SEARCH · Search PubMed

Results for “Fowlpox”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

PubMed1990

Comparative analysis of vaccinia virus promoter activity in fowlpox and vaccinia virus recombinants.

A quantitative and qualitative comparison of vaccinia virus (VV) promoter activity in fowlpox virus (FPV) and VV recombinants was performed. The VV PL11 late promoter was used to express beta-galactosidase from the E. coli LacZ gene in FPV (FPV-LacZ) and VV (VV-LacZ) recombinants. Time courses of FPV-LacZ beta-galactosidase expression in chicken embryo skin (CES) cells demonstrated temporal regulation of the PL11 promoter with maximum enzyme activity nine- and four-fold lower than those obtained in VV-LacZ infected 143B and CES cells, respectively. The level of beta-galactosidase activity per LacZ DNA gene copy was determined for each recombinant and found to be greater for VV-LacZ than FPV-LacZ. The VV P7.5 early/late promoter was used to express the E. coli xanthine-guanine phosphoribosyl transferase (Ecogpt) gene in FPV and VV recombinants. Northern blot analysis showed early Ecogpt RNA transcripts to be of defined lengths. Transcript size estimations mapped the termination sites to regions containing sequences associated with VV early transcript termination, providing supportive evidence for a common poxvirus early transcript termination signal. Late LacZ and Ecogpt transcripts were heterogeneous in length. S1 nuclease mapping of the 5'-ends of early and late Ecogpt RNA transcripts produced by FPV and VV recombinants showed transcription initiation occurred at the same sites in both poxviruses and corresponded to the regions previously identified as the early and late start sites of the P7.5 promoter. These results would indicate a high level of conservation in the expression and regulation of genes by poxviruses.

Animals↗

PubMed1994

Studies of fowlpox virus recombination in the generation of recombinant vaccines.

A p7.5/beta-galactosidase (7.5 lacZ) gene construct, cloned adjacent to the fowlpox virus (FPV) thymidine kinase (tk) gene was used as a marker to identify the products of recombination as 'blue' FPV plaques. The rFPVs were detected as early as 4 h after the introduction of plasmid DNAs and by 72 h post-infection (p.i.) for one transfer vector comprised 0.48% of the viral population. The proportion of rFPV increased linearly from 0.073% to 0.62% as the cumulative length of homologous sequences in the transfer vector increased from 0.73 to 4.5 kb. Two approaches using a second reporter gene, the Newcastle disease virus haemagglutinin-neuraminidase (NDV HN) gene were tested to differentiate between single and double cross-over events. In one, the HN gene was cloned into the FPV tk gene and the 7.5 lacZ cloned outside of the homologous region. Progeny of a single cross-over with FPV DNA generated an unstable plaque containing the HN gene and subsequent intramolecular recombination resulted in excision of the 7.5 lacZ and the generation of a stable 'white' plaque. For virus grown in CEF cells (tk+) in the presence of 5-bromo-deoxyuridine, only those viruses which contained a tk gene disrupted by the HN gene formed plaques. This approach allowed us to easily identify rFPV containing the HN gene but lacking 7.5 lacZ or other bacterial sequences. In a second approach, a double cross-over between rFPV DNA containing a stably expressed beta-galactosidase gene cloned into the tk gene (blue plaque) and plasmid DNA containing the HN gene flanked by tk sequences would allow transplacement of the 7.5 lacZ gene with the HN gene, and generating a white plaque. We were unable to generate recombinant viruses with the HN gene and which generated a white plaque, indicating that double cross-over events do not occur at a sufficiently high frequency in FPV.

Base Sequence↗

PubMed1990

Fowlpox virus recombinant encoding the measles virus fusion protein: protection of mice against fatal measles encephalitis.

A recombinant Fowlpox virus engineered to encode the measles virus fusion protein was shown to protect mice against a challenge measles infection. A vaccine dose of about 10(6) p.f.u. was needed to protect nearly 100% of the animals. Mice failed to develop a significant level of antibodies directed against measles virus suggesting that other components of the immune system may be involved.

Animals↗

PubMed1991

Efficacy of nucleoprotein and haemagglutinin antigens expressed in fowlpox virus as vaccine for influenza in chickens.

