Development of an armed oncolytic herpes simplex virus type 1 for the treatment of glioblastoma

Glioblastoma (GBM) is the most common and aggressive form of brain tumor; nowadays, the prognosis of GBM patients is still poor and an urgent improvement of the current treatment options is needed. Among the different immunotherapeutic approaches, oncolytic virotherapy is demonstrating promising results in the field of cancer treatment. Oncolytic viruses are agents characterized by a tumor-specific replication and their therapeutic potential can be improved by the combination with other tumor treatments. In this thesis, we developed an innovative approach of targeted photodynamic virotherapy to treat glioblastoma, based on the combination of an oncolytic virus with photodynamic therapy. Specifically, we generated an oncolytic vector based on HSV-1 armed with KillerRed photosensitizer employing Lambda Red BAC mutagenesis approach. Upon reconstitution in HEK-293T cells, its replication ability was evaluated by infecting LN229 human glioblastoma cells. A comparative infection assay was performed in LN229 cells and Vero CCL81 cells to compare the replication potential of the newly generated oHSV-1 with its parental virus. Finally, KillerRed protein photoactivation was evaluated by irradiating infected glioblastoma cells and the consequent effect on cell viability was analyzed.