[Chemokines in health and diseases]

A large number of lymphocytes are recruited to the sites of inflammation where they form an essential component for the response to infection, injury, autoimmune disorders, allergy, tumor invasion, atherosclerosis and so on. The recruitment of leukocytes into tissue is regulated by a sequence of interactions between the circulating leukocytes and the endothelial cells. Leukocyte integrins play a pivotal role in leukocyte adhesion to endothelial cells. During the process, the activation of integrins by chemokines is essential for integrin-mediated adhesion in which a signal transduced to the leukocyte converts the functionally inactive integrin to an active adhesive configuration. Such a regulation is most emphasized in inflammatory processes, in which leukocytes migrate from circulation into the tissue. The concept, concerning chemokines in diseases and health, would be an enormous help in clarifying pathological processes of inflammation as well as the new pharmacological approaches to more specifically control particular inflammation.