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Cold Spring Harbor Perspectives in... Sep 2013Poxviruses are large, enveloped viruses that replicate in the cytoplasm and encode proteins for DNA replication and gene expression. Hairpin ends link the two strands of... (Review)
Review
Poxviruses are large, enveloped viruses that replicate in the cytoplasm and encode proteins for DNA replication and gene expression. Hairpin ends link the two strands of the linear, double-stranded DNA genome. Viral proteins involved in DNA synthesis include a 117-kDa polymerase, a helicase-primase, a uracil DNA glycosylase, a processivity factor, a single-stranded DNA-binding protein, a protein kinase, and a DNA ligase. A viral FEN1 family protein participates in double-strand break repair. The DNA is replicated as long concatemers that are resolved by a viral Holliday junction endonuclease.
Topics: DNA Packaging; DNA Replication; DNA, Viral; DNA-Binding Proteins; Genome, Viral; Models, Biological; Poxviridae
PubMed: 23838441
DOI: 10.1101/cshperspect.a010199 -
Microbiology Spectrum Aug 2016Smallpox is considered among the most devastating of human diseases. Its spread in populations, initiated for thousands of years following a probable transmission from... (Review)
Review
Smallpox is considered among the most devastating of human diseases. Its spread in populations, initiated for thousands of years following a probable transmission from an animal host, was concomitant with movements of people across regions and continents, trade and wars. Literature permitted to retrace the occurrence of epidemics from ancient times to recent human history, smallpox having affected all levels of past society including famous monarchs. The disease was officially declared eradicated in 1979 following intensive vaccination campaigns.Paleomicrobiology dedicated to variola virus is restricted to few studies, most unsuccessful, involving ancient material. Only one recent approach allowed the identification of viral DNA fragments from lung tissue of a 300-year-old body excavated from permafrost in Eastern Siberia; phylogenetic analysis revealed that this ancient strain was distinct from those described during the 20th century.
Topics: Animals; Disease Transmission, Infectious; Epidemics; Global Health; History, 15th Century; History, 16th Century; History, 17th Century; History, 18th Century; History, 19th Century; History, 20th Century; History, Ancient; History, Medieval; Human Migration; Humans; Paleopathology; Poxviridae; Smallpox; Travel; Virology
PubMed: 27726788
DOI: 10.1128/microbiolspec.PoH-0004-2014 -
Cell Host & Microbe Jun 2023Mpox represents a persistent health concern with varying disease severity. Reinfections with mpox virus (MPXV) are rare, possibly indicating effective memory responses...
Mpox represents a persistent health concern with varying disease severity. Reinfections with mpox virus (MPXV) are rare, possibly indicating effective memory responses to MPXV or related poxviruses, notably vaccinia virus (VACV) from smallpox vaccination. We assessed cross-reactive and virus-specific CD4 and CD8 T cells in healthy individuals and mpox convalescent donors. Cross-reactive T cells were most frequently observed in healthy donors over 45 years. Notably, long-lived memory CD8 T cells targeting conserved VACV/MPXV epitopes were identified in older individuals more than four decades after VACV exposure and exhibited stem-like characteristics, defined by T cell factor-1 (TCF-1) expression. In mpox convalescent donors, MPXV-reactive CD4 and CD8 T cells were more prevalent than in controls, demonstrating enhanced functionality and skewing toward effector phenotypes, which correlated with milder disease. Collectively, we report robust effector memory MPXV-specific T cell responses in mild mpox and long-lived TCF-1 VACV/MPXV-specific CD8 T cells decades after smallpox vaccination.
Topics: Humans; CD8-Positive T-Lymphocytes; Mpox (monkeypox); Smallpox; Vaccinia virus; Poxviridae
PubMed: 37236191
DOI: 10.1016/j.chom.2023.04.015 -
Current Opinion in Virology Oct 2022Poxviruses are large double-stranded DNA viruses that encode their own DNA replication, transcription, and mRNA biogenesis machinery, which underlies their ability to... (Review)
Review
Poxviruses are large double-stranded DNA viruses that encode their own DNA replication, transcription, and mRNA biogenesis machinery, which underlies their ability to replicate entirely in the cytoplasm. However, like all other viruses, poxviruses remain dependent on host ribosomes to translate their mRNAs into the viral proteins needed to complete their replication cycle. While earlier studies established a fundamental understanding of how poxviruses wrestle with their hosts for control of translation initiation and elongation factors that guide ribosome recruitment and mRNA decoding, recent work has begun to reveal the extent to which poxviruses directly target the ribosome itself. This review summarizes our current understanding of the regulation of ribosomes and translation in poxvirus infection.
