IL-1
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Cytokines
Summary
Interleukin-1 (IL-1) is a cytokine primarily produced by macrophages that plays a major role in acute inflammation. By promoting vasodilation, capillary permeability, and activation of endothelial cells, IL-1 stimulates inflammation, which creates a hostile environment for pathogens and helps white blood cells reach sites of infection. IL-1 also acts indirectly on the hypothalamus to cause fever. Lastly, IL-1 promotes bone resorption by osteoclast activation, which plays an important role in the pathogenesis of osteolytic lesions in cancer.
Key Points
- IL-1 (interleukin-1)
- Secreted by Macrophages
- Also by cancer/neoplastic and some epithelial cells
- Actions
- Fever (pyrogen)
- Via production of PGE2, which acts on hypothalamic nuclei
- Stimulates inflammation
- Promotes vasodilation and capillary permeability
- Activates endothelium to express adhesion molecules
- Induces chemokine secretion to recruit WBCs
- Osteoclast-activating factor
- IL-1 promotes bone resorption leading to osteopenia
- Tumor production of IL-1 plays a role in creation of lytic (hole-punch) bone lesions in cancer
- Fever (pyrogen)
- Secreted by Macrophages