scholarly journals Increased Immunogenicity of a DNA-Launched Venezuelan Equine Encephalitis Virus-Based Replicon DNA Vaccine

2007 ◽  
Vol 81 (24) ◽  
pp. 13412-13423 ◽  
Author(s):  
Karl Ljungberg ◽  
Alan C. Whitmore ◽  
Meagan E. Fluet ◽  
Timothy P. Moran ◽  
Reed S. Shabman ◽  
...  
Keyword(s):  
Immune Responses ◽  
Dna Vaccine ◽  
Type I Interferon ◽  
Interleukin 2 ◽  
Venezuelan Equine Encephalitis Virus ◽  
Encephalitis Virus ◽  
Type I ◽  
Venezuelan Equine Encephalitis ◽  
Equine Encephalitis Virus ◽  
Replicon Particle

ABSTRACT A novel genetic vaccine that is based on a Venezuelan equine encephalitis virus (VEE) replicon launched from plasmid DNA is described. The plasmid encodes a VEE replicon under the transcriptional control of the cytomegalovirus immediate-early promoter (VEE DNA). The VEE DNA consistently expressed 3- to 15-fold more green fluorescent protein in vitro than did a conventional DNA vaccine. Furthermore, transfection with the DNA-launched VEE replicon induced apoptosis and type I interferon production. Inoculation of mice with VEE DNA encoding human immunodeficiency virus type 1 gp160 significantly increased humoral responses by several orders of magnitude compared to an equal dose of a conventional DNA vaccine. These increases were also observed at 10- and 100-fold-lower doses of the VEE DNA. Cellular immune responses measured by gamma interferon and interleukin 2 enzyme-linked immunospot assay were significantly higher in mice immunized with the VEE DNA at decreased doses. The immune responses induced by the VEE DNA-encoded antigen, however, were independent of an intact type I interferon signaling pathway. Moreover, the DNA-launched VEE replicon induced an efficient prime to a VEE replicon particle (VRP) boost, increasing humoral and cellular immunity by at least 1 order of magnitude compared to VEE DNA only. Importantly, immunization with VEE DNA, as opposed to VRP, did not induce any anti-VRP neutralizing antibodies. Increased potency of DNA vaccines and reduced vector immunity may ultimately have an impact on the design of vaccination strategies in humans.

scholarly journals A DNA Vaccine for Venezuelan Equine Encephalitis Virus Delivered by Intramuscular Electroporation Elicits High Levels of Neutralizing Antibodies in Multiple Animal Models and Provides Protective Immunity to Mice and Nonhuman Primates

2011 ◽  
Vol 18 (5) ◽  
pp. 707-716 ◽  
Author(s):  
Lesley C. Dupuy ◽  
Michelle J. Richards ◽  
Barry Ellefsen ◽  
Lillian Chau ◽  
Alain Luxembourg ◽  
...  
Keyword(s):  
Dna Vaccine ◽  
Neutralizing Antibodies ◽  
Protective Efficacy ◽  
Clinical Signs ◽  
Neutralizing Antibody ◽  
Venezuelan Equine Encephalitis Virus ◽  
Encephalitis Virus ◽  
Antibody Responses ◽  
Venezuelan Equine Encephalitis ◽  
Equine Encephalitis Virus

ABSTRACTWe evaluated the immunogenicity and protective efficacy of a DNA vaccine expressing codon-optimized envelope glycoprotein genes of Venezuelan equine encephalitis virus (VEEV) when delivered by intramuscular electroporation. Mice vaccinated with the DNA vaccine developed robust VEEV-neutralizing antibody responses that were comparable to those observed after administration of the live-attenuated VEEV vaccine TC-83 and were completely protected from a lethal aerosol VEEV challenge. The DNA vaccine also elicited strong neutralizing antibody responses in rabbits that persisted at high levels for at least 6 months and could be boosted by a single additional electroporation administration of the DNA performed approximately 6 months after the initial vaccinations. Cynomolgus macaques that received the vaccine by intramuscular electroporation developed substantial neutralizing antibody responses and after an aerosol challenge had no detectable serum viremia and had reduced febrile reactions, lymphopenia, and clinical signs of disease compared to those of negative-control macaques. Taken together, our results demonstrate that this DNA vaccine provides a potent means of protecting against VEEV infections and represents an attractive candidate for further development.

scholarly journals Interplay of Acute and Persistent Infections Caused by Venezuelan Equine Encephalitis Virus Encoding Mutated Capsid Protein

