Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Orthopoxvirus”

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.

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

At least 19 recordsLinked to original sources
PubMed1979

Conservation and variation in Orthopoxvirus genome structure.

Orthopoxvirus DNA from representative strains of rabbitpox, vaccinia, monkeypox, variola, cowpox and ectromelia viruses was analysed by cleavage with restriction endonucleases HindIII, XhoI or SmaI. Genome mol. wt. vary from about 120 x 10(6) for rabbitpox to about 145 x 10(6) for cowpox. Physical maps of cleavage sites are similar and characteristic for strains of the same Orthopoxvirus type. The distribution of HindIII sites suggests that an internal region of mol. wt. about 30 x 10(6) is highly conserved between Orthopoxvirus genomes although some type-specific differences occur within this region, especially with strains of ectromelia virus. Conservation of internal sequences is less marked following analysis with XhoI although cleavages within this central region of particular genomes appear to represent a subset of preferred sites. Endonuclease SmaI cleaves exceptionally infrequently and distinguishes variola, monkeypox, vaccinia, cowpox or ectromelia viruses. Type specific differences result largely from extensive, near terminal variations in length and sequence. Representative Orthopoxvirus genomes have rapidly renaturing terminal restriction fragments confirming the presence of near terminal, covalent cross-links. Terminal restriction fragments from the same or different genomes generally cross hybridize indicating the presence of near terminal repetitions of mol. wt. up to 6 x 10(6) and which share at least a subset of common sequences. Variola strains however, appear to lack such sequences from one specific terminus which maps shorter than that of related viruses.

Base Sequence↗
PubMed2025

Bioluminescence Imaging to Study Recombinant Orthopoxvirus Infection in Animal Models.

Bioluminescent images of viral replication in live animals (in vivo) reveal disease dynamics and effects of medical countermeasures over time. After selecting an appropriate orthopoxvirus animal model for the study, a recombinant virus with the firefly luciferase gene inserted in the genome is used to infect the animals. On the day of bioluminescent imaging, the substrate, D-luciferin, is prepared; animals are sedated and injected with the substrate and IVIS imager is utilized; various bioluminescent images are acquired; then animals recover and are able to continue in the study. Ex vivo imaging can also be completed after animals are euthanized at experimental endpoint. This approach allows real-time imaging of viral kinetics within an animal, and analysis of images can provide an additional quantitative measure throughout the study. Bioluminescent imaging not only provides scientific benefits but also benefits to animal welfare. For these reasons, bioluminescent imaging should be considered for any in vivo orthopoxvirus study.

Animals↗
PubMed1992

Characterization of orthopoxviruses isolated from feline infections in Britain.

The biological properties and genomes of orthopoxviruses isolated from cats in Britain were compared with strains of cowpox virus isolated from cows and their handlers. All the isolates tested produced haemorrhagic pocks and A-type inclusions on the CAM, but did not produce pocks above 40 degrees C. Thus the feline isolates behaved as typical strains of cowpox virus. Differences were found in the heat resistance of the virions and in the character of the A-type inclusion which did not correlate with the host from which the viruses were isolated. Analysis of the genomes with a variety of restriction endonucleases showed very close relationship between all the isolates and also failed to separate feline isolates from cowpox virus. However again minor differences, which may prove to be of epidemiological value were detected. We conclude that the orthopoxvirus currently isolated from domestic cats in Britain is cowpox virus and that there is no evidence that a feline variant or subspecies circulates in Britain.

Animals↗
PubMedDate not supplied

[Search for unique segments of the ectromelia virus genome by cross blot hybridization with DNA from other orthopoxviruses].

