Human B-Cell Differentiation Antigen CD72 (CD72) Protein

Background

CD72 is a type II transmembrane glycoprotein belonging to the C-type lectin superfamily. It is mainly expressed on the surface of B cells, as well as some other immune cells such as dendritic cells. CD72 serves as a negative regulator of B cell receptor (BCR) signaling, modulating immune responses by attenuating excessive B cell activation and preventing autoimmunity. CD72 interacts with protein tyrosine phosphatases, including SHP-1 and SHP-2, through its immunoreceptor tyrosine-based inhibitory motif (ITIM) in the cytoplasmic domain. When activated, CD72 negatively regulates BCR signaling, contributing to the maintenance of immune tolerance and B cell homeostasis. Given its central role in B cell regulation, CD72 is involved in autoimmune diseases, chronic inflammatory conditions, and lymphomas.