The Experts below are selected from a list of 1188 Experts worldwide ranked by ideXlab platform
Michael A Skinner - One of the best experts on this subject based on the ideXlab platform.
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modulation of early host innate immune response by a Fowlpox Virus fwpv lateral body protein
bioRxiv, 2020Co-Authors: Stephen M Laidlaw, Efstathios S Giotis, Susanna R Bidgood, David Albrecht, Jemima J Burden, Rebecca C Robey, Jason Mercer, Michael A SkinnerAbstract:The avian pathogen, Fowlpox Virus (FWPV) has been successfully used as vaccine vector in poultry and humans but relatively little is known about its ability to modulate host antiviral immune responses in these hosts, which are replication permissive and non-permissive, respectively. FWPV is highly resistant to avian type I interferon (IFN) and able to completely block the host IFN-response. Microarray screening of host IFN-regulated gene expression in cells infected with 59 different, non-essential FWPV gene knock-out mutants revealed that FPV184 confers immunomodulatory capacity. We report that FPV184-knockout Virus (FWPV{Delta}184) induces the cellular IFN response as early as 2 hours post-infection. The wild-type, uninduced phenotype can be rescued by transient expression of FPV184 in FWPV{Delta}184-infected cells. Ectopic expression of FPV184 inhibited polyI:C activation of the chicken IFN-{beta} promoter and IFN- activation of the chicken Mx promoter. Confocal and correlative super-resolution light and electron microscopy demonstrated that FPV184 has a functional nuclear localisation signal domain and is packaged in the lateral bodies of the virions. Taken together, these results provide a paradigm for a late poxVirus structural protein packaged in the lateral bodies and capable of supressing IFN induction early during the next round of infection.
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structural basis of apoptosis inhibition by the Fowlpox Virus protein fpv039
Journal of Biological Chemistry, 2017Co-Authors: Mohd Ishtiaq Anasir, Michael A Skinner, Sofia Caria, Marc KvansakulAbstract:Abstract Programmed cell death or apoptosis of infected host cells is an important defense mechanism in response to viral infections. This process is regulated by pro-apoptotic and pro-survival members of the B-cell lymphoma 2 (Bcl-2) protein family. To counter premature death of a Virus-infected cell, poxViruses use a range of different molecular strategies, including the mimicry of pro-survival Bcl-2 proteins. One such viral pro-survival protein is the Fowlpox Virus protein FPV039, which is a potent apoptosis inhibitor, but the precise molecular mechanism by which FPV039 inhibits apoptosis is unknown. To understand how Fowlpox Virus inhibits apoptosis we examined FPV039 using isothermal titration calorimetry, small-angle X-ray scattering and X-ray crystallography. Here, we report that the Fowlpox Virus pro-survival protein FPV039 promiscuously binds to cellular pro-apoptotic Bcl-2, and engages all major pro-apoptotic Bcl-2 proteins. Unlike other identified viral Bcl-2 proteins to date, FPV039 engaged with cellular pro-apoptotic Bcl-2 with affinities comparable to those of Bcl-2's endogenous cellular counterparts. Structural studies revealed that FPV039 adopts the conserved Bcl-2 fold observed in cellular pro-survival Bcl-2 proteins, and closely mimics the structure of the pro-survival Bcl-2 family protein Mcl-1. Our findings suggest that FPV039 is a pan Bcl-2 protein inhibitor that can engage all host BH3-only proteins as well as Bcl-2 associated X, apoptosis regulator (Bax) and Bcl-2 antagonist/killer (Bak) proteins to inhibit premature apoptosis of an infected host cell. This work therefore provides a mechanistic platform to better understand FPV039-mediated apoptosis inhibition.
