IL-8（Interleukin-8）
is one of the first discovered chemokines and belongs to the CXCL family, in
which the first two conserved cysteines are separated by one residue. In vivo,
IL-8 exists in two forms: a 77-amino acid protein produced by endothelial cells,
and the more active 72- amino acid protein produced by monocytes. IL-8 is often
associated with inflammation, it has been cited as a proinflammatory mediator
in gingivitis and psoriasis. The functions of IL-8 are to induce rapid changes
in cell morphology, activate integrins, and release the granule contents of
neutrophils. Thus, IL-8 can enhance the antimicrobial actions of defense cells.
It is secreted by monocytes, macrophages and endothelial cells. IL-8 signals
through CXCR1 and CXCR2 to chemoattract neutrophils, basophils, and T cells.
IL-8 is also a potent promoter of angiogenesis.