How do oncolytic viruses target cancer cells in immunotherapy?

Oncolysis is the destruction of tumor cells. Oncolytic viruses are selectively derived via targeting and destroying cancer cells by releasing infectious particles which replicate the virus in cancer cells without damaging healthy cells and tissue. Several oncolytic viruses including myxoma poxvirus, NDV paramyxovirus, and SVV picornavirus prefer cancer cells over normal cells due to their dependence on tumor signaling pathways for replication.¹ Vaccines often use genetically modified oncolytic viruses such as measles paramyxovirus and poliovirus picornavirus as vaccine vectors. Furthermore, genetic engineering has harnessed the potential of pathogenic viruses like adenovirus and herpes simplex virus (HSV) for efficiently targeting gene therapy in cells that require them. Oncolytic viruses can be specifically targeted to tumors by modifying the viral coat proteins so that adaptive and innate immune responses can be activated. Virus infections initiate an inflammatory response in these tumor cells and help reduce anti-tumor immunity. Since oncolytic viruses can target multiple oncogenic pathways, they can be used as a highly efficient immunotherapy against various types of cancer without raising concerns about pathogenic side effects or toxicity. Also compared to classical drugs, the virus dose in tumors increases with time due to virus replication. For additional information on immunotherapy please visit our resource center.

Reference:
1. E.A. Chiocca and S.D. Rabkin, "Oncolytic Viruses and Their Application to Cancer Immunotherapy," Cancer Immunol Res 2(4) 295-300, 2014.