Interleukin-16
Synonym(s)
DefinitionThis section has been translated automatically.
Interleukins (from Latin/Greek inter = between; leukos = white; kinein = to move) are a group of endogenous, short-chain regulatory proteins (cytokines) of the immune system (IL1-IL38). Interleukins are mediators for induction, course and control of T-cell-mediated cytotoxic immune reactions as well as B-cell activation (antibody production). They are mainly formed and secreted by stimulated leukocytes, monocytes and macrophages. So far, about 38 different interleukins have been clearly identified. Each cytokine of the interleukin group is nomenclatically assigned a number for its classification (IL-1 to IL-38).
Interleukin-16 is a pleiotropic, growth-promoting cytokine that is primarily produced by T-cells that express the CD8 antigen. The cytokine acts as a chemoattractant, modulator of T cell activation, and inhibitor of HIV replication. The coding interleukin-16 gene is located on chromosome 15.
The release of interleukin-16 is stimulated by histamine. The cytokine is formed and secreted by mast cells, eosinophilic granulocytes, CD4+T cells and macrophages.
General informationThis section has been translated automatically.
The cytokine does not resemble any other member of a known cytokine family. Originally, Interleukin-16 was named "Lymphocyte chemoattractant factor (LCF)" after its skin ppt function.
Interleukin-16 is primarily formed as an 80 kDa precursor peptide (Pro-IL-16). This precursor peptide is cleaved by a proteolytic enzyme (caspase-3) into a 14 kDa monomer, which then aggregates to form the actual biologically active homotetramer. Interleukin-16 binds via CD4 (which thus also performs the function of a cytokine receptor).
Dormant CD4+ cells then resume their division activity and enter the G1 phase of the cell cycle. At the same time, it promotes the expression of the interleukin-2 receptor on T lymphocytes. As a result of this receptor expression, T cells proliferate after exposure to interleukin-2 and -16. Via T cell activation, interleukin-16 binds to monocytes, eosinophilic granulocytes and dendritic cells. Cells lacking CD4 cannot react to interleukin-16.
Clinical pictureThis section has been translated automatically.
Increases in interleukin-16 levels are observed in a number of aetiologically different diseases. Their significance remains to be seen.
IL-16 is elevated in both acute and chronic atopic eczema and can serve as a marker for disease activity.
Furthermore, increases in interleukin levels are found in ovarian cancer, obesity and multiple sclerosis.
Polymorphisms of the interleukin-16 gene lead to an increased risk of developing a glioma (genotype: rs11556218 T/G). Furthermore, polymorphisms of the gene have been detected in contact sensitizations.
Note(s)This section has been translated automatically.
Interleukin-16 plays an additive role in blocking the replication of the HIV virus in CD4+ lymphocytes. Its role in Crohn's disease, multiple sclerosis, and autoimmune thyroiditis still needs to be explained.
LiteratureThis section has been translated automatically.
- Baier M et al (1997) Molecular cloning, sequence, expression, and processing of the interleukin 16 precursor. Proc Natl Acad Sci U S A 94: 5273-5277.
Barua A et al (2015) Interleukin 16 (IL-16-) Targeted Ultrasound Imaging Agent Improves Detection of Ovarian Tumours in Laying Hens, a Preclinical Model ofSpontaneous
Ovarian Cancer. Biomed Res Int:210: 272 e1-e10- Cruikshank WW et al (1994) Molecular and functional analysis of a lymphocyte chemoattractant factor: association of biological function with CD4 expression". Proc. Natl. Acad. Sci. U.S.A. 91: 5109-5113.
Lichtenauer M et al.(2015) Elevated plasma levels of interleukin-12p40 and interleukin-16 in overweight adolescents Biomed Res Int 2015:940910.
Luo QS et al (2014) Interleukin-16 polymorphism is associated with an increased risk of glioma. Genet Test Mol Biomarkers 18:711-714.
Nischwitz S et al (2014) Interferon β-1a reduces increased interleukin-16 levels in multiple sclerosis patients. Acta Neurol Scand 130:46-52.
Tsai KH et al (2014) Association of interleukin-16 polymorphisms with graves' disease in a Taiwanese population. Chin J Physiol 57:69-75.
Yellapa A et al (2014) Interleukin 16 expression changes in association with ovarian malignant transformation. Am J Obstet Gynecol 210:272