Figure 1.

Possible antitumor mechanisms of oncolytic viruses. The possible mechanisms exerted by oncolytic viruses include the recognition and elimination of infected tumor cells by (A) natural killer (NK) cells or (B) cluster of differentiation 8 positive (CD8⁺) T cells, which can generate central and effector memory CD8⁺ T cells. It remains unknown if (C) NK cells and (D) CD8⁺ T cells can also eliminate uninfected tumor cells. (E) The oncolytic virus can also infect tumor cells and induce direct cell lysis. In addition, (F) inoculation with oncolytic viruses can enhance the secretion of several pro-inflammatory cytokines. Several pathways may occur simultaneously.