CYTOKINES (Interleukin)

Cytokines that regulate the inter

IL-1

• Source (major): MACROPHAGE

• plays critical role in inflammation (not restricted to it)

• key role in pyrexia, hematopoiesis, apetite control, bone metabolism, and acquired immunity

• Induces the production of PROSTAGLANDIN

IL-2

• Source: Th1 cells

• Target: T cells, B cells, and NK cells

• Activates Helper & Cytotoxic T cells and NK cells (responsiveness to IL-2 ← ← [antigen & IL-12 activate → T cells] & [Induce expression of both IL-2 and its receptor)

• Triggera Th1 proliferation & stimulates proliferation and cytotoxicity of Th1 cells

IL-3

• Sources: Activated Th1 & Th2 cells, NK cells, eosinophils and mast cells

• Stimulates growth and maturation of bone marrow stem cells (eosinophils, neutrophils, and monocytes)

• Stimulates mast cell and basophil differentiation and activation

• Activates eosinophils

• promotes macrophage cytotoxicity and phagocytosis

• Promotes Ig secretion by cells

IL-4

• Sources: Activated Th2 cells, mast cells, and activated basophils

• Targets: B cells, T cells, macrophages, endothelial cells, fibroblast & mast cells

• Stimulates growth and differentiation of B cells

• Impt. in the devt. of allergic reactions (inducing B cells to switch to IgE production