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Lee HN, Xu B, Lewkowicz AP, Engel K, Kelley-Baker L, McWilliams IL, Ireland DDC, Kielczewski JL, Li J, Fariss RN, Campos MM, Baum A, Kyratsous C, Pascal K, Chan CC, Caspi RR, Manangeeswaran M, Verthelyi D. Ebola virus-induced eye sequelae: a murine model for evaluating glycoprotein-targeting therapeutics. EBioMedicine 2024; 104:105170. [PMID: 38823088 PMCID: PMC11169960 DOI: 10.1016/j.ebiom.2024.105170] [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: 11/21/2023] [Revised: 04/17/2024] [Accepted: 05/14/2024] [Indexed: 06/03/2024] Open
Abstract
BACKGROUND Ebola virus disease (EVD) survivors experience ocular sequelae including retinal lesions, cataracts, and vision loss. While monoclonal antibodies targeting the Ebola virus glycoprotein (EBOV-GP) have shown promise in improving prognosis, their effectiveness in mitigating ocular sequelae remains uncertain. METHODS We developed and characterized a BSL-2-compatible immunocompetent mouse model to evaluate therapeutics targeting EBOV-GP by inoculating neonatal mice with vesicular stomatitis virus expressing EBOV-GP (VSV-EBOV). To examine the impact of anti-EBOV-GP antibody treatment on acute retinitis and ocular sequelae, VSV-EBOV-infected mice were treated with polyclonal antibodies or monoclonal antibody preparations with antibody-dependent cellular cytotoxicity (ADCC-mAb) or neutralizing activity (NEUT-mAb). FINDINGS Treatment with all anti-EBOV-GP antibodies tested dramatically reduced viremia and improved survival. Further, all treatments reduced the incidence of cataracts. However, NEUT-mAb alone or in combination with ADCC-mAb reduced viral load in the eyes, downregulated the ocular immune and inflammatory responses, and minimized retinal damage more effectively. INTERPRETATION Anti-EBOV-GP antibodies can improve survival among EVD patients, but improved therapeutics are needed to reduce life altering sequelae. This animal model offers a new platform to examine the acute and long-term effect of the virus in the eye and the relative impact of therapeutic candidates targeting EBOV-GP. Results indicate that even antibodies that improve systemic viral clearance and survival can differ in their capacity to reduce acute ocular inflammation, and long-term retinal pathology and corneal degeneration. FUNDING This study was partly supported by Postgraduate Research Fellowship Awards from ORISE through an interagency agreement between the US DOE and the US FDA.
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MESH Headings
- Animals
- Mice
- Disease Models, Animal
- Ebolavirus/immunology
- Ebolavirus/pathogenicity
- Hemorrhagic Fever, Ebola/virology
- Hemorrhagic Fever, Ebola/drug therapy
- Hemorrhagic Fever, Ebola/immunology
- Antibodies, Viral/immunology
- Antibodies, Monoclonal/therapeutic use
- Antibodies, Monoclonal/pharmacology
- Humans
- Viral Load
- Glycoproteins/immunology
- Glycoproteins/metabolism
- Viral Envelope Proteins/immunology
- Antibodies, Neutralizing/immunology
- Antibodies, Neutralizing/pharmacology
- Antibodies, Neutralizing/therapeutic use
- Antibody-Dependent Cell Cytotoxicity
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Affiliation(s)
- Ha-Na Lee
- Division of Biotechnology Review and Research-III, Office of Biotechnology Products, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Biying Xu
- Laboratory of Immunology, National Eye Institute, NIH, Bethesda, MD, 20892, USA
| | - Aaron P Lewkowicz
- Division of Biotechnology Review and Research-III, Office of Biotechnology Products, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Kaliroi Engel
- Division of Biotechnology Review and Research-III, Office of Biotechnology Products, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Logan Kelley-Baker
- Division of Biotechnology Review and Research-III, Office of Biotechnology Products, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Ian L McWilliams
- Division of Biotechnology Review and Research-III, Office of Biotechnology Products, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Derek D C Ireland
- Division of Biotechnology Review and Research-III, Office of Biotechnology Products, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD, 20993, USA
| | | | - Jinbo Li
- Biological Imaging Core, National Eye Institute, NIH, Bethesda, MD, 20892, USA
| | - Robert N Fariss
- Biological Imaging Core, National Eye Institute, NIH, Bethesda, MD, 20892, USA
| | - Mercedes M Campos
- Biological Imaging Core, National Eye Institute, NIH, Bethesda, MD, 20892, USA
| | - Alina Baum
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY, 10591, USA
| | | | - Kristen Pascal
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY, 10591, USA
| | - Chi-Chao Chan
- Laboratory of Immunology, National Eye Institute, NIH, Bethesda, MD, 20892, USA
| | - Rachel R Caspi
- Laboratory of Immunology, National Eye Institute, NIH, Bethesda, MD, 20892, USA
| | - Mohanraj Manangeeswaran
- Division of Biotechnology Review and Research-III, Office of Biotechnology Products, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Daniela Verthelyi
- Division of Biotechnology Review and Research-III, Office of Biotechnology Products, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD, 20993, USA.
