The recruitment of activation induced cytidine deaminase to the immunoglobulin locus by a regulatory element

2010 ◽  
Vol 47 (9) ◽  
pp. 1860-1865 ◽  
Author(s):  
Yonghwan Kim ◽  
Ming Tian
Keyword(s):  
Cytidine Deaminase ◽  
Regulatory Element ◽  
Activation Induced Cytidine Deaminase ◽  
Immunoglobulin Locus

AID constrains germinal center size by rendering B cells susceptible to apoptosis

Blood ◽  
2009 ◽  
Vol 114 (3) ◽  
pp. 547-554 ◽  
Author(s):  
Ahmad Zaheen ◽  
Bryant Boulianne ◽  
Jahan-Yar Parsa ◽  
Shaliny Ramachandran ◽  
Jennifer L. Gommerman ◽  
...  
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Germinal Center ◽  
Cytidine Deaminase ◽  
Enzyme Activation ◽  
Specific Enzyme ◽  
Tissue Microenvironment ◽  
Activation Induced Cytidine Deaminase ◽  
Immunoglobulin Locus

Abstract The germinal center (GC) is a transient lymphoid tissue microenvironment that fosters T cell–dependent humoral immunity. Within the GC, the B cell–specific enzyme, activation-induced cytidine deaminase (AID), mutates the immunoglobulin locus, thereby altering binding affinity for antigen. In the absence of AID, larger GC structures are observed in both humans and mice, but the reason for this phenomenon is unclear. Because significant apoptosis occurs within the GC niche to cull cells that have acquired nonproductive mutations, we have examined whether a defect in apoptosis could account for the larger GC structures in the absence of AID. In this report, we reveal significantly reduced death of B cells in AID−/− mice as well as in B cells derived from AID−/− bone marrow in mixed bone marrow chimeric mice. Furthermore, AID-expressing B cells show decreased proliferation and survival compared with AID−/− B cells, indicating an AID-mediated effect on cellular viability. The GC is an etiologic site for B-cell autoimmunity and lymphomagenesis, both of which have been linked to aberrant AID activity. We report a link between AID-induced DNA damage and B-cell apoptosis that has implications for the development of B-cell disorders.

scholarly journals Upregulated Expression of Activation-Induced Cytidine Deaminase in Ocular Adnexal Marginal Zone Lymphoma with IgG4-Positive Cells

2021 ◽  
Vol 22 (8) ◽  
pp. 4083
Author(s):  
Asami Nishikori ◽  
Yoshito Nishimura ◽  
Rei Shibata ◽  
Koh-ichi Ohshima ◽  
Yuka Gion ◽  
...  
Keyword(s):  
Marginal Zone ◽  
Somatic Hypermutation ◽