Interleukin 16 (IL16)

IL-16 is constitutively expressed by both CD4+ and CD8+ T cells. Airway epithelium from asthmatics, eosinophils, and mast cells also produce IL-16, albeit only after stimulation.
In lymphocytes, IL-16 is generated as a precursor molecule which is enzymatically cleaved following stimulation with T-cell mitogens. IL-16 is a proinflammatory and immunomodulatory cytokine.

It is a potent chemoattractant for all CD4+ cells including T cells, monocytes, and eosinophils and, as such, has been identified at inflammatory sites characterized by infiltrating CD4+ cells.In addition to cell motility, IL-16 induces cell cycle progression and cytokine synthesis in CD4+ T cells.