Which layer of the epithelium does HPV infect?
Figure 2. HPVs infect specifically the cells in the basal layer of the stratified epithelium through lesions. Viral genomes are maintained as episomal DNA in the nuclei of infected cells.
How does HPV infect epithelial cells?
The replication cycle of HPV is tightly linked to differentiation of the epithelium it infects. HPVs may access the basement membrane or dividing basal epithelial cells via microabrasions in the epithelium and certain HPVs may attach to cells using common cell surface molecules such as heparin sulphate proteoglycans.
What tissue does HPV infect?
HPVs can infect basal epithelial cells of the skin or inner lining of tissues and are categorized as cutaneous types or mucosal types. Cutaneous types of HPV are epidermitrophic and target the skin of the hands and feet. Mucosal types infect the lining of the mouth, throat, respiratory tract, or anogenital epithelium.
Why does HPV replicate only on squamous epithelium?
Papillomaviruses are absolutely species specific and tissue specific. HPV will infect and replicate in a fully differentiating squamous epithelium only. The virus infectious cycle is rather complex and can explain the duration of an HPV infection.
Does HPV infect keratinocytes?
The HPV life cycle is tightly linked to epithelial cell differentiation, where HPVs only infect the basal proliferating keratinocytes, and progeny virus assembly and release only occurs in differentiated upper-layer keratinocytes.
What’s squamous epithelial cells?
Squamous epithelial cells are large, polygonal cells with small round nuclei. They tend to fold on themselves and sometimes are confused with casts. Their large size allows them to be easily distinguished from casts. (2) Common in voided or catheterized samples due to urethral or vaginal contamination.
Is HPV lytic or lysogenic?
Viruses like HPV have the capacity to form virions and become transmissible at some point in their natural lifecycles, but within tumors these infections are generally latent so that productive virus replication (also known as lytic replication) is either diminished or absent.
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 layer of the skin does HPV affect?
HPVs infect cells in the basal layer of squamous epithelium at multiple sites in the anogenital tract, including the cervical squamo-columnar junction, the portio surface of the cervix, the upper and lower epithelia of the vagina, multiple sites on the vulva, the perianal and intra-anal mucosa, the penile shaft, and …
What parts of the integumentary system does HPV affect?
HPV infects the top layer of skin, usually entering the body in an area of broken skin. The virus causes the top layer of skin to grow rapidly, forming a wart. Most warts go away on their own within months or years.
Is it bad to have squamous epithelial cells?
It’s normal to have one to five squamous epithelial cells per high power field (HPF) in your urine. Having a moderate number or many cells may indicate: a yeast or urinary tract infection (UTI) kidney or liver disease.