B-cell antigen receptor complex-associated protein beta chain (CD79B) (CD79B)

The B-cell antigen receptor complex-associated protein beta chain, commonly known as CD79B, is an essential transmembrane component of the B-cell receptor (BCR) complex. It forms a disulfide-linked heterodimer with the alpha chain (CD79A), which is required for the transport of the BCR to the cell surface and the initiation of intracellular signaling upon antigen binding (UniProt P40259). CD79B contains an Immunoreceptor Tyrosine-based Activation Motif (ITAM) that, when phosphorylated, recruits kinases like Syk to propagate signals for B-cell activation and survival (NIH Gene ID 974). Because CD79B is highly expressed on mature B-cells and many B-cell malignancies, it has become a significant therapeutic target for cancers such as diffuse large B-cell lymphoma (DLBCL) and chronic lymphocytic leukemia (StatPearls). The primary clinical intervention targeting CD79B is polatuzumab vedotin, an antibody-drug conjugate that induces cell death by delivering a potent antimitotic agent directly into malignant B-cells (FDA Label: Polivy). Mutations in the CD79B gene are also identified as drivers of chronic active BCR signaling in specific subtypes of lymphoma, making it both a diagnostic marker and a therapeutic vulnerability (PubMed: 20061626).

Other names

CD79BB-cell-specific glycoprotein B29B29IGBAGM6Immunoglobulin-associated B29 protein

Antibody-drug conjugate (ADC) targeting CD79B to deliver a cytotoxic agent (monomethyl auristatin E) into the cell through receptor-mediated internalization, leading to cell cycle arrest and apoptosis.