Human papillomavirus, abbreviated as HPV, a big family which contains over 170 types of HPV and they are designated by numbers as they has been identified. Different subtypes can cause different symptoms: clinical or non-clinical symptom, such as the patients who infected by HPV-5 through a life time may not display a disease symptom. While in those disease strains, HPV-1, HPV-2, HPV-6 or HPV-11 will cause common or genital warts in patients. And clinical statistics shows that many HPV types are considered carcinogenic, such as HPV-16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 73, and 82. Part of the family tree of HPV illustrated as Fig. 1.
Fig. 1 Family Tree of Human Papillomavirus (Part)
HPV, a typical DNA virus, which mainly transmits between individuals through sexual contact and also can spread from a mother to her baby during pregnancy. The vaccine could be used to prevent this disease caused by HPV, however, it can work only for the kids who age from nine to 13. Surface structure of HPV illustrated as Fig. 2.
Fig. 2 Electron Microscopy Structure of Human Papillomavirus
Human Papillomavirus, HPV-16
During those subtypes, nearly all cervical cancer is due to HPV with two types, HPV16 and HPV18, accounting for 70% of cases. HPV may induce cancer in patients when viral genetic substance, DNA sequence integrated into the DNA of host cells, because some genes called as “early genes” will play a role as oncogenes did, what is, promoting tumor growth and malignant transformation. The genome organization of human HPV-16 contains several “early genes”, show as E1-7 in this diagram, and L1/L2 late genes which regulates the signal pathway of capsid assembly.
Fig. 3 Genome Organization of Human HPV-16