Immune Netw.  2012 Dec;12(6):230-239. 10.4110/in.2012.12.6.230.

Activation-induced Cytidine Deaminase in B Cell Immunity and Cancers

• Park SR

• KMID: 2150754
• DOI: http://doi.org/10.4110/in.2012.12.6.230

Abstract

Activation-induced cytidine deaminase (AID) is an enzyme that is predominantly expressed in germinal center B cells and plays a pivotal role in immunoglobulin class switch recombination and somatic hypermutation for antibody (Ab) maturation. These two genetic processes endow Abs with protective functions against a multitude of antigens (pathogens) during humoral immune responses. In B cells, AID expression is regulated at the level of either transcriptional activation on AID gene loci or post-transcriptional suppression of AID mRNA. Furthermore, AID stabilization and targeting are determined by post-translational modifications and interactions with other cellular/nuclear factors. On the other hand, aberrant expression of AID causes B cell leukemias and lymphomas, including Burkitt's lymphoma caused by c-myc/IgH translocation. AID is also ectopically expressed in T cells and non-immune cells, and triggers point mutations in relevant DNA loci, resulting in tumorigenesis. Here, I review the recent literatures on the function of AID, regulation of AID expression, stability and targeting in B cells, and AID-related tumor formation.

Keyword

Activation-induced cytidine deaminase; B cell; Antibody; Cancer

MeSH Terms

B-Lymphocytes
Burkitt Lymphoma
Cell Transformation, Neoplastic
Cytidine
Cytidine Deaminase
DNA
Genetic Processes
Germinal Center
Hand
Immunity, Humoral
Immunoglobulins
Leukemia, B-Cell
Lymphoma
Point Mutation
Protein Processing, Post-Translational
Recombination, Genetic
RNA, Messenger
T-Lymphocytes
Transcriptional Activation
Cytidine
Cytidine Deaminase
DNA
Immunoglobulins
RNA, Messenger