Immune inflammatory system

The glucocorticoids influence or regulate functions such as the immune response system, the regulation of glucose, fat and protein metabolism, and control of the anti-inflammatory response. Table 50-1 describes the activity of the glucocorticoids within the body. 

Most cytokines act upon, or are produced by, leukocytes (white blood cells), which constitute the immune and inflammatory systems (Box 8.1). They thus play a central role in regulating both immune and inflammatory function and in related processes such as haematopoiesis (the production of blood cells from haematopoietic stem cells in the adult bone marrow), as well as in wound healing. Indeed, several immunosuppressive and anti-inflammatory drugs are now known to induce their biological effects by regulating production of several cytokines. 

Cytokins Several extracellular signaling proteins interact with cells of the immune or inflammatory systems by activating or modulating the proliferative properties of these cells. Cytokines that induce inflammation are pro-inflammatory mediators, whereas antiinflammatory mediators reduce it. Chemokines are cytokines that bring about local inflammation by recruiting inflammatory cells by chemotaxis and subsequently activating them. TNFa, interleukins, GM-CSF... 

Sinee the initial finding that IFN-y secretion from activated T cells can induce indirect cytotoxicity by release of reactive species (later identified as NO and per-oxynitrite) from macrophages (Nathan et al. 1983 Nathan et al. 1984) an increasing amount of data on the role of NO in the immune and inflammatory systems have accumulated. NO has been shown to influence different immune functions both during innate and adaptive immune responses, including T-ceU activation and proliferation, cytokine production, APC expansion and maturation, central and peripheral tolerance, Th cell differentiation, as well as T-ceU apoptosis (Brito et al. 1999 MacMicking et al. 1997). 

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