ITGAE

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).^[7] It has also been reported on lamina propria T cells.^[8] A subset of dendritic cells in the gut mucosa and mesenteric lymph nodes, known as CD103 dendritic cells, also expresses this marker.^[9]

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.^[10]

The chief ligand for αEβ7 is E-cadherin, a cellular adhesion molecule (CAM) found on epithelial cells.^[11] It is probably important for T cell homing to the intestinal sites^[12] and thymocyte contacts with thymic reticuloepithelial cells.^[13]

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.^[14] 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.

• Cluster of differentiation
• Tissue-resident memory T cell

• ITGAE+protein,+human at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
• ITGAE Info with links in the Cell Migration Gateway Archived 2014-12-11 at the Wayback Machine