PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Cowpox virus”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 19 recordsLinked to original sources

A comparison of the antigens present on the surface of virus released artificially from chick cells infected with vaccinia virus, and cowpox virus and its white pock mutant.

Antisera prepared against vaccinia and cowpox viruses were absorbed with purified suspensions of vaccinia virus, red cowpox and white cowpox viruses. They were then tested for their ability to neutralize the viruses, and to precipitate the virus soluble antigens.The results showed that some virus specific antigens were not virus surface components and that some components were present on the surface of all three viruses. However, certain components were detected on the surface of vaccinia virus but not on the surface of cowpox virus, and vice versa. Some evidence for the existence of a vaccinia-specific surface component was also obtained.Comparisons between results of cross-neutralization tests and immunodiffusion tests on the absorbed sera indicated that antibody to a number of antigens, including the classical LS, and the cowpox-specific d antigen play no part in the process of poxvirus neutralization.

Animals↗

Comparison of the susceptibility of the red fox (Vulpes vulpes) to a vaccinia-rabies recombinant virus and to cowpox virus.

Sylvatic rabies can be efficiently controlled by vaccination of foxes with a vaccinia-rabies recombinant virus. However, the risk of recombination between the engineered vaccine virus and other orthopoxviruses endemic in wildlife, such as cowpox virus, still needs to be investigated. In this study, foxes inoculated orally and intradermally with cowpox virus were found to be not very susceptible to cowpox virus, which was isolated from only the oropharynx and tonsils, at low titre and for only five days after inoculation. Thus the risk of recombination between these viruses in foxes is very low.

Animals↗

Practical synthesis of D- and l-2-cyclopentenone and their utility for the synthesis of carbocyclic antiviral nucleosides against orthopox viruses (smallpox, monkeypox, and cowpox virus).

Highly efficient and practical methodology for the syntheses of D- and l-4,5-O-isopropylidene-2-cyclopentenone (9 and 22), versatile intermediates for the synthesis of carbocyclic nucleosides, have been developed via a ring-closing metathesis reaction from d-ribose in eight steps. The utility of D- and l-4,5-O-isopropylidene-2-cyclopentenone is demonstrated by their application for the preparation of D-cyclopentyl-6-azauridine 12 and D-cyclopentenyl-5-halocytosine nucleosides (33-35) using Mitsunobu reaction to introduce pyrimidine bases as potential antiviral agents. Preliminary antiviral activity against orthopox viruses (smallpox, monkeypox, and cowpox virus) of the synthesized nucleosides are described.

Antiviral Agents↗

Amplification of 'variola virus-specific' sequences in German cowpox virus isolates.

In 1995 a polymerase chain reaction (PCR) protocol describing the specific detection of variola virus, the causative agent of smallpox, was published by Knight and others. Virulent variola major strains could be differentiated from less virulent variola minor strains because of the distinct amplicon sizes. Here, we applied this PCR protocol to DNA from various orthopoxvirus isolates. There was no amplification with the orthopoxvirus species vaccinia, monkeypox, mousepox, or camelpox viruses. However, amplification was observed in six out of 15 cowpox virus strains investigated. The size of the amplicons corresponded exactly with the size described for variola minor strains and the nucleotide sequence identity accounted for 97%. Findings are discussed with respect to the evolution of orthopoxvirus species assuming that variola virus most probably stems from a rodent-transmitted cowpox virus-like progenitor.

Animals↗

The inflammation modulatory protein (IMP) of cowpox virus drastically diminishes the tissue damage by down-regulating cellular infiltration resulting from complement activation.

Vaccinia virus (VV) and other pathogenic poxviruses encode for a complement control protein. The VV complement control protein or VCP, was one of the first soluble microbial proteins postulated to have an active role in the immunomodulation of the host defense. Since then, 2 other poxviruses, including variola virus and cowpox virus (CPV), were found to have corresponding proteins. Based upon earlier studies which demonstrated the role of the CPV complement control protein in modulating the specific tissue responses in BALB/c and congenic-matched C5-sufficient and C5-deficient mice, the CPV equivalent has been renamed the inflammation modulatory protein (IMP), so as to specifically reflect its function. In this study, the in vivo cellular response of mice injected with CPV or a recombinant virus lacking the IMP sequence (CPV-IMP) was examined using a connective tissue air pouch model. Microscopic examination revealed that CPV-IMP caused a significant mononuclear cell infiltration into the connective tissue and adjacent dermal tissue of the skin. To characterize IMP's ability to regulate the observed cellular infiltration through both complement derived and non-complement derived chemotactic factors, footpad and skin connective tissue of C3 knockout mice and footpad of MIP-1alpha knockout mice received injections of CPV and CPV-IMP. In comparison to the matched control, significantly greater footpad specific swelling response was seen in C3 -/- mice injected with CPV. This indicates an important role for C3 in poxvirus pathogenesis. However, MIP-1 alpha -/- mice injected with CPV-IMP recovered earlier than mice injected with CPV alone. This indicates that the function of IMP in vivo in mice with a complete repertoire of immune components is to limit cellular infiltration by down regulating the complement derived chemotactic analphylotoxins, thereby modulating the inflammatory response contributing to a diminished tissue pathology and preservation of viral habitat.

