B-cell antigen receptor complex-associated protein alpha (CD79A)

B-cell antigen receptor complex-associated protein alpha, also known as CD79A or Ig-alpha, is a vital component of the B-cell receptor (BCR) complex (UniProt P11912). It forms a disulfide-linked heterodimer with CD79B (Ig-beta), which non-covalently associates with membrane-bound immunoglobulin (mIg) molecules to facilitate signal transduction (NCBI Gene 973). CD79A contains an immunoreceptor tyrosine-based activation motif (ITAM) in its cytoplasmic domain, which is phosphorylated by Src-family kinases upon antigen binding, initiating downstream signaling pathways essential for B-cell development and survival (PubMed 25607555). Clinically, CD79A is a highly specific marker for B-lineage cells, making it a primary diagnostic tool for B-cell malignancies like B-cell acute lymphoblastic leukemia and various lymphomas (PubMed 10449296). While CD79B is the target of the approved drug polatuzumab vedotin, CD79A is being investigated as a target for novel CAR-T cell therapies and bispecific antibodies (PubMed 33619375). Mutations in the CD79A gene lead to autosomal recessive agammaglobulinemia, characterized by a failure of B-cell maturation (PubMed 17110948).

Other names

CD79aIg-alphaMB-1MB1IGASurface antigen B29

Targeted cell lysis via CAR-T or antibody-dependent cellular cytotoxicity (ADCC); inhibition of B-cell receptor signaling (PubMed 33619375, PubMed 31533937)