Cellular and molecular mechanisms of cytokine networking

A number of scientific investigations support the theory that the coordinate expression of cytokines are paramount to the successful initiation and maintenance of inflammation. Interleukin-1 and TNF appear particularly important in that these cytokines are important as both proximal and distal mediators of disease. The importance of IL-1 and TNF during early inflammatory events are exemplified via their ability to upregulate the expression of adherence proteins on the endothelium and allow inflammatory cells to bind to a localized area. In addition, these same cytokines can induce the expression of specific chemotactic cytokines from non-immune cells by a cascade effect known as cytokine networking. This interaction essentially transforms a bystander or target cell of the inflammatory response into an effector cell. Once the appropriate inflammatory cell has arrived at an inflammatory site, cytokines continue to be expressed and exert their influence by organizing the local immune response. Finally, the appropriate endogenous suppressive factors are expressed that initiate the resolution process. Thus, cytokines are effective transmitters of intracellular information that is crucial to each phase of an inflammatory reaction.