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Slack J, Nguyen C, Ibe-Enwo A. A Lac Repressor-Inducible Baculovirus Expression Vector for Controlling Adeno-Associated Virus Capsid Ratios. Viruses 2023; 16:51. [PMID: 38257750 PMCID: PMC10820722 DOI: 10.3390/v16010051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 12/19/2023] [Accepted: 12/23/2023] [Indexed: 01/24/2024] Open
Abstract
The baculovirus expression vector (BEV) system is an efficient, cost-effective, and scalable method to produce recombinant adeno-associated virus (rAAV) gene therapy vectors. Most BEV designs emulate the wild-type AAV transcriptome and translate the AAV capsid proteins, VP1, VP2, and VP3, from a single mRNA transcript with three overlapping open reading frames (ORFs). Non-canonical translation initiation codons for VP1 and VP2 reduce their abundances relative to VP3. Changing capsid ratios to improve rAAV vector efficacy requires a theoretical modification of the translational context. We have developed a Lac repressor-inducible system to empirically regulate the expression of VP1 and VP2 proteins relative to VP3 in the context of the BEV. We demonstrate the use of this system to tune the abundance, titer, and potency of a neurospecific rAAV9 serotype derivative. VP1:VP2:VP3 ratios of 1:1:8 gave optimal potency for this rAAV. It was discovered that the ratios of capsid proteins expressed were different than the ratios that ultimately were in purified capsids. Overexpressed VP1 did not become incorporated into capsids, while overexpressed VP2 did. Overabundance of VP2 correlated with reduced rAAV titers. This work demonstrates a novel technology for controlling the production of rAAV in the BEV system and shows a new perspective on the biology of rAAV capsid assembly.
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Affiliation(s)
- Jeffrey Slack
- Voyager Therapeutics, 64 Sidney St., Cambridge, MA 02139, USA;
| | | | - Amanda Ibe-Enwo
- Voyager Therapeutics, 64 Sidney St., Cambridge, MA 02139, USA;
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2
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Powers JM, Haese NN, Denton M, Ando T, Kreklywich C, Bonin K, Streblow CE, Kreklywich N, Smith P, Broeckel R, DeFilippis V, Morrison TE, Heise MT, Streblow DN. Non-replicating adenovirus based Mayaro virus vaccine elicits protective immune responses and cross protects against other alphaviruses. PLoS Negl Trop Dis 2021; 15:e0009308. [PMID: 33793555 PMCID: PMC8051823 DOI: 10.1371/journal.pntd.0009308] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 04/16/2021] [Accepted: 03/15/2021] [Indexed: 11/20/2022] Open
Abstract
Mayaro virus (MAYV) is an alphavirus endemic to South and Central America associated with sporadic outbreaks in humans. MAYV infection causes severe joint and muscle pain that can persist for weeks to months. Currently, there are no approved vaccines or therapeutics to prevent MAYV infection or treat the debilitating musculoskeletal inflammatory disease. In the current study, a prophylactic MAYV vaccine expressing the complete viral structural polyprotein was developed based on a non-replicating human adenovirus V (AdV) platform. Vaccination with AdV-MAYV elicited potent neutralizing antibodies that protected WT mice against MAYV challenge by preventing viremia, reducing viral dissemination to tissues and mitigating viral disease. The vaccine also prevented viral-mediated demise in IFN⍺R1-/- mice. Passive transfer of immune serum from vaccinated animals similarly prevented infection and disease in WT mice as well as virus-induced demise of IFN⍺R1-/- mice, indicating that antiviral antibodies are protective. Immunization with AdV-MAYV also generated cross-neutralizing antibodies against two related arthritogenic alphaviruses-chikungunya and Una viruses. These cross-neutralizing antibodies were protective against lethal infection in IFN⍺R1-/- mice following challenge with these heterotypic alphaviruses. These results indicate AdV-MAYV elicits protective immune responses with substantial cross-reactivity and protective efficacy against other arthritogenic alphaviruses. Our findings also highlight the potential for development of a multi-virus targeting vaccine against alphaviruses with endemic and epidemic potential in the Americas.
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Affiliation(s)
- John M Powers
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Nicole N Haese
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Michael Denton
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Takeshi Ando
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Craig Kreklywich
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Kiley Bonin
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Cassilyn E Streblow
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Nicholas Kreklywich
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Patricia Smith
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Rebecca Broeckel
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Victor DeFilippis
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Thomas E Morrison
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Mark T Heise
- Department of Genetics, Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Daniel N Streblow
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
- Division of Pathobiology and Immunology, Oregon National Primate Research Center, Beaverton, Oregon, United States of America
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Almuqrin A, Davidson AD, Williamson MK, Lewis PA, Heesom KJ, Morris S, Gilbert SC, Matthews DA. SARS-CoV-2 vaccine ChAdOx1 nCoV-19 infection of human cell lines reveals low levels of viral backbone gene transcription alongside very high levels of SARS-CoV-2 S glycoprotein gene transcription. Genome Med 2021; 13:43. [PMID: 33722288 PMCID: PMC7958140 DOI: 10.1186/s13073-021-00859-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 02/23/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND ChAdOx1 nCoV-19 is a recombinant adenovirus vaccine against SARS-CoV-2 that has passed phase III clinical trials and is now in use across the globe. Although replication-defective in normal cells, 28 kbp of adenovirus genes is delivered to the cell nucleus alongside the SARS-CoV-2 S glycoprotein gene. METHODS We used direct RNA sequencing to analyse transcript expression from the ChAdOx1 nCoV-19 genome in human MRC-5 and A549 cell lines that are non-permissive for vector replication alongside the replication permissive cell line, HEK293. In addition, we used quantitative proteomics to study over time the proteome and phosphoproteome of A549 and MRC5 cells infected with the ChAdOx1 nCoV-19 vaccine. RESULTS The expected SARS-CoV-2 S coding transcript dominated in all cell lines. We also detected rare S transcripts with aberrant splice patterns or polyadenylation site usage. Adenovirus vector transcripts were almost absent in MRC-5 cells, but in A549 cells, there was a broader repertoire of adenoviral gene expression at very low levels. Proteomically, in addition to S glycoprotein, we detected multiple adenovirus proteins in A549 cells compared to just one in MRC5 cells. CONCLUSIONS Overall, the ChAdOx1 nCoV-19 vaccine's transcriptomic and proteomic repertoire in cell culture is as expected. The combined transcriptomic and proteomics approaches provide a detailed insight into the behaviour of this important class of vaccine using state-of-the-art techniques and illustrate the potential of this technique to inform future viral vaccine vector design.
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Affiliation(s)
- Abdulaziz Almuqrin
- School of Cellular and Molecular Medicine, Faculty of Life Sciences, University Walk, University of Bristol, Bristol, BS8 1TD, UK
- Department of Clinical Laboratory Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Andrew D Davidson
- School of Cellular and Molecular Medicine, Faculty of Life Sciences, University Walk, University of Bristol, Bristol, BS8 1TD, UK
| | - Maia Kavanagh Williamson
- School of Cellular and Molecular Medicine, Faculty of Life Sciences, University Walk, University of Bristol, Bristol, BS8 1TD, UK
| | - Philip A Lewis
- School of Cellular and Molecular Medicine, Faculty of Life Sciences, University Walk, University of Bristol, Bristol, BS8 1TD, UK
| | - Kate J Heesom
- Proteomics Facility, Faculty of Life Sciences, University Walk, University of Bristol, Bristol, BS8 1TD, UK
| | - Susan Morris
- Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7DQ, UK
| | - Sarah C Gilbert
- Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7DQ, UK
| | - David A Matthews
- School of Cellular and Molecular Medicine, Faculty of Life Sciences, University Walk, University of Bristol, Bristol, BS8 1TD, UK.
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Characterization of the Herpes Simplex Virus (HSV) Tegument Proteins That Bind to gE/gI and US9, Which Promote Assembly of HSV and Transport into Neuronal Axons. J Virol 2020; 94:JVI.01113-20. [PMID: 32938770 DOI: 10.1128/jvi.01113-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 09/11/2020] [Indexed: 01/14/2023] Open
Abstract
The herpes simplex virus (HSV) heterodimer gE/gI and another membrane protein, US9, which has neuron-specific effects, promote the anterograde transport of virus particles in neuronal axons. Deletion of both HSV gE and US9 blocks the assembly of enveloped particles in the neuronal cytoplasm, which explains why HSV virions do not enter axons. Cytoplasmic envelopment depends upon interactions between viral membrane proteins and tegument proteins that encrust capsids. We report that tegument protein UL16 is unstable, i.e., rapidly degraded, in neurons infected with a gE-/US9- double mutant. Immunoprecipitation experiments with lysates of HSV-infected neurons showed that UL16 and three other tegument proteins, namely, VP22, UL11, and UL21, bound either to gE or gI. All four of these tegument proteins were also pulled down with US9. In neurons transfected with tegument proteins and gE/gI or US9, there was good evidence that VP22 and UL16 bound directly to US9 and gE/gI. However, there were lower quantities of these tegument proteins that coprecipitated with gE/gI and US9 from transfected cells than those of infected cells. This apparently relates to a matrix of several different tegument proteins formed in infected cells that bind to gE/gI and US9. In cells transfected with individual tegument proteins, this matrix is less prevalent. Similarly, coprecipitation of gE/gI and US9 was observed in HSV-infected cells but not in transfected cells, which argued against direct US9-gE/gI interactions. These studies suggest that gE/gI and US9 binding to these tegument proteins has neuron-specific effects on virus HSV assembly, a process required for axonal transport of enveloped particles.IMPORTANCE Herpes simplex viruses 1 and 2 and varicella-zoster virus cause significant morbidity and mortality. One basic property of these viruses is the capacity to establish latency in the sensory neurons and to reactivate from latency and then cause disease in peripheral tissues, such as skin and mucosal epithelia. The transport of nascent HSV particles from neuron cell bodies into axons and along axons to axon tips in the periphery is an important component of this reactivation and reinfection. Two HSV membrane proteins, gE/gI and US9, play an essential role in these processes. Our studies help elucidate how HSV gE/gI and US9 promote the assembly of virus particles and sorting of these virions into neuronal axons.
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Broeckel RM, Haese N, Ando T, Dmitriev I, Kreklywich CN, Powers J, Denton M, Smith P, Morrison TE, Heise M, DeFilippis V, Messaoudi I, Curiel DT, Streblow DN. Vaccine-Induced Skewing of T Cell Responses Protects Against Chikungunya Virus Disease. Front Immunol 2019; 10:2563. [PMID: 31736977 PMCID: PMC6834551 DOI: 10.3389/fimmu.2019.02563] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 10/16/2019] [Indexed: 11/13/2022] Open
Abstract
Chikungunya virus (CHIKV) infections can cause severe and debilitating joint and muscular pain that can be long lasting. Current CHIKV vaccines under development rely on the generation of neutralizing antibodies for protection; however, the role of T cells in controlling CHIKV infection and disease is still unclear. Using an overlapping peptide library, we identified the CHIKV-specific T cell receptor epitopes recognized in C57BL/6 infected mice at 7 and 14 days post-infection. A fusion protein containing peptides 451, 416, a small region of nsP4, peptide 47, and an HA tag (CHKVf5) was expressed using adenovirus and cytomegalovirus-vectored vaccines. Mice vaccinated with CHKVf5 elicited robust T cell responses to higher levels than normally observed following CHIKV infection, but the vaccine vectors did not elicit neutralizing antibodies. CHKVf5-vaccinated mice had significantly reduced infectious viral load when challenged by intramuscular CHIKV injection. Depletion of both CD4+ and CD8+ T cells in vaccinated mice rendered them fully susceptible to intramuscular CHIKV challenge. Depletion of CD8+ T cells alone reduced vaccine efficacy, albeit to a lesser extent, but depletion of only CD4+ T cells did not reverse the protective phenotype. These data demonstrated a protective role for CD8+ T cells in CHIKV infection. However, CHKVf5-vaccinated mice that were challenged by footpad inoculation demonstrated equal viral loads and increased footpad swelling at 3 dpi, which we attributed to the presence of CD4 T cell receptor epitopes present in the vaccine. Indeed, vaccination of mice with vectors expressing only CHIKV-specific CD8+ T cell epitopes followed by CHIKV challenge in the footpad prevented footpad swelling and reduced proinflammatory cytokine and chemokines associated with disease, indicating that CHIKV-specific CD8+ T cells prevent CHIKV disease. These results also indicate that a T cell-biased prophylactic vaccination approach is effective against CHIKV challenge and reduces CHIKV-induced disease in mice.
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Affiliation(s)
- Rebecca M. Broeckel
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR, United States
| | - Nicole Haese
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR, United States
| | - Takeshi Ando
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR, United States
| | - Igor Dmitriev
- Department of Radiation Oncology, Washington University, St. Louis, MO, United States
| | - Craig N. Kreklywich
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR, United States
| | - John Powers
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR, United States
| | - Michael Denton
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR, United States
| | - Patricia Smith
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR, United States
| | - Thomas E. Morrison
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Mark Heise
- Department of Genetics, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Victor DeFilippis
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR, United States
| | - Ilhem Messaoudi
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, United States
| | - David T. Curiel
- Department of Radiation Oncology, Washington University, St. Louis, MO, United States
| | - Daniel N. Streblow
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR, United States
- Division of Pathobiology and Immunology, Oregon National Primate Research Center, Beaverton, OR, United States
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Kumar D, Gauthami S, Uma M, Nagalekshmi K, Rao PP, Basu A, Ella KM, Hegde NR. Immunogenicity of a Candidate Ebola Hemorrhagic Fever Vaccine in Mice Based on Controlled In Vitro Expression of Ebolavirus Glycoprotein. Viral Immunol 2018; 31:500-512. [PMID: 30095362 DOI: 10.1089/vim.2017.0122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Ebolavirus (EBOV) is the etiology of Ebola hemorrhagic fever (EHF). A major EHF outbreak in 2014-2015 in West Africa claimed >11,000 lives. A licensed vaccine is not available for EHF, although several vaccines have undergone clinical trials. We developed a human adenovirus (Ad) serotype 5-based candidate EHF vaccine based on controlled expression of the EBOV (Makona strain) glycoprotein (GP) as the immunogen. Two clones, AdGP72 and AdGP75, and a control Ad515 vector, were generated and tested for protein expression in vitro and immunogenicity in mice. Eight groups of mice were immunized with three doses of buffer, Ad515, AdGP72, and AdGP75, by two different dose regimens. Three different antigens (AdGP75-infected Vero E6 cell extract and two baculovirus expressed EBOV GP antigens, namely, GP alone or GP with EBOV VP40) were used to evaluate the immune response. Expression studies indicated that full-length GP was cleaved into its component subunits when expressed in mammalian cells through the Ad vectors. Moreover, in coimmunoprecipitation studies, EBOV GP was found to be associated with VP40 when expressed in baculoviruses. The candidate vaccines were immunogenic in mice, as evaluated by enzyme-linked immunosorbent assay using mammalian- or baculovirus-derived antigens. Further characterization and development of the candidate vaccines are warranted.
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Affiliation(s)
| | | | | | | | | | - Atanu Basu
- 2 National Institute of Virology , Pune, India
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Yıldırım-Buharalıoğlu G, Bond M, Sala-Newby GB, Hindmarch CCT, Newby AC. Regulation of Epigenetic Modifiers, Including KDM6B, by Interferon-γ and Interleukin-4 in Human Macrophages. Front Immunol 2017; 8:92. [PMID: 28228757 PMCID: PMC5296311 DOI: 10.3389/fimmu.2017.00092] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 01/19/2017] [Indexed: 11/25/2022] Open
Abstract
Background Interferon-γ (IFN-γ) or interleukin-4 (IL-4) drives widely different transcriptional programs in macrophages. However, how IFN-γ and IL-4 alter expression of histone-modifying enzymes involved in epigenetic regulation and how this affects the resulting phenotypic polarization is incompletely understood. Methods and results We investigated steady-state messenger RNA levels of 84 histone-modifying enzymes and related regulators in colony-stimulating factor-1 differentiated primary human macrophages using quantitative polymerase chain reaction. IFN-γ or IL-4 treatment for 6–48 h changed 11 mRNAs significantly. IFN-γ increased CIITA, KDM6B, and NCOA1, and IL-4 also increased KDM6B by 6 h. However, either cytokine decreased AURKB, ESCO2, SETD6, SUV39H1, and WHSC1, whereas IFN-γ alone decreased KAT2A, PRMT7, and SMYD3 mRNAs only after 18 h, which coincided with decreased cell proliferation. Rendering macrophages quiescent by growth factor starvation or adenovirus-mediated overexpression of p27kip1 inhibited expression of AURKB, ESCO2, SUV39H1, and WHSC1, and mRNA levels were restored by overexpressing the S-phase transcription factor E2F1, implying their expression, at least partly, depended on proliferation. However, CIITA, KDM6B, NCOA1, KAT2A, PRMT7, SETD6, and SMYD3 were regulated independently of effects on proliferation. Silencing KDM6B, the only transcriptional activator upregulated by both IFN-γ and IL-4, pharmacologically or with short hairpin RNA, blunted a subset of responses to each cytokine. Conclusion These findings demonstrate that IFN-γ or IL-4 can regulate the expression of histone acetyl transferases and histone methyl transferases independently of effects on proliferation and that upregulation of the histone demethylase, KDM6B, assists phenotypic polarization by both cytokines.
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Affiliation(s)
| | - Mark Bond
- Chair of Vascular Cell Biology, School of Clinical Sciences, University of Bristol , Bristol , UK
| | - Graciela B Sala-Newby
- Chair of Vascular Cell Biology, School of Clinical Sciences, University of Bristol , Bristol , UK
| | - Charles C T Hindmarch
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada; Department of Physiology, Faculty of Medicine, University of Malaya, Lembah Pantai, Kuala Lumpur, Malaysia
| | - Andrew C Newby
- Chair of Vascular Cell Biology, School of Clinical Sciences, University of Bristol , Bristol , UK
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Vanarsdall AL, Howard PW, Wisner TW, Johnson DC. Human Cytomegalovirus gH/gL Forms a Stable Complex with the Fusion Protein gB in Virions. PLoS Pathog 2016; 12:e1005564. [PMID: 27082872 PMCID: PMC4833381 DOI: 10.1371/journal.ppat.1005564] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 03/21/2016] [Indexed: 11/19/2022] Open
Abstract
Human cytomegalovirus (HCMV) is a ubiquitous virus that is a major pathogen in newborns and immunocompromised or immunosuppressed patients. HCMV infects a wide variety of cell types using distinct entry pathways that involve different forms of the gH/gL glycoprotein: gH/gL/gO and gH/gL/UL128-131 as well as the viral fusion glycoprotein, gB. However, the minimal or core fusion machinery (sufficient for cell-cell fusion) is just gH/gL and gB. Here, we demonstrate that HCMV gB and gH/gL form a stable complex early after their synthesis and in the absence of other viral proteins. gH/gL can interact with gB mutants that are unable to mediate cell-cell fusion. gB-gH/gL complexes included as much as 16–50% of the total gH/gL in HCMV virus particles. In contrast, only small amounts of gH/gL/gO and gH/gL/UL128-131 complexes were found associated with gB. All herpesviruses express gB and gH/gL molecules and most models describing herpesvirus entry suggest that gH/gL interacts with gB to mediate membrane fusion, although there is no direct evidence for this. For herpes simplex virus (HSV-1) it has been suggested that after receptor binding gH/gL binds to gB either just before, or coincident with membrane fusion. Therefore, our results have major implications for these models, demonstrating that HCMV gB and gH/gL forms stable gB-gH/gL complexes that are incorporated virions without receptor binding or membrane fusion. Moreover, our data is the best support to date for the proposal that gH/gL interacts with gB. Like all herpesviruses, HCMV expresses two envelope proteins, gH/gL and gB that are essential for entry. Models for how herpesvirus gB and gH/gL molecules function describe binding of gH/gL to gB that leads to conformational changes and activation of membrane fusion and virus entry. However, no evidence for direct binding of any gH/gL molecule to gB, especially from infected cells or virus particles, has been described. We report the novel observations that HCMV gB and gH/gL form stable, preformed complexes in extracellular virions independent of receptor binding. These observations are fundamentally important for understanding how herpesvirus glycoproteins mediate entry into cells. Moreover, the description of gB-gH/gL complexes in virions has major implications in terms of designing HCMV vaccines.
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Affiliation(s)
- Adam L. Vanarsdall
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, Oregon, United States of America
- * E-mail:
| | - Paul W. Howard
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Todd W. Wisner
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - David C. Johnson
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, Oregon, United States of America
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Pierantoni A, Esposito ML, Ammendola V, Napolitano F, Grazioli F, Abbate A, del Sorbo M, Siani L, D’Alise AM, Taglioni A, Perretta G, Siccardi A, Soprana E, Panigada M, Thom M, Scarselli E, Folgori A, Colloca S, Taylor G, Cortese R, Nicosia A, Capone S, Vitelli A. Mucosal delivery of a vectored RSV vaccine is safe and elicits protective immunity in rodents and nonhuman primates. Mol Ther Methods Clin Dev 2015; 2:15018. [PMID: 26015988 PMCID: PMC4441047 DOI: 10.1038/mtm.2015.18] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 03/20/2015] [Indexed: 01/27/2023]
Abstract
Respiratory Syncytial Virus (RSV) is a leading cause of severe respiratory disease in infants and the elderly. No vaccine is presently available to address this major unmet medical need. We generated a new genetic vaccine based on chimpanzee Adenovirus (PanAd3-RSV) and Modified Vaccinia Ankara RSV (MVA-RSV) encoding the F, N, and M2-1 proteins of RSV, for the induction of neutralizing antibodies and broad cellular immunity. Because RSV infection is restricted to the respiratory tract, we compared intranasal (IN) and intramuscular (M) administration for safety, immunogenicity, and efficacy in different species. A single IN or IM vaccination completely protected BALB/c mice and cotton rats against RSV replication in the lungs. However, only IN administration could prevent infection in the upper respiratory tract. IM vaccination with MVA-RSV also protected cotton rats from lower respiratory tract infection in the absence of detectable neutralizing antibodies. Heterologous prime boost with PanAd3-RSV and MVA-RSV elicited high neutralizing antibody titers and broad T-cell responses in nonhuman primates. In addition, animals primed in the nose developed mucosal IgA against the F protein. In conclusion, we have shown that our vectored RSV vaccine induces potent cellular and humoral responses in a primate model, providing strong support for clinical testing.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Alessandra Taglioni
- Cellular Biology and Neurobiology Institute (IBCN) National Research Council of Italy, Rome, Italy
| | - Gemma Perretta
- Cellular Biology and Neurobiology Institute (IBCN) National Research Council of Italy, Rome, Italy
| | | | | | | | | | | | | | | | | | - Riccardo Cortese
- ReiThera Srl, Rome, Italy (former Okairos Srl)
- Keires AG, Basel, Switzerland
| | - Alfredo Nicosia
- ReiThera Srl, Rome, Italy (former Okairos Srl)
- CEINGE, Naples, Italy
- Department of Molecular Medicine and Medical Biotechnology, University Federico II, Naples, Italy
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Gilbert R, Guilbault C, Gagnon D, Bernier A, Bourget L, Elahi SM, Kamen A, Massie B. Establishment and validation of new complementing cells for production of E1-deleted adenovirus vectors in serum-free suspension culture. J Virol Methods 2014; 208:177-88. [DOI: 10.1016/j.jviromet.2014.08.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 08/12/2014] [Accepted: 08/15/2014] [Indexed: 11/17/2022]
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Combined adenovirus vector and hepatitis C virus envelope protein prime-boost regimen elicits T cell and neutralizing antibody immune responses. J Virol 2014; 88:5502-10. [PMID: 24599994 DOI: 10.1128/jvi.03574-13] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
UNLABELLED Despite the recent progress in the development of new antiviral agents, hepatitis C virus (HCV) infection remains a major global health problem, and there is a need for a preventive vaccine. We previously reported that adenoviral vectors expressing HCV nonstructural proteins elicit protective T cell responses in chimpanzees and were immunogenic in healthy volunteers. Furthermore, recombinant HCV E1E2 protein formulated with adjuvant MF59 induced protective antibody responses in chimpanzees and was immunogenic in humans. To develop an HCV vaccine capable of inducing both T cell and antibody responses, we constructed adenoviral vectors expressing full-length and truncated E1E2 envelope glycoproteins from HCV genotype 1b. Heterologous prime-boost immunization regimens with adenovirus and recombinant E1E2 glycoprotein (genotype 1a) plus MF59 were evaluated in mice and guinea pigs. Adenovirus prime and protein boost induced broad HCV-specific CD8+ and CD4+ T cell responses and functional Th1-type IgG responses. Immune sera neutralized luciferase reporter pseudoparticles expressing HCV envelope glycoproteins (HCVpp) and a diverse panel of recombinant cell culture-derived HCV (HCVcc) strains and limited cell-to-cell HCV transmission. This study demonstrated that combining adenovirus vector with protein antigen can induce strong antibody and T cell responses that surpass immune responses achieved by either vaccine alone. IMPORTANCE HCV infection is a major health problem. Despite the availability of new directly acting antiviral agents for treating chronic infection, an affordable preventive vaccine provides the best long-term goal for controlling the global epidemic. This report describes a new anti-HCV vaccine targeting the envelope viral proteins based on adenovirus vector and protein in adjuvant. Rodents primed with the adenovirus vaccine and boosted with the adjuvanted protein developed cross-neutralizing antibodies and potent T cell responses that surpassed immune responses achieved with either vaccine component alone. If combined with the adenovirus vaccine targeting the HCV NS antigens now under clinical testing, this new vaccine might lead to a stronger and broader immune response and to a more effective vaccine to prevent HCV infection. Importantly, the described approach represents a valuable strategy for other infectious diseases in which both T and B cell responses are essential for protection.
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Comparative analysis of gO isoforms reveals that strains of human cytomegalovirus differ in the ratio of gH/gL/gO and gH/gL/UL128-131 in the virion envelope. J Virol 2013; 87:9680-90. [PMID: 23804643 DOI: 10.1128/jvi.01167-13] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Herpesvirus glycoprotein complex gH/gL provides a core entry function through interactions with the fusion protein gB and can also influence tropism through receptor interactions. The Epstein-Barr virus gH/gL and gH/gL/gp42 serve both functions for entry into epithelial and B cells, respectively. Human cytomegalovirus (HCMV) gH/gL can be bound by the UL128-131 proteins or gO. The phenotypes of gO and UL128-131 mutants suggest that gO-gH/gL interactions are necessary for the core entry function on all cell types, whereas the binding of UL128-131 to gH/gL likely relates to a distinct receptor-binding function for entry into some specific cell types (e.g., epithelial) but not others (e.g., fibroblasts and neurons). There are at least eight isoforms of gO that differ by 10 to 30% of amino acids, and previous analysis of two HCMV strains suggested that some isoforms of gO function like chaperones, disassociating during assembly to leave unbound gH/gL in the virion envelope, while others remain bound to gH/gL. For the current report, we analyzed the gH/gL complexes present in the virion envelope of several HCMV strains, each of which encodes a distinct gO isoform. Results indicate that all strains of HCMV contain stable gH/gL/gO trimers and gH/gL/UL128-131 pentamers and little, if any, unbound gH/gL. TR, TB40/e, AD169, and PH virions contained vastly more gH/gL/gO than gH/gL/UL128-131, whereas Merlin virions contained mostly gH/gL/UL128-131, despite abundant unbound gO remaining in the infected cells. Suppression of UL128-131 expression during Merlin replication dramatically shifted the ratio toward gH/gL/gO. These data suggest that Merlin gO is less efficient than other gO isoforms at competing with UL128-131 for binding to gH/gL. Thus, gO diversity may influence the pathogenesis of HCMV through effects on the assembly of the core versus tropism gH/gL complexes.
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13
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Vitelli A, Quirion MR, Lo CY, Misplon JA, Grabowska AK, Pierantoni A, Ammendola V, Price GE, Soboleski MR, Cortese R, Colloca S, Nicosia A, Epstein SL. Vaccination to conserved influenza antigens in mice using a novel Simian adenovirus vector, PanAd3, derived from the bonobo Pan paniscus. PLoS One 2013; 8:e55435. [PMID: 23536756 PMCID: PMC3594242 DOI: 10.1371/journal.pone.0055435] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 12/23/2012] [Indexed: 12/11/2022] Open
Abstract
Among approximately 1000 adenoviruses from chimpanzees and bonobos studied recently, the Pan Adenovirus type 3 (PanAd3, isolated from a bonobo, Pan paniscus) has one of the best profiles for a vaccine vector, combining potent transgene immunogenicity with minimal pre-existing immunity in the human population. In this study, we inserted into a replication defective PanAd3 a transgene expressing a fusion protein of conserved influenza antigens nucleoprotein (NP) and matrix 1 (M1). We then studied antibody and T cell responses as well as protection from challenge infection in a mouse model. A single intranasal administration of PanAd3-NPM1 vaccine induced strong antibody and T cell responses, and protected against high dose lethal influenza virus challenge. Thus PanAd3 is a promising candidate vector for vaccines, including universal influenza vaccines.
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MESH Headings
- Adenoviruses, Human/immunology
- Adenoviruses, Simian/genetics
- Adenoviruses, Simian/immunology
- Amino Acid Sequence
- Animals
- Antibodies, Neutralizing/immunology
- Antibodies, Viral/blood
- Antibodies, Viral/immunology
- Antigens, Viral/genetics
- Antigens, Viral/immunology
- Cross Reactions/immunology
- Female
- Gene Expression
- Genetic Vectors/administration & dosage
- Genetic Vectors/genetics
- Genetic Vectors/immunology
- Humans
- Immunity, Mucosal
- Influenza A Virus, H1N1 Subtype/genetics
- Influenza A Virus, H1N1 Subtype/immunology
- Influenza Vaccines/administration & dosage
- Influenza Vaccines/immunology
- Mice
- Molecular Sequence Data
- Nucleocapsid Proteins
- Nucleophosmin
- Orthomyxoviridae Infections/prevention & control
- Pan paniscus
- RNA-Binding Proteins/chemistry
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/immunology
- Recombinant Fusion Proteins/chemistry
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/immunology
- T-Lymphocytes/immunology
- Viral Core Proteins/chemistry
- Viral Core Proteins/genetics
- Viral Core Proteins/immunology
- Viral Matrix Proteins/chemistry
- Viral Matrix Proteins/genetics
- Viral Matrix Proteins/immunology
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Affiliation(s)
| | - Mary R. Quirion
- Gene Therapy and Immunogenicity Branch, Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, United States of America
| | - Chia-Yun Lo
- Gene Therapy and Immunogenicity Branch, Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, United States of America
| | - Julia A. Misplon
- Gene Therapy and Immunogenicity Branch, Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, United States of America
| | | | | | | | - Graeme E. Price
- Gene Therapy and Immunogenicity Branch, Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, United States of America
| | - Mark R. Soboleski
- Gene Therapy and Immunogenicity Branch, Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, United States of America
| | | | | | - Alfredo Nicosia
- Okairòs, Rome, Italy
- Centro di Ingegneria Genetica e Biotecnologia Avanzate (CEINGE), Naples, Italy
- Department of Biochemistry and Medical Biotechnology, University of Naples Federico II, Naples, Italy
| | - Suzanne L. Epstein
- Gene Therapy and Immunogenicity Branch, Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, United States of America
- * E-mail:
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Human cytomegalovirus TR strain glycoprotein O acts as a chaperone promoting gH/gL incorporation into virions but is not present in virions. J Virol 2009; 84:2597-609. [PMID: 20032193 DOI: 10.1128/jvi.02256-09] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Human cytomegalovirus (HCMV) produces the following two gH/gL complexes: gH/gL/gO and gH/gL/UL128-131. Entry into epithelial and endothelial cells requires gH/gL/UL128-131, and we have provided evidence that gH/gL/UL128-131 binds saturable epithelial cell receptors to mediate entry. HCMV does not require gH/gL/UL128-131 to enter fibroblasts, and laboratory adaptation to fibroblasts results in mutations in the UL128-131 genes, abolishing infection of epithelial and endothelial cells. HCMV gO-null mutants produce very small plaques on fibroblasts yet can spread on endothelial cells. Thus, one prevailing model suggests that gH/gL/gO mediates infection of fibroblasts, while gH/gL/UL128-131 mediates entry into epithelial/endothelial cells. Most biochemical studies of gO have involved the HCMV lab strain AD169, which does not assemble gH/gL/UL128-131 complexes. We examined gO produced by the low-passage clinical HCMV strain TR. Surprisingly, TR gO was not detected in purified extracellular virus particles. In TR-infected cells, gO remained sensitive to endoglycosidase H, suggesting that the protein was not exported from the endoplasmic reticulum (ER). However, TR gO interacted with gH/gL in the ER and promoted export of gH/gL from the ER to the Golgi apparatus. Pulse-chase experiments showed that a fraction of gO remained bound to gH/gL for relatively long periods, but gO eventually dissociated or was degraded and was not found in extracellular virions or secreted from cells. The accompanying report by P. T. Wille et al. (J. Virol., 84:2585-2596, 2010) showed that a TR gO-null mutant failed to incorporate gH/gL into virions and that the mutant was unable to enter fibroblasts and epithelial and endothelial cells. We concluded that gO acts as a molecular chaperone, increasing gH/gL ER export and incorporation into virions. It appears that gO competes with UL128-131 for binding onto gH/gL but is released from gH/gL, so that gH/gL (lacking UL128-131) is incorporated into virions. Thus, our revised model suggests that both gH/gL and gH/gL/UL128-131 are required for entry into epithelial and endothelial cells.
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Zhao C, Crews CJ, Derdeyn CA, Blackwell JL. Lac-regulated system for generating adenovirus 5 vaccine vectors expressing cytolytic human immunodeficiency virus 1 genes. J Virol Methods 2009; 160:101-10. [PMID: 19409930 PMCID: PMC2704014 DOI: 10.1016/j.jviromet.2009.04.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2009] [Accepted: 04/23/2009] [Indexed: 01/14/2023]
Abstract
Adenovirus (Ad) vectors have been developed as human immunodeficiency-1 (HIV-1) vaccine vectors because they consistently induce immune responses in preclinical animal models and human trials. Strong promoters and codon-optimization are often used to enhance vaccine-induced HIV-1 gene expression and immunogenicity. However, if the transgene is inherently cytotoxic in the cell line used to produce the vector, and is expressed at high levels, it is difficult to rescue a stable Ad HIV-1 vaccine vector. Therefore we hypothesized that generation of Ad vaccine vectors expressing cytotoxic genes, such as HIV-1 env, would be more efficient if expression of the transgene was down-regulated during Ad rescue. To test this hypothesis, a Lac repressor-operator system was applied to regulate expression of reporter luciferase and HIV-1 env transgenes during Ad rescue. The results demonstrate that during Ad rescue, constitutive expression of the Lac repressor in 293 cells reduced transgene expression levels to approximately 5% of that observed in the absence of regulation. Furthermore, Lac-regulation translated into more efficient Ad rescue compared to traditional 293 cells. Importantly, Ad vectors rescued with this system showed high levels of transgene expression when transduced into cells that lack the Lac repressor protein. The Lac-regulated system also facilitated the rescue of modified Ad vectors that have non-native receptor tropism. These tropism-modified Ad vectors infect a broader range of cell types than the unmodified Ad, which could increase their effectiveness as a vaccine vector. Overall, the Lac-regulated system described here (i) is backwards compatible with Ad vector methods that employ bacterial-mediated homologous recombination, (ii) is adaptable for the engineering of tropism-modified Ad vectors, and (iii) does not require co-expression of regulatory genes from the vector or the addition of exogenous chemicals to induce or repress transgene expression. This system therefore could facilitate the development of Ad-based vaccine candidates that otherwise would not be feasible to generate.
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Affiliation(s)
- Chunxia Zhao
- Emory Vaccine Center, Emory University, Atlanta, GA 30329, United States
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16
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Adenovirus vectors expressing hantavirus proteins protect hamsters against lethal challenge with andes virus. J Virol 2009; 83:7285-95. [PMID: 19403663 DOI: 10.1128/jvi.00373-09] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hantaviruses infect humans following aerosolization from rodent feces and urine, producing hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome. Due to the high rates of mortality and lack of therapies, vaccines are urgently needed. Nonreplicating adenovirus (Ad) vectors that express Andes hantavirus (ANDV) nucleocapsid protein (AdN) or glycoproteins (AdG(N) and AdG(C)) were constructed. Ad vectors were tested for their ability to protect Syrian hamsters from a lethal ANDV infection that mimics the pulmonary disease seen in humans. When administered once, all three Ad vectors, individually or in combination, elicited a robust immune response that protected hamsters. No vaccinated animal died, and there were no obvious clinical signs of disease. Further, hantavirus RNA was not detected by sensitive reverse transcription-PCR in tissues and blood of hamsters immunized with both AdG(N) and AdG(C). Cellular immunity appeared to be important for protection because the AdN vector completely protected animals. All three Ad vectors produced strong cytotoxic T-lymphocyte responses directed to hantavirus proteins in mice. Moreover, hamsters vaccinated with AdN, AdG(N), or AdG(C) produced no detectable neutralizing antibodies yet were protected. These Ad vectors represent the first vaccines that prevent lethal hantavirus disease and, in some instances (AdG(N) and AdG(C)), provide sterile immunity. These observations set the stage for a more detailed characterization of the types of immunity required to protect humans from hantavirus infections.
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Herpesvirus gB-induced fusion between the virion envelope and outer nuclear membrane during virus egress is regulated by the viral US3 kinase. J Virol 2009; 83:3115-26. [PMID: 19158241 DOI: 10.1128/jvi.01462-08] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Herpesvirus capsids collect along the inner surface of the nuclear envelope and bud into the perinuclear space. Enveloped virions then fuse with the outer nuclear membrane (NM). We previously showed that herpes simplex virus (HSV) glycoproteins gB and gH act in a redundant fashion to promote fusion between the virion envelope and the outer NM. HSV mutants lacking both gB and gH accumulate enveloped virions in herniations, vesicles that bulge into the nucleoplasm. Earlier studies had shown that HSV mutants lacking the viral serine/threonine kinase US3 also accumulate herniations. Here, we demonstrate that HSV gB is phosphorylated in a US3-dependent manner in HSV-infected cells, especially in a crude nuclear fraction. Moreover, US3 directly phosphorylated the gB cytoplasmic (CT) domain in in vitro assays. Deletion of gB in the context of a US3-null virus did not add substantially to defects in nuclear egress. The majority of the US3-dependent phosphorylation of gB involved the CT domain and amino acid T887, a residue present in a motif similar to that recognized by US3 in other proteins. HSV recombinants lacking gH and expressing either gB substitution mutation T887A or a gB truncated at residue 886 displayed substantial defects in nuclear egress. We concluded that phosphorylation of the gB CT domain is important for gB-mediated fusion with the outer NM. This suggested a model in which the US3 kinase is incorporated into the tegument layer (between the capsid and envelope) in HSV virions present in the perinuclear space. By this packaging, US3 might be brought close to the gB CT tail, leading to phosphorylation and triggering fusion between the virion envelope and the outer NM.
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18
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Gall JGD, Lizonova A, EttyReddy D, McVey D, Zuber M, Kovesdi I, Aughtman B, King CR, Brough DE. Rescue and production of vaccine and therapeutic adenovirus vectors expressing inhibitory transgenes. Mol Biotechnol 2007; 35:263-73. [PMID: 17652790 DOI: 10.1007/bf02686012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 12/26/2022]
Abstract
Expression of certain transgenes from an adenovirus vector can be deleterious to its own replication. This can result in the inhibition of virus rescue, reduced viral yields, or, in the worst case, make it impossible to construct a vector expressing the inhibiting transgene product. A gene regulation system based on the tet operon was used to allow the rescue and efficient growth of adenovectors that express transgenes to high levels. A key advantage to this system is that repression of transgene expression is mediated by the packaging cell line, thus, expression of regulatory products from the adenovector are not required. This provides a simple, broadly applicable system wherein transgene repression is constitutive during vector rescue and growth and there is no effect on adenovector-mediated expression of gene products in transduced cells. Several high-level expression vectors based on first- and second-generation adenovectors were rescued and produced to high titer that otherwise could not be grown. Yields of adenovectors expressing inhibitory transgene products were increased, and the overgrowth of cultures by adenovectors with nonfunctional expression cassettes was prevented. The gene regulation system is a significant advancement for the development of adenovirus vectors for vaccine and other gene transfer applications.
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Affiliation(s)
- Jason G D Gall
- GenVec, Inc. 65 West Watkins Mill Rd, Gaithersburg MD 20878, USA
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19
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Xian J, Lin Y, Liu Y, Gong P, Liu S. Signal transduction-related gene transfer leads to inhibition of proliferation and induction of differentiation in laryngeal squamous cell carcinoma in vitro. Eur Arch Otorhinolaryngol 2007; 264:1467-73. [PMID: 17628821 DOI: 10.1007/s00405-007-0392-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2006] [Accepted: 06/22/2007] [Indexed: 02/05/2023]
Abstract
The aim of this study is to target the interference therapy of signal transduction which is a novel therapeutic strategy in laryngeal squamous cell carcinoma (LSCC). We successfully constructed recombinant adenoviruses Ad-p14ARF, and Ad-antisense EGFR using AdEasy-1 vector System. Clonogenic cell assay, western blotting assay, 3'(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, flow cytometer (FCM) assay, and immunocytochemical technique were designed to examine the inhibition of proliferation, protein expression of p14ARF and EGFR and induction of differentiation, respectively. Furthermore the synergistic effect of Ad-p14ARF and Ad-antisense EGFR on Hep-2 cell was examined. We successfully used AdEasy-1 vector system to construct recombinant adenoviruses Ad-p14ARF and Ad-antisense EGFR. The activity of proliferation of Hep-2 cells was inhibited markedly by infecting Ad-p14ARF or Ad-antisense EGFR by comparing Ad-sense EGFR (P=0.005) with vector control (Ad-Ctrl) (P=0.005) and with PBS (P=0.003). This effect, combining Ad-antisense-EGFR with Ad-p14ARF became more noticeable than alone (P=0.01, P=0.02, respectively). P14 ARF protein overexpression, EGFR protein down expression, and inhibition of proliferation were observed in Hep-2 cells infected by either Ad-p14ARF or Ad-antisense EGFR. FCM revealed that the proportion of apoptosis cells transfected by Ad-p14ARF and Ad-antisense EGFR increased more obviously than the control. The proportion of (Hep-2 cells in) G0/G1 phases was increased by up to 78.5, 77.7, and 86.9% in Ad-antisense EGFR, Ad-p14ARF, and Ad-antisense EGFR+Ad-p14ARF, respectively. Our findings demonstrated that not only EGFR but p14ARF also plays a major role on the genesis and in modulating the cell growth and differentiation of human laryngocarcinoma. They efficaciously blocked the signal transduction of human laryngocarcinoma cell, and may therefore, be an effective potential target of gene therapy to prevent human laryngocarcinoma cell proliferation.
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Affiliation(s)
- Junming Xian
- Department of Otolaryngology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, 37# Guoxue Street, Chengdu, 610041, People's Republic of China
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Xian J, Lin Y, Liu Y, Gong P, Liu S. Combined p14ARFand Antisense EGFR Potentiate the Efficacy of Adenovirus-Mediated Gene Therapy in Laryngeal Squamous Cell Carcinoma (LSCC). DNA Cell Biol 2007; 26:71-9. [PMID: 17328665 DOI: 10.1089/dna.2006.0533] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The tumor suppressor p14(ARF) and protooncogene epidermal growth factor receptor (EGFR) play an important role in the development of laryngeal squamous cell carcinoma (LSCC). We explored the inhibition of proliferation and induction of differentiation in human larynx cancer cells (Hep-2) in vitro when p14(ARF) couples with antisense complementary DNA of EGFR to transfect into Hep-2 cells via the AdEasy-1 vector system. In vitro studies, using standard isobologram analyses, identified whether Ad-antisense EGFR is synergistic with Ad-14(ARF). To evaluate the cytotoxicity of these agents the gold standard clonogenic survival assay was used. Western blotting analyses, 3'(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, and flow cytometer (FCM) analysis was used to detect protein expression, proliferation, and cell cycle distribution of Hep-2 cells, respectively. Meanwhile, empty vector and PBS were set as a control. The activity of proliferation of Hep-2 cells was inhibited markedly by infection of Ad-p14(ARF) combined with Ad-antisense EGFR compared with Ad-p14(ARF) or Ad-antisense EGFR alone (P = 0.001, P = 0.002, respectively), with Ad-sense EGFR (P = 0.0005), with vector control (Ad-Ctrl) (P = 0.0001), and with PBS (P = 0.0001). FCM revealed that the proportion in the G(0)/G(1) phases increased by up to 86.9% when Ad-p14(ARF) was associated with Ad-antisense EGFR to transfect Hep-2 cells. A weakened expression of EGFR protein and P14 (ARF) protein overexpression was observed. Our study in vitro indicated that association of Ad-p14(ARF) with Ad-antisense EGFR remarkably inhibited activity of proliferation and inducted differentiation of Hep-2 cells. Therefore, not only EGFR, but also p14(ARF), plays a major role in the genesis and in modulating cell growth and differentiation of LSCC, and their synergistic effect was obvious. An effective potential target of gene therapy to prevent LSCC proliferation was provided.
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Affiliation(s)
- Junming Xian
- Department of Otolaryngology, West China Hospital, Sichuan University, Chengdu, People's Republic of China
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Mullick A, Xu Y, Warren R, Koutroumanis M, Guilbault C, Broussau S, Malenfant F, Bourget L, Lamoureux L, Lo R, Caron AW, Pilotte A, Massie B. The cumate gene-switch: a system for regulated expression in mammalian cells. BMC Biotechnol 2006; 6:43. [PMID: 17083727 PMCID: PMC1654148 DOI: 10.1186/1472-6750-6-43] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2006] [Accepted: 11/03/2006] [Indexed: 11/24/2022] Open
Abstract
Background A number of expression systems have been developed where transgene expression can be regulated. They all have specific characteristics making them more suitable for certain applications than for others. Since some applications require the regulation of several genes, there is a need for a variety of independent yet compatible systems. Results We have used the regulatory mechanisms of bacterial operons (cmt and cym) to regulate gene expression in mammalian cells using three different strategies. In the repressor configuration, regulation is mediated by the binding of the repressor (CymR) to the operator site (CuO), placed downstream of a strong constitutive promoter. Addition of cumate, a small molecule, relieves the repression. In the transactivator configuration, a chimaeric transactivator (cTA) protein, formed by the fusion of CymR with the activation domain of VP16, is able to activate transcription when bound to multiple copies of CuO, placed upstream of the CMV minimal promoter. Cumate addition abrogates DNA binding and therefore transactivation by cTA. Finally, an adenoviral library of cTA mutants was screened to identify a reverse cumate activator (rcTA), which activates transcription in the presence rather than the absence of cumate. Conclusion We report the generation of a new versatile inducible expression system.
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Affiliation(s)
- Alaka Mullick
- Institut de Recherche en Biotechnologie, Conseil National de Recherches du Canada, 6100 Royalmount Avenue, Montréal, Québec, H4P 2R2, Canada
- Départment de microbiologie et immunologie de l'Université de Montréal, Montréal, Québec, H3C 3J7, Canada
| | - Yan Xu
- Institut de Recherche en Biotechnologie, Conseil National de Recherches du Canada, 6100 Royalmount Avenue, Montréal, Québec, H4P 2R2, Canada
| | - René Warren
- Institut de Recherche en Biotechnologie, Conseil National de Recherches du Canada, 6100 Royalmount Avenue, Montréal, Québec, H4P 2R2, Canada
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, 570 West 7th Avenue, Vancouver, BC, V5Z 4S6, Canada
| | - Maria Koutroumanis
- Institut de Recherche en Biotechnologie, Conseil National de Recherches du Canada, 6100 Royalmount Avenue, Montréal, Québec, H4P 2R2, Canada
- Invitrogen, 688 East Main Street, Branford, CT, 06405, USA
| | - Claire Guilbault
- Institut de Recherche en Biotechnologie, Conseil National de Recherches du Canada, 6100 Royalmount Avenue, Montréal, Québec, H4P 2R2, Canada
| | - Sophie Broussau
- Institut de Recherche en Biotechnologie, Conseil National de Recherches du Canada, 6100 Royalmount Avenue, Montréal, Québec, H4P 2R2, Canada
- Départment de microbiologie et immunologie de l'Université de Montréal, Montréal, Québec, H3C 3J7, Canada
| | - Félix Malenfant
- Institut de Recherche en Biotechnologie, Conseil National de Recherches du Canada, 6100 Royalmount Avenue, Montréal, Québec, H4P 2R2, Canada
| | - Lucie Bourget
- Institut de Recherche en Biotechnologie, Conseil National de Recherches du Canada, 6100 Royalmount Avenue, Montréal, Québec, H4P 2R2, Canada
| | - Linda Lamoureux
- Institut de Recherche en Biotechnologie, Conseil National de Recherches du Canada, 6100 Royalmount Avenue, Montréal, Québec, H4P 2R2, Canada
- AstraZeneca, 7171, Frédérick-Banting, Ville St.-Laurent, Montréal, Québec, H4S 1Z9, Canada
| | - Rita Lo
- Institut de Recherche en Biotechnologie, Conseil National de Recherches du Canada, 6100 Royalmount Avenue, Montréal, Québec, H4P 2R2, Canada
| | - Antoine W Caron
- Institut de Recherche en Biotechnologie, Conseil National de Recherches du Canada, 6100 Royalmount Avenue, Montréal, Québec, H4P 2R2, Canada
| | - Amelie Pilotte
- Institut de Recherche en Biotechnologie, Conseil National de Recherches du Canada, 6100 Royalmount Avenue, Montréal, Québec, H4P 2R2, Canada
- Départment de microbiologie et immunologie de l'Université de Montréal, Montréal, Québec, H3C 3J7, Canada
| | - Bernard Massie
- Institut de Recherche en Biotechnologie, Conseil National de Recherches du Canada, 6100 Royalmount Avenue, Montréal, Québec, H4P 2R2, Canada
- INRS-IAF, Université du Québec, Laval, Québec, H7N 4Z3, Canada
- Départment de microbiologie et immunologie de l'Université de Montréal, Montréal, Québec, H3C 3J7, Canada
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22
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See RH, Zakhartchouk AN, Petric M, Lawrence DJ, Mok CPY, Hogan RJ, Rowe T, Zitzow LA, Karunakaran KP, Hitt MM, Graham FL, Prevec L, Mahony JB, Sharon C, Auperin TC, Rini JM, Tingle AJ, Scheifele DW, Skowronski DM, Patrick DM, Voss TG, Babiuk LA, Gauldie J, Roper RL, Brunham RC, Finlay BB. Comparative evaluation of two severe acute respiratory syndrome (SARS) vaccine candidates in mice challenged with SARS coronavirus. J Gen Virol 2006; 87:641-650. [PMID: 16476986 DOI: 10.1099/vir.0.81579-0] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Two different severe acute respiratory syndrome (SARS) vaccine strategies were evaluated for their ability to protect against live SARS coronavirus (CoV) challenge in a murine model of infection. A whole killed (inactivated by beta-propiolactone) SARS-CoV vaccine and a combination of two adenovirus-based vectors, one expressing the nucleocapsid (N) and the other expressing the spike (S) protein (collectively designated Ad S/N), were evaluated for the induction of serum neutralizing antibodies and cellular immune responses and their ability to protect against pulmonary SARS-CoV replication. The whole killed virus (WKV) vaccine given subcutaneously to 129S6/SvEv mice was more effective than the Ad S/N vaccine administered either intranasally or intramuscularly in inhibiting SARS-CoV replication in the murine respiratory tract. This protective ability of the WKV vaccine correlated with the induction of high serum neutralizing-antibody titres, but not with cellular immune responses as measured by gamma interferon secretion by mouse splenocytes. Titres of serum neutralizing antibodies induced by the Ad S/N vaccine administered intranasally or intramuscularly were significantly lower than those induced by the WKV vaccine. However, Ad S/N administered intranasally, but not intramuscularly, significantly limited SARS-CoV replication in the lungs. Among the vaccine groups, SARS-CoV-specific IgA was found only in the sera of mice immunized intranasally with Ad S/N, suggesting that mucosal immunity may play a role in protection for the intranasal Ad S/N delivery system. Finally, the sera of vaccinated mice contained antibodies to S, further suggesting a role for this protein in conferring protective immunity against SARS-CoV infection.
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MESH Headings
- Administration, Intranasal
- Animals
- Antibodies, Viral/blood
- Antibodies, Viral/immunology
- Antibody Specificity
- Disease Models, Animal
- Drug Evaluation, Preclinical
- Female
- Immunoglobulin A/blood
- Immunoglobulin A/immunology
- Injections, Intramuscular
- Injections, Subcutaneous
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/immunology
- Mice
- Neutralization Tests
- Nucleocapsid Proteins/genetics
- Severe acute respiratory syndrome-related coronavirus/chemistry
- Severe acute respiratory syndrome-related coronavirus/immunology
- Severe Acute Respiratory Syndrome/immunology
- Severe Acute Respiratory Syndrome/prevention & control
- Spike Glycoprotein, Coronavirus
- Vaccination
- Vaccines, DNA/administration & dosage
- Vaccines, DNA/genetics
- Viral Envelope Proteins/genetics
- Viral Envelope Proteins/immunology
- Viral Vaccines/administration & dosage
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Affiliation(s)
- Raymond H See
- University of British Columbia Centre for Disease Control, Vancouver, BC V5Z 4R4, Canada
| | - Alexander N Zakhartchouk
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada
| | - Martin Petric
- University of British Columbia Centre for Disease Control, Vancouver, BC V5Z 4R4, Canada
| | - David J Lawrence
- University of British Columbia Centre for Disease Control, Vancouver, BC V5Z 4R4, Canada
| | - Catherine P Y Mok
- University of British Columbia Centre for Disease Control, Vancouver, BC V5Z 4R4, Canada
| | - Robert J Hogan
- Emerging Pathogens Department, Southern Research Institute, Birmingham, AL 35205, USA
| | - Thomas Rowe
- Emerging Pathogens Department, Southern Research Institute, Birmingham, AL 35205, USA
| | - Lois A Zitzow
- Emerging Pathogens Department, Southern Research Institute, Birmingham, AL 35205, USA
| | - Karuna P Karunakaran
- University of British Columbia Centre for Disease Control, Vancouver, BC V5Z 4R4, Canada
| | - Mary M Hitt
- Departments of Pathology and Molecular Medicine and Biology, McMaster University, Hamilton, ON L8N 3Z5, Canada
| | - Frank L Graham
- Departments of Pathology and Molecular Medicine and Biology, McMaster University, Hamilton, ON L8N 3Z5, Canada
| | - Ludvik Prevec
- Departments of Pathology and Molecular Medicine and Biology, McMaster University, Hamilton, ON L8N 3Z5, Canada
| | - James B Mahony
- Departments of Pathology and Molecular Medicine and Biology, McMaster University, Hamilton, ON L8N 3Z5, Canada
| | - Chetna Sharon
- Departments of Molecular and Medical Genetics and Microbiology and Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Thierry C Auperin
- Departments of Molecular and Medical Genetics and Microbiology and Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - James M Rini
- Departments of Molecular and Medical Genetics and Microbiology and Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Aubrey J Tingle
- Michael Smith Foundation for Health Research, Vancouver, BC V6H 3X8, Canada
| | - David W Scheifele
- Vaccine Evaluation Centre, British Columbia Institute for Children's and Women's Health, BC Children's Hospital, Vancouver, BC V6H 3V4, Canada
| | - Danuta M Skowronski
- University of British Columbia Centre for Disease Control, Vancouver, BC V5Z 4R4, Canada
| | - David M Patrick
- University of British Columbia Centre for Disease Control, Vancouver, BC V5Z 4R4, Canada
| | - Thomas G Voss
- Emerging Pathogens Department, Southern Research Institute, Birmingham, AL 35205, USA
| | - Lorne A Babiuk
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada
| | - Jack Gauldie
- Departments of Pathology and Molecular Medicine and Biology, McMaster University, Hamilton, ON L8N 3Z5, Canada
| | - Rachel L Roper
- Brody School of Medicine, Department of Microbiology and Immunology, East Carolina University, Greenville, NC 27834, USA
| | - Robert C Brunham
- University of British Columbia Centre for Disease Control, Vancouver, BC V5Z 4R4, Canada
| | - B Brett Finlay
- Michael Smith Laboratories and Departments of Biochemistry and Molecular Biology and Microbiology and Immunology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
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23
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Berenjian S, Akusjärvi G. Binary AdEasy vector systems designed for Tet-ON or Tet-OFF regulated control of transgene expression. Virus Res 2005; 115:16-23. [PMID: 16102868 DOI: 10.1016/j.virusres.2005.07.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2005] [Revised: 07/01/2005] [Accepted: 07/05/2005] [Indexed: 11/23/2022]
Abstract
Here, we describe the construction of a set of binary adenovirus vectors encoding for a tetracycline-regulatable expression cassette and the Tet-ON or the Tet-OFF transcriptional activator proteins from a single viral chromosome. The rabies virus glycoprotein was cloned into the E1 region and the tetracycline activator proteins were inserted in both orientation in place of the E3 region. To further restrict background transcription, we also introduced a Lac repressor protein based roadblock to transcription elongation. To make the system more versatile it has been engineered into the commonly used AdEasy system. We show that rabies virus glycoprotein expression is tightly regulated with an essentially undetectable basal expression and a several 100-fold induced expression. In our vector backbone, the Tet-ON and the Tet-OFF systems appears to work with essentially the same efficiency. Thus, the choice of principle can be based on whether a positive or negative regulation of reporter gene activity is desirable. Taken together our results suggest that the binary vectors described here should be a valuable addition to the repertoire of viral vectors used in basic and medical research.
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Affiliation(s)
- Saideh Berenjian
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC, Box 582, 751 23 Uppsala, Sweden
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24
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Ha MN, Graham FL, D'Souza CK, Muller WJ, Igdoura SA, Schellhorn HE. Functional rescue of vitamin C synthesis deficiency in human cells using adenoviral-based expression of murine l-gulono-γ-lactone oxidase. Genomics 2004; 83:482-92. [PMID: 14962674 DOI: 10.1016/j.ygeno.2003.08.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2003] [Accepted: 08/20/2003] [Indexed: 02/06/2023]
Abstract
l-Gulono-gamma-lactone oxidase (GULO) is a critical enzyme present in most mammalian species that is required for the terminal step in vitamin C biosynthesis. Primates are absolutely dependent on exogenously supplied dietary vitamin C due to inactivation of the Gulo gene by mutation over 40 million years ago. In this study, we report the cloning and expression of the murine l-gulono-gamma-lactone oxidase cDNA and gene. The cDNA (2.3 kb) encodes an open reading frame of 440 amino acids that shows high homology to the rat l-gulono-gamma-lactone oxidase (>94%). The Gulo gene is 22 kb long and contains 12 exons. The 11 introns range in size from 479 to 5641 bp. Northern blot analysis revealed high expression of Gulo transcript in the liver. To investigate whether metabolic loss of vitamin C biosynthesis in human cells can be corrected by heterologous expression of GULO, we constructed a first-generation adenoviral vector expressing the murine GULO cDNA under the transcriptional control of the murine cytomegalovirus (MCMV) early promoter. Low rescue efficiency of Gulo-expressing adenoviral constructs and reduced viral growth in HEK293 cells were observed, suggesting that overexpression of Gulo may be inhibitory to cell growth. Placement of a removable stuffer fragment flanked by lox sites between the MCMV promoter and the Gulo gene resulted in efficient vector rescue and normal viral replication in parental HEK293 cells and high-level expression of Gulo in HEK293 cells expressing Cre recombinase. Cells infected with Gulo-expressing vectors overexpressed an FAD-containing protein that corresponded in size to that predicted for recombinant GULO protein and expressed a functional enzyme as measured by the conversion of l-gulono-gamma-lactone to ascorbic acid in cell-free extracts. The cloning of the murine Gulo cDNA and the construction of Gulo-expressing adenoviral vectors are vital steps toward determining the role of vitamin C in basic metabolism and in disease.
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Affiliation(s)
- Michael N Ha
- Department of Biology, McMaster University, Hamilton, ON, Canada L8S 4K1
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25
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Carlson CA, Shayakhmetov DM, Lieber A. Restoration of a functional open reading frame by homologous recombination between two adenoviral vectors. Mol Ther 2002; 6:99-105. [PMID: 12095309 DOI: 10.1006/mthe.2002.0635] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In this study, we examined the ability of adenoviral (Ad) vectors to undergo homologous recombination. The lacZ gene was divided between two parental, first-generation vectors such that neither encoded a functional product but both shared 494 bp in common. The open reading frame could only be restored by homologous recombination. We observed beta-galactosidase activity only upon co-infection of both parental vectors and after the onset of viral DNA replication, creating a delay in expression of 24-36 hours in HeLa cells. At peak efficiency, this recombination vector system resulted in beta-galactosidase activity levels 100x above background and just 18x less than a conventional, first-generation vector in HeLa cells. After recombination, the resultant progeny vector genomes containing reconstituted expression cassettes were devoid of all viral genes and contained two packaging signals. These progeny genomes were efficiently packaged, could be separated from their parental vectors based on their lighter buoyant densities in CsCl gradients, and were subsequently used as functional gene transfer vectors. This novel recombination vector system should be useful for transferring large transgenes (because the carrying capacity of two Ad vectors can be exploited) or expressing any cytotoxic or Ad replication inhibitory protein (because the parental vectors exhibit no background expression).
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Affiliation(s)
- Cheryl A Carlson
- Department of Pathology, University of Washington, Seattle, Washington 98195, USA
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26
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Rubinchik S, Norris JS, Dong JY. Construction, purification and characterization of adenovirus vectors expressing apoptosis-inducing transgenes. Methods Enzymol 2002; 346:529-47. [PMID: 11883089 DOI: 10.1016/s0076-6879(02)46075-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Affiliation(s)
- Semyon Rubinchik
- Department of Microbiology, Medical University of South Carolina, Charleston, South Carolina 29425, USA
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27
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Baboval T, Liang S, Smith FI. Viral vector-mediated delivery of competing glycosyltransferases modifies epitope expression cell specifically. J Neurosci Res 2002; 67:583-94. [PMID: 11891771 DOI: 10.1002/jnr.10149] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The glycoconjugate epitopes 3-fucosyl-N-acetyllactosamine (CD15) and sulfoglucuronylcarbohydrate (SGC) mediate cell adhesion events in several systems, and are regulated both spatially and temporally during cerebellar development. In cotransfection studies using COS-1 cells, competition between glycosyltransferases that utilize a common precursor involved in the final synthetic steps of these epitopes, can modulate epitope expression. For example, cotransfection of rat alpha1,3-fucosyltransferase IV (Fuc-TIV) and either rat glucuronic acid transferase P (GlcAT) or pig alpha1,3-galactosyltransferase (GalT) resulted in the dominance of either SGC or GalalphaGal epitope expression, respectively, with blockage of CD15 epitope expression. Viral vectors expressing these glycosyltransferases were used to determine whether competition plays a role in establishing epitope dominance in cerebellar cells, and whether overexpression of competing glycosyltransferases could be used to block epitope expression. Infection of cerebellar astrocytes with viral vectors expressing either Fuc-TIV, or Fuc-TIX, caused dramatic increases in CD15 expression in the presence of continued endogenous SGC epitope expression. Likewise, viral transduction with GalT resulted in GalalphaGal expression without affecting endogenous CD15 or SGC expression. Thus, competition between these enzymes does not appear to play a role in establishing epitope expression in astrocytes, and transduction of these enzymes does not provide a method of blocking the expression of endogenous epitopes. In contrast to what was observed for astrocytes, infection with viral vectors expressing either Fuc-T, GlcAT, or GalT did not result in significant expression of the relevant epitopes (CD15, SGC or GalalphaGal, respectively) on granule neurons. These results suggest a different complement of precursors are present in granule neurons and astrocytes, presumably due to the presence of different complements of glycosyltransferases in these cells.
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Affiliation(s)
- Thia Baboval
- Biomedical Sciences Department, E.K. Shriver Center for Mental Retardation, Waltham, Massachusetts 02452, USA
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28
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Abstract
To construct recombinant adenoviruses expressing biologically active proteins may be impossible, or result in a significant reduction in virus yield, if the protein expressed has an inhibitory effect on virus replication or cellular growth. To overcome this problem, we previously designed adenovirus vectors expressing foreign proteins from inducible promoters. However, during our work with a replication-deficient virus expressing the ASF/SF2 splicing factor from a progesterone antagonist-inducible gene cassette, we discovered that ASF/SF2 was expressed at a significant level in the 293 producer cell line, even in the absence of inducer. 293 cells code for adenovirus E1A and E1B proteins and thus support the growth of E1-deficient adenoviruses. Here we show that this background ASF/SF2 expression results from a low level of E1A-mediated transactivation of the basal promoter driving transgene expression. To overcome the problem of leaky expression, we reconstructed a novel gene cassette that combines an inducible promoter and a Lac repressor protein-based block to reduce transcriptional elongation. We show that this novel vector system dramatically reduced background transgene expression and therefore should be useful for the rescue and propagation of high-titer stocks of recombinant adenoviruses expressing toxic proteins.
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Affiliation(s)
- D Edholm
- Department of Medical Biochemistry and Microbiology, BMC, Uppsala University, SE-751 23 Uppsala, Sweden
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29
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Affiliation(s)
- W C Russell
- Biomolecular Sciences Building, School of Biology, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, UK1
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