The immunogenicity of therapeutic cytokines

Therapeutic cytokines that modulate immune responses are designed to enhance host defense to combat tumors and chronic infections. In general, cytokines are pleiotropic molecules and mediate both systemic and local immune activities. Therapeutic recombinant human cytokines currently in clinical use include interferons (IFN alpha, IFN beta and IFN gamma), interleukins (IL-2 and IL-12) and hematopoietic factors such as granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, erythropoietin and thrombopoietin. Their use as therapeutic agents has been challenging since the safety and efficacy of these products are complicated by immunogenicity issues.