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Short communication Expression of bacteriophage T7 RNA polymerase in avian and mammalian cells by a recombinant Fowlpox Virus
2013Co-Authors: P Britton, K L Mawditt, Z Penzes, D Cavanagh, Philip Green, Sanneke Kotfier, Michael A SkinnerAbstract:The bacteriophage T7 RNA polymerase gene was integrated into the Fowlpox Virus genome under the control of the vaccinia Virus early/late promoter, P7.5-The recombinant Fowlpox Virus, fpEFLT7pol, stably expressed T7 RNA polymerase in avian and mammalian cells, allowing transient expression of transfected genes under the control of the T7 promoter. The recombinant Fowlpox Virus expressing T7 RNA polymerase offers an alternative to the widely used vaccinia Virus vTF7-3, or the recently developed modified vaccinia Virus Ankara (MVA) T7 RNA polymerase recombinant, a highly attenuated strain with restricted host-range. Recombinant Fowlpox Viruses have the advantage that as no infectious Virus are produced from mammalian cells they do not have to be used under stringent microbiologica
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recovery of genetically defined murine noroVirus in tissue culture by using a Fowlpox Virus expressing t7 rna polymerase
Journal of General Virology, 2007Co-Authors: Yasmin Chaudhry, Michael A Skinner, Ian GoodfellowAbstract:Despite the significant disease burden caused by human noroVirus infection, an efficient tissue-culture system for these Viruses remains elusive. Murine noroVirus (MNV) is an ideal surrogate for the study of noroVirus biology, as the Virus replicates efficiently in tissue culture and a low-cost animal model is readily available. In this report, a reverse-genetics system for MNV is described, using a Fowlpox Virus (FWPV) recombinant expressing T7 RNA polymerase to recover genetically defined MNV in tissue culture for the first time. These studies demonstrated that approaches that have proved successful for other members of the family Caliciviridae failed to lead to recovery of MNV. This was due to our observation that vaccinia Virus infection had a negative effect on MNV replication. In contrast, FWPV infection had no deleterious effect and allowed the recovery of infectious MNV from cells previously transfected with MNV cDNA constructs. These studies also indicated that the nature of the 3′-terminal nucleotide is critical for efficient Virus recovery and that inclusion of a hepatitis delta Virus ribozyme at the 3′ end can increase the efficiency with which Virus is recovered. This system now allows the recovery of genetically defined noroViruses and will facilitate the analysis of the effects of genetic variation on noroVirus pathogenesis.
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different levels of immunogenicity of two strains of Fowlpox Virus as recombinant vaccine vectors eliciting t cell responses in heterologous prime boost vaccination strategies
Clinical and Vaccine Immunology, 2006Co-Authors: Matthew G Cottingham, Andre Van Maurik, Manola Zago, Angela T Newton, Richard J Anderson, Keith M Howard, Jorg Schneider, Michael A SkinnerAbstract:The FP9 strain of Fowlpox Virus has been described as a more immunogenic recombinant vaccine vector than the Webster FPV-M (FPW) strain (R. J. Anderson et al., J. Immunol. 172:3094-3100, 2004). This study expands the comparison to include two separate recombinant antigens and multiple, rather than single, independent viral clones derived from the two strains. Dual-poxVirus heterologous prime-boost vaccination regimens using individual clones of recombinant FP9 or FPW in combination with recombinant modified Vaccinia Virus Ankara expressing the same antigen were evaluated for their ability to elicit T-cell responses against recombinant antigens from Plasmodium berghei (circumsporozoite protein) or human immunodeficiency Virus type 1 (a Gag-Pol-Nef fusion protein). Gamma interferon enzyme-linked immunospot assay and fluorescence-activated cell sorting assays of the responses to specific epitopes confirmed the approximately twofold-greater cellular immunogenicity of FP9 compared to FPW, when given as the priming or boosting immunization. Equality of transgene expression in mouse cells infected with the two strains in vitro was verified by Western blotting. Directed partial sequence analysis and PCR analysis of FPW and comparison to available whole-genome sequences revealed that many loci that are mutated in the highly attenuated and culture-adapted FP9 strain are wild type in FPW, including the seven multikilobase deletions. These “passage-specific” alterations are hypothesized to be involved in determining the immunogenicity of Fowlpox Virus as a recombinant vaccine vector.
David B. Boyle - One of the best experts on this subject based on the ideXlab platform.
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dose response relationship of dna and recombinant Fowlpox Virus prime boost hiv vaccines implications for future trials
Human Vaccines, 2006Co-Authors: Robert De Rose, David B. Boyle, Ian A. Ramshaw, Mark T Sullivan, Jane C Dale, Anthony D Kelleher, Sean Emery, David A Cooper, Stephen J KentAbstract:Estimating effective doses of novel HIV vaccines is challenging. Dose-response analyses of DNA and Fowlpox Virus HIV vaccines showed that 1 mg of DNA vaccine and 5 x 10(7)pfu of Fowlpox Virus booster was immunogenic in macaques. However, this dose was poorly immunogenic in humans. When adjusted for body surface area, the human dose studied was equivalent to a poorly immunogenic lower dose in monkeys. These data provide a rationale for guiding dosing in future trials of HIV vaccine technologies.
