Cytokines are protein molecules that help regulate and direct the immune system. Cells release cytokines, which act as messengers to other cells, telling them when and where to launch an immune response. Various types of cytokines are naturally produced by the body. In cancer treatment, cytokines are synthesized in the lab and injected in larger doses than the body would normally produce. Two common cytokines are used in cancer immunotherapy:
Interleukin 2 (IL-2) is naturally produced by the body to help fight infection and prevent autoimmune diseases. In cancer treatment, IL-2 is designed to target adaptive immune cells, such as T-cells and B-cells, to respond to tumors. IL-2 may help the body produce antigen-fighting T-cells and stimulate B-cells to produce more antibodies.
Interferon-alpha (IFN-alpha) is one of several proteins that help the body fend off viruses and bacteria. In cancer treatment, IFN-alpha helps the body generate innate immune cells, such as dendritic cells and macrophages, that are designed to attack unhealthy cells.
Cytokines may stimulate the rapid growth of immune cells, and if left unchecked, they often produce severe side effects, such as depression, flu-like symptoms and profound fatigue. They have been approved to treat circulatory cancers, such as leukemia