Fig. 3.

Armed oncolytic virus (OV) enhances antitumor activity. a There are numerous means to prove the lytic activity of OVs, some of which might be more immunogenic and prime antiviral adaptive immune responses. b The administration of OV-expressing chemokines promotes the secretion of chemokines into the tumor microenvironment (TME), which increases T-cell trafficking to tumors. The secretion of cytokines induced by OVs maintains T-cell survival and expansion. c Armed OVs can provide local antigen targets for chimeric antigen receptor T-cell therapy (CAR T) cells or human leukocyte antigen (HLA)/costimulation molecules directed to T-cell receptor (TCR)-T cells. Furthermore, OVs expressing bispecific T-cell engagers (BiTEs) are capable of overcoming antigen heterogeneity and inducing tumor cell death. d Immune checkpoint inhibitors (ICIs) or mini bodies and immunosuppressive ligands locally delivered by armed OVs reverse T-cell exhaustion