The living body is exposed to various pathogens, yet its health is maintained through defense mechanisms that sense and eliminate pathogens such as the immune system or through coexistence mechanisms in the case of some pathogens. Pathogens act as a danger signal to the host. Pattern recognition receptors (PRRs) expressed in some immune cells immediately recognize the danger signal and trigger activation of the immune system1.
As mentioned above, inflammasomes play a critical role in the defense system against pathogens. Therefore, breakdown of this system will lead directly to the onset of disease. Mutations in NLRP3/cryopyrin (a member of the NLR family) cause excessive production of mature IL-1 in association with constitutive activation of inflammasomes and may result in the development of cryopyrin-associated periodic syndrome (CAPS), an autoinflammatory disease. Mutations in the pyrin domain of ASC or the NOD2 gene are detected in patients with familial Mediterranean fever or inflammatory colitis-associated Crohn’s disease. Many IL-1 family members function as inflammatory cytokines and their immunoreaction-inducing ability varies widely. As a matter of fact, the immunosuppressive activity of IL-37 has been reported. No reports are available on the physiological functions of other IL-1 family members. Future analysis will reveal their functions and significance. Further, inflammasomes modulate immunoreactions by (indirectly) recognizing substances (such as inorganic substance and metal salts) via unknown receptors. It is thus expected that use of this characteristic feature will enable the application not only to treatment of cancer and autoimmune diseases, but also to improvement of vaccine efficiency, via artificial compounds controlling inflammasomes activity.
Bronchial asthma and eosinophil
Eosinophil Cationic Protein (ECP), Eosinophil Derived Neurotoxin (EDN) and Major Basic Protein (MBP) are known to be major protein-mediators derived from activated eosinophils. Activated eosinophils play an important role in inflammatory processes, especially in allergic diseases. The level of eosinophil activation can serve as complimentary data for monitoring asthma inflammation.
- Matzinger P, The danger model: a renewed sense of self. Science, 296, 301-5 (2002) PMID:11951032
- Kawai T, Akira S, Toll-like receptors and their crosstalk with other innate receptors in infection and immunity. Immunity, 34, 637-50 (2011) PMID: 21616434
- Martinon F, Mayor A, and Tschopp J, The inflammasomes: guardians of the body. Annu. Rev. Immunol., 27, 229-65 (2009) PMID: 19302040