Description:
AbstractHuman papillomaviruses (HPVs) are small DNA viruses that infect various epithelial tissues. The more than 100 types of HPV described share a circular DNA genome of about 8000 base pairs organized into an early, a late, and a long control region. The products of 2 genes from the early control region, E6 and E7, are essential in the HPV‐induced processes of cellular transformation and immortalization, and 2 genes from the late control region, L1 and L2, encode the viral capsid proteins. A few high‐risk types of HPV types, including HPV‐16 and HPV‐18, are asso‐ciated with more than 99% of cervical carcinomas. Continuous expression of the E6 and E7 oncoproteins by high‐risk types of HPV often leads to genomic aberrations, a step toward malignant conversion. Although in most cases innate and adaptive im‐mune responses control HPV infection, the high‐risk types of virus have the ability to subvert immune defenses, which explains persistent infection and progression to neoplasia.