Human Papillomavirus Biology: Review

Sexually transmitted infections (STIs) are more dynamic than any other diseases in both developing and developed countries. Human Papillomaviruses (HPVs) are icosahedral, small, non-enveloped particle measuring ~55 nm in diameter. They are ~8000 base-pair (bp), double stranded circular DNA molecule which wrapped into a protein shell by two molecules namely, L1 and L2. The HPV genome has the coding capacity for two late proteins (L1 and L2) and for six early proteins (E1, E2, E4–E7) which are necessary for the replication of the viral DNA and for the assembly of newly produced virus particles within the infected cells. More than 100 HPV types have been characterized molecularly and about 40 types are able to infect the epithelial lining of the anogenital tract and other mucosal areas of the human body. Human papillomavirus (HPV) is a necessary cause of cervical, anogenital, upper aerodigestive tract and skin cancers. Other cofactors are necessary for progression from cervical HPV infection to cancer. HPVs are highly specific for hosts where they exploit the host cellular machinery for their own purposes by perfectly adapting to their natural host tissue, the differentiating epithelial cell of skin or mucosa. Thus it appears that the biology of Human papillomavirus is still being explored. Therefore this review is an attempt to gather information about biology of HPV which may provide new insight to combat HPV related diseases.