In order to identify ectromelia virus (EMV) genome regions which may contain genes responsible for the specific pathogenicity of this virus, blot cross-hybridization of EMV DNA with those of other orthopoxviruses was performed. Two hybridization schemes were employed: one of them included hybridization of labelled cloned fragments of EMV with digests of other viral DNAs, the other, reciprocal, consisted in hybridization of labelled total DNAs of various orthopoxviruses with digests of the region of EMV DNA adjacent to the right-terminal inverted repeat. It was demonstrated that the counterpart to an approximately 8-kilobase pair portion of EMV genome flanking the inverted repeat could be detected only in the cowpox virus genome but not in the genomes of vaccinia and rabbitpox viruses. XhoI-O and XhoI-K fragments of EMV DNA contained, along with genes found in other poxviruses, certain genes which appeared to be unique for EMV. It is postulated that some of these genes may determine the specific biological properties of EMV, including its pathogenicity for mice.

DNA, Viral↗
PubMedDate not supplied

[Possible mechanism of orthopoxvirus preservation in nature].

Until recently, virus carrier state in the absence of overt clinical infection has been known for only one species of orthopoxviruses, namely, ectromelia virus. The paper describes the results of the modelling of asypmtomatic infection caused by monkeypox, cowpox, and ratpox viruses. Persistence of these viruses up to 6 weeks in animals (hamsters, cotton and white rats) with experimental asymptomatic infection as well as in apparently normal naturally infected white rats was established by isolation of virus from the organs of these animals. These results suggest that asymptomatic virus carrier state may occur both with ectromelia and a number of other orthopoxviruses. The mechanism may be of ecological importance, providing for circulation of these viruses and their preservation as biological species in nature.

Animals↗
PubMed2025

Orthopoxvirus Genome Sequencing, Assembly, and Analysis.

Poxviruses have exceptionally large genomes compared to most other viruses, which represent unique challenges to sequencing and assembly due to complex features such as repeat elements and low complexity sequences. The 2022 global mpox outbreak led to an unprecedented level of poxvirus sequencing as public health and research institutions faced with large sample numbers and demand for fast turnaround, merged NGS protocols designed for small RNA viruses with poxvirus expertise. Traditional manual assembly, checking, and editing of genomes was not feasible. Here, we present a protocol for metagenomic sequencing and orthopoxvirus genome assembly directly from DNA extracted from a patient lesion swab with no viral enrichment or host depletion. This sequencing approach is cost effective when using high throughput sequencing instruments and allows for detection of genomic insertions, deletions, and large rearrangement with confidence. We describe usage of two publicly available bioinformatic pipelines for genome assembly, quality control, annotation, and submission to sequence repositories.

Orthopoxvirus↗
PubMed1979

Structural polypeptides of Orthopoxvirus: their distribution in various members and location within the virion.

The structural polypeptides of accepted species and recently isolated members of the genus Orthopoxvirus have been examined by SDS-polyacrylamide gel electrophoresis. The viruses shared many polypeptides but some differences were found. The viruses could be divided into a vaccinia group (including buffalopox, 'Lenny' and MK-10), an ectromelia group (including elephant virus and Moscow virus), cowpox, camelpox and monkeypox. Minor differences were found in the polypeptides of monkeypox virus strains from human and monkey outbreaks. Controlled degradation of virions showed that the polypeptides which enabled the viruses to be differentiated were located in the surface and sub-surface layers. The cores of the viruses all gave the same complex polypeptide pattern.

Animals↗
PubMed1979

Orthopoxvirus strains defective in surface antigen induction.

Various strains of vaccinia, variola, whitepox, monkeypox and cowpox viruses were examined for their capacity to induce a specific early antigen detectable on the surface of infected cells. The Elstree strain of vaccinia, two strains of variola minor and white variants of cowpox and monkeypox viruses lacked the capacity to induce the antigen. Variation of the parent cowpox and monkeypox viruses to white variants was always accompanied by the loss of the antigen-inducing capacity.

Animals↗
PubMed1977

Serological relatedness of monkeypox, variola, and vaccinia viruses.

