immunoglobulin-D (IgD)

Function

• IgD is the major antigen receptor isotype on the surface of most peripheral B cells, where it is coexpressed with IgM
• membrane-bound IgD (mIgD) induces phosphorylation of CD79A & CD79B by the Src family of protein tyrosine kinases
• soluble IgD (sIgD) concentration in serum is below those of IgG, IgA, & IgM but much higher than that of IgE
• IgM & IgD molecules present on B cells have identical V regions & antigen-binding sites
• after the antigen binds to the B cell receptor, the secreted form sIgD is shut off
• IgD is a potent inducer of TNF, IL1B, & IL1RN
• IgD also induces release of IL6, IL10, & LIF from monocytes
• kappa light chains are found predominantly on the membrane IgD (mIgD) form & lambda on the secreted IgD (sIgD) form
• membrane-bound IgD molecules are non-covalently associated with a heterodimer of CD79A & CD79B
• associates with/activates blk, lyn, fyn, hck, & lck & Syk

More general terms

• cell surface immunoglobulin
• adhesion receptor

Additional terms

• IgD in serum

Component of

• B-cell antigen receptor (BCR)