Inflammation underlies a wide variety of physiological and pathological processes. Although the pathological aspects of many types of inflammation are well appreciated, their physiological functions are mostly unknown. The classic instigators of inflammation - infection and tissue injury - are at one end of a large range of adverse conditions that induce inflammation, and they trigger the recruitment of leukocytes and plasma proteins to the affected tissue site. Tissue stress or malfunction similarly induces an adaptive response, which is referred to here as para-inflammation. This response relies mainly on tissue-resident macrophages and is intermediate between the basal homeostatic state and a classic inflammatory response. Para-inflammation is probably responsible for the chronic inflammatory conditions that are associated with modern human diseases.
Inflammation is triggered when innate immune cells detect infection or tissue injury. Pattern recognition receptors (PRRs) respond to pathogen-associated molecular patterns (PAMPs) or host-derived damage-associated molecular patterns (DAMPs) by triggering activation of NF-κB, AP1, CREB, c/EBP, and IRF transcription factors. Induction of genes encoding enzymes, chemokines, cytokines, adhesion molecules, and regulators of the extracellular matrix promotes the recruitment and activation of leukocytes. Besides resolving infection and injury, chronic inflammation is a risk factor for cancer.Immunity has a major impact on inflammatory diseases and cancer, and biologics targeting immune cells and their factors. Immunosuppressant drugs suppress, or reduce, the strength of the body’s immune system, and have been used in the treatment of organ transplantation or autoimmunine diseases. Immunomodulator drugs have contributed to the significant improvement against cancer and other related diseases.