Therapeutic vaccines for HPV infection

Abstract

Persistent infection with oncogenic HPV types, particularly HPV 16 and 18, is a prerequisite for the development of anogenital intra-epithelial lesions a proportion of which progress to invasive squamous cell carcinoma of the cervix, anus, vulva, vagina and penis. Since the HPV genome encodes two potent oncoproteins E6 and E7 and these are invariably expressed in HPV associated cancers and precancers they are obvious immune targets raising the prospect of successful immunotherapy against HPV associated neoplastic disease. The approach of deliberate immunisation with oncogenic HPV E6 and/or E7 proteins and the generation of antigen specific cytotoxic T cells as an immunotherapy for HPV associated cancer and their high grade precancers has been tested with a wide array of potential vaccine delivery systems in Phase I/II trials with varying success. It is clear that understanding local viral and tumour immune evasion strategies is a prerequisite for the rational design of therapeutic vaccines for HPV associated infection and disease and recent progress in this and priorities for future investigation is discussed in this chapter.