- Rafael Sanjuán
- Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, València, Spain.
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13
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Kulkarni R, Sapkal G, Mahishi L, Shil P, Gore MM. Design and characterization of polytope construct with multiple B and TH epitopes of Japanese encephalitis virus. Virus Res 2012; 166:77-86. [DOI: 10.1016/j.virusres.2012.03.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Revised: 02/27/2012] [Accepted: 03/06/2012] [Indexed: 12/22/2022]
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