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Fowlpox Virus vaccines for hiv and shiv clinical and pre clinical trials
Vaccine, 2006Co-Authors: Barbara E.h. Coupar, Scott Thomson, Ian A. Ramshaw, Stephen J Kent, Damian F J Purcell, David B. BoyleAbstract:DNA prime and recombinant Fowlpox Virus (rFPV) boost vaccines were designed to express multiple HIV or SIV antigens for use in human clinical trials and in pre-clinical trials in macaques. Three sets of vaccines with matching HIV or SIV antigen sets, modified for vaccine safety considerations, were constructed and shown to express the relevant proteins. The rFPV vaccines with inserts at up to three sites, were stable on passage in chick cell culture, including during GMP manufacture of vaccines for human Phase I clinical trials. Cellular and humoral immunogenicity in mice was demonstrated using a DNA prime/rFPV boost and vaccinia Virus challenge model. These data establish a preliminary safety and efficacy profile for these multigenic vaccines suggesting they are suitable for advanced development as candidate HIV vaccines.
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efficacy of dna and Fowlpox Virus priming boosting vaccines for simian human immunodeficiency Virus
Journal of Virology, 2004Co-Authors: C. J. Dale, Barbara E.h. Coupar, David B. Boyle, R. De Rose, Ivan Stratov, Socheata Chea, David C. Montefiori, Scott Thomson, Ian A. Ramshaw, Matthew LawAbstract:Further advances are required in understanding protection from AIDS by T-cell immunity. We analyzed a set of multigenic simian/human immunodeficiency Virus (SHIV) DNA and Fowlpox Virus priming and boosting vaccines for immunogenicity and protective efficacy in outbred pigtail macaques. The number of vaccinations required, the effect of DNA vaccination alone, and the effect of cytokine (gamma interferon) coexpression by the Fowlpox Virus boost was also studied. A coordinated induction of high levels of broadly reactive CD4 and CD8 T-cell immune responses was induced by sequential DNA and Fowlpox Virus vaccination. The immunogenicity of regimens utilizing Fowlpox Virus coexpressing gamma interferon, a single DNA priming vaccination, or DNA vaccines alone was inferior. Significant control of a virulent SHIV challenge was observed despite a loss of SHIV-specific proliferating T cells. The outcome of challenge with virulent SHIVmn229 correlated with vaccine immunogenicity except that DNA vaccination alone primed for protection almost as effectively as the DNA/Fowlpox Virus regimen despite negligible immunogenicity by standard assays. These studies suggest that priming of immunity with DNA and Fowlpox Virus vaccines could delay AIDS in humans.
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enhanced t cell immunogenicity and protective efficacy of a human immunodeficiency Virus type 1 vaccine regimen consisting of consecutive priming with dna and boosting with recombinant Fowlpox Virus
Journal of Virology, 1998Co-Authors: Stephen J Kent, David B. Boyle, Anne Zhao, Susan J Best, Jenalle D Chandler, Ian A. RamshawAbstract:The induction of human immunodeficiency Virus (HIV)-specific T-cell responses is widely seen as critical to the development of effective immunity to HIV type 1 (HIV-1). Plasmid DNA and recombinant Fowlpox Virus (rFPV) vaccines are among the most promising safe HIV-1 vaccine candidates. However, the immunity induced by either vaccine alone may be insufficient to provide durable protection against HIV-1 infection. We evaluated a consecutive immunization strategy involving priming with DNA and boosting with rFPV vaccines encoding common HIV-1 antigens. In mice, this approach induced greater HIV-1-specific immunity than either vector alone and protected mice from challenge with a recombinant vaccinia Virus expressing HIV-1 antigens. In macaques, a dramatic boosting effect on DNA vaccine-primed HIV-1-specific helper and cytotoxic T-lymphocyte responses, but a decline in HIV-1 antibody titers, was observed following rFPV immunization. The vaccine regimen protected macaques from an intravenous HIV-1 challenge, with the resistance most likely mediated by T-cell responses. These studies suggest a safe strategy for the enhanced generation of T-cell-mediated protective immunity to HIV-1.