Fowlpox virus (FPV) recombinants expressing influenza virus H5 haemagglutinin (HA), nucleoprotein (NP) or co-expressing both of these antigens were tested for vaccine efficacy in chickens. Immunization with the recombinant FPV-HA was highly efficacious but provided no cross protection between subtypes. Bursectomy established that immunity against the H5 subtype was antibody-mediated despite the presence of very low levels of antibody in the vaccinated birds. Immunization with the recombinant FPV expressing the cross-reactive NP antigen did not provide protective immunity despite hyperimmunization and provided no benefit above HA expressed alone. The results suggest that the kinetics of viral replication outpaces immunity induced by NP.

Animals↗

PubMed2005

Inhibition of fowlpox virus by an aqueous acetone extract from galls of Guiera senegalensis J. F. Gmel (Combretaceae).

An aqueous acetone extract from the galls of Guiera senegalensis was screened for in vitro antiviral activity against fowlpox virus (FPV). Cytopathic effect (CPE) inhibition and plaque inhibition assays were used to show presence of antiviral effects against FPV, whilst cytotoxicity assays established the relative safety of the extract for cells in vitro. Phytochemical analyses revealed the presence of phenolic compounds including flavonoids, tannins and anthocyanins as well as steroids and alkaloids. Thin-layer chromatographical (TLC) analysis also revealed the presence of quercitrin, quercetin, kaempferol, apigenin, rutin, gallic acid as well as unknown flavonoids and unknown phenolic acids. The antiviral effect of the extract was partially attributed to phenolic components including flavonoids.

Acetone↗

PubMed2005

Fowlpox virus vaccines for HIV and SHIV clinical and pre-clinical trials.

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.

AIDS Vaccines↗

PubMed2006

Safety of recombinant fowlpox strain FP9 and modified vaccinia virus Ankara vaccines against liver-stage P. falciparum malaria in non-immune volunteers.

The ability to generate potent antigen-specific T cell responses by vaccination has been a major hurdle in vaccinology. Vaccinia virus and avipox viruses have been shown to be capable of expressing antigens in mammalian cells and can induce a protective immune response against several mammalian pathogens. We report on two such vaccine constructs, modified vaccinia virus Ankara and FP9 (an attenuated fowlpox virus) both expressing the pre-erythrocytic malaria antigen thrombospondin-related adhesion protein and a string of CD8+ epitopes (ME-TRAP). In prime-boost combinations in a mouse model MVA and FP9 are highly immunogenic and induce substantial protective efficacy. A series of human clinical trials using the recombinant MVA and FP9 malaria vaccines encoding ME-TRAP, both independently and in prime-boost combinations with or without the DNA vaccine DNA ME-TRAP, has shown them to be both immunogenic for CD8+ T cells and capable of inducing protective efficacy. We report here a detailed analysis of the safety profiles of these viral vectors and show that anti-vector antibody responses induced by the vectors are generally low to moderate. We conclude that these vectors are safe and show acceptable side effect profiles for prophylactic vaccination.

Adolescent↗

PubMed2006

In ovo DNA immunisation followed by a recombinant fowlpox boost is fully protective to challenge with virulent IBDV.

The aim of this study was to investigate the potential use of DNA vaccination delivered in ovo for protecting against challenge with infectious bursal disease virus (IBDV). Using a plasmid expressing the beta-galactosidase gene, DNA was successfully delivered to the embryo after in ovo injection and localises to the proventriculus and thymus. The coding sequence for the immunogenic IBDV protein, VP2, was cloned into pCI-neo, creating pCI-Vp2. Complete protection against IBDV was obtained by priming in ovo with pCI-Vp2, followed by boosting with the fowlpox recombinant, fpIBD1, also expressing the VP2 gene. This complete protection was not evident with either of the experimental vaccines on their own. An antibody response was not detected after the prime-boost vaccination, even after chicks had been challenged with IBDV, implying that the DNA prime delivered in ovo stimulated a protective cellular immune response.

Amniotic Fluid↗

PubMed2005

Genetic manipulation of two fowlpox virus late transcriptional regulatory elements influences their ability to direct expression of foreign genes.

