Cytokines in Relation to Inflammatory Skin Disease

Cytokines are soluble, non-antibody proteins that orchestrate many immunological reactions including cell-mediated immune responses; lymphocyte activation, proliferation and differentiation; and haemopoietic mechanisms. The term encompasses the mediators derived from activated T-lymphocytes, i.e. lymphokines (LKs) (DUMONDE et al. 1969); monocytes/macrophages, i.e. monokines (MKs) (WAKSMAN and NAMBA 1976); and those mediators whose cellular origin is known to be more diverse, e.g. interferons. All cytokines were originally described in terms of their biological activity(ies) with little knowledge of their chemical structure. From the application of more precise biological assays, immunoassays, and more sensitive biochemical techniques, it became apparent that different lymphokine or cytokine activities could actually be mediated by the same molecule(s). Consequently, at the 2nd International Workshop on Lymphokines in 1979, the generic term “interleukin” (“between leucocytes”) was introduced to bring together some of these mediators (AARDEN et al. 1979). Historically, the concept of special mediators of immunological regulation, rather than direct cellular or anti-body-mediated mechanisms, evolved from studies of delayed-type hypersensitivity and inflammation, and has been extensively documented (ADELMAN et al. 1979; ROCKLIN et al. 1980; WATSON 1981; HANSON et al. 1982; DUMONDE and HAMBLIN 1983).