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field and vaccine strains of Fowlpox Virus carry integrated sequences from the avian retroVirus reticuloendotheliosis Virus
Virology, 1997Co-Authors: Christian Hertig, Barbara E.h. Coupar, Allan R Gould, David B. BoyleAbstract:For baculoViruses and herpesViruses, integration of transposons or retroViruses into the Virus genome has been documented. We report here that field and vaccine strains of Fowlpox Virus (FPV) carry integrated sequences from the avian retroVirus, reticuloendotheliosis Virus (REV). Using PCR and hybridization analysis we observed that vaccine and field strains of FPV carry REV sequences integrated into a previously uncharacterized region of the right 1/3 of the FPV genome. Long-range PCR, hybridization, and nucleotide sequence determination demonstrated that one vaccine strain (FPV S) and recently isolated field strains carry a near-full-length REV proVirus. For another vaccine strain (FPV M) a rearranged remnant of the LTR was found at the same insertion site. By Western blotting and reverse transcriptase assays we were unable to demonstrate free REV in supernatants of FPV S cultures. The near-full-length REV proVirus integrated into the FPV genome is infectious since FPV S DNA gave rise to REV upon transfection into chicken embryo fibroblasts. Upon infection of chickens with FPV S, all chickens developed high-titered antibodies to REV, and REV was isolated from the blood of half of the inoculated chickens. Our observations add to the list of targets for retroVirus integration into DNA Virus genomes. The integration of a near-full-length, and apparently infectious, REV proVirus into FPV provides additional transmission routes for the retroVirus by way of the infectious cycle of FPV, including the possibility of mechanical transmission by biting insects since FPV is believed to be transmitted by this route. For large DNA Viruses, including the poxViruses, retroVirus integration with attendant possibilities of gene transduction may be an important mechanism for Virus evolution, including the acquisition of cellular genes with the potential to modify Virus virulence and pathogenicity.
Deoki N. Tripathy - One of the best experts on this subject based on the ideXlab platform.
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detection of Fowlpox Virus carrying distinct genome segments of reticuloendotheliosis Virus
Virus Research, 2019Co-Authors: Lok R Joshi, Deoki N. Tripathy, Claudio L. Afonso, G. F. Kutish, Fernando V Bauermann, Kyle S Hain, Anibal G Armien, Chad P Lehman, Regg Neiger, Diego G DielAbstract:Abstract Fowlpox Virus (FWPV), the type species of the genus AvipoxVirus family Poxviridae, is a large double-stranded DNA Virus that causes Fowlpox in chickens and turkeys. Notably, sequences of the avian retroVirus reticuloendotheliosis Virus (REV) are frequently found integrated into the genome of FWPV. While some FWPV strains carry remnants of the REV long terminal repeats (LTRs), other strains have been shown to contain insertions of nearly the full-length REV proVirus in their genome. In the present study we detected heterogeneous FWPV populations carrying the REV LTR or the near full-length REV proVirus genome in a Merriam’s wild turkey (Meleagris gallopavo merriami). The bird presented papules distributed throughout the non-feathered areas of the head. AvipoxVirus-like virions were observed in the lesions by transmission electron microscopy and the presence of FWPV was confirmed by DNA sequencing. Metagenomic sequencing performed on nucleic acid extracted from the skin lesions revealed two FWPV genome populations carrying either a 197-nt remnant of the REV LTR or a 7939-nt long fragment corresponding to the full-length REV proVirus. Notably, PCR amplification using primers targeting FWPV sequences flanking the REV insertion site, confirmed the natural occurrence of the heterogeneous FWPV genome populations in one additional clinical sample from another turkey affected by Fowlpox. Additionally, sequencing of a historical FWPV isolate obtained from chickens in the US in 2000 also revealed the presence of the two FWPV-REV genome populations. Results here demonstrate distinct FWPV populations containing variable segments of REV genome integrated into their genome. These distinct genome populations are likely a result of homologous recombination events that take place during FWPV replication.
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construction and characterization of a Fowlpox Virus field isolate whose genome lacks reticuloendotheliosis proVirus nucleotide sequences
Avian Diseases, 2005Co-Authors: Pratik Singh, William M. Schnitzlein, Deoki N. TripathyAbstract:Fowlpox Virus (FWPV) has been isolated from vaccinated chicken flocks during subsequent Fowlpox outbreaks that were characterized by a high degree of mortality and significant economic losses. This inability of current vaccines to induce adequate immunity in poultry could be reflective of an antigenic and/or biologic distinctiveness of FWPV field isolates. In this regard, whereas an infectious reticuloendotheliosis Virus (REV) proVirus is present in the majority of the field Viruses' genomes, only remnants of REV long terminal repeats (LTR) have been retained in the DNAs of each vaccine strain. Although it has not been demonstrated whether the partial LTRs can provide an avenue for FWPV to reacquire the REV proVirus by homologous recombination, utilizing Viruses of which genomes lack any known integrated retroviral sequences could resolve concern over this issue. Therefore, such an entity was created by genetically modifying a recently isolated field strain of FWPV. This selection, in lieu of a commercial vaccine Virus, as the progenitor was based on the probability that a Virus circulating in the environment would be more antigenically similar to others in this locale and thus might be a better candidate for vaccine development. A comparison in vivo of the pathogenic traits of the parental wild-type field isolate, its genetically modified progeny, and a rescue mutant in whose genome the REV proVirus was inserted at its previous location, indicated that elimination of the proVirus sequence correlated with reduced virulence. However, even with elimination of the parasitic REV, the modified FWPV was still slightly more invasive than a commercial vaccine Virus. Interestingly, both types of attenuated FWPV elicited a similar degree of antibody production in inoculated chickens and afforded them protection against a subsequent challenge by a field Virus, the origin of which was temporally and geographically distinct from that of the progenitor strain. Due to its antigenicity being retained despite a decrease in virulence, this REV-less FWPV could potentially be developed as a vaccine against Fowlpox.