Fowlpox virus (FWPV) is currently used as a vector to express foreign genes of various poultry and mammalian pathogens. However, due to limited information available about the primary structure of FWPV promoters required for an optimal transcriptional efficiency, the full potential of FWPV as an expression vector has not been completely realized. To dissect such transcriptional regulatory elements at the molecular level, we selected two FWPV promoters dictating contrasting levels of expression of acidic-type inclusion body protein gene (P190) and A15L vaccinia virus homolog of FWPV (P180) for site-directed mutagenesis studies. The transcriptional activity of mutated promoters was analyzed based on their ability to transcribe a reporter gene, lacZ, and translation of the resultant mRNA into functional protein. Replacement of the spacer sequences of P180 with those of P190 resulted in a five-fold increase in mRNA and a 17.6-fold increase in protein over those with its parental promoter, P180. Similarly, replacement of a thymidine after the start codon with guanosine resulted in a 2.3-fold increase in lacZ mRNA and a seven-fold increase in protein. Combining these substitutions in P180SG produced a maximum increase in mRNA and protein of 6.7- and 29.9-fold, respectively, over concentrations with its parental P180 promoter. The promoter activity of P180SG was comparable to that of the strongest natural promoter, P190. The amount of protein per transcript generated by the mutated promoters of P180 increased to at least three times that with the parental P180. In contrast, similar replacements in P190 resulted in a 40-50% reduction in mRNA and protein in all the mutated promoters. We discuss the significance of spacer sequence and the purine after the start codon in the context of a high level of expression.

Animals↗

PubMed1998

Cytotoxic T lymphocyte response in chickens immunized with a recombinant fowlpox virus expressing Marek's disease herpesvirus glycoprotein B.

Previously, we demonstrated that cytotoxic T lymphocytes (CTLs) from MHC: B19B19 and MHC: B21B21 chickens inoculated with a non-oncogenic Marek's disease virus (MDV) vaccine strain, SB-1/12 can lyse syngeneic reticuloendotheliosis virus (REV)-transformed cell lines expressing MDV pp38 or gB genes. In this study, we report the characterization of MDV gB-specific CTLs in chickens immunized with recombinant fowlpox virus expressing MDV gB gene (rFPV-gB). Spleen cells from rFPV-gB inoculated chickens (MHC: B19B19), depleted for CD4+, CD8+, TCR gamma delta+, TCR alpha beta 1+ or TCR alpha beta 2+ cells were used as effector cells in chromium release assays. Effector cells depleted of CD8+ or TCR alpha beta 1+, but not CD4+, TCR gamma delta+ or TCR alpha beta 2+ markedly reduced the percentage of specific release (%SR). Compared to the %SR caused by the SB-1/12-sensitized CTLs, the %SR caused by rFPV-gB-sensitized CTLs was low, but statistically significant. This is a first report on the induction of MDV gB-specific CD8+ CTLs in chickens immunized with rFPV-gB vaccine.

Animals↗

PubMed2000

Improved technique for transient expression and negative strand virus rescue using fowlpox T7 recombinant virus in mammalian cells.

The suitability of recombinant T7 polymerase produced using either the highly attenuated MVA strain of vaccinia (MVA-T7) or fowlpox virus (FP-T7) for transient expression and negative strand virus rescue was compared in two mammalian cell lines (MDBK and Vero) and in primary cells of bovine, ovine and caprine origin. Such primary cells are more permissive for the growth of wild type strains of morbilliviruses, such as Rinderpest virus and Peste des petits ruminants virus. MVA-T7 was found to be highly cytopathic in the primary cells, multiplying rapidly and killing the cells within 3-5 days of infection, even when very low multiplicities of infection (MOI) were used. In contrast, FP-T7, which appeared to express similar amounts of T7 polymerase, was found to be non-cytopathic in a variety of primary and established cell lines of mammalian origin and was suitable for use in virus rescue experiments. MDBK cells and primary cells, unlike Vero cells, could not be efficiently transfected and so were unsuitable for virus rescue. Optimal conditions for rinderpest virus rescue in Vero cells were established using FP-T7 in place of MVA-T7. This system will be suitable for rescuing other viruses which grow in Vero cells.

Animals↗

PubMed1997

Recombinant fowlpox virus vaccines against Australian virulent Marek's disease virus: gene sequence analysis and comparison of vaccine efficacy in specific pathogen free and production chickens.

