Cytokine Network

Cytokine Network contains the extremely complex interactions of cytokines. The involved factors include interleukins, TNF, interferons, etc. Cytokine is a general name; other names are defined based on their presumed function, cell of secretion, or target of action. For example, cytokines made by lymphocytes can also be referred to as lymphokines, while interleukins are made by one leukocyte and act on other leukocytes. And chemokines are cytokines with chemotactic activities. Cytokine communication is often local, within a tissue or between cells in close proximity. These interactions often resemble cytokine cascades with one cytokine initially triggering the expression of one or more other cytokines that, in turn, trigger the expression of further factors and create complicated feedback regulatory circuits. Virtually all nucleated cells, but especially endo/epithelial cells and resident macrophages (many near the interface with the external environment) are potent producers of IL-1, IL-6, and TNF-α. Some cytokines, like IL-1, interferons and TNF, stimulate a broad inflammatory response in response to infection or injury. Other cytokines have more specific functions. IL-2 is a type I cytokine produced primarily by T helper cells. It is the major growth factor for T cells. It also promotes the growth of B cells and can activate NK cells and monocytes. IL-4 is produced by T cells and mast cells. It stimulates proliferation and differentiation of Th2 cells, while inhibit Th17 development. IL-4 also stimulates Ig class switching to the IgE isotype. IL-5 is a cytokine produced by Th2 cells. It functions to promote the growth and differentiation of B cells and eosinophiles. IL-8 is a chemokine, a chemotactic factor that attracts neutrophils, basophils and T cells to sites of inflammation. IL-10 is produced by activated macrophages, B cells, and T helper cells. It is predominantly an inhibitory cytokine. IL- 12 is produced by activated macrophages, B cells and dendritic cells. It induces the differentiation of Th cells to become Th1 cells and enhances the cytolytic functions of T cytotoxic cells and NK cells. Interferon-alpha and interferon-beta are cytokines produced by macrophages, dendritic cells, and many other cell types. They represent a large family of molecules that function to recruit leukocytes to sites of infection and play a role in lymphocyte trafficking.

Click gene symbol on the map to view ORF/cDNA clone.

Data source: KEGG, BioCarta