IgH chain class switch recombination: mechanism and regulation

J Stavnezer, CE Schrader - The Journal of Immunology, 2014 - journals.aai.org
J Stavnezer, CE Schrader
The Journal of Immunology, 2014journals.aai.org
IgH class switching occurs rapidly after activation of mature naive B cells, resulting in a
switch from expression of IgM and IgD to expression of IgG, IgE, or IgA; this switch improves
the ability of Abs to remove the pathogen that induces the humoral immune response. Class
switching occurs by a deletional recombination between two switch regions, each of which is
associated with a H chain constant region gene. Class switch recombination (CSR) is
instigated by activation-induced cytidine deaminase, which converts cytosines in switch …
Abstract
IgH class switching occurs rapidly after activation of mature naive B cells, resulting in a switch from expression of IgM and IgD to expression of IgG, IgE, or IgA; this switch improves the ability of Abs to remove the pathogen that induces the humoral immune response. Class switching occurs by a deletional recombination between two switch regions, each of which is associated with a H chain constant region gene. Class switch recombination (CSR) is instigated by activation-induced cytidine deaminase, which converts cytosines in switch regions to uracils. The uracils are subsequently removed by two DNA-repair pathways, resulting in mutations, single-strand DNA breaks, and the double-strand breaks required for CSR. We discuss several aspects of CSR, including how CSR is induced, CSR in B cell progenitors, the roles of transcription and chromosomal looping in CSR, and the roles of certain DNA-repair enzymes in CSR.
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