Papillomaviruses
Papillomaviruses are a large group of non-enveloped, double-stranded DNA viruses in the family Papillomaviridae. They infect epithelial tissues of humans and many animals. The genome is a circular ~8 kilobase pair molecule encoding early regulatory proteins (E1, E2, E4, E5, E6, E7) and late structural proteins (L1, L2). E6 and E7 oncoproteins can interfere with p53 and RB pathways, contributing to deregulation of the cell cycle in high-risk types.
Most infections are asymptomatic and cleared by the immune system. Some produce benign warts on skin or
High-risk HPV types, notably 16 and 18 (often with 31, 33, 45 among others), are associated with
Transmission occurs mainly through sexual contact for mucosal infections and through skin-to-skin contact for cutaneous infections;
Prevention relies on vaccines based on virus-like particles from the L1 major capsid protein. Prophylactic vaccines
The role of papillomaviruses in cancer was established by research led by Harald zur Hausen, for which