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At least 19 recordsLinked to original sources
PubMed1988

Comparison of a conserved region in fowlpox virus and vaccinia virus genomes and the translocation of the fowlpox virus thymidine kinase gene.

The DNA sequence of a clustered set of genes which are conserved in orthopoxviruses has been determined for the avipoxvirus, fowlpox virus. The arrangement of the genes in fowlpox virus is nearly identical to that in vaccinia virus, and genes which are overlapping in vaccinia virus overlap in fowlpox virus. One major difference exists however, as the thymidine kinase (TK) gene is absent in fowlpox virus from the position it occupies within this cluster of genes in vaccinia virus. Instead, in fowlpox virus there is a 32 bp non-coding region present between the genes that flank the TK gene in vaccinia virus. The fowlpox virus TK gene has been cloned and sequenced. The sequences immediately flanking the TK gene show no homology to any previously reported poxvirus gene. These results are discussed in terms of genome stability in poxviruses and the use of the TK gene as a non-essential region for the introduction of foreign genes into poxviruses.

Amino Acid Sequence↗
PubMed1994

Vaccination of chickens with a recombinant fowlpox virus containing the hemagglutinin-neuraminidase gene of Newcastle disease virus under the control of the fowlpox virus thymidine kinase promoter.

When chickens were vaccinated with a recombinant fowlpox virus (FPV) containing the Newcastle disease virus (NDV) hemagglutinin-neuraminidase (HN) cDNA under the control of the thymidine kinase (TK) promoter and inserted into the FPV TK gene, the FPV antibody response to the recombinant virus was similar to the response to vaccination with standard FPV, and the recombinant virus protected chickens against challenge with virulent FPV. While the presence of the NDV HN cDNA was demonstrated in the recombinant virus, which was stable on serial passage, expression of HN was not detected by hemagglutination, Western blot analysis or immunoprecipitation of infected cell lysate. Chickens vaccinated with the recombinant virus failed to mount an NDV hemagglutination-inhibition antibody response, and they did not resist challenge with velogenic NDV. It was concluded that the TK promoter was too weak to drive the HN gene, but that the insertion into the FPV TK gene did not reduce the immunogenicity of the virus.

Animals↗
PubMed1990

Activity of a fowlpox virus late gene promoter in vaccinia and fowlpox virus recombinants.

Characterization of a late promoter of fowlpox virus (FPV) and a study of its activity in FPV and vaccinia virus (VV) was carried out. The 5'-mRNA start site of the FPV late gene mapped to a TAAAT sequence near the translation start site (ATG). A cloned DNA fragment of FPV genome (PFL1) comprising of the 5'-end of the late gene was used to express the LacZ gene of E. coli in FPV and VV recombinants. A comparative analysis of beta-galactosidase (BG) expression from the LacZ gene under the control of the FPV promoter and a VV late promoter (PL11) was performed. Like FPV-PL11-LacZ and VV-PL11-LacZ constructs, FPV-PFL1-LacZ and VV-PFL1-LacZ virus recombinants expressed BG indicating that essential features of transcription were conserved in the two viruses. Furthermore, the LacZ transcripts originating from PFL1 in FPV and VV recombinants mapped to the expected TAAAT sequence. Time course analysis of BG expressed by VV and FPV recombinants suggested that although the transcription machinery in the two viruses was essentially conserved, subtle differences in the efficiency of transcription or translation may exist.

Animals↗
PubMed1974

In vitro cellular immunity to unrelated pathogens in chickens infected with fowlpox virus.

Peritoneal macrophages recovered from chickens 15 to 20 days after inoculation with fowlpox virus and showing a delayed hypersensitivity reaction against fowlpox antigens demonstrated an enhanced antimicrobial effect against fowlpox virus as well as unrelated viruses and bacteria. Inoculation of normal chicken macrophage cultures with fowlpox virus resulted in approximately a 200-fold increase in virus titer by 96 h, whereas the virus showed less than a fourfold increase in macrophage cultures from fowlpox-immune chickens. Similarly, the titer of Newcastle disease virus increased by more than 1 log in cultures of normal macrophages, whereas the titer decreased by approximately 1 log after infection of fowlpox-immune macrophages. Vaccinia, vesicular stomatitis, and herpes simplex viruses, which are not natural pathogens of chickens, failed to replicate in cultures of either normal or fowlpox-immune macrophages. By using Salmonella gallinarum, it was further demonstrated that the antimicrobial activity of fowlpox-immune macrophages encompassed not only nonspecific viruses but also bacteria. Infection of normal macrophages with Salmonella resulted in intracellular replication of the organism between 0 and 24 h as determined by microscope examination and viable bacteria counts. In contrast, cultures of fowlpox-immune macrophages failed to show an increase in intracellular organisms and showed a marked decrease in viable bacteria. In conclusion, these studies clearly showed that cellular immunity, previously demonstrated in mammalian species, develops in chickens after infection with fowlpox virus.

