HUMAN PAPILLOMAVIRUSES TARGET DIFFERENTIATING EPITHELIA FOR VIRION PRODUCTION AND MALIGNANT CONVERSION

Human papillomaviruses infect stratified epithelial cells and induce h yperproliferative lesions. Over 70 different HPV types have been ident ified and each targets epithelia at distinct body locations. A subset, including HPV types IG, 18, 31, 45 and 54, target the genital tract a nd are the etiological agents of cervical cancers. While viral infecti on is a necessary prerequisite for the development of most cervical ca ncers, it is not by itself sufficient indicating that secondary mutati onal events are also required. The viral life is closely linked to epi thelial differentiation and this process is disrupted in the developme nt of malignancies. lit a productive infection, vegetative replication and production of virions is restricted to highly differentiated supr abasal cells. Analysis of the mechanisms regulating the viral life cir cle in differentiating epithelia provides insight into why certain typ es induce cancers of the genital tract.