What is J chain in antibody?

The joining (J) chain is a small polypeptide, expressed by mucosal and glandular plasma cells, which regulates polymer formation of immunoglobulin (Ig)A and IgM. J-chain incorporation into polymeric IgA (pIgA, mainly dimers) and pentameric IgM endows these antibodies with several salient features.

What is the purpose of the J chain?

The J chain has a crucial role in the generation of secretory antibodies because it provides pIgA as well as pentameric IgM with the capacity to bind the polymeric immunoglobulin receptor (pIgR), and it regulates the pIg structure.

Which immunoglobulin has AJ chain?

A J chain is a protein component of the antibodies IgM and IgA.

Do cytokines contain J chain?

Transcriptional regulation of the J-chain gene involving cytokines such as interleukin (IL)-2, IL-4, IL-5, and IL-6 has been described in mice, and both positive and negative regulatory elements appear to be present in the promoter region (Tigges et al., 1989; Takayasu and Brooks, 1991; Randall et al., 1992; Shin and …

How many J chains are there in IgM?

Although it is generally believed that pentameric IgM and dimeric IgA contain one J chain per polymeric molecule, Brandtzaeg (20) have reported two J chains for IgA and three or four J chains for IgM.

Can IgG exist as a dimer?

An IgG dimer is the smallest possible immune complex (containing two IgG molecules) and therefore the least effective in cross-linking multiple Fc receptor molecules.

Where is IgG found?

IgG is the main type of antibody found in blood and extracellular fluid, allowing it to control infection of body tissues. By binding many kinds of pathogens such as viruses, bacteria, and fungi, IgG protects the body from infection.

Does IgM have J chain?

The J chain is a part of the polymeric immunoglobulin molecules IgM and IgA. It is generally assumed that the J chain participates somehow in the polymerization of these molecules (Koshland, 1985). If B lymphocytes express high levels of J chain, the secreted IgM molecules are mostly pentamers.

Does IgG have J chain?

Previous studies have demonstrated that J chain is expressed not only in cells that produce polymeric immunoglobulins, but also in those engaged in synthesis of monomers including IgG and IgD. The presence of J chain in these cells suggested that its role may not be restricted to the formation of polymers.

Does IgG contain J chain?

What are the 5 antibody isotypes?

There are 5 types of heavy chain constant regions in antibodies (immunoglobulin) and according to these types, they are classified into IgG, IgM, IgA, IgD, and IgE. They are distributed and function differently in the body.