In the rapidly evolving landscape of cancer immunotherapy, oncolytic virotherapy has emerged as a dynamic force capable of amplifying the immune response against tumors. Once seen merely as a means of direct tumor lysis, oncolytic viruses (OVs) are now recognized for their ability to reshape the tumor microenvironment, recruit immune cells, and enhance the effectiveness of existing therapeutic modalities.
The synergy between oncolytic virotherapy combined with cancer immunotherapy lies in its dual action—while OVs selectively infect and destroy malignant cells, they also release tumor-associated antigens and inflammatory signals that stimulate a systemic antitumor immune response. This makes them ideal partners for immunotherapies that rely on the patient’s immune system to eliminate cancer cells.
Among these, the combination of oncolytic viruses and immune checkpoint inhibitors has shown particularly promising outcomes. Checkpoint inhibitors such as anti-PD-1 or anti-CTLA-4 antibodies can unleash T cells from immune suppression, yet their effectiveness often depends on preexisting immune infiltration within tumors. Oncolytic viruses can help overcome this limitation by converting immunologically “cold” tumors into “hot” ones, thereby improving patient responses to checkpoint blockade therapy. This partnership not only increases immune cell trafficking to tumor sites but also enhances the expression of checkpoint molecules that make the tumor more susceptible to inhibition.
In addition to checkpoint blockade, oncolytic virus-assisted adoptive T cell therapy offers another compelling frontier. Adoptive T cell transfer, including CAR-T or TCR-T approaches, relies on engineered immune cells that specifically recognize tumor antigens. However, these cells often face an immunosuppressive tumor microenvironment. Oncolytic viruses can modify this environment by promoting local cytokine release, improving antigen presentation, and providing homing signals that guide T cells to tumor sites. This synergy results in stronger, more sustained antitumor responses.
What makes oncolytic virotherapy particularly exciting is its versatility—it can be customized to target specific tumor types, encode immunostimulatory transgenes, and interact with multiple arms of the immune system simultaneously. As researchers continue to explore these combinations, the vision of a truly integrated immuno-oncology strategy is becoming more tangible.
Together, these strategies illustrate a paradigm shift: cancer treatment is no longer about one therapy replacing another, but about leveraging the complementary strengths of biological tools to create smarter, more adaptive therapeutic systems. Oncolytic virotherapy, when intelligently combined with immune modulators and cell-based therapies, stands at the forefront of this new era of precision cancer immunotherapy.
