HLA-DR Antibody (L203) [FITC]

HLA-DR is a transmembrane human major histocompatibility complex 2 (MHC II) family member and consists of a 34 kDa (alpha) subunit and one of several 28 kDa (beta) subunits. HLA-DR is expressed primarily by B cells and dendritic cells (DC), in which it binds peptides derived from internalized and processed antigenic proteins. It presents these peptides on the cell surface for recognition by the T cell receptor on CD4⁺ T cells. This interaction is central to antigen specificity in the adaptive immune response. HLA-DR alleles, polymorphisms, and aberrant expression are linked to a variety of diseases including autoimmunity and cancer.