Viruses are microscopic invaders that infect and reproduce inside cells. Some viruses target and infect cancer cells specifically, these viruses called oncolytic viruses (OVs) selectively replicate in and kill cancer cells, and spread within the tumor, while not harming normal tissue. Oncolytic viruses can be involved in tumor immunotherapies and thus improve the immune system to fight the cancer cells as they target multiple steps within cancer–immunity cycle (Bommareddy et al.,2018).
There are two main ways that oncolytic viruses help fight cancer. First. They kill cancer cells directly when they infect these cells and cause them to burst second when the cancer cells die they release tell-tale markers called antigens into the body these cancer antigens are taken up by cells of immune system which then alert the body to attack the cells the t cells to look for and kill cancer cells elsewhere in the body (Bommareddy et al.,2018).The goal of most immunotherapies is the activation of immune effectors, such as T cells and natural killer cells, as the presence of these active mediators reflects the results of the patient in a positive way(Lee et al.,2018). The efficacy of both immune and OV therapies can increase by combining the Oncolytic viruses that can replicate in cancer cells with immune modulators.
One example is the Combination of OVs with cytokines and chemokines, many viruses have been designed to express unique cytokines or chemokines. Cytokines and chemokines are appealing transgenes since they are encoded by small genes and it’s simple to work in a viral genome. In addition, they regularly have pleiotropic impacts, which implies they can target distinctive immune cells at the same time(De Graaf et al.,2018).
In conclusion, the overall effect of the oncolytic immune therapy depends on the interplay between virus, immune modulator, and tumor. Not only tumors develop over time, but the immune system as well. This means that every stage of immune activation should be considered while deciding on the incorporation of an immune modulator (De Graaf et al.,2018