Chapter 6 - Adenovirus vectors for vaccination and cancer gene therapy

Abstract

Adenoviruses (Adv), members of the family Adenoviridae, are medium-sized (90–100nm), nonenveloped viruses with an icosahedral nucleocapsid containing a double-stranded DNA genome. Their name derives from their initial isolation from human adenoids in 1953. Adenovirus vectors are the most commonly employed vector for cancer gene therapy. They are also used as vaccines to express foreign antigens. Nonetheless, since their initial use in gene therapy, they have garnered widespread recognition as a vaccine antigen delivery vehicle and have proven to be safe and efficient vaccine vectors for eliciting protective immune responses against transgene antigens in many animal and human studies. Additionally, owing to their strong immunogenicity, both replicative and nonreplicative Adv can be used as in situ cancer vaccines. Oncolytic vectors are engineered to replicate preferentially in cancer cells and to destroy cancer cells through the natural process of lytic virus replication. Many clinical trials indicate that replication-defective and replication-competent adenovirus vectors are safe and have therapeutic activity. Adv have transitioned from tools for gene replacement therapy to bona fide vaccine delivery vehicles. In this chapter, we introduce different Adv and their biology and potential for use in gene delivery, vaccine, and therapeutics in cancer diseases. In addition, we will discuss their limitations and future prospects.