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the dna repair enzyme cpd photolyase restores the infectivity of uv damaged Fowlpox Virus isolated from infected scabs of chickens
Veterinary Microbiology, 2005Co-Authors: V Srinivasan, Deoki N. TripathyAbstract:Fowlpox Virus (FWPV), an important pathogen of poultry, replicates very efficiently in the featherless areas of skin, and persists in dried and desiccated scabs for prolonged periods. Although the molecular mechanisms underlying the stability of the Virus are not completely known, we recently identified the presence of a Virus-encoded novel DNA repair enzyme, CPD-photolyase, in FWPV. This enzyme repairs the ultraviolet (UV)-induced pyrimidine dimers, converting them to monomers using photons from white light as a renewable source of energy. In this study, we examined the role of photolyase in the pathogenesis of Fowlpox. A comparison of pathogenesis of Fowlpox in chickens infected with parental FWPV with that in chickens infected with photolyase-deficient FWPV (Phr(-) FWPV) found no significant differences in terms of replication of Virus or formation of secondary lesions. When the virions isolated from infected scabs were exposed to UV light, UV-damaged parental FWPV, unlike Phr(-) FWPV, were rescued through the CPD-photolyase-mediated photoreactivation pathway by at least 48%. However, the mutant Virus triggered host's immune response and conferred complete protection against subsequent challenge with Virus similar to that conferred by the parental Virus. Since the mutant Virus is less stable than the parental Virus in the infected scabs but is as immunogenic, Phr(-) FWPV might be less persistent in the environment. Furthermore, this particular genetic locus can also be used to insert foreign genes for the development of FWPV recombinant vaccines.
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reticuloendotheliosis Virus sequences within the genomes of field strains of Fowlpox Virus display variability
Journal of Virology, 2003Co-Authors: Pratik Singh, William M. Schnitzlein, Deoki N. TripathyAbstract:Nine field strains of Fowlpox Virus (FPV) isolated during a 24-year span from geographically diverse outbreaks of Fowlpox in the United States were screened for the presence of reticuloendotheliosis Virus (REV) sequences in their genomes by PCR. Each isolate appeared to be heterogeneous in that either a nearly intact proVirus or just a 248- or 508-nucleotide fusion of portions of the integrated REV 5′ and 3′ long terminal repeats (LTRs) was exclusively present at the same genomic site. In contrast, four Fowlpox vaccines of FPV origin and three originating from pigeonpox Virus were genetically homogeneous in having retained only the 248-bp LTR fusion, whereas two other FPV-based vaccines had only the larger one. These remnants of integrated REV presumably arose during homologous recombination at one of the two regions common to both LTRs or during retroviral excision from the FPV genome. Loss of the proVirus appeared to be a natural event because the tripartite population could be detected in a field sample (tracheal lesion). Moreover, the proVirus was also readily deleted during propagation of FPV in cultured cells, as evidenced by the detection of truncated LTRs after one passage of a plaque-purified FPV recombinant having a “genetically marked” proVirus. However, the deletion mutants did not appear to have a substantial replicative advantage in vitro because even after 55 serial passages the original recombinant FPV was still prevalent. As to the in vivo environment, retention of the REV proVirus may confer some benefit to FPV for infection of poultry previously vaccinated against Fowlpox.
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identification and characterization of Fowlpox Virus strains using monoclonal antibodies
Journal of Veterinary Diagnostic Investigation, 2003Co-Authors: Pratik Singh, Taejoong Kim, Deoki N. TripathyAbstract:The use of 2 monoclonal antibodies (MAbs), P1D9 and P2D4, which recognize different Fowlpox Virus (FPV) antigens, for the identification and characterization of FPV strains was evaluated. Initially, the MAbs were used in conjunction with a dot blot assay that enabled FPV to be differentiated from the avian herpesVirus, infectious laryngotracheitis Virus. Confirmation of the specificity of these MAbs was provided by the demonstration that only FPV antigens were recognized by a combination of both antibodies when used for immunoblotting proteins contained in various avipoxViruses. Later, an antigenic characterization of 11 FPV field isolates, 6 FPV vaccine strains, and 3 pigeonpox Virus vaccines was performed by Western blotting with the individual MAbs. Whereas MAb P2D4 consistently recognized a protein with an apparent molecular weight of 60 kD, there was variability in the size of the antigen that was immunoreactive with the other MAb. For example, MAb P1D9 recognized an antigen of apparent molecular weight of 46 kD in all vaccine strains except 2 of FPV origin. In these exceptions, either only a 39-kD or both a 42- and 46-kD protein were immunoreactive. As for the field isolates, a 39-kD antigen was recognized in 8 of them, whereas a 42-kD antigen was detected in the remaining 3. Therefore, the more extensive immunoblotting technique may facilitate FPV strain differentiation, whereas routine diagnosis of Fowlpox could be accomplished by using the MAb-based dot blot assay.
