ABSTRACT
Oncolytic viruses [OVs] are an emerging class of novel anti-cancer therapeutic agents that selectively infect and destroy cancerous tissues without damaging normal cells. With the recent US Food and Drug Administration [FDA] approval of Herpes Virus [T-VEC] for the treatment of advanced melanoma, oncolytic virotherapy has gained more attention for further development as a novel form of immunotherapy. A viable approach to maximize the efficacy of OVs involves arming them with immuneenhancing cytokines that are capable of boosting the host's immune response to effectively attack tumour cells. Interleukin-12 [IL-12] is a powerful cytokine with potent antitumour activities that activates both innate and adaptive anti-tumour responses. Several studies have demonstrated that IL-12-expressing OVs improve the therapeutic index in pre-clinical tumour models by activating and recruiting dendritic cells [DCs], cytotoxic natural killer [NK] cells and cytotoxic T cells, which subsequently improve tumour clearance. In this review, the immunological mechanisms of IL-12eexpressing viruses are discussed