Integrin, alpha E (ITGAE) also known as CD103 (cluster of differentiation 103) is an
integrin
Integrins are transmembrane receptors that help cell–cell and cell–extracellular matrix (ECM) adhesion. Upon ligand binding, integrins activate signal transduction pathways that mediate cellular signals such as regulation of the cell cycle, o ...
protein that in human is encoded by the ''ITGAE''
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
.
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
CD49d is an integrin
Integrins are transmembrane receptors that help cell–cell and cell–extracellular matrix (ECM) adhesion. Upon ligand binding, integrins activate signal transduction pathways that mediate cellular signals such as regulat ...
).
Tissue distribution
CD103 is expressed widely on
intraepithelial lymphocyte Intraepithelial lymphocytes (IEL) are lymphocytes found in the epithelial layer of mammalian mucosal linings, such as the gastrointestinal (GI) tract and reproductive tract. However, unlike other T cells, IELs do not need priming. Upon encounterin ...
(IEL) T cells (both αβ T cells and
γδ T cells
Gamma delta T cells (γδ T cells) are T cells that have a γδ T-cell receptor (TCR) on their surface. Most T cells are αβ (alpha beta) T cells with TCR composed of two glycoprotein chains called α (alpha) and β (beta) TCR chains. In contrast, ...
) and on some peripheral
regulatory T cell
The regulatory T cells (Tregs or Treg cells), formerly known as suppressor T cells, are a subpopulation of T cells that modulate the immune system, maintain immune tolerance, tolerance to self-antigens, and prevent autoimmune disease. Treg ...
s (Tregs).
It has also been reported on
lamina propria
The lamina propria is a thin layer of connective tissue that forms part of the moist linings known as mucous membranes or mucosae, which line various tubes in the body, such as the respiratory tract, the gastrointestinal tract, and the urogenital ...
T cells.
A subset of
dendritic cells
A dendritic cell (DC) is an antigen-presenting cell (also known as an ''accessory cell'') of the mammalian immune system. A DC's main function is to process antigen material and present it on the cell surface to the T cells of the immune system ...
in the gut
mucosa
A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It ...
and
mesenteric lymph nodes
The superior mesenteric lymph nodes may be divided into three principal groups:
* mesenteric lymph nodes
* ileocolic lymph nodes
* mesocolic lymph nodes
Structure
Mesenteric lymph nodes
The mesenteric lymph nodes or mesenteric glands are one of ...
, known as CD103 dendritic cells, also expresses this marker.
It is useful in identifying
hairy cell leukemia
Hairy cell leukemia is an uncommon hematological malignancy characterized by an accumulation of abnormal B lymphocytes. The incidence of hairy cell leukemia (HCL) is 0.28-0.30 cases per 100,000 people in Europe and the United States and the pre ...
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.
Function
The chief ligand for αEβ7 is
E-cadherin
Cadherin-1 or Epithelial cadherin (E-cadherin), is a protein that in humans is encoded by the ''CDH1'' gene (not to be confused with the APC/C activator protein CDH1). Mutations are correlated with Hereditary diffuse gastric cancer, gastric, Here ...
, a cellular adhesion molecule (
CAM
Cam or CAM may refer to:
Science and technology
* Cam (mechanism), a mechanical linkage which translates motion
* Camshaft, a shaft with a cam
* Camera or webcam, a device that records images or video
In computing
* Computer-aided manufacturin ...
) found on
epithelial
Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial ( mesothelial) tissues line the outer surfaces of man ...
cells.
It is probably important for T cell homing to the intestinal sites
and thymocyte contacts with thymic reticuloepithelial cells.
Tregs are important for decreasing the immune response and appear to play a crucial role in the prevention of
autoimmune disease
An autoimmune disease is a condition that results from an anomalous response of the adaptive immune system, wherein it mistakenly targets and attacks healthy, functioning parts of the body as if they were foreign organisms. It is estimated tha ...
s. Tregs are defined as
CD4
In molecular biology, CD4 (cluster of differentiation 4) is a glycoprotein that serves as a co-receptor for the T-cell receptor (TCR). CD4 is found on the surface of immune cells such as helper T cells, monocytes, macrophages, and dendritic c ...
+/
CD25
The interleukin-2 receptor alpha chain (also called Tac antigen, P55, and mainly CD25) is a protein involved in the assembly of the high-affinity interleukin-2 receptor, consisting of alpha (''IL2RA''), beta ('' IL2RB'') and the common gamma cha ...
+/
Foxp3
FOXP3 (forkhead box P3), also known as scurfin, is a protein involved in immune system responses. A member of the FOX protein family, FOXP3 appears to function as a master regulator of the regulatory pathway in the development and function of r ...
+ cells.
Some CD4
+/FoxP3
− cells also express
CD103
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. CD103 binds integrin beta 7 (β7– ITGB7) to form the complete heterodimeric integrin molecul ...
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
*
Cluster of differentiation
The cluster of differentiation (also known as cluster of designation or classification determinant and often abbreviated as CD) is a protocol used for the identification and investigation of cell surface molecules providing targets for immunophe ...
*
Tissue-resident memory T cell
References
Further reading
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External links
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{{Integrins