Ian A. Ramshaw - One of the best experts on this subject based on the ideXlab platform.
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dose response relationship of dna and recombinant Fowlpox Virus prime boost hiv vaccines implications for future trials
Human Vaccines, 2006Co-Authors: Robert De Rose, David B. Boyle, Ian A. Ramshaw, Mark T Sullivan, Jane C Dale, Anthony D Kelleher, Sean Emery, David A Cooper, Stephen J KentAbstract:Estimating effective doses of novel HIV vaccines is challenging. Dose-response analyses of DNA and Fowlpox Virus HIV vaccines showed that 1 mg of DNA vaccine and 5 x 10(7)pfu of Fowlpox Virus booster was immunogenic in macaques. However, this dose was poorly immunogenic in humans. When adjusted for body surface area, the human dose studied was equivalent to a poorly immunogenic lower dose in monkeys. These data provide a rationale for guiding dosing in future trials of HIV vaccine technologies.
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Fowlpox Virus vaccines for hiv and shiv clinical and pre clinical trials
Vaccine, 2006Co-Authors: Barbara E.h. Coupar, Scott Thomson, Ian A. Ramshaw, Stephen J Kent, Damian F J Purcell, David B. BoyleAbstract:DNA prime and recombinant Fowlpox Virus (rFPV) boost vaccines were designed to express multiple HIV or SIV antigens for use in human clinical trials and in pre-clinical trials in macaques. Three sets of vaccines with matching HIV or SIV antigen sets, modified for vaccine safety considerations, were constructed and shown to express the relevant proteins. The rFPV vaccines with inserts at up to three sites, were stable on passage in chick cell culture, including during GMP manufacture of vaccines for human Phase I clinical trials. Cellular and humoral immunogenicity in mice was demonstrated using a DNA prime/rFPV boost and vaccinia Virus challenge model. These data establish a preliminary safety and efficacy profile for these multigenic vaccines suggesting they are suitable for advanced development as candidate HIV vaccines.
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efficacy of dna and Fowlpox Virus priming boosting vaccines for simian human immunodeficiency Virus
Journal of Virology, 2004Co-Authors: C. J. Dale, Barbara E.h. Coupar, David B. Boyle, R. De Rose, Ivan Stratov, Socheata Chea, David C. Montefiori, Scott Thomson, Ian A. Ramshaw, Matthew LawAbstract:Further advances are required in understanding protection from AIDS by T-cell immunity. We analyzed a set of multigenic simian/human immunodeficiency Virus (SHIV) DNA and Fowlpox Virus priming and boosting vaccines for immunogenicity and protective efficacy in outbred pigtail macaques. The number of vaccinations required, the effect of DNA vaccination alone, and the effect of cytokine (gamma interferon) coexpression by the Fowlpox Virus boost was also studied. A coordinated induction of high levels of broadly reactive CD4 and CD8 T-cell immune responses was induced by sequential DNA and Fowlpox Virus vaccination. The immunogenicity of regimens utilizing Fowlpox Virus coexpressing gamma interferon, a single DNA priming vaccination, or DNA vaccines alone was inferior. Significant control of a virulent SHIV challenge was observed despite a loss of SHIV-specific proliferating T cells. The outcome of challenge with virulent SHIVmn229 correlated with vaccine immunogenicity except that DNA vaccination alone primed for protection almost as effectively as the DNA/Fowlpox Virus regimen despite negligible immunogenicity by standard assays. These studies suggest that priming of immunity with DNA and Fowlpox Virus vaccines could delay AIDS in humans.
