CD44 antigen (CD44) (CD44)

The CD44 antigen is a versatile cell-surface glycoprotein that serves as the primary receptor for hyaluronic acid (HA), an essential component of the extracellular matrix. It plays a critical role in mediating cell-cell and cell-matrix interactions, which are vital for lymphocyte homing, hematopoiesis, and tissue remodeling. Beyond its structural roles, CD44 acts as a signaling platform, interacting with various ligands like osteopontin and collagens to activate pathways involving Rho GTPases and receptor tyrosine kinases such as EGFR. In disease, CD44 is extensively linked to cancer progression, where its over-expression on cancer stem cells facilitates tumor initiation, epithelial-mesenchymal transition, and metastasis. In addition to oncology, it is involved in chronic inflammatory conditions like rheumatoid arthritis and fibrosis by modulating immune cell recruitment. Therapeutic strategies targeting CD44 include monoclonal antibodies that block ligand binding, antibody-drug conjugates for targeted cytotoxicity, and HA-based nanocarriers designed for specific drug delivery to CD44-expressing cells.

Other names

HCAMPgp-1Hermes antigenLymphocyte homing receptorECMR-IIIHUTCH-IMC56MDU2MDU3MIC4Phagocytic glycoprotein-1Extracellular matrix receptor IIIGP90 lymphocyte homing/adhesion receptor

Competitive inhibition of hyaluronic acid binding; induction of receptor internalization; Fc-mediated phagocytosis of target cells; antibody-dependent cellular cytotoxicity (ADCC); targeted delivery of cytotoxic payloads via antibody-drug conjugates (ADCs); and carrier-mediated delivery using hyaluronic acid-drug conjugates.