Fractalkine(CX3CL1) is a single-pass type I membrane protein and belongs to the intercrine delta family. It consists of an extracellular NH2-terminal domain, a mucin-like stalk, a transmembrane α helix, and a short cytoplasmic tail. CX3CL1 exists in two forms: as a membrane-anchored or as a shed 80-95K glycoprotein. Soluble CX3CL1 is generated by limited proteolysis on the cell surface, and a disintegrin and metallopeptidase 10 (ADAM10) and ADAM17 tumor necrosis factor-α-converting enzyme (ADAM17 TACE) participate in this shedding. It has been suggested that ADAM10 acts in the constitutive shedding, and ADAM17 acts in response to cell activation. The protein may play a role in regulating leukocyte adhesion and migration processes at the endothelium.
C-X-C motif ligand 10 (CXCL10), or interferon-inducible protein-10, is a small chemokine belonging to the CXC chemokine family. Its members are responsible for leukocyte trafficking and act on tissue cells, like endothelial and vascular smooth muscle cells. CXCL10 is secreted by leukocytes and tissue cells and functions as a chemoattractant, mainly for lymphocytes.