Immune therapy for human papillomaviruses-related cancers

Figure 2 Papilloma virus replication is tissue specific. The human papilloma virus (HPV) infects a keratinocyte in the basal layer of the epithelium after a micro trauma (a small cut of the epithelium that uncovers the basal membrane). The virus DNA is maintained in the proliferating cells at a low-copy number (E1 and E2 viral proteins are expressed). When the infected cells begin to differentiate into mature keratinocytes, the virus activates other genes (E4, E6, E7 viral proteins are expressed) and replicates its DNA to a high-copy number. In the top layers of the epithelium all viral proteins (including E4 and the capsid proteins L1 and L2) are expressed. Thousands of new virions are formed and released from the cells without causing cell death.