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enhanced t cell immunogenicity and protective efficacy of a human immunodeficiency Virus type 1 vaccine regimen consisting of consecutive priming with dna and boosting with recombinant Fowlpox Virus
Journal of Virology, 1998Co-Authors: Stephen J Kent, David B. Boyle, Anne Zhao, Susan J Best, Jenalle D Chandler, Ian A. RamshawAbstract:The induction of human immunodeficiency Virus (HIV)-specific T-cell responses is widely seen as critical to the development of effective immunity to HIV type 1 (HIV-1). Plasmid DNA and recombinant Fowlpox Virus (rFPV) vaccines are among the most promising safe HIV-1 vaccine candidates. However, the immunity induced by either vaccine alone may be insufficient to provide durable protection against HIV-1 infection. We evaluated a consecutive immunization strategy involving priming with DNA and boosting with rFPV vaccines encoding common HIV-1 antigens. In mice, this approach induced greater HIV-1-specific immunity than either vector alone and protected mice from challenge with a recombinant vaccinia Virus expressing HIV-1 antigens. In macaques, a dramatic boosting effect on DNA vaccine-primed HIV-1-specific helper and cytotoxic T-lymphocyte responses, but a decline in HIV-1 antibody titers, was observed following rFPV immunization. The vaccine regimen protected macaques from an intravenous HIV-1 challenge, with the resistance most likely mediated by T-cell responses. These studies suggest a safe strategy for the enhanced generation of T-cell-mediated protective immunity to HIV-1.
Antonia Radaelli - One of the best experts on this subject based on the ideXlab platform.
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Prime-boost therapeutic vaccination in mice with DNA/DNA or DNA/Fowlpox Virus recombinants expressing the Human Papilloma Virus type 16 E6 and E7 mutated proteins fused to the coat protein of Potato Virus X.
Virus Research, 2016Co-Authors: Elena Illiano, Carlo Zanotto, Massimiliano Bissa, Carlo De Giuli Morghen, Antonia Radaelli, Francesca Paolini, Rosella Franconi, Aldo VenutiAbstract:The therapeutic antitumor potency of a prime–boost vaccination strategy was explored, based on the mutated, nontransforming forms of the E6 (E6F47R) and E7 (E7GGG) oncogenes of Human Papilloma Virus type 16 (HPV16), fused to the Potato Virus X (PVX) coat protein (CP) sequence. Previous data showed that CP fusion improves the immunogenicity of tumor-associated antigens and may thus increase their efficacy. After verifying the correct expression of E6F47RCP and E7GGGCP inserted into DNA and Fowlpox Virus recombinants by Western blotting and immunofluorescence, their combined use was evaluated for therapy in a pre-clinical mouse model of HPV16-related tumorigenicity. Immunization protocols were applied using homologous (DNA/DNA) or heterologous (DNA/Fowlpox) prime–boost vaccine regimens. The humoral immune responses were determined by ELISA, and the therapeutic efficacy evaluated by the delay in tumor appearance and reduced tumor volume after inoculation of syngeneic TC-1* tumor cells. Homologous DNA/DNA genetic vaccines were able to better delay tumor appearance and inhibit tumor growth when DNAE6F47RCP and DNAE7GGGCP were administered in combination. However, the heterologous DNA/Fowlpox vaccination strategy was able to delay tumor appearance in a higher number of animals when E6F47RCP and in particular E7GGGCP were administered alone.
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The L1 protein of human papilloma Virus 16 expressed by a Fowlpox Virus recombinant can assemble into Virus-like particles in mammalian cell lines but elicits a non-neutralising humoral response.
Antiviral Research, 2015Co-Authors: Massimiliano Bissa, Carlo Zanotto, Sole Pacchioni, Carlo De Giuli Morghen, Luca Volonté, Aldo Venuti, David Lembo, Antonia RadaelliAbstract:Human papilloma Virus (HPV)-16 is the prevalent genotype associated with cervical tumours. Virus-like-particle (VLP)-based vaccines have proven to be effective in limiting new infections of high-risk HPVs, but their high cost has hampered their use, especially in the poor developing countries. Avipox-based recombinants are replication-restricted to avian species and represent efficient and safe vectors also for immunocompromised hosts, as they can elicit a complete immune response. A new Fowlpox Virus recombinant encoding HPV-L1 (FPL1) was engineered and evaluated side-by-side with a FP recombinant co-expressing L1 and green fluorescent protein (FPL1GFP) for correct expression of L1 in vitro in different cell lines, as confirmed by Western blotting, immunofluorescence, real-time PCR, and electron microscopy. Mice were also immunised to determine its immunogenicity. Here, we demonstrate that the FPL1 recombinant better expresses L1 in the absence of GFP, correctly assembles structured capsomers into VLPs, and elicits an immune response in a preclinical animal model. To our knowledge, this is the first report of HPV VLPs assembled in eukaryotic cells using an avipox recombinant.
