Interleukin-8 (IL-8) is a chemokine produced by macrophages and other cell types such as epithelial cells. It is also synthesized by endothelial cells, which
store IL-8 in their storage vesicles, the Weibel-Palade bodies[1][2].
Toll-like receptors are the receptors of the innate immune system. These receptors
recognize antigen patterns (like LPS in gram negative bacteria). Through a chain of biochemical reactions IL-8 is secreted and is
a important mediator of the immune reaction in the innate immune system response.
The protein encoded by this gene is a member of the CXC chemokine family. This chemokine is one of the major mediators of the
inflammatory response. This chemokine is secreted by several cell types. It functions as a chemoattractant, and is also a potent
angiogenic factor. This gene is believed to play a role in the pathogenesis of bronchiolitis, a common respiratory tract disease
caused by viral infection. This gene and other ten members of the CXC chemokine gene family form a chemokine gene cluster in a
region mapped to chromosome 4q.[3]
It is also secreted in urinary tract infections.
Function
IL-8 can be secreted by any cells with toll-like receptors which are involved in
the innate immune response. IL-8's primary function is to recruit neutrophils to
phagocytose the antigen which trigger the antigen pattern toll-like receptors.
When first encountering an antigen, the primary cells to encounter it are the
macrophages who phagocytose the particle. Upon
processing, they release chemokines to signal other immune cells to come in to the site of
inflammation. IL-8 is one such chemokine. It serves as a chemical signal that attracts neutrophils at the site of inflammation, and therefore is
also known as Neutrophil Chemotactic Factor.
Clinical significance
If a pregnant mother has high levels of interleukin-8, she has a higher risk of inducing schizophrenia in her
offspring.[4] High levels of Interleukin 8 have been shown
to reduce the chance of good treatment responses to antipsychotic medication in schizophrenia.[5]
Interleukin-8 is often associated with inflammation.
Nomenclature
IL-8 was renamed CXCL8 by the Chemokine Nomenclature Subcommittee of the Nomenclature Committee of the International Union of
Immunological Societies, although its approved gene symbol remains IL8.
References
- ^ Wolff B, Burns AR, Middleton J, Rot A. Endothelial cell "memory" of
inflammatory stimulation: human venular endothelial cells store interleukin 8 in Weibel-Palade bodies. J Exp Med. 1998 Nov
2;188(9):1757-62. PMID 9802987
- ^ Utgaard JO, Jahnsen FL, Bakka A, Brandtzaeg P, Haraldsen G. Rapid secretion
of prestored interleukin 8 from Weibel-Palade bodies of microvascular endothelial cells. J Exp Med. 1998 Nov 2;188(9):1751-6.
PMID 9802986
- ^ Entrez Gene: IL8 interleukin 8.
- ^ Brown AS, Hooton J, Schaefer CA, Zhang H, Petkova E, Babulas V, Perrin M,
Gorman JM, Susser ES. Elevated maternal interleukin-8 levels and risk of schizophrenia in adult offspring. Am J Psychiatry. 2004
May;161(5):889-95. Abstract fulltext
- ^ Zhang XY, Zhou DF, Cao LY, Zhang PY, Wu GY, Shen YC. Changes in serum
interleukin-2, -6, and -8 levels before and during treatment with risperidone and haloperidol: relationship to outcome in
schizophrenia. J Clin Psychiatry. 2004 Jul;65(7):940-7.
Further reading
- Baggiolini M, Clark-Lewis I (1992). "Interleukin-8, a chemotactic and inflammatory
cytokine.". FEBS Lett. 307 (1): 97-101. PMID 1639201.
- Wahl SM, Greenwell-Wild T, Hale-Donze H, et al. (2000). "Permissive factors for HIV-1
infection of macrophages.". J. Leukoc. Biol. 68 (3): 303-10. PMID 10985244.
- Starckx S, Van den Steen PE, Wuyts A, et al. (2003). "Neutrophil gelatinase B and
chemokines in leukocytosis and stem cell mobilization.". Leuk. Lymphoma 43 (2): 233-41. PMID
11999552.
- Smirnova MG, Kiselev SL, Gnuchev NV, et al. (2003). "Role of the pro-inflammatory
cytokines tumor necrosis factor-alpha, interleukin-1 beta, interleukin-6 and interleukin-8 in the pathogenesis of the otitis
media with effusion.". Eur. Cytokine Netw. 13 (2): 161-72. PMID 12101072.
- Struyf S, Proost P, Van Damme J (2004). "Regulation of the immune response by the interaction
of chemokines and proteases.". Adv. Immunol. 81: 1-44. PMID 14711052.
- Chakravorty M, Ghosh A, Choudhury A, et al. (2004). "Ethnic differences in allele
distribution for the IL8 and IL1B genes in populations from eastern India.". Hum. Biol. 76 (1): 153-9. PMID
15222686.
- Yuan A, Chen JJ, Yao PL, Yang PC (2006). "The role of interleukin-8 in cancer cells and
microenvironment interaction.". Front. Biosci. 10: 853-65. PMID 15569594.
- Copeland KF (2006). "Modulation of HIV-1 transcription by cytokines and chemokines.". Mini
reviews in medicinal chemistry 5 (12): 1093-101. PMID 16375755.
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