Integrin alpha-4 (CD49d) (CD49d)

Integrin alpha-4 (CD49d) is a transmembrane glycoprotein that functions as a component of the heterodimeric integrin receptors, particularly α4β1 (VLA-4) and α4β7, which are central to leukocyte adhesion, migration, and immune surveillance[1][2][3]. CD49d binds to extracellular matrix molecules such as fibronectin, as well as to endothelial cell-surface molecules like VCAM-1 and MAdCAM-1, playing a critical role in directing lymphocyte homing and trafficking into inflamed tissues[1][2]. It is targeted therapeutically in several autoimmune and inflammatory conditions, most notably by drugs such as natalizumab, which block its function to prevent pathological leukocyte migration[2][3]. CD49d is used as a cell-surface marker in flow cytometry for certain hematological malignancies and as a predictive/prognostic biomarker in specific clinical contexts. Safety concerns for integrin alpha-4 blockade include an increased risk of opportunistic infections and PML due to impaired immune cell migration to the central nervous system[1][2].

Other names

Integrin alpha-4ITGA4VLA-4 alpha subunitCD49d

Inhibition of integrin-mediated cell adhesion Blockade of leukocyte migration across the blood-brain barrier or gut endothelium