2010 ◽  
Vol 84 (19) ◽  
pp. 10004-10015 ◽  
Author(s):  
Svetlana Atasheva ◽  
Valentina Krendelchtchikova ◽  
Anton Liopo ◽  
Elena Frolova ◽  
Ilya Frolov
Keyword(s):  
Capsid Protein ◽  
Virus Replication ◽  
Persistent Infection ◽  
Venezuelan Equine Encephalitis Virus ◽  
Encephalitis Virus ◽  
Type I ◽  
Venezuelan Equine Encephalitis ◽  
Antiviral State ◽  
Equine Encephalitis Virus

ABSTRACT Venezuelan equine encephalitis virus (VEEV) is a significant human and animal pathogen. The highlight of VEEV replication in vitro, in cells of vertebrate origin, is the rapid development of cytopathic effect (CPE), which is strongly dependent upon the expression of viral capsid protein. Besides being an integral part of virions, the latter protein is capable of (i) binding both the nuclear import and nuclear export receptors, (ii) accumulating in the nuclear pore complexes, (iii) inhibiting nucleocytoplasmic trafficking, and (iv) inhibiting transcription of cellular ribosomal and messenger RNAs. Using our knowledge of the mechanism of VEEV capsid protein function in these processes, we designed VEEV variants containing combinations of mutations in the capsid-coding sequences. These mutations made VEEV dramatically less cytopathic but had no effect on infectious virus production. In cell lines that have defects in type I interferon (IFN) signaling, the capsid mutants demonstrated very efficient persistent replication. In other cells, which have no defects in IFN production or signaling, the same mutants were capable of inducing a long-term antiviral state, downregulating virus replication to an almost undetectable level. However, ultimately, these cells also developed a persistent infection, characterized by continuous virus replication and beta IFN (IFN-β) release. The results of this study demonstrate that the long-term cellular antiviral state is determined by the synergistic effects of type I IFN signaling and the antiviral reaction induced by replicating viral RNA and/or the expression of VEEV-specific proteins. The designed mutants represent an important model for studying the mechanisms of cell interference with VEEV replication and development of persistent infection.

scholarly journals Expression of the Two Major Envelope Proteins of Equine Arteritis Virus as a Heterodimer Is Necessary for Induction of Neutralizing Antibodies in Mice Immunized with Recombinant Venezuelan Equine Encephalitis Virus Replicon Particles

2000 ◽  
Vol 74 (22) ◽  
pp. 10623-10630 ◽  
Author(s):  
Udeni B. R. Balasuriya ◽  
Hans W. Heidner ◽  
Jodi F. Hedges ◽  
Jacqueline C. Williams ◽  
Nancy L. Davis ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Venezuelan Equine Encephalitis Virus ◽  
Envelope Proteins ◽  
Encephalitis Virus ◽  
Equine Arteritis Virus ◽  
M Protein ◽  
Venezuelan Equine Encephalitis ◽  
Reading Frame ◽  
Equine Encephalitis Virus ◽  
Replicon Particle

ABSTRACT RNA replicon particles derived from a vaccine strain of Venezuelan equine encephalitis virus (VEE) were used as a vector for expression of the major envelope proteins (GL and M) of equine arteritis virus (EAV), both individually and in heterodimer form (GL/M). Open reading frame 5 (ORF5) encodes the GL protein, which expresses the known neutralizing determinants of EAV (U. B. R. Balasuriya, J. F. Patton, P. V. Rossitto, P. J. Timoney, W. H. McCollum, and N. J. MacLachlan, Virology 232:114–128, 1997). ORF5 and ORF6 (which encodes the M protein) of EAV were cloned into two different VEE replicon vectors that contained either one or two 26S subgenomic mRNA promoters. These replicon RNAs were packaged into VEE replicon particles by VEE capsid protein and glycoproteins supplied intrans in cells that were coelectroporated with replicon and helper RNAs. The immunogenicity of individual replicon particle preparations (pVR21-GL, pVR21-M, and pVR100-GL/M) in BALB/c mice was determined. All mice developed antibodies against the recombinant proteins with which they were immunized, but only the mice inoculated with replicon particles expressing the GL/M heterodimer developed antibodies that neutralize EAV. The data further confirmed that authentic posttranslational modification and conformational maturation of the recombinant GL protein occur only in the presence of the M protein and that this interaction is necessary for induction of neutralizing antibodies.

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