Oncolytic virus-mediated infection and transgene expression in tumor cells

Oncolytic virus-mediated infection and transgene expression in tumor cells is a therapeutic modality that utilizes viruses to selectively infect and destroy malignant cells while sparing healthy tissue (Source: National Cancer Institute). These viruses, such as the FDA-approved talimogene laherparepvec (T-VEC), are often genetically modified to enhance their safety profile and tumor specificity by exploiting defective antiviral pathways or specific surface receptors in cancer cells (Source: FDA). The therapeutic effect is twofold: direct viral-mediated lysis of the tumor cell and the subsequent induction of a systemic anti-tumor immune response triggered by the release of antigens and inflammatory signals (Source: Nature Reviews Cancer). Furthermore, these viruses can serve as vectors for transgene expression, delivering therapeutic proteins like cytokines directly into the tumor microenvironment to overcome local immunosuppression. While this approach shows significant promise in treating 'cold' tumors, its efficacy can be hindered by the host's pre-existing immunity and the physical barriers within the tumor stroma. Monitoring viral load and immune cell infiltration is critical for assessing treatment response and managing potential safety risks like systemic inflammation or viral shedding.

Other names

Oncolytic virotherapyViral oncolysisOncolytic immunotherapyOV-mediated transgene deliveryOncolytic viral therapy

The mechanism involves the selective infection and replication of viruses within neoplastic cells, leading to direct cellular lysis (oncolysis) and the release of tumor-associated antigens (TAAs) and pathogen-associated molecular patterns (PAMPs). This process induces immunogenic cell death, which stimulates a systemic anti-tumor immune response. Additionally, engineered viruses can express therapeutic transgenes, such as granulocyte-macrophage colony-stimulating factor (GM-CSF), to further modulate the tumor microenvironment and enhance immune activation (Source: National Cancer Institute, Nature Reviews Cancer).