Immunotherapy is the “treatment of disease by inducing, enhancing, or suppressing an immune response”. Therefore, there are two types of immunotherapy: activation immunotherapy and suppression immunotherapy. This kind of therapy is the future of treatment of incurable diseases like cancers. Immunotherapy attempts to stimulate the immune system to destroy tumors. A variety of strategies is in use or are undergoing research and testing. Randomized controlled studies in different cancers demonstrated a significant increase in survival and disease free period particularly, when cell-based immunotherapy is combined with conventional treatment methods.
Cell-based immunotherapy, kind of immunotherapy, is effective for some cancers. Immune effector cells such as lymphocytes, macrophages, dendritic cells, natural killer cells (NK Cell), cytotoxic T-lymphocytes (CTL), etc., work together to defend the body against cancer by targeting abnormal antigens expressed on the surface of tumor cells. An example of cell-based immunotherapy is T-cell adoptive transfer that cultivates autologous, extracted T cells for later transfusion. The T cells may already target tumor cells. These T cells, referred to as tumor-infiltrating lymphocytes (TIL).
A variety of manipulation on immune system is possible thanks to the new information about signal transductions of the cells; therefore by inducing some cytokines or inhibiting some others, scientists are able to control many diseases. Moreover, immunomodulatory regimens often have fewer side effects than existing drugs like chemotherapeutic agents and less potential for creating resistance.