We have cloned and sequenced the glycoprotein genes gB, gC and gD of the Australian virulent Marek's disease virus (MDV) isolate Woodlands No. 1. The glycoprotein gB and gC sequences were identical to the homologs of other virulent MDV type 1 strains, and the glycoprotein gD sequence contained only one unique amino acid substitution. Recombinant fowlpox viruses (rFPVs) expressing the MDV glycoprotein genes were constructed and their efficacy as vaccines was evaluated in specific pathogen free (SPF) and production chickens. Vaccination with the FPV-gB recombinant protected SPF chickens from Marek's disease mortality and tumour formation following challenge with virulent MDV Woodlands No. 1. The degree of protection from Marek's disease was dependent on the vaccine dose and route of inoculation. The rFPVs expressing gC or gD did not provide protection from Marek's disease. A rFPV expressing both gB and gC did not provide enhanced protection in comparison with the rFPV-gB alone. The rFPV-gB vaccine failed to protect commercial chickens from MD mortality and provided little protection from tumour formation in comparison with the commercial herpesvirus of turkey (HVT) vaccine. The failure to provide protection against MD may be related to the impact of maternally derived immunity to MDV and FPV and possibly the genotype of the chickens.

Amino Acid Sequence↗

PubMed2000

Protection from IBDV-induced bursal damage by a recombinant fowlpox vaccine, fpIBD1, is dependent on the titre of challenge virus and chicken genotype.

Expression of the VP2 capsid protein of infectious bursal disease virus (IBDV) in an vaccine strain of fowlpox has produced an experimental recombinant vaccine, fpIBD1. Successful vaccination with fpIBD1 was dependent on the titre of challenge virus for high titres of challenge virus were able to overcome protection induced by fpIBD1 whereas challenge with a low titre of virus did not. The genotype of chicken also has an important effect on the outcome of challenge possibly as a result of the major histocompatability complex and its ability to present VP2-derived peptides to the immune system. It was not possible to protect the inbred white leghorn chicken strain, line 15I, from IBDV-induced bursal damage by vaccination with fpIBD1 even at the lowest titre of challenge virus used. All other inbred white leghorn chickens examined (line 6(1), C. B4 and C.B12) and outbred Rhode Island Red chickens were protected by fpIBD1. Protection by the fpIBD1 vaccine is induced in the absence of detectable serum antibodies, suggesting the possibility of a significant role for cell-mediated immunity in protection from IBDV challenge.

Animals↗

PubMed2003

Comparative analysis of immune responses and cytokine profiles elicited in rabbits by the combined use of recombinant fowlpox viruses, plasmids and virus-like particles in prime-boost vaccination protocols against SHIV.

Three different prime-boost immunization protocols were tested in rabbits and their immune response was evaluated and compared with the final aim of identifying a vaccine strategy that might be able to protect non-human primates from infection with the pathogenic chimera simian/human immunodeficiency virus (SHIV)(89.6P). Protocols were based on priming with two fowlpox (FP) recombinant vectors and two expression plasmids, which express either the simian immunodeficiency virus (SIV)mac(239) gag/pol or the human immunodeficiency virus (HIV-1)env(89.6P) genes, followed by boosting with virus-like particles (VLP). All protocols were effective in eliciting homologous neutralizing Ab and highlighted the efficacy of VLP boosting. The FP vector was less efficient than plasmid DNA in inducing Ab against the gag core proteins. Analysis of cytokine expression 5 months after last immunization indicated that priming with pcDNA3gag/pol(SIV) and FPenv(89.6P) followed by VLP boosting generated a T helper (Th0) profile and a good Ab titer, suggesting a potential protocol to be tested in the SHIV-macaque model of HIV-1 infection.

Animals↗

PubMed1999

Embryo vaccination of turkeys against Newcastle disease infection with recombinant fowlpox virus constructs containing interferons as adjuvants.

