REA675 recognizes the human CD19 antigen, a type I transmembrane glycoprotein of 95 kDa that belongs to the immunglobulin superfamily. CD19 is expressed on B cells throughout most stages of B cell differentiation, though its expression is down-regulated during their terminal differentiation to plasma cells. Expression of CD19 is also found in the majority of B cell–derived malignancies. CD19 is further present on follicular dendritic cells. On B cells, CD19 associates with CD21, CD81, and CD225 (Leu-13) forming a signal transduction complex.
Additional information: Clone REA675 displays negligible binding to Fc receptors.