What is the life cycle of human papillomavirus?
HPV DNA replication during its life cycle occurs in three separate phases (reviewed in [1, 2]). After viral entry into the cell nucleus and the activation of viral gene expression, the viral genome copy number increases to several hundred copies per cell during the initial phase of genome amplification.
How does HPV cause cervical cancer?
When the body’s immune system can’t get rid of an HPV infection with oncogenic HPV types, it can linger over time and turn normal cells into abnormal cells and then cancer. About 10% of women with HPV infection on their cervix will develop long-lasting HPV infections that put them at risk for cervical cancer.
How does HPV proliferate?
HPV infects dividing basal epithelial cells where its dsDNA episomal genome enters the nuclei. Upon basal cell division, an infected daughter cell begins the process of keratinocyte differentiation that triggers a tightly orchestrated pattern of viral gene expression to accomplish a productive infection.
Where does HPV hide?
We have found that the means by which HPV enters our bodies and makes its way to the cell’s nucleus, or control center, is incredibly unique and not shared by any other virus. Upon infection, the virus hides within a special compartment of the cell until the cell is ready to divide.
How does HPV damage DNA?
“HPV can act like a tornado hitting the genome, disrupting and rearranging nearby host-cell genes,” Symer explains. “This can lead to overexpression of cancer-causing genes in some cases, or it can disrupt protective tumor-suppressor genes in others. Both kinds of damage likely promote the development of cancer.”
What does Episomal mean?
(ĕp′ĭ-sōm′) A segment of DNA in certain cells, especially bacterial cells, that can exist either autonomously in the cytoplasm or as part of a chromosome.
Is HPV single or double stranded?
HPV consists of a family of small, double-stranded DNA viruses that infect the epithelium. More than 200 distinct types have been identified; they are differentiated by their genomic sequence. Most HPV types infect the cutaneous epithelium and can cause common skin warts.
What is a pseudovirus (PSV)?
Papillomavirus-based gene transfer vectors, also known as pseudoviruses (PsV), have become standard tools for studying papillomavirus assembly, cellular entry and neutralization and may have future utility as laboratory gene transfer tools or vaccine vehicles. This protocol outlines methods for PsV production.
What are orphan Pseudovirions?
Orphan pseudovirions, for example, contain fragments of the host cell’s genetic material that is encapsulated within a protein structure that closely resembles that of bacterial proteins. To date, the protein structures present on the surface of orphan pseudovirion particles are not the gene product of any known infectious virus.
What is the history of pseudovirus?
The first documented use of the term “pseudovirus” was in 1967, wherein researchers described a particle that had been produced from cultured mouse cells that were infected by polyomavirus. Upon further analysis of this particle, the researchers found fragments of mouse DNA to be encapsulated within the protein coat of the polyomavirus.
What are the different types of Pseudoviridae?
The family Pseudoviridae is comprised of three genera: Pseudovirus, Hemivirus, and Sirevirus (Table 1). The genus Pseudovirus has the most species and the broadest host range.
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