Animals↗
PubMed1988

Recombinant fowlpox virus inducing protective immunity in non-avian species.

The natural host of fowlpox virus is limited to avian species. When inoculated into non-avian tissue culture cells, however, fowlpox virus can initiate an abortive infection. A fowlpox virus was engineered to express rabies virus glycoprotein. On inoculation of the recombinant virus into either avian (permissive) or non-avian (non-permissive) cells, the rabies glycoprotein was expressed as a membrane-associated antigen. Inoculation of the fowlpox virus recombinant into six different species of mammal resulted in specific immune responses to both fowlpox antigens and to rabies glycoprotein. In mice, cats and dogs the immune response was sufficient to protect against a live rabies virus challenge. The results demonstrate the utility of a fowlpox virus vector in immunizing non-avian species against rabies in the absence of productive viral replication of the fowlpox vector.

Animals↗
PubMed1990

Analysis of the fowlpox virus genome region corresponding to the vaccinia virus D6 to A1 region: location of, and variation in, non-essential genes in poxviruses.

The DNA sequence of the fowlpox virus genome corresponding to the vaccinia virus D6 to A1 region has been determined. Translation of this sequence reveals fowlpoxvirus gene homologues corresponding to the D6, D7, D9, D10, D11, D12, D13 and A1 genes of vaccinia virus. In contrast, no gene homologue for the non-essential vaccinia virus D8 gene was present in fowlpox virus. Instead, a gene transcribed from the opposite strand to the vaccinia virus D8 gene showing no homology to any previously sequenced poxvirus gene was present. The amino terminus of the fowlpox virus D9 homologue had undergone substantial changes, including frameshifts which would be predicted to inactivate the gene. Insertion of a gene cartridge composed of the vaccinia virus p7.5 promoter and the lacZ gene into the fowlpox virus D8, D9 and D10 genes in vitro, followed by recombination into fowlpox virus, was carried out. Stable insertion mutants with the correct genotype were obtained for D8 and D9 which, when tested in chickens did not appear to have been attenuated. No stable insertion mutants were obtained for D10, indicating that this gene probably encodes a function which is essential for virus replication. The D8 and D9 genes of fowlpox virus represent useful insertion sites for the construction of recombinant fowlpox virus vaccines.

Amino Acid Sequence↗
PubMedDate not supplied

Cell-culture virus-neutralization test and enzyme-linked immunosorbent assay for evaluation of immunity in chickens against fowlpox.

Two serological tests--the virus-neutralization (VN) test in chicken embryo fibroblasts (CEF) using a cell-culture-adapted virus, and the enzyme-linked immunosorbent assay (ELISA)--were used for evaluating the immune response in chickens against fowlpox virus. The VN test was conducted in 96-well tissue-culture plates using a fowlpox virus that was adapted to induce cytopathic effects (CPE) in CEF in 48 hr. The ELISA was carried out with an antigen prepared by precipitation of a cell-culture-propagated virus suspension with ammonium sulfate and concentration by centrifugation. A 0.1 M acetate buffer, pH 5, was used as the sensitizing solution for maximum specific binding of the antigen to the microplate plastic well. No antibodies were detected by the VN test in 228 serum samples taken from chickens at irregular intervals between 1 and 39 weeks of age, even though the birds were vaccinated against fowlpox at 13 weeks of age. However, in sera collected 4 weeks after a sample of laying hens was challenged with fowlpox virus, VN titers of 1/10 to 1/40 were detectable. On the other hand, significant antibody reactions were detected by the ELISA on sera from chickens during the growing period, following vaccination and challenge. Although no maternal antibodies were found at 1 week of age, a continuous increase in the mean ELISA titers to fowlpox was demonstrated during the entire experimental period. This study showed that the ELISA was considerably more sensitive and practical than the VN test.

