Figure 1.

Mesenchymal stem cells, carriers for oncolytic viruses and beyond.

Notes: (A) The immune system interferes with the action of OV, reducing or eliminating their efficacy as anticancer agents. Independently, the tumor microenviroment inactivates the attack of the immune system. (B) MSCs enhance the oncolytic action of OV by protecting them from the immune system while delivering them at the tumor sites. In addition, MSCs may interfere with the mechanisms of immunosuppression developed by the tumor microenvironment, enabling an antitumor immune response. Solid lines indicate dominant action whereas dotted lines indicate impaired action. Colors identify each main character, ie, immune response (red), tumor (blue), and virotherapy (green).

Abbreviations: OV, oncolytic viruses; MSCs, mesenchymal stem cells.