interleukin-1, a predominately macrophage-produced interleukin that mediates the host inflammatory response in innate immunity; two principal forms exist, designated α and β, with apparently identical biological activity. At low concentrations, IL-1 principally acts to mediate local inflammation, causing mononuclear phagocytes and endothelial cells to synthesize leukocyte-activating chemokines; at high concentrations IL-1 enters the blood stream and acts as an endocrine hormone, in some actions resembling tumor necrosis factor by its ability to cause fever, initiate hepatic synthesis of acute phase proteins, and induce cachexia.
interleukin-2, an interleukin produced by T cells in response to antigenic or mitogenic stimulation, acting to regulate the immune response. It stimulates the proliferation of T cells and the synthesis of other T cell–derived cytokines, stimulates the growth and cytolytic function of NK cells to produce lymphokine-activated killer cells, is a growth factor for and stimulates antibody synthesis in B cells, and may promote apoptosis in antigen-activated T cells. IL-2 is used as an anticancer drug in the treatment of a wide variety of solid malignant tumors. Formerly called T-cell growth factor.
interleukin-3, a lymphokine produced by antigen- or mitogen-activated T lymphocytes, which stimulates proliferation of hematopoietic as well as lymphoid stem cells; a colony-stimulating factor for all bone marrow progenitor cells. IL-3 supports the growth and differentiation of early hematopoietic and lymphoid stem cells as well as that of more mature hematopoietic cells, including granulocytes, macrophages, and mast cells.
interleukin-4, a lymphokine produced by antigen- or mitogen-activated T cells; its principal role is regulation of IgE- and eosinophil-mediated immune reactions. It stimulates switching of B cells for production of IgE, is a growth and differentiation factor for T cells, particularly TH2 cells, is a growth factor for mast cells, and stimulates the expression of some adhesion molecules on endothelial cells. Formerly called B lymphocyte stimulatory factor 1.
interleukin-5, a lymphokine produced by antigen- or mitogen-activated T cells and by activated mast cells that stimulates the growth and differentiation of eosinophils and activates mature eosinophils to kill helminths. It may act as a cofactor in the growth and differentiation of B cells and may also be involved in increasing synthesis of IgA by mature B cells.
interleukin-6, a lymphokine produced by antigen- or mitogen-activated T cells, fibroblasts, macrophages, and adipose and other cells that serves as a differentiation factor for B cells and thymocytes and stimulates immunoglobulin production by B cells; it also induces hepatocytes to synthesize various plasma proteins involved in the acute phase response and is a cofactor in initiation of the cell cycle in primitive hematopoietic cells in vitro.
interleukin-7, an interleukin produced by epithelial and mesangial stromal cells that serves as a differentiation factor for B cells in the early stages of their development and also supports the growth of some thymocytes and T lymphocytes.
interleukin-8, a chemokine produced by monocytes, endothelial cells, and other cells that acts as a chemotactic and activator for neutrophils and may play a role in the extravasation of neutrophils in inflammation.
interleukin-9, a cytokine produced by T cells and macrophages that acts as a growth factor for some T cell populations and bone marrow–mast cell progenitors.
interleukin-10, a cytokine produced by activated macrophages, certain lymphocytes, and other cells that decreases both innate and T cell–mediated immune inflammation; it inhibits the production of cytokines by activated T cells, plays a role in B cell activation, inhibits production of interferon-γ, and blocks antigen presentation and macrophage formation of IL-1, IL-6, and tumor necrosis factor.
interleukin-11, a cytokine produced by bone marrow stromal cells that stimulates megakaryocyte proliferation and B cell differentiation.
interleukin-12, a heterodimeric cytokine produced by phagocytic cells, B cells, and other antigen-presenting cell types; it is a potent inducer of cytokine production, causes T and NK cells to secrete interferon-γ, is a growth factor for preactivated T and NK cells, and enhances cytotoxic activity in CD8+ T cells and NK cells. It also has a role in the generation of T-helper type 1 cells and in the differentiation of cytotoxic T lymphocytes.
interleukin-13, a cytokine produced by activated T lymphocytes that has structural and functional similarities to IL-4; it inhibits inflammatory cytokine production by lipopolysaccharide in human peripheral blood monocytes and may be involved in promoting B cell division.
interleukin-14, a cytokine produced by T lymphocytes and malignant B lymphocytes that induces B cell proliferation and inhibits immunoglobulin secretion.
interleukin-15, a cytokine released by mononuclear phagocytes and some tissue cells in response to events triggering innate immunity; such as viral infection; its primary function appears to be promotion of NK cell proliferation

Readmore