Animals↗

The mode of death of pig kidney cells infected with cowpox virus is governed by the expression of the crmA gene.

Pig kidney cells (LLC-PK1) were infected with one of three viruses: wild-type cowpox virus (Brighton red strain) expressing the crmA gene; recombinant cowpox virus A602, lacking the crmA gene; or cowpox virus A604, a revertant of virus A602, expressing the crmA gene. The wild-type virus and virus A604 produced identical cytopathic effects consistent with death by necrosis. In these cells, the structural features of the plasma membrane, the nuclear membrane, and the chromatin were maintained until lysis of the cells. In contrast, cowpox virus A602 produced cytopathic effects consistent with death by apoptosis. These effects included loss of microvilli on the cell surface, margination and condensation of the chromatin, progressive convolution of the nuclear membrane, release of dense chromatin masses on disintegration of the nucleus, fragmentation of the DNA, and the generation of apoptotic bodies. These results suggest that the crmA gene is necessary to inhibit processes of apoptosis induced in LLC-PK1 cells by infection with cowpox virus. Thus in cells of certain types, the crmA gene can act with other viral genes to control the mode of death of the virus-infected cell. This capability may be advantageous to virus replication in vivo, potentially facilitating both virus trafficking and interference with antiviral immune defenses.

Animals↗

Comparative studies on LS antigens induced by vaccinia and cowpox viruses.

The constituents of LS antigen from cells infected with vaccinia virus and with cowpox virus were compared by immunoprecipitation and SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Antiserum to the LS antigen from cells infected with vaccinia virus reacted with at least five polypeptides in cells infected with either virus. Four of these polypeptides were similar sizes in cells infected with the two viruses. However, one major polypeptide with a mol. wt. of about 100 000 (100 K) detected in cells infected with vaccinia virus was not found in cells infected with cowpox virus. Conversely, a polypeptide with a mol. wt. of about 60 000 (60K) was detected only in cells infected with cowpox virus.

Animals↗

Effects of deletions of kelch-like genes on cowpox virus biological properties.

Cowpox virus (CPXV) strain GRI-90 contains six genes encoding kelch-like proteins. All six proteins contain both, the N-terminal BTB domain and the C-terminal kelch domain. We constructed mutant variants of a CPXV strain with targeted deletions of one to four genes of the kelch family, namely D11L, C18L, G3L, and A57R. As kelch genes are located in terminal variable regions of the CPXV genome, we studied the relationship of these genes with integral biological characteristics such as virulence, host range, reproduction in vitro and in ovo (in chicken embryos). It was demonstrated that the following effects occurred in a gene dose dependent manner with an increase of the number of genes deleted: (1) range of sensitive cells altered--deletion mutants lacking three genes displayed a considerably decreased ability to reproduce in MDCK cells; mutants lacking four genes lost this ability completely; (2) analysis of pocks formed by mutants with deletion of three and four kelch-like genes on chorioallantoic membranes of chicken embryos demonstrated that pock size and virus yield were significantly decreased; (3) light microscopic analysis of the pocks revealed impaired proliferation and reduced vascularisation in the pock region. More alterations were detected by electron microscopic analysis: the reproduction of mutants results in a reduction of the number of mature virions formed, and in many cells this process was arrested at the stage of assembly of immature virions; and (4) the evaluation of LD(50) and body weight loss in BALB/c mice infected intranasally with CPXVs revealed a reduction of the virulence of the deletion mutants, which became statistically significant when four kelch-like genes were excised.

Animals↗

New outlook on the biology of cowpox virus.

Analysis of cowpox outbreaks revealed an extremely wide range of virus pathogenicity including 9 orders of mammals. Recent serological and virological data support the hypothesis that wild rodents may be a natural reservoir of cowpox virus. Cowpox infection of humans occurring without any contact with infected cattle (registered in the U. K. and Poland) is especially interesting for medical and veterinary virology. Surveillance seems justified of the possible virus dissemination beyond its natural reservoir resulting in further infection of man and animals.

Animals↗

Comparison of thymidine kinase and A-type inclusion protein gene sequences from Norwegian and Swedish cowpox virus isolates.

During the last decades, cowpox virus, a member of the genus Orthopoxvirus within the Poxviridae family, has appeared as a pathogen in domestic cats, zoo animal species, and humans. At the same time, vaccinia virus, another orthopoxvirus, has been used as a recombinant vaccine vector with foreign genes inserted in the thymidine kinase (TK) gene. By PCR and cycle sequencing, we have determined the nucleotide sequences of the TK gene and the A-type inclusion protein (ATIP) gene of virus isolates from two human cowpox cases in Sweden, as well as a human and a feline case from Norway. We also obtained the corresponding sequences from ectromelia virus (strain Moscow), cowpox virus (strain Brighton) and vaccinia virus (strain Western Reserve). The new virus isolates differed from ectromelia virus and vaccinia virus, and were confirmed to be cowpox virus strains. Isolates originating from the same country had nearly identical TK sequences and fully identical ATIP sequences. They probably represent local geographical strains of cowpox virus.

