Interleukin 16

Pro-interleukin-16 is a is_associated_with::protein that in humans is encoded by the IL16 is_associated_with::gene. This gene was discovered in 1982 at is_associated_with::Boston University by Dr. David Center and Dr. William Cruikshank.

Function
The protein encoded by this gene is a pleiotropic cytokine that functions as a chemoattractant, a modulator of T cell activation, and an inhibitor of HIV replication. The signaling process of this cytokine is mediated by CD4. The product of this gene undergoes proteolytic processing, which is found to yield two functional proteins. The cytokine function is exclusively attributed to the secreted C-terminal peptide, while the N-terminal product may play a role in cell cycle control. Caspase 3 is reported to be involved in the proteolytic processing of this protein. Two alternatively spliced transcript variants encoding distinct isoforms have been reported.

Interleukin 16 (IL-16) is a is_associated_with::cytokine that is released by a variety of cells (including is_associated_with::lymphocytes and some is_associated_with::epithelial cells) that has been characterized as a is_associated_with::chemoattractant for certain immune cells expressing the cell surface molecule is_associated_with::CD4.

IL-16 was originally described as a factor that could attract activated is_associated_with::T cells in humans, it was previously called lymphocyte chemoattractant factor (LCF). Since then, this interleukin has been shown to recruit and activate many other cells expressing the CD4 molecule, including is_associated_with::monocytes, is_associated_with::eosinophils, and is_associated_with::dendritic cells.

The structure of IL-16 was determined following its cloning in 1994. This cytokine is produced as a precursor peptide (pro-IL-16) that requires processing by an is_associated_with::enzyme called is_associated_with::caspase-3 to become active. CD4 is the is_associated_with::cell signaling receptor for mature IL-16.

Interactions
Interleukin 16 has been shown to interact with:
 * is_associated_with::GRIN2A,
 * is_associated_with::GRIN2D,
 * is_associated_with::KCNJ10,
 * is_associated_with::KCNJ15,
 * is_associated_with::Kir2.1,
 * is_associated_with::PPP1R12A, and
 * is_associated_with::PPP1R12B.