The new research - which is published in the journal Science Translational Medicine - shows how a modified poliovirus enables the body to use its own resources to fight off cancer. The modified virus bears the name of recombinant oncolytic poliovirus (PVS-RIPO). PVS-RIPO has been in clinical trials since 2011 and preliminary results have offered hope to patients with one of the most aggressive forms of brain tumor: recurrent glioblastoma. So, the researchers set out to investigate more deeply how exactly PVS-RIPO works. Explaining the rationale behind their research endeavor, Dr. Gromeier says, "Knowing the steps that occur to generate an immune response will enable us to rationally decide whether and what other therapies make sense in combination with poliovirus to improve patient survival." The researchers examined the behavior of the poliovirus in two human cell lines: melanoma and triple-negative breast cancer. They observed that the poliovirus attaches itself to cancerous cells. These cells have an excess of the CD155 protein, which acts as a receptor for the poliovirus. Then, the poliovirus starts to attack the malignant cells, triggering the release of antigens from the tumor. Antigens are toxic substances that the body does not recognize, therefore setting off an immune attack against them. So, when the tumor cells release antigens, this alerts the body's immune system to start attacking. At the same time, the poliovirus infects the dendritic cells and macrophages.