Manipulation of the Host Immune Response by Small DNA Tumor Viruses

Abstract

Viral infection accounts for up to 15% of cancer cases worldwide. Many oncogenic viruses maintain asymptomatic, persistent infections in immunocompetent hosts and only induce tumorigenesis in the immunocompromised population, highlighting the critical role of the host immune system in controlling virus-induced carcinogenesis. Emerging evidence demonstrates important themes of immune evasion utilized by oncogenic viruses in order to maintain persistent infection. In this chapter, we focus on the immune evasion tactics employed by two small DNA tumor viruses: human papillomavirus (HPV) and the more recently discovered Merkel cell polyomavirus (MCPyV). We will highlight how their manipulation of host immune responses helps to create a cellular environment that supports persistent infection and viral oncogenesis. A comprehensive understanding of the immunomodulatory mechanisms utilized by these viruses during the onset of oncogenesis may contribute to the development of novel therapeutic strategies targeting virus-associated cancers.