Figure 1.

Engineering modifications of OVs. (A) Enhancement of in vivo immune response by arming OVs with scFV targeting PD-1 or by overexpressing specific cytokines through genetic engineering. (B) Enhancement of replication efficiency of OVs in tumor cells through genetic engineering by overexpressing or downregulating certain genes or proteins in tumor cells, or by selecting and designing more efficient virus vectors. (C) OVs are engineered to reduce off-target effects and damage to normal cells, making it a safer and more high-fidelity attenuated virus, thereby improving the safety profile of OV therapy. (D) Enhancement of tumor targeting of OVs through five main modification strategies: 1) Increasing virus affinity and binding activity to receptors overexpressed on tumor surfaces. 2) Utilizing differentiation of tumor cells to improve targeting accuracy. 3) Incorporating differentially expressed microRNAs into OVs through transgenic technology. 4) Arming OVs with bispecific or trispecific T cell engagers.