Topics: Humans; Vaccinia virus; Ribosomes; Poxviridae; Poxviridae Infections; RNA, Messenger; Virus Replication
PubMed: 36270183
DOI: 10.1016/j.coviro.2022.101256 -
Viruses Dec 2023Smallpox was a highly contagious disease caused by the variola virus. The disease affected millions of people over thousands of years and variola virus ranked as one of... (Review)
Review
Smallpox was a highly contagious disease caused by the variola virus. The disease affected millions of people over thousands of years and variola virus ranked as one of the deadliest viruses in human history. The complete eradication of smallpox in 1980, a major triumph in medicine, was achieved through a global vaccination campaign using a less virulent poxvirus, vaccinia virus. Despite this success, the herd immunity established by this campaign has significantly waned, and concerns are rising about the potential reintroduction of variola virus as a biological weapon or the emergence of zoonotic poxviruses. These fears were further fueled in 2022 by a global outbreak of monkeypox virus (mpox), which spread to over 100 countries, thereby boosting interest in developing new vaccines using molecular approaches. However, poxviruses are complex and creating modern vaccines against them is challenging. This review focuses on the structural biology of the six major neutralization determinants on poxviruses (D8, H3, A27, L1, B5, and A33), the localization of epitopes targeted by neutralizing antibodies, and their application in the development of subunit vaccines.
Topics: Humans; Poxviridae; Smallpox; Vaccinia virus; Smallpox Vaccine; Variola virus
PubMed: 38140637
DOI: 10.3390/v15122396 -
Oncotarget Oct 2015
Topics: Evolution, Molecular; Gene Expression Regulation, Viral; Genome, Viral; Host-Pathogen Interactions; Open Reading Frames; Poxviridae; Transcription, Genetic; Viral Proteins
PubMed: 26429864
DOI: 10.18632/oncotarget.5892 -
Viruses Dec 2022The Salmon gill poxvirus (SGPV) has emerged in recent years as the cause of an acute respiratory disease that can lead to high mortality in farmed Atlantic salmon... (Review)
Review
The Salmon gill poxvirus (SGPV) has emerged in recent years as the cause of an acute respiratory disease that can lead to high mortality in farmed Atlantic salmon presmolts, known as Salmon gill poxvirus disease. SGPV was first identified in Norway in the 1990s, and its large DNA genome, consisting of over 206 predicted protein-coding genes, was characterized in 2015. This review summarizes current knowledge relating to disease manifestation and its effects on the host immune system and describes dissemination of the virus. It also demonstrates how newly established molecular tools can help us to understand SGPV and its pathogenesis. Finally, we conclude and ask some burning questions that should be addressed in future research.
Topics: Animals; Salmo salar; Gills; Fish Diseases; Poxviridae; Chordopoxvirinae
PubMed: 36560705
DOI: 10.3390/v14122701 -
ELife Oct 2022As long suspected, poxviruses capture host genes through a reverse-transcription process now shown to be mediated by retrotransposons.
As long suspected, poxviruses capture host genes through a reverse-transcription process now shown to be mediated by retrotransposons.
Topics: Retroelements; Poxviridae; Vaccinia virus; Virus Replication
PubMed: 36282171
DOI: 10.7554/eLife.83488 -
Revista Clinica Espanola Oct 2022
Topics: Humans; Mpox (monkeypox); Monkeypox virus; Poxviridae
PubMed: 35750596
DOI: 10.1016/j.rceng.2022.05.001 -
MBio Feb 2023Poxviruses are often thought to evolve relatively slowly because they are double-stranded DNA pathogens with proofreading polymerases. However, poxviruses have highly... (Review)
Review
Poxviruses are often thought to evolve relatively slowly because they are double-stranded DNA pathogens with proofreading polymerases. However, poxviruses have highly adaptable genomes and can undergo relatively rapid genotypic and phenotypic change, as illustrated by the recent increase in human-to-human transmission of monkeypox virus. Advances in deep sequencing technologies have demonstrated standing nucleotide variation in poxvirus populations, which has been underappreciated. There is also an emerging understanding of the role genomic architectural changes play in shaping poxvirus evolution. These mechanisms include homologous and nonhomologous recombination, gene duplications, gene loss, and the acquisition of new genes through horizontal gene transfer. In this review, we discuss these evolutionary mechanisms and their potential roles for adaption to novel host species and modulating virulence.
Topics: Humans; Evolution, Molecular; Poxviridae; Host Specificity; Gene Duplication
PubMed: 36515529
DOI: 10.1128/mbio.01526-22