What is the main purpose of somatic hypermutation in B cells?

Somatic hypermutation is a process that allows B cells to mutate the genes that they use to produce antibodies. This enables the B cells to produce antibodies that are better able to bind to bacteria, viruses and other infections.

Do B cells undergo somatic recombination?

There are also individual gene segments in the DNA for each heavy chain domain and membrane region of each isotype, arranged in the order in which they are expressed by B cells. Somatic recombination occurs prior to antigen contact, during B cell development in the bone marrow.

What is somatic cell recombination?

Somatic recombination, as opposed to the genetic recombination that occurs in meiosis, is an alteration of the DNA of a somatic cell that is inherited by its daughter cells. In neurons of the human brain, somatic recombination occurs in the gene that encodes the amyloid precursor protein APP.

What is somatic mutation in B cells?

Somatic hypermutation involves a programmed process of mutation affecting the variable regions of immunoglobulin genes. Unlike germline mutation, SHM affects only an organism’s individual immune cells, and the mutations are not transmitted to the organism’s offspring.

Why is somatic recombination necessary for B cells and T cells?

The cells of the adaptive immune system attack foreign pathogens by producing proteins, such as antibodies, that use a lock-and-key mechanism to recognize pathogenic antigens, or molecules that can elicit an immune response (Figure 1). The answer is found in the process of somatic recombination. …

What is the significance of somatic hypermutation in antibody diversity?

Most antibodies that express germ-line sequences are of relatively low affinity. Once antigen enters the system, it stimulates a somatic mutational mechanism that generates antibodies of higher affinity and selects for the expression of those antibodies to produce a more effective immune response.

What is somatic recombination that takes place during lymphocytes development?

V(D)J recombination is the mechanism of somatic recombination that occurs only in developing lymphocytes during the early stages of T and B cell maturation. It results in the highly diverse repertoire of antibodies/immunoglobulins and T cell receptors (TCRs) found in B cells and T cells, respectively.

How somatic hypermutation is different from somatic recombination?

The key difference between somatic hypermutation and V(D)J recombination is that somatic hypermutation is a process that allows B cells to mutate their genes to produce high-affinity antibodies, while V(D)J recombination is a process of somatic recombination that happens during the lymphocyte development in order to …

At which stage of B cell development does somatic recombination occur?

What is somatic hypermutation in immunology?

Somatic hypermutation is a process in which point mutations accumulate in the antibody V-regions of both the heavy and light chains, at rates that are about 106-fold higher than the background mutation rates observed in other genes (Figure 1).

What is B cell gene rearrangement?

B-cell immunoglobulin gene rearrangement tests are used to help diagnose non-Hodgkin B-cell lymphomas and evaluate for residual or recurrent disease after treatment. There are many different types of B-cell lymphoma and each has different characteristics, prognoses, and a likely response to therapy.

Where does B cell isotype switching occur?

Repetitive areas of DNA known as ‘switch regions’ are found in the introns upstream of each isotype gene, which is used to guide AID and other enzymes to the site.