Immunity to Oncogenic Viruses

In this chapter, we review the oncogenic viruses that together cause 10% of all cancer cases worldwide. The responsible viruses are from diverse families but can all escape host immunity to establish persistent, often lifelong, infection. The resultant infections can remain asymptomatic or can have a variety of consequences, only driving oncogenic changes in a minority of individuals. In many cases, individual viral components have roles in promoting tumor formation by integration into the host genome and in evasion from innate and adaptive immunity. However, the immune responses these viruses do elicit can also contribute to oncogenesis through chronic inflammation and/or can restrain tumor formation through active immune surveillance, as evidenced by the increased emergence of several of these tumors in the setting of immunosuppression. Here we summarize current knowledge of the immune responses to oncogenic viruses and their associated tumors, highlighting prospects for harnessing immunity in prevention and treatment.