UMass Chan Medical School Faculty Publications


IgH chain class switch recombination: mechanism and regulation

UMMS Affiliation

Department of Microbiology and Physiological Systems

Publication Date


Document Type



Animals; B-Lymphocytes; Cytidine Deaminase; DNA Repair; Humans; *Immunoglobulin Class Switching; Immunoglobulin Heavy Chains; Lymphocyte Activation


Cellular and Molecular Physiology | Immunity


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.

DOI of Published Version



J Immunol. 2014 Dec 1;193(11):5370-8. doi: 10.4049/jimmunol.1401849. Link to article on publisher's site

Related Resources

Link to Article in PubMed

Journal/Book/Conference Title

Journal of immunology (Baltimore, Md. : 1950)

PubMed ID