Designing and building oncolytic viruses

Maroun, Justin; Muñoz-Alía, Miguel; Ammayappan, Arun; Schulze, Autumn; Peng, Kah-Whye; Russell, Stephen

In nature, viruses are continuously evolving and adapting to occupy almost every imaginable biological niche. Viruses infect bacterial, archaea, protist, fungal, plant and animal cells. Their genomes are composed of DNA or RNA, which may be single or double stranded, positive or negative sense, ranging in size from 2 to 300 kb, in complexity from 1 to 300 genes and in capacity for foreign genetic material from a few hundred bases to several kilobases. The particles of viruses from different families also vary enormously in size and structure, ranging from 20 to 1000 nm, from icosahedral to helical symmetry, with or without lipid envelope, integument or matrix and with variable susceptibility to physical disruption. Naturally occurring viruses also offer a vast diversity of virus life cycles, cell entry and replication mechanisms, cell and species tropisms, cycle times, burst sizes, innate immune evasion, apoptosis, antiviral state prevention and immune combat strategies, modes of transmission and pathogenic mechanisms. The diversity of viruses that have been investigated as oncolytic platforms and the different strategies used to improve their efficacy continue to be expanded (Table 1) .