CD103 Unconjugated

CD103, also known as αE integrin or human mucosal lymphocyte antigen 1, is a type I transmembrane glycoprotein belonging to the integrin family. It is primarily expressed on intestinal intraepithelial lymphocytes (IELs), as well as a subset of lamina propria T cells, epithelial and lamina propria-derived dendritic cells, and a small population of peripheral lymphocytes. Regulatory T cells (Tregs) also exhibit high levels of CD103 expression. Additionally, CD103 is a marker for hairy cell leukemia and can be induced on lymphocytes upon activation and TGF-β stimulation. CD103 forms a heterodimer with integrin β7 (αE/β7) and plays a crucial role in mediating lymphocyte adhesion by binding to E-cadherin, facilitating homing to the intestinal epithelium. The mature protein undergoes cleavage, yielding a 150 kDa C-terminal chain and a 25 kDa N-terminal chain, linked by disulfide bonds. It reacts with most T cells in the oral and bronchial mucosa and is found in CD8+CD103+ cytolytic T lymphocytes, which are involved in graft rejection by attacking transplanted epithelial cells.