Animals↗

Variola and camelpox virus-specific sequences are part of a single large open reading frame identified in two German cowpox virus strains.

A large open reading frame (ORF) has been identified in two German cowpox virus strains. The ORFs (5676 and 5679 nt, respectively) differ in 10 nucleotides, resulting in an amino acid homology of 99.8%. In searching GenBank nucleotide sequences (>90% identity) were present in several small ORFs in variola major, variola minor and camelpox virus genomes. Alignments revealed that these small ORFs are fragments of a large ORF. However, sequences of the ORF described here are entirely absent in the two cowpox virus reference strains. Databank analysis revealed amino acid identities (ranging from 25 to 39%) with so-called B22R-like poxviral proteins with unknown function encoded by several chordopoxviruses. Further sequencing of one cowpox virus strain under study identified an ORF (5790 nt) which displays high levels of nucleotide identity to ORFs present in several orthopoxvirus species. Taken together, the two cowpox viruses analyzed here contain one large ORF which is conserved within the genus Orthopoxvirus and a unique, more distantly related ORF of similar size, which is conserved in the subfamily Chordopoxvirinae.

Chordopoxvirinae↗

Plasma membrane localization and fusion inhibitory activity of the cowpox virus serpin SPI-3 require a functional signal sequence and the virus encoded hemagglutinin.

The cowpox virus (CPV) glycoprotein serpin SPI-3, a functional protease inhibitor, and the viral hemagglutinin (HA) are required to prevent fusion of wt CPV infected cells. SPI-3 and HA from CPV infected cells co-localize to the plasma membrane and are found in extracellular enveloped virus (EEV). We also show that an N-terminal SPI-3 signal sequence, but not glycosylation, is required for membrane localization and fusion inhibition. In the absence of HA (CPVDeltaHA), no SPI-3 is found on the membrane and infected cells fuse. Conversely, HA from both wt CPV and CPVDeltaSPI-3 infections is on the membrane, indicating a requirement of HA for SPI-3 plasma membrane localization. In the absence of HA, secretion of SPI-3 or SPI-3 N-glyc(-) was markedly enhanced, suggesting HA serves to retain SPI-3 on the plasma membrane,thereby preventing cell fusion.

Animals↗

Characteristics of four cowpox virus isolates from Norway and Sweden.

We report the first isolation of cowpox virus from a domestic cat in Norway, and the first confirmed isolation of cowpox virus from a human case in Norway. These two Norwegian cowpox virus isolates, as well as two Swedish human isolates, were partially characterized and compared with each other and with cowpox virus Brighton and vaccinia virus strain Western Reserve. Restriction enzyme analysis of the genomes revealed differences between all six viruses examined, but suggested that the two Norwegian isolates are closely related, as are the two Swedish isolates. Restriction endonuclease digestion of genomic DNA demonstrated that one of the Swedish isolates and the two Norwegian isolates have larger genomes than vaccinia virus strain Western Reserve, but smaller than cowpox Brighton. All four Scandinavian isolates lacked a 72 base-pair region within the A-type inclusion body protein gene which is present in the prototype cowpox virus Brighton.

Adolescent↗

A cowpox virus gene required for multiplication in Chinese hamster ovary cells.

Cowpox virus, in contrast to vaccinia virus, can multiply in Chinese hamster ovary cells. To study the genetic basis for this difference in host range, recombinants between vaccinia and cowpox viruses were isolated and their DNA restriction patterns were examined. The ability to multiply in Chinese hamster ovary cells could be correlated with the conservation of cowpox virus sequences mapping at the left end of the genome. This was further demonstrated by marker rescue of the host range phenotype with restricted cowpox virus DNA. Marker rescue with cloned restriction fragments of decreasing size enabled the fine localization of the host range function to a 2.3-kilobase-pair fragment. Nucleotide sequencing revealed that the fragment encoded a single major polypeptide of approximately 77,000 daltons. It is suggested that the role of the host range gene from cowpox virus is to prevent the early and extensive shutoff of protein synthesis that normally occurs in Chinese hamster ovary cells infected by vaccinia virus.

Amino Acid Sequence↗

[The biotype and genetic characteristics of an isolate of the cowpox virus causing infection in a child].

A virus, identified as cowpox virus by its biological properties and the results of the analysis of its DNA, was isolated from a sick 4-year-old child with a clinical picture of pox, though having had no contacts with known natural carriers of the causative agent of this infection. At the same time the isolated virus was found to differ from the reference strain, as well as from other isolates of vaccinia virus by some biological markers (and in particular by the structure of cytoplasmic inclusions of type A) and by the restriction profile of DNA. The Hind III maps indicating the location of restriction sites made it possible to localize the genome differences established in this study. The specific feature of this case was the previous close contact of the child with a mole which was probably the source of infection.

Animals↗