Biology:ITGAE

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A representation of the 3D structure of the protein myoglobin showing turquoise α-helices.
Generic protein structure example

Integrin, alpha E (ITGAE) also known as CD103 (cluster of differentiation 103) is an integrin protein that in human is encoded by the ITGAE gene.[1][2] CD103 binds integrin beta 7 (β7– ITGB7) to form the complete heterodimeric integrin molecule αEβ7, which has no distinct name. The αEβ7 complex is often referred to as "CD103" though this strictly refers only to the αE chain. Note that the β7 subunit can bind with other integrin α chains, such as α4 (CD49d).

Tissue distribution

CD103 is expressed widely on intraepithelial lymphocyte (IEL) T cells (both αβ T cells and γδ T cells) and on some peripheral regulatory T cells (Tregs).[3] It has also been reported on lamina propria T cells.[4] A subset of dendritic cells in the gut mucosa and mesenteric lymph nodes, known as CD103 dendritic cells, also expresses this marker.[5]

It is useful in identifying hairy cell leukemia which is positive for this marker in contrast to most other hematologic malignancies which are negative for CD103 except for hairy cell leukemia variant, a fraction of splenic marginal zone lymphomas, and enteropathy-associated T cell lymphoma.[6]

Function

The chief ligand for αEβ7 is E-cadherin, a cellular adhesion molecule (CAM) found on epithelial cells.[7] It is probably important for T cell homing to the intestinal sites[8] and thymocyte contacts with thymic reticuloepithelial cells.[9]

Tregs are important for decreasing the immune response and appear to play a crucial role in the prevention of autoimmune diseases. Tregs are defined as CD4+/CD25+/Foxp3+ cells.[10] Some CD4+/FoxP3 cells also express CD103 and have been attributed regulatory activity. It is unclear whether the presence of CD103 on Treg cells represents a specialized feature for Treg, or Treg differentiation of IEL T cells.

See also

References

  1. "Alpha E: no more rejection?". J. Exp. Med. 196 (7): 873–5. 2002. doi:10.1084/jem.20021404. PMID 12370249. 
  2. "Entrez Gene: integrin". https://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=3682. 
  3. "Expression of the integrin alpha Ebeta 7 identifies unique subsets of CD25+ as well as CD25- regulatory T cells". Proc. Natl. Acad. Sci. U.S.A. 99 (20): 13031–6. October 2002. doi:10.1073/pnas.192162899. PMID 12242333. Bibcode2002PNAS...9913031L. 
  4. "Replication of M-tropic HIV-1 in activated human intestinal lamina propria lymphocytes is the main reason for increased virus load in the intestinal mucosa". J. Acquir. Immune Defic. Syndr. 38 (1): 23–30. January 2005. doi:10.1097/00126334-200501010-00005. PMID 15608520. 
  5. "Functional specialization of gut CD103+ dendritic cells in the regulation of tissue-selective T cell homing". J. Exp. Med. 202 (8): 1063–73. October 2005. doi:10.1084/jem.20051100. PMID 16216890. 
  6. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues (World Health Organization Classification of Tumours) (4th ed.). Geneva: World Health Organization. 2008. ISBN 978-92-832-2431-0. 
  7. "The epithelial cell-specific integrin, CD103 (alpha E integrin), defines a novel subset of alloreactive CD8+ CTL". J. Immunol. 159 (8): 3748–56. October 1997. PMID 9378961. http://www.jimmunol.org/cgi/pmidlookup?view=long&pmid=9378961. 
  8. "T-lymphocyte-epithelial-cell interactions: integrin alpha(E)(CD103)beta(7), LEEP-CAM and chemokines". Curr. Opin. Cell Biol. 12 (5): 563–8. October 2000. doi:10.1016/S0955-0674(00)00132-0. PMID 10978890. 
  9. Kutleša, Snježana; Wessels, Johannes T.; Speiser, Angelika; Steiert, Inge; Müller, Claudia A.; Klein, Gerd (2002-12-01). "E-cadherin-mediated interactions of thymic epithelial cells with CD103+ thymocytes lead to enhanced thymocyte cell proliferation" (in en). Journal of Cell Science 115 (23): 4505–4515. doi:10.1242/jcs.00142. ISSN 1477-9137. PMID 12414996. https://journals.biologists.com/jcs/article/115/23/4505/27018/E-cadherin-mediated-interactions-of-thymic. 
  10. "Expression of CD103 identifies human regulatory T-cell subsets". J. Allergy Clin. Immunol. 118 (6): 1342–9. December 2006. doi:10.1016/j.jaci.2006.07.034. PMID 17137867. 

Further reading

External links