IgM (human) Monoclonal Antibody

Immunoglobulin M (IgM) is a member of the immunoglobulin superfamily of glycoproteins that plays a central role in the adaptive immune response and in mucosal immunology.{28520,53830} IgM consists of two light chains of approximately 25 kDa each, as well as two heavy chains of approximately 70 kDa each that contain C-terminal extensions, known as tailpieces, which allow for IgM oligomerization.{53830,53831} The heavy chains are linked together by disulfide bonds to form an Fc region and also combine with the light chains to form the Fab region, which mediate receptor and antigen binding, respectively.{55171} Five IgM proteins oligomerize via disulfide bonds in the presence of a 15-kDa joining chain, a process that is required for transcytosis of IgM from plasma cells to mucosal epithelial cells via the polyimmunoglobulin receptor (pIgR).{53830} Monomeric and oligomeric IgM are both ligands for the IgM and IgA-binding high affinity Ig? and the Ig? Fc receptor (Fc?/?-R) on dendritic cells, which mediates cellular uptake of IgM-conjugated antigens, and the IgM-binding Fc?-R on B and T cells, which is important for B cell maturation among other functions.{53830,53832,53833,53834} IgM is produced primarily in the plasma by naïve B cells and expressed in its monomeric low-affinity form on the cell surface.{28520} Activated B cells secrete pentameric high-affinity IgM, which opsonizes antigens to target them for removal by phagocytes and to activate complement via the classical pathway.{28520,53835} IgM antibodies are produced early in infection and have been used to determine exposure to a specific pathogen.{28520} IgM levels are elevated in hyper-IgM syndromes, which are characterized by dysfunctions in Ig class switching recombination.{53836} Cayman’s IgM (human) Monoclonal Antibody (Clone RM121) can be used for ELISA, immunocytochemistry (ICC), and immunohistochemistry (IHC) applications.