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Lee SS, Phy K, Peden K, Sheng-Fowler L. Development of a micro-neutralization assay for ebolaviruses using a replication-competent vesicular stomatitis hybrid virus and a quantitative PCR readout. Vaccine 2017; 35:5481-5486. [PMID: 28427845 DOI: 10.1016/j.vaccine.2017.03.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 03/01/2017] [Accepted: 03/08/2017] [Indexed: 01/11/2023]
Abstract
Development of vaccines against highly pathogenic viruses that could also be used as agents of bioterrorism is both a public health issue and a national security priority. Methods that can quantify neutralizing antibodies will likely be crucial in demonstrating vaccine effectiveness, as most licensed viral vaccines are effective due to their capacity to elicit neutralizing antibodies. Assays to determine whether antibodies are neutralizing traditionally involve infectious virus, and the assay most commonly used is the plaque-reduction neutralization test (PRNT). However, when the virus is highly pathogenic, this assay must be done under the appropriate level of containment; for tier one select agents, such as Ebola virus (EBOV), it is performed under Biological Safety Level 4 (BSL-4) conditions. Developing high-throughput neutralization assays for these viruses that can be done in standard BSL-2 laboratories should facilitate vaccine development. Our approach is to use a replication-competent hybrid virus whose genome carries the envelope gene from the pathogenic virus on the genetic backbone of a non-pathogenic virus, such as vesicular stomatitis virus (VSV). We have generated hybrid VSVs carrying the envelope genes for several species of ebolavirus. The readout for infectivity is a one-step reverse transcriptase quantitative PCR (RT-qPCR), an approach that we have used for other viruses that allows robustness and adaptability to automation. Using this method, we have shown that neutralization can be assessed within 6-16h after infection. Importantly, the titers obtained in our assay with two characterized antibodies were in agreement with titers obtained in other assays. Finally, although in this paper we describe the VSV platform to quantify neutralizing antibodies to ebolaviruses, the platform should be directly applicable to any virus whose envelope is compatible with VSV biology.
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Affiliation(s)
- Stella S Lee
- Laboratory of DNA Viruses, Division of Viral Products, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, United States
| | - Kathryn Phy
- Laboratory of DNA Viruses, Division of Viral Products, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, United States
| | - Keith Peden
- Laboratory of DNA Viruses, Division of Viral Products, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, United States.
| | - Li Sheng-Fowler
- Laboratory of DNA Viruses, Division of Viral Products, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, United States
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Coleman JW, Wright KJ, Wallace OL, Sharma P, Arendt H, Martinez J, DeStefano J, Zamb TP, Zhang X, Parks CL. Development of a duplex real-time RT-qPCR assay to monitor genome replication, gene expression and gene insert stability during in vivo replication of a prototype live attenuated canine distemper virus vector encoding SIV gag. J Virol Methods 2014; 213:26-37. [PMID: 25486083 PMCID: PMC7111484 DOI: 10.1016/j.jviromet.2014.11.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 11/10/2014] [Accepted: 11/18/2014] [Indexed: 11/16/2022]
Abstract
The duplex assay monitored replication, tissue distribution, and mRNA expression. The duplex assay monitored insert genetic stability during in vivo replication. Primary site of CDV replication in ferrets was abdominal cavity lymphoid tissue. CDV gRNA or mRNA was undetectable in brain tissue. Specific primers were used in the RT step to distinguish gRNA from mRNA.
