Interleukin

Interleukins are cytokines that are made by one leukocyte, acting on other leukocytes).

Selected cytokines

Name(s)	Source	Target	Function
Il-1a, IL-1b	monocytes, macrophages, B-lymphocytes, DC	Th cells, B cells, NK cells, general inflammation-susceptible	Th cell co-stimulation, B-lymphocyte maturation and proliferation, NK cell activation, general inflammation
IL-2	Th1 cells	activated T- and B-lymphocytes, NK cells	growth, proliferation, activation
IL-3	Th cells, NK cells	stem cells, mast cells	stem cell growth and differentiation, mast cells growth and histamine release
IL-4	Th2 cells	activated B cells, macrophages, T cells	IgG1 and IgE synthesis ,macrophage MHC Class II, T cell growth, B cell growth
IL-5	Th2 cells	activated B cells	proliferation and differentiation, IgA synthesis
IL-6	monocytes, macrophages, T-helper subtype 2 lymphocytes (Th2 cells), stromal cells	activated B cells, plasma cells, stem cells,	differentiate B lymphocytes (B cells) into plasma cells, promotes immunoglobulin synthesis by B lymphocytes, plasma cell antibody secretion, stem cell differentiation, general acute phase response, increases hepcidin secretion
IL-7	marrow and thymus stroma	stem cells	differentiation
IL-8	macrophages and endothelial cells	neutrophils	chemotaxic attraction of neutrophils
IL-10	Th2 cells	macrophages, B-cells	downregulate cytokine production by macrophages, activate B-lymphocytes
IL-12	macrophages, B cells	activated Tc cells, natural killer cells	In combination with IL-2, differentiate Tc cells into CTL; activate NK
IL-13	TH2 cells		Similar to IL-4 }}</ref>