Growth Factors & Cytokines

IL-16 is a CD8+ T cell-derived cytokine that induces chemotaxis of CD4+ T cells, CD4+ monocytes, and eosinophils.  Analysis by gel filtration suggests that, under physiological conditions, hIL-16 exists predominantly as a noncovalently linked multimer, but that some IL-16 may exist as a monomer.  However, only the multimeric form appears to possess chemotactic activity, suggesting that receptor cross-linking may be required for activity.  IL-16 also induces expression of IL-2 receptor (IL-2R) and MHC class II molecules on CD4 + T cells.  Human and murine IL-16 show significant cross-species reactivity.  Recombinant Human IL-16 is a 12.4 kDa protein consisting of 121 amino acid residues.