Table of Contents
How do antibodies switch isotypes?
Class switching occurs by a mechanism called class switch recombination (CSR) binding. Class switch recombination is a biological mechanism that allows the class of antibody produced by an activated B cell to change during a process known as isotype or class switching.
What induces isotype switching?
Isotype switching is preceded by transcriptional activation of the isotype in question (Chapter 4). 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.
How does IgM change to IgG?
Antibody-producing cells undergo a process of differentiation and class switch recombination (CSR) such that the antibodies produced start as immunoglobulin M (IgM) and then switch to IgG and IgA as the concentration of antigen changes and as the cells differentiate.
What is class switching recombination?
Definition. 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).
What is the importance of class switching?
Ig heavy chain class switching occurs rapidly after activation of mature naïve B cells, resulting in a switch from expressing IgM and IgD to expression of IgG, IgE, or IgA; this switch improves the ability of antibodies to remove the pathogen that induces the humoral immune response.
What determines the class of an antibody?
An antibody class is determined by the heavy chain of the antibody. Changes in this region by class switching will, therefore, alter the functional abilities of the antibody without altering the specificity of the paratope.
What is the purpose of the class switch?
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.
Which class of antibody is found in mucus?
IgA is the main class of antibody found in many body secretions, including tears, saliva, respiratory and intestinal secretions, and colostrum (the first milk produced by lactating mothers). Very little IgA is present in the serum. IgA is produced by B cells located in the mucous membranes of the body.