Inflammation results from activation of the immune system in response to a broad range of different stimuli. The immune system is a highly complex and evolutionary optimized defense system with cellular and humoral components. The course of an inflammatory response is influenced by the immune condition of the host, the virulence e. g. of an infectious agent, and the fine tuning of the local tissue reaction, which may be influenced by individual genetic factors. Immunity is a compromise between insufficient (immunodeficiency) or exaggerated (autoimmunity) immune reactions. The dynamic balance between these two extremes is achieved through stringent T- and B-cell selection in the bone marrow and thymus on the one hand and through "checkpoint control" in peripheral lymphatic tissues. Many tumors have ways to suppress local immune responses and to escape destruction through the immune system (one of the so-called "hallmarks of cancer"). In recent years, different approaches have successfully been able to reverse this local immunosuppression. First clinical trials using these strategies have shown highly promising results indicating that the therapeutic use of the immune system will be a very effective instrument in the arsenal of cancer treatment agents.
Keywords: B-cell; T-cell; antigen presentation; autoimmunity; checkpoint; immunodeficiency; immunsuppression; inhibitor; therapy; tumor.