CD74 antigen (invariant chain of major histocompatibility complex, class II antigen-associated) (CD74)

CD74 antigen, also known as the invariant chain, is a type II transmembrane glycoprotein that associates with MHC class II molecules and directs their intracellular transport, folding, and assembly, ensuring correct antigen presentation to CD4+ T cells. CD74 blocks premature peptide loading by occupying the binding cleft, and its regulated digestion results in a controlled exchange of peptides in endosomes. CD74 also acts as a receptor for the cytokine macrophage migration inhibitory factor (MIF), mediating signal transduction pathways important for cell survival, inflammation, and carcinogenesis. Its expression on cell surfaces is associated with chronic inflammatory conditions and cancers, making it a therapeutic target in inflammatory diseases and certain lymphomas.

Other names

HLA class II histocompatibility antigen gamma chainHLA-DR antigens-associated invariant chainCluster of Differentiation 74invariant chain (Ii)Ia-associated invariant chainmajor histocompatibility complex, class II invariant chainCD74 molecule

Blockade of CD74 inhibits MIF signaling, reduces chronic inflammation, and impairs malignant cell survival/proliferation Targeting CD74 disrupts antigen presentation pathways critical for immune activation