Admin Table of Contents
- 1 What is the purpose of class switching?
- 2 What is the point of antibody class switching?
- 3 Why does class switch recombination occur?
- 4 What is aid in immunology?
- 5 Which cytokine is responsible for antibody class switching?
- 6 When does class switching occur anatomy?
- 7 What is the importance of somatic hypermutation?
- 8 Why is somatic hypermutation important?
What is the purpose of class switching?
Class switching is a process which takes place in B cells to alter the class of antibody produced during an immune response from IgM to one of the other classes.
What is the point of antibody class switching?
During class switching, the constant region of the immunoglobulin heavy chain changes but the variable regions, and therefore antigenic specificity, stay the same. This allows different daughter cells from the same activated B cell to produce antibodies of different isotypes or subtypes (e.g. IgG1, IgG2 etc.).
Why does class switch recombination occur?
Class switch recombination (CSR) occurs between switch (S) regions located upstream of each of the CH regions except Cδ and results in a change from IgM and IgD expression by naive B cells to expression of one of the downstream isotypes.
What is the result of class switch recombination?
Class-switch DNA recombination (CSR) results in the replacement of the expressed CH exon cluster — for example, Cμ for IgM — with Cγ, Cα or Cɛ, thereby giving rise, respectively, to IgG, IgA or IgE in which the antigen-binding variable region is unaltered6,7.
What is the difference between somatic hypermutation and class switching?
V(D)J recombination occurs in the bone marrow, whereas somatic hypermutation and class-switch recombination occur in the peripheral lymphoid tissues. Class-switch recombination alters the immunoglobulin heavy-chain (h) constant (C) region gene that will be expressed from the Cμ region to one of the other C h genes.
What is aid in immunology?
Activation-induced cytidine deaminase (AID), primarily expressed in activated mature B lymphocytes in germinal centers, is the key factor in adaptive immune response against foreign antigens.
Which cytokine is responsible for antibody class switching?
Two major cytokines, IL-4 and TGF-β, induce surface IgM-positive (sIgM+) B cells to switch to downstream isotypes, including IgE and IgA (Fig. 19.7). The addition of TGF-β1 to LPS-triggered mouse B-cell cultures can lead to increased IgA synthesis, an effect that can be enhanced by IL-2 or IL-5.
When does class switching occur anatomy?
The process of changing the class of antibody (immunoglobulin or Ig) to another is known as class switching. A secondary response occurs when a same antigen is encountered for the second time by a person’s body; it is known as a secondary response.
What is class switch recombination in B cells?
Class switch recombination is a process by which proliferating B cells rearrange the constant region genes in the immunoglobulin heavy chain locus to switch from expressing one class of immunoglobulin (such as IgM) to another (such as IgG).
Can plasma cells class switch?
This occurs within the first few days of exposure to a novel antigen. Then, once a week or more has gone by, germinal centers form in secondary lymphoid organs, resulting in the production of class-switched, affinity-matured memory cells and plasma cells.
What is the importance of somatic hypermutation?
A major component of the process of affinity maturation, SHM diversifies B cell receptors used to recognize foreign elements (antigens) and allows the immune system to adapt its response to new threats during the lifetime of an organism.
Why is somatic hypermutation important?
Somatic hypermutation is a process that is critical for the generation of B cells with affinity-matured B cell receptor (BCR). This process is most efficient when occurring as part of a T cell–dependent GC reaction (Allen et al., 2007).