[Interleukins and inflammation].

Interleukins (IL) are a heterogeneous class of cytokines involved in activation of T lymphocytes (IL-1, 2, 4, 6 and 7), B lymphocytes (IL-1, 2, 4, 5, 6 and 7), and macrophages (IL-1 and 4), and hematopoiesis (IL-1, 2, 3, 4, 5, 6 and 7), acting either by themselves, or as co-stimulator factors. Interleukin-1 (IL-1 alpha and IL-1 beta) is induced by different signals including microbial products; it mediates various events occurring during inflammation (e.g. fever, osteolysis, leucopenia, hypotension, hyperalgia, etc...). Such mechanisms are often the consequences of the induction by IL-1 of lipid mediators (e.g. prostaglandins, platelet activating factor, etc). IL-1 often acts synergistically with Tumor Necrosis Factor during the pro-inflammatory process. IL-1 as well as microbial products induces the production of interleukin-6 and interleukin-8. IL-6 also plays a role in inflammation, mainly as an inducer of acute phase proteins synthesis by hepatocytes. IL-8 has chemotactic and activating properties for neutrophils.