Recombinant fowlpox viruses (rFPV) expressing the fusion and hemagglutinin-neuraminidase glycoproteins of Newcastle disease virus (NDV) as well as chicken type I interferon (IFN) or type II IFN were used to vaccinate specific pathogen-free (SPF) turkeys in ovo. No significant changes in the hatchability, survival rate, performance and weight gain were observed after vaccination with the rFPV vaccines in comparison to diluent-inoculated embryos. The rFPV-NDV-IFN-II construct induced the onset of anti-NDV antibody production in SPF birds at one week post hatch, one week earlier than other vaccine constructs. Three to five weeks post hatch, the turkeys were challenged with the neurotropic velogenic NDV strain Texas GB (NDV-GB-Tx). The rFPV-NDV-IFN-II construct was the most protective vaccine against NDV. rFPV vaccines significantly (p<0.05) suppressed the mitogenic response of peripheral blood leukocytes in vaccinated turkeys in comparison to placebo inoculated controls at 25 days post vaccination. Birds vaccinated with rFPV-NDV-IFN-I construct did not have an inhibition in the mitogenic response.

Animals↗

PubMed1998

Nucleotide sequence of the 4.3 kbp BamHI-N fragment of fowlpox virus FP9.

Nucleotide sequence analysis of the 4.3 kbp BamHI-N fragment of the fowlpox virus (FPV) genome revealed that it encodes 7 proteins with homology to vaccinia virus (VV) E11L, E10R, O1L, O3L, I1L, I2L and I3L encoded proteins. No evidence of FPV homolog of VV O2L could be found.

Amino Acid Sequence↗

PubMed2001

Characterization of a recombinant fowlpox virus expressing the native hexon of hemorrhagic enteritis virus.

The structure of the icosahedral adenovirus capsid is highly conserved among Adenoviridae. In its native form, the hexon is the major capsid protein. The nascent hexon requires the 100 kDa folding protein to fold into its native, trimeric form. The hexon and 100 kDa folding protein were co-expressed in a fowlpox virus (FPV) vector and in the recombinant FPVs (rFPVs) in which the hexon and 100 kDa folding protein genes are cloned head to tail, the native hexon could be detected with indirect immunofluorescence and immunoprecipitation using a native hexon monoclonal antibody. The FPV-@X100 construct, in which the 100kDa folding protein gene follows the hexon gene in a head to tail fashion, elicited the best humoral response in chickens. An attenuated HEV commercial vaccine elicited higher and longer lasting anti-HEV titers than FPV-@X100. Humoral immunity was also compared in turkeys inoculated with rFPVs expressing the hexon alone, the 100 kDa folding protein alone, or expressing both genes in different configurations. No anti-HEV humoral immune response was detected in turkeys inoculated with the rFPVs expressing the hexon alone or the 100 kDa folding protein alone.

Adenoviridae↗

PubMed2000

Dendritic cells infected with recombinant fowlpox virus vectors are potent and long-acting stimulators of transgene-specific class I restricted T lymphocyte activity.

The identification of dendritic cells (DC) as the major antigen-presenting cell type of the immune system, combined with the development of procedures for their ex vivo culture, has opened possibilities for tumour immunotherapy based on the transfer of recombinant tumour antigens to DC. It is anticipated that the most effective type of response would be the stimulation of specific, MHC class I restricted cytotoxic T lymphocytes capable of recognising and destroying tumour cells. In order to make this approach possible, methods must be developed for the transfer of recombinant antigen to the DC in such a way that they will initiate an MHC class I restricted response. Here, we demonstrate that murine DC infected with a recombinant fowlpox virus (rFWPV) vector stimulate a powerful, MHC class I restricted response against a recombinant antigen. A rFWPV containing the OVA gene was constructed and used to infect the DC line DC2.4. The infected DC2.4 cells were found to stimulate the T-T cell hybridoma line RF33. 70, which responds specifically to the MHC class I restricted OVA peptide SIINFEKL. The stimulatory ability of the rFWPV-infected DC2.4 cells lasted for at least 72 h after infection and was eventually limited by proliferation of uninfected cells. By comparison, DC2.4 cells pulsed with synthetic SIINFEKL peptide stimulated RF33.70 well initially, but the stimulatory ability had declined to zero by 24 h after pulsing. FWPV infection of DC2.4 up-regulated MHC and costimulatory molecule expression. rFWPV was also found to infect both immature and mature human DC derived from cord blood CD34+ progenitors and express transgenes for up to 20 days after infection. We conclude that rFWPV shows promise as a vector for antigen gene transfer to DC in tumour immunotherapy protocols.

Animals↗