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Construction and characterisation of a recombinant Fowlpox Virus that expresses the human papilloma Virus L1 protein
Journal of Translational Medicine, 2011Co-Authors: Carlo Zanotto, Eleana Pozzi, Sole Pacchioni, Massimiliano Bissa, Carlo De Giuli Morghen, Antonia RadaelliAbstract:Background Human papilloma Virus (HPV)-16 is the most prevalent high-risk mucosal genotype. Virus-like-particle (VLP)-based immunogens developed recently have proven to be successful as prophylactic HPV vaccines, but are still too expensive for developing countries. Although vaccinia Viruses expressing the HPV-16 L1 protein (HPV-L1) have been studied, Fowlpox-based recombinants represent efficient and safer vectors for immunocompromised hosts due to their ability to elicit a complete immune response and their natural host-range restriction to avian species. Methods A new Fowlpox Virus recombinant encoding HPV-L1 (FP_L1) was engineered and evaluated for the correct expression of HPV-L1 in vitro , using RT-PCR, immunoprecipitation, Western blotting, electron microscopy, immunofluorescence, and real-time PCR assays. Results The FP_L1 recombinant correctly expresses HPV-L1 in mammalian cells, which are non-permissive for the replication of this vector. Conclusion This FP_L1 recombinant represents an appropriate immunogen for expression of HPV-L1 in human cells. The final aim is to develop a safe, immunogenic, and less expensive prophylactic vaccine against HPV.
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Joint production of prime/boost pairs of Fowlpox Virus and Modified Vaccinia Ankara recombinants carrying the same transgene.
Journal of virological methods, 2011Co-Authors: Elisa Soprana, Antonia Radaelli, Maddalena Panigada, Mathias Knauf, Luisa Vigevani, Alessio Palini, Chiara Villa, Mauro Malnati, Giulia Cassina, Reinhard KurthAbstract:Pairs of recombinant MVA (Modified Vaccinia Ankara) and FPV (Fowlpox Virus) expressing the same transgene are reasonable candidates for prime/boost regimens, because cross-reacting immune responses between the two vectors, both non-replicative in mammalian hosts, are very limited. The acceptor Virus FPD-Red, a derivative of FPV, carrying a red fluorescent protein gene flanked by the homology regions of MVA deletion III, was constructed. The same MVA Transfer Plasmid Green, designed to insert transgenes into the MVA deletion III locus, can therefore be used to transfer transgenes into both acceptor Viruses MVA-Red and FPD-Red with the described recently Red-to-Green gene swapping method. Cells infected by either recombinant Virus can be sorted differentially by a simple and reliable FACS-based purification protocol. The procedure is carried out in primary chick embryo fibroblasts grown in serum-free media and was applied to the production of three rMVA/rFPV pairs expressing the H5N1 avian influenza antigens M1, M2 and NP. The viral genes were human codon-optimized and expressed at high levels in both chick and mammalian cells. Both single-step and multiple-step growth analyses showed no significant differences in growth due to the transgenes in either rMVA or rFPV derivatives.
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joint production of prime boost pairs of Fowlpox Virus and modified vaccinia ankara recombinants carrying the same transgene
Journal of Virological Methods, 2011Co-Authors: Elisa Soprana, Antonia Radaelli, Maddalena Panigada, Mathias Knauf, Luisa Vigevani, Alessio Palini, Chiara Villa, Mauro Malnati, Giulia Cassina, Reinhard KurthAbstract:Pairs of recombinant MVA (Modified Vaccinia Ankara) and FPV (Fowlpox Virus) expressing the same transgene are reasonable candidates for prime/boost regimens, because cross-reacting immune responses between the two vectors, both non-replicative in mammalian hosts, are very limited. The acceptor Virus FPD-Red, a derivative of FPV, carrying a red fluorescent protein gene flanked by the homology regions of MVA deletion III, was constructed. The same MVA Transfer Plasmid Green, designed to insert transgenes into the MVA deletion III locus, can therefore be used to transfer transgenes into both acceptor Viruses MVA-Red and FPD-Red with the described recently Red-to-Green gene swapping method. Cells infected by either recombinant Virus can be sorted differentially by a simple and reliable FACS-based purification protocol. The procedure is carried out in primary chick embryo fibroblasts grown in serum-free media and was applied to the production of three rMVA/rFPV pairs expressing the H5N1 avian influenza antigens M1, M2 and NP. The viral genes were human codon-optimized and expressed at high levels in both chick and mammalian cells. Both single-step and multiple-step growth analyses showed no significant differences in growth due to the transgenes in either rMVA or rFPV derivatives.
