Abstract
Another novel type of immunotherapy that is being developed to specifically kill cancer cells is oncolytic viruses, which are genetically engineered to destroy cancer cells while leaving normal tissues virtually intact. Progress in genetic engineering has improved their therapeutic impact, allowing the integration of immune-activating factors such as GM-CSF and facilitating their use alongside checkpoint inhibitors. Beyond the direct killing of tumor cells, oncolytic viruses are also known to cause immunogenic cell death, resulting in the release of tumor-related antigens. Such antigens stimulate dendritic cells and cytotoxic T lymphocytes, thereby intensifying the antitumor immune response in the body. However, several barriers still restrict their clinical effectiveness, including poor penetration within tumors, rapid clearance, and immune escape mechanisms. In order to deal with these obstacles, scientists are exploring higher-order platforms of delivery such as nanoparticle-based carriers, mesenchymal stem cells, and vesicle-mediated systems. These modalities will enhance the stability of the virus and the precision of the tumor targeting. Tailoring OV therapy to match the molecular and immunological characteristics of individual tumors could further optimize outcomes. Successfully overcoming these challenges would solidify oncolytic virotherapy as a transformative strategy in cancer immunotherapy, emphasizing the need for ongoing study and rigorously designed clinical trials to unlock its full potential.