Closely related human and monkey orthopoxviruses were differentiated by serologic techniques. Antiviral sera were tested by immunodiffusion for reactivity against six different viral antigens prepared from either infected cell cultures or infected chorioallantoic membranes (CAMs) of embryonated eggs. Portions of each antiserum were separately absorbed with heterologous antigens from infected CAMs to remove common reactivity. The absorbed sera formed immunodiffusion precipitates with both types of antigen preparation and revealed specific-character differences that made it possible to classify the viruses as variola, vaccinia, or monkeypox. Cross-complement fixation tests were also used to examine the immunologic reactivities of antisera to detergent-treated, purified preparations of three orthopoxviruses. Only common reactivities were detected by this method, however, and differentiating reactivities were not observed.

Complement Fixation Tests↗
PubMed2025

Potential of MRNA vaccines for mpox prevention: current evidence and future directions.

In 2022, the presumption of monkeypox (mpox) to be of limited epidemiology shifted when a global outbreak was announced. Being a member of the Orthopoxvirus genus in the Poxviridae family, it'd been reported in over 82 countries with over 17 000 confirmed cases by July 2022, thus showing its capability for spreading rapidly. As the smallpox vaccine offers 85% cross-immunity against mpox, the outbreak highlighted the attenuation of global immunity against orthopoxviruses after the cessation of vaccination campaigns against smallpox. The mortality of this virus is higher in vulnerable populations such as children, pregnant women, the elderly, and immunosuppressed individuals. With treatment methods being limited to off-label use of antivirals, the need for urgent and efficient preventative measures is emphasized. At present, JYNNEOS (Modified Vaccinia Ankara-Bavarian Nordic), showing favorable safety, and ACAM2000, a live attenuated virus with a high risk of side effects, are two vaccines that are indicated for mpox immunization. However, neither of them has proven full safety, efficacy, and widespread accessibility against mpox. Hence, the use of mRNA vaccines has emerged as a better alternative to traditional vaccinations, as they leverage synthetic messenger RNA to instruct host cells to produce antigens, eliciting both humoral and cellular immune responses. Though they provided rapid scalability, adaptability to emerging viral variants, and an established safety profile after the COVID-19 pandemic, their usage in preventing mpox remains an area of research. This paper elucidates the potential of mRNA technology to address the unmet needs in mpox prevention. It also highlights the need for genomic surveillance, immunological insights, and innovative delivery systems.

COVID-19↗
PubMed1992

Further characterization of the biological and pathogenic properties of erythromelalgia-related poxviruses.

Six isolates of erythromelalgia-related poxvirus (ERPV) were characterized with respect to host range, c.p.e. and inclusions, pock formation on chorioallantoic membrane (CAM), morphogenesis, serological reactivity, pathogenesis in animals and DNA restriction fragment profile. The results suggest that ERPV is either a new member of the Orthopoxvirus genus or a subspecies of ectromelia virus. Evidence is provided that (i) ERPV has a wide host range in vitro in which characteristic viral c.p.e. and inclusion bodies are induced; (ii) ERPV, unlike ectromelia virus, causes the formation of tiny greyish-white pocks on CAM both at 34 degrees C and 39 degrees C; (iii) eosinophilic A-type inclusions of ERPV do not contain viral particles; (iv) ERPV isolates are neutralized by both rabbit anti-vaccinia virus and mouse anti-ectromelia virus sera, but not vice versa; (v) young rabbits are not susceptible to ERPV by skin and/or corneal scratch infection even though ERPV is lethal for mice by intraperitoneal inoculation; (vi) the HindIII and SalI fragment profiles of ERPV P-4 DNA are similar to, but obviously different from, those of Chinese ectromelia virus. These biological and pathogenic characteristics of ERPV are distinguishable from those of other members of the genus Orthopoxvirus currently described in the literature.

Animals↗
PubMed2026

Integrated molecular, epidemiological, and bioinformatics perspectives on the Mpox virus: Implications for surveillance and Global Health preparedness.