Animals↗
PubMed1990

Construction of fowlpox virus vectors with intergenic insertions: expression of the beta-galactosidase gene and the measles virus fusion gene.

A DNA fragment from fowlpox virus cloned on a plasmid vector was modified to contain foreign DNA inserts within an intergenic region. In a first step, a 32-base-pair intergenic region from the fowlpox virus genome corresponding to the position of the thymidine kinase locus in the vaccinia virus genome was enlarged to 55 base pairs by site-directed mutagenesis. A unique restriction endonuclease site introduced upstream of the intergenic region was then used to insert various foreign DNA fragments. The lacZ gene encoding beta-galactosidase and the measles virus gene encoding the fusion protein were positioned downstream of two vaccinia virus p7.5 promoter elements in either a direct repeat or inverted repeat orientation. Foreign DNA inserts contained within the fowlpox virus sequence were transferred to the viral genome by homologous recombination occurring in cells infected with a fowlpox virus temperature-sensitive mutant and transfected with both wild-type viral DNA and plasmid DNA. Recombinant viruses were selected for the expression of beta-galactosidase activity by screening for blue plaques in the presence of a chromogenic substrate. Stable recombinants expressing both the lacZ gene and the unselected measles gene were obtained when the p7.5 promoter was present as an inverted repeat. However, when the p7.5 promoter was in the direct repeat orientation, viral recombinants which initially expressed both gene inserts readily deleted the lacZ gene flanked by the promoter repeat. The methods described enable precise insertion and deletion of foreign genes in the fowlpox virus genome and could be applied to other intergenic regions of the same virus as well as other poxviruses.

Amino Acid Sequence↗
PubMed1991

Fowlpox virus: pathogenicity and vaccination of day-old chickens via the aerosol route.

Day-old chickens were given a single fowlpox virus vaccination (strain HP201) either via the aerosol or wing-web route. Both methods induced protective immunity against a wing-web or intravenous challenge with virulent fowlpox virus at 47 days old, although high titred virus preparations were required for successful aerosol vaccination. However, no clinical signs of infection were observed as a result of aerosol vaccination even if invasive strains of Escherichia coli were administered simultaneously. The use of aerosol fowlpox virus vaccination of day-old chicks has been shown to be a possible means of mass vaccination and could be applied to the use of fowlpox virus in recombinant vaccines.

Aerosols↗
PubMed1990

Mapping of a major early/late gene of fowlpox virus.

Identification, cloning and mapping of a major gene expressed during the early and late stages of infection with fowlpox virus is described. The gene is located within a 17.3 kb PstI fragment of the fowlpox virus genome and has an open reading frame of 501 bp. Analysis of the 5'-ends of mRNA transcribed from this gene showed that the start sites of both early and late transcripts map to the sequence TAAAT near the translation start site (ATG). This is the first poxvirus early/late gene described in which both early and late transcription start sites map to same DNA sequence. From northern hybridization analysis it was shown that the early function of this gene gives rise to the most abundant early mRNA coded by 17% of the fowlpox virus genome. The strong early function of this gene promoter will be useful in the construction of recombinant fowlpox viruses.

Base Sequence↗
PubMed1992

Gene translocations in poxviruses: the fowlpox virus thymidine kinase gene is flanked by 15 bp direct repeats and occupies the locus which in vaccinia virus is occupied by the ribonucleotide reductase large subunit gene.

By sequencing a fragment of 7351 bp the fowlpox virus thymidine kinase gene has been found to map to a position within the equivalent of the vaccinia HindIII I fragment. The deduced gene arrangement in fowlpox virus is I3, X, TK, I5, I6, I7, I8, G1, indicating that the homologue of the vaccinia I4 gene has been replaced by two genes X and TK. The non-essential TK gene has therefore replaced another non-essential gene, I4 (the ribonucleotide reductase large subunit) in this region. The X/TK insertion in fowlpox virus is precisely flanked by direct repeats of 15 bp suggesting that the translocation event may have involved transposition. The % identities between the fowlpox virus and vaccinia virus proteins ranged between 58.5% and 31.3%.

