Strategies to improve DNA vaccine potency: HPV-associated cervical cancer as a model system

Cancer immunotherapy, particularly antigen-specific immunotherapy, has become a potentially promising approach for control of cancer due to its ability to kill tumor cells without harming normal cells. Among different forms of antigen-specific immunotherapy, DNA vaccines are an attractive approach because of their safety, simplicity and ease of mass production. However, they suffer from low immunogenicity due to their inability to amplify and spread in vivo and therefore require innovative strategies to enhance the immune response stimulated by DNA vaccines. Strategies to improve DNA vaccine efficacy should focus on dendritic cells (DCs) because they are the most potent activators of an antigen-specific T cell response, which is crucial in the control of tumors. Increased understanding of DC biology has created opportunities to improve DNA vaccine potency through the applications of strategies that modify the function of DCs. In this review, we use human papillomavirus (HPV)-associated cervical cancer as a model system to illustrate the various strategies that improve DNA vaccine potency. Specifically, we will discuss the various strategies to improve targeting of DNA to DCs, antigen processing and presentation by DCs and DC interactions with T cells in this book chapter.