Mpox has re-emerged as a significant global zoonotic threat, driven mainly by two large waves the 2022 worldwide Clade IIb outbreak and the 2024 Clade Ib epidemic in Central Africa. This review examines the challenges of interpreting this evolving virus from molecular, epidemiological, and bioinformatics perspectives, with a focus on global health workforce preparedness. Clade IIb largely moved through sexual transmission across countries, but Clade Ib has appeared in a wider population-women, children, and individuals infected through household spread without any sexual contact. Early case series suggest that Clade Ib may cause a more severe disease burden, but more research is needed to directly compare severity and fatality rates with Clade IIb due to the limited number of current studies. The review examines the virus's strategies for evading the host's immune defenses throughout its ∼197 kbp genome, including how it disrupts interferon signaling and creates decoy receptors. This review summarizes the clinical findings of PALM007 and STOMP, noting that neither trial achieved its main efficacy endpoint making routine tecovirimat use less compelling-while leaving open whether it helps particular high-risk groups. A further point is that immunity from the MVA-BN vaccine wanes with time, leading to the growing adoption of booster vaccinations. In conclusion, the review calls for a One Health approach pairing genomic tracking with ecological intelligence and including wastewater surveillance to fill existing gaps in knowledge and enhance the global handling of new orthopoxvirus threats.

Animals↗
PubMed2006

Recognition of vaccinia virus-infected cells by human natural killer cells depends on natural cytotoxicity receptors.

Natural Killer (NK) cells are important in the immune response to a number of viruses; however, the mechanisms used by NK cells to discriminate between healthy and virus-infected cells are only beginning to be understood. Infection with vaccinia virus provokes a marked increase in the susceptibility of target cells to lysis by NK cells, and we show that recognition of the changes in the target cell induced by vaccinia virus infection depends on the natural cytotoxicity receptors NKp30, NKp44, and NKp46. Vaccinia virus infection does not induce expression of ligands for the activating NKG2D receptor, nor does downregulation of major histocompatibility complex class I molecules appear to be of critical importance for altered target cell susceptibility to NK cell lysis. The increased susceptibility to lysis by NK cells triggered upon poxvirus infection depends on a viral gene, or genes, transcribed early in the viral life cycle and present in multiple distinct orthopoxviruses. The more general implications of these data for the processes of innate immune recognition are discussed.

Cell Line↗
PubMed1992

In vitro recognition of an orf virus early promoter in a vaccinia virus extract.

DNA fragments containing varying lengths of the 5' end of an orf virus early gene (ORF3) and its associated promoter were introduced into sodium deoxycholate-solubilized vaccinia virus extracts capable of initiating transcription in vitro from vaccinia virus early promoters. After separation of the radiolabelled products of the reactions on a 5% polyacrylamide/7 M urea gel, discrete transcripts were detected the sizes of which were consistent with initiation of transcription from the orf virus early promoter. This is the first demonstration in a functional assay of the conservation of early transcriptional promoters between an orthopoxvirus and a parapoxvirus.

Base Sequence↗
PubMed1979

Physical characterization of a stomatitis papulosa virus genome: a cleavage map for the restriction endonucleases HindIII and EcoRI.

The genome of stomatitis papulosa virus (a parapoxvirus) was cleaved with the restriction endonucleases HindIII and EcoRI, each giving rise to 6 fragments respectively. Double digestion with both enzymes resulted in 8 bands, two of which contained DNA fragments in double molar concentrations as revealed by reciprocal digests of isolated DNA fragments. The genome size, estimated by summation of the molecular weights of the fragments, is approximately 86 X 10(6) daltons, some 30 X 10(6) daltons smaller than vaccinia virus (an orthopoxvirus) DNA. The cleavage sites of HindIII and EcoRI endonucleases were mapped on the genome by analysis of reciprocal digests of isolated DNA fragments and by cross-hybridization experiments. This yielded two mapped segments which were then oriented relative to one another by cleavage of isolated partial digestion products. The terminal restriction fragments show rapid renaturation after alkali denaturation and subsequent neutralization, indicating that stomatitis papulosa virus DNA contains terminal cross-links analogous to those found in vaccinia virus DNA.

Animals↗