Amino Acid Sequence↗
PubMed1990

A 39,000 Mr immunodominant protein of fowlpox virus contains multiple copies of a 12 amino acid repeat sequence.

The nucleotide sequence of an unusual fowlpox virus gene which maps immediately upstream from the fowlpox virus 4b gene has been determined. The 34,000 Mr protein predicted to be encoded by the gene contains 11 copies of a 12 amino acid serine-rich repeat sequence. The seven amino-terminal copies of the repeat sequence are perfectly conserved but variation exists in the four carboxy-terminal copies. Three peptides were synthesized which contained either one copy of the repeat sequence, two copies of the repeat sequence or a hydrophilic amino-terminal region of the protein. All three peptides when injected with adjuvant into rabbits gave rise to antibodies which reacted strongly on Western blots of purified fowlpox virus proteins with a 39,000 Mr protein. When directly compared in Western blots the antipeptide sera were shown to recognize a protein comigrating with one of the two immunodominant proteins recognized by chicken anti-fowlpox virus sera taken 2 weeks post-infection. The virion protein is removed by treatment with sodium deoxycholate suggesting that it is located at or near the surface of the virus.

Amino Acid Sequence↗
PubMed1996

Expression of bacteriophage T7 RNA polymerase in avian and mammalian cells by a recombinant fowlpox virus.

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 microbiological safety conditions.

Animals↗
PubMedDate not supplied

Regulation of foreign gene in fowlpox virus by a vaccinia virus promoter.

A vaccinia virus promoter was evaluated for regulation of a foreign gene in fowlpox virus by a transient expression assay. Fowlpox virus-infected quail cells, transfected with plasmid DNA containing chloramphenicol acetyltransferase (CAT) gene ligated to a vaccinia virus promoter, expressed CAT activity. No CAT activity was detected either in uninfected cells or fowlpox virus-infected cells. These results indicated that a heterologous vaccinia virus promoter can regulate expression of a foreign gene in fowlpox virus.

Animals↗
PubMed1994

The safe and effective use of fowlpox virus as a vector for poultry vaccines.

The safety and efficacy of a fowlpox-Newcastle disease vaccine were evaluated by in vitro and in vivo methods. Genetic and phenotypic stability following cell culture and chick passage were demonstrated. The safety characteristics of the recombinant virus equalled or exceeded those of the parent fowlpox virus, as determined by lack of shed and spread to contacts, failure to revert to virulence following passage in chicks and innocuity in other avian species. The fowlpox-Newcastle Disease virus effectively immunized against virulent fowlpox challenge and virulent Newcastle disease challenge (intramuscular or intra-ocular administration). These results indicate that the recombinant FPV/NDV virus is a safe and effective vaccine for poultry.

Animals↗
PubMed1993

Infectious bursal disease virus structural protein VP2 expressed by a fowlpox virus recombinant confers protection against disease in chickens.

Two fowlpox virus recombinants were constructed which expressed the host-protective antigen, VP2, of infectious bursal disease virus (IBDV). Recombinant FPV-VP 2.4.3 contained the gene for the VP 2-VP4-VP3 polyprotein under the control of the vaccinia virus late promoter P.L 11 inserted within the thymidine kinase (TK) gene of FPV. In infected chicken embryo skin (CES) cells VP2 and VP3 proteins were correctly processed from the polyprotein precursor molecule. Recombinant FPV-VP2 contained only the VP2 encoding region under the control of the fowlpox early/late promoter P.E/L inserted immediately downstream of the TK gene. The expression level of VP2 from FPV-VP2 was approximately 5 times higher than from FPV-VP2.4.3. Wing web inoculation of birds resulted in the development of typical fowlpox lesions and the development of antibodies to FPV with either of the recombinants, but only birds vaccinated with FPV-VP2 developed antibodies to IBDV. When challenged with IBDV (strain 002-73), a significant level of protection was provided by FPV-VP2 vaccination, although the level was lower than the protection provided by an oil adjuvanted inactivated whole IBDV vaccine. Birds vaccinated with FPV-VP2.4.3 were not protected from infection as assessed by ELISA for the presence of IBD virus in bursae.

Amino Acid Sequence↗