CD79ACD79B

CD79ACD79B is not a standard name for a single gene or protein in major public databases. It is sometimes used informally as a shorthand to refer collectively to the CD79A and CD79B components of the B cell receptor (BCR) signaling complex. As such, it does not represent a distinct molecular entity, but rather a way to discuss the pairing of these two subunits.

CD79A (Igα) and CD79B (Igβ) are transmembrane proteins that associate with membrane-bound immunoglobulin to form the BCR signaling complex. Each protein contains an immunoreceptor tyrosine-based activation motif (ITAM) in its cytoplasmic tail, which becomes phosphorylated upon receptor engagement, enabling downstream signaling.

When an antigen binds the BCR, Src family kinases phosphorylate the ITAMs, recruiting Syk kinase and activating signaling cascades that converge on pathways such as NF-κB, MAPK, and PI3K. This signaling drives B cell activation, proliferation, antibody production, and differentiation.

Expression of CD79A and CD79B is largely restricted to B-lineage cells, spanning from early development through mature B cells. In plasma cells, expression can be reduced, and certain B cell malignancies exhibit altered CD79A/CD79B expression or mutations, which can impact signaling dynamics and therapeutic responses.

Clinical relevance includes the targeting of CD79B by antibody-drug conjugates such as polatuzumab vedotin, used in combination regimens for relapsed or refractory B cell lymphomas. The CD79A/CD79B axis remains an area of ongoing research for understanding BCR signaling mechanisms and their roles in health and disease.