Advancement of new vaccines based on live viral vectors requires sensitive assays to analyze in vivo replication, gene expression and genetic stability. In this study, attenuated canine distemper virus (CDV) was used as a vaccine delivery vector and duplex 2-step quantitative real-time RT-PCR (RT-qPCR) assays specific for genomic RNA (gRNA) or mRNA have been developed that concurrently quantify coding sequences for the CDV nucleocapsid protein (N) and a foreign vaccine antigen (SIV Gag). These amplicons, which had detection limits of about 10 copies per PCR reaction, were used to show that abdominal cavity lymphoid tissues were a primary site of CDV vector replication in infected ferrets, and importantly, CDV gRNA or mRNA was undetectable in brain tissue. In addition, the gRNA duplex assay was adapted for monitoring foreign gene insert genetic stability during in vivo replication by analyzing the ratio of CDV N and SIV gag genomic RNA copies over the course of vector infection. This measurement was found to be a sensitive probe for assessing the in vivo genetic stability of the foreign gene insert.
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Affiliation(s)
- John W Coleman
- The International AIDS Vaccine Initiative, The AIDS Vaccine Design & Development Laboratory, Brooklyn, NY 11220, United States.
| | - Kevin J Wright
- The International AIDS Vaccine Initiative, The AIDS Vaccine Design & Development Laboratory, Brooklyn, NY 11220, United States
| | - Olivia L Wallace
- The International AIDS Vaccine Initiative, The AIDS Vaccine Design & Development Laboratory, Brooklyn, NY 11220, United States
| | - Palka Sharma
- The International AIDS Vaccine Initiative, The AIDS Vaccine Design & Development Laboratory, Brooklyn, NY 11220, United States
| | - Heather Arendt
- The International AIDS Vaccine Initiative, The AIDS Vaccine Design & Development Laboratory, Brooklyn, NY 11220, United States
| | - Jennifer Martinez
- The International AIDS Vaccine Initiative, The AIDS Vaccine Design & Development Laboratory, Brooklyn, NY 11220, United States
| | - Joanne DeStefano
- The International AIDS Vaccine Initiative, The AIDS Vaccine Design & Development Laboratory, Brooklyn, NY 11220, United States
| | - Timothy P Zamb
- The International AIDS Vaccine Initiative, The AIDS Vaccine Design & Development Laboratory, Brooklyn, NY 11220, United States
| | - Xinsheng Zhang
- The International AIDS Vaccine Initiative, The AIDS Vaccine Design & Development Laboratory, Brooklyn, NY 11220, United States; Program in Molecular and Cellular Biology, School of Graduate Studies, The State University of New York Downstate Medical Center, Brooklyn, NY 11203, United States
| | - Christopher L Parks
- The International AIDS Vaccine Initiative, The AIDS Vaccine Design & Development Laboratory, Brooklyn, NY 11220, United States; Program in Molecular and Cellular Biology, School of Graduate Studies, The State University of New York Downstate Medical Center, Brooklyn, NY 11203, United States
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Rabinovich S, Powell RLR, Lindsay RWB, Yuan M, Carpov A, Wilson A, Lopez M, Coleman JW, Wagner D, Sharma P, Kemelman M, Wright KJ, Seabrook JP, Arendt H, Martinez J, DeStefano J, Chiuchiolo MJ, Parks CL. A novel, live-attenuated vesicular stomatitis virus vector displaying conformationally intact, functional HIV-1 envelope trimers that elicits potent cellular and humoral responses in mice. PLoS One 2014; 9:e106597. [PMID: 25215861 PMCID: PMC4162551 DOI: 10.1371/journal.pone.0106597] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 08/03/2014] [Indexed: 01/09/2023] Open
Abstract
Though vaccination with live-attenuated SIV provides the greatest protection from progressive disease caused by SIV challenge in rhesus macaques, attenuated HIV presents safety concerns as a vaccine; therefore, live viral vectors carrying HIV immunogens must be considered. We have designed a replication-competent vesicular stomatitis virus (VSV) displaying immunogenic HIV-1 Env trimers and attenuating quantities of the native surface glycoprotein (G). The clade B Env immunogen is an Env-VSV G hybrid (EnvG) in which the transmembrane and cytoplasmic tail regions are derived from G. Relocation of the G gene to the 5'terminus of the genome and insertion of EnvG into the natural G position induced a ∼1 log reduction in surface G, significant growth attenuation compared to wild-type, and incorporation of abundant EnvG. Western blot analysis indicated that ∼75% of incorporated EnvG was a mature proteolytically processed form. Flow cytometry showed that surface EnvG bound various conformationally- and trimer-specific antibodies (Abs), and in-vitro growth assays on CD4+CCR5+ cells demonstrated EnvG functionality. Neither intranasal (IN) or intramuscular (IM) administration in mice induced any observable pathology and all regimens tested generated potent Env-specific ELISA titers of 10(4)-10(5), with an IM VSV prime/IN VSV boost regimen eliciting the highest binding and neutralizing Ab titers. Significant quantities of Env-specific CD4+ T cells were also detected, which were augmented as much as 70-fold by priming with IM electroporated plasmids encoding EnvG and IL-12. These data suggest that our novel vector can achieve balanced safety and immunogenicity and should be considered as an HIV vaccine platform.
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Affiliation(s)
- Svetlana Rabinovich
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
- Molecular and Cellular Biology Program, The School of Graduate Studies, State University of New York Downstate Medical Center, Brooklyn, New York, United States of America
| | - Rebecca L. R. Powell
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Ross W. B. Lindsay
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Maoli Yuan
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Alexei Carpov
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Aaron Wilson
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Mary Lopez
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - John W. Coleman
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Denise Wagner
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Palka Sharma
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Marina Kemelman
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Kevin J. Wright
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - John P. Seabrook
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Heather Arendt
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Jennifer Martinez
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Joanne DeStefano
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
| | - Maria J. Chiuchiolo
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
- Molecular and Cellular Biology Program, The School of Graduate Studies, State University of New York Downstate Medical Center, Brooklyn, New York, United States of America
| | - Christopher L. Parks
- International AIDS Vaccine Initiative, Design and Development Laboratory, Brooklyn, New York, United States of America
- Molecular and Cellular Biology Program, The School of Graduate Studies, State University of New York Downstate Medical Center, Brooklyn, New York, United States of America
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Efficient production of Hantaan and Puumala pseudovirions for viral tropism and neutralization studies. Virology 2011; 423:134-42. [PMID: 22209230 DOI: 10.1016/j.virol.2011.08.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 06/07/2011] [Accepted: 08/18/2011] [Indexed: 02/06/2023]
Abstract
Puumala (PUUV) and Hantaan (HTNV) viruses are hantaviruses within the family Bunyaviridae and associated with Hemorrhagic Fever with Renal Syndrome (HFRS) in humans. Little is known about how these viruses interact with host cells, though pathogenic hantaviruses interact with α(v)β(3) integrin. To study host cell interactions and rapidly test the ability of antibodies to prevent infection, we produced HTNV and PUUV pseudovirions on a vesicular stomatitis virus (VSV) core. Similar to replication-competent hantaviruses, infection was low-pH-dependent. Despite broad cell tropism, several human T cell lines were poorly permissive to hantavirus pseudovirions, compared to VSV, indicating a relative block to infection at the level of entry. Stable expression of α(v)β(3) integrin in SupT1 cells did not restore infectivity. Finally, the pseudovirion system provided a rapid, quantitative, and specific method to screen for neutralizing antibodies in immune sera.
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Johnson JE, Coleman JW, Kalyan NK, Calderon P, Wright KJ, Obregon J, Ogin-Wilson E, Natuk RJ, Clarke DK, Udem SA, Cooper D, Hendry RM. In vivo biodistribution of a highly attenuated recombinant vesicular stomatitis virus expressing HIV-1 Gag following intramuscular, intranasal, or intravenous inoculation. Vaccine 2009; 27:2930-9. [PMID: 19428903 PMCID: PMC2747378 DOI: 10.1016/j.vaccine.2009.03.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2008] [Revised: 03/03/2009] [Accepted: 03/04/2009] [Indexed: 12/19/2022]
Abstract
Recombinant vesicular stomatitis viruses (rVSVs) are being developed as potential HIV-1 vaccine candidates. To characterize the in vivo replication and dissemination of rVSV vectors in mice, high doses of a highly attenuated vector expressing HIV-1 Gag, rVSVIN-N4CT9-Gag1, and a prototypic reference virus, rVSVIN-HIVGag5, were delivered intramuscularly (IM), intranasally (IN), or intravenously (IV). We used quantitative, real-time RT-PCR (Q-PCR) and standard plaque assays to measure the temporal dissemination of these viruses to various tissues. Following IM inoculation, both viruses were detected primarily at the injection site as well as in draining lymph nodes; neither virus induced significant weight loss, pathologic signs, or evidence of neuroinvasion. In contrast, following IN inoculation, the prototypic virus was detected in all tissues tested and caused significant weight loss leading to death. IN administration of rVSVIN-N4CT9-Gag1 resulted in detection in numerous tissues (brain, lung, nasal turbinates, and lymph nodes) albeit in significantly reduced levels, which caused little or no weight loss nor any mortality. Following IV inoculation, both prototypic and attenuated viruses were detected by Q-PCR in all tissues tested. In contrast to the prototype, rVSVIN-N4CT9-Gag1 viral loads were significantly lower in all organs tested, and no infectious virus was detected in the brain following IV inoculation, despite the presence of viral RNA. These studies demonstrated significant differences in the biodistribution patterns of and the associated pathogenicity engendered by the prototypic and attenuated vectors in a highly susceptible host.
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Coleman JW, Johnson JE, Clarke DK. Simultaneous quantification of four RNA targets by multiplex, real-time RT-PCR without optimization. Biotechniques 2007; 43:369-71. [PMID: 17907580 DOI: 10.2144/000112590] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Attenuation of recombinant vesicular stomatitis virus-human immunodeficiency virus type 1 vaccine vectors by gene translocations and g gene truncation reduces neurovirulence and enhances immunogenicity in mice. J Virol 2007; 82:207-19. [PMID: 17942549 DOI: 10.1128/jvi.01515-07] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recombinant vesicular stomatitis virus (rVSV) has shown great potential as a new viral vector for vaccination. However, the prototypic rVSV vector described previously was found to be insufficiently attenuated for clinical evaluation when assessed for neurovirulence in nonhuman primates. Here, we describe the attenuation, neurovirulence, and immunogenicity of rVSV vectors expressing human immunodeficiency virus type 1 Gag. These rVSV vectors were attenuated by combinations of the following manipulations: N gene translocations (N4), G gene truncations (CT1 or CT9), noncytopathic M gene mutations (Mncp), and positioning of the gag gene into the first position of the viral genome (gag1). The resulting N4CT1-gag1, N4CT9-gag1, and MncpCT1-gag1 vectors demonstrated dramatically reduced neurovirulence in mice following direct intracranial inoculation. Surprisingly, in spite of a very high level of attenuation, the N4CT1-gag1 and N4CT9-gag1 vectors generated robust Gag-specific immune responses following intramuscular immunization that were equivalent to or greater than immune responses generated by the more virulent prototypic vectors. MncpCT1-gag1 also induced Gag-specific immune responses following intramuscular immunization that were equivalent to immune responses generated by the prototypic rVSV vector. Placement of the gag gene in the first position of the VSV genome was associated with increased in vitro expression of Gag protein, in vivo expression of Gag mRNA, and enhanced immunogenicity of the vector. These findings demonstrate that through directed manipulation of the rVSV genome, vectors that have reduced neurovirulence and enhanced immunogenicity can be made.
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Simultaneous Quantification of Four RNA Targets by Multiplex, Real-Time RT-PCR without Optimization. Biotechniques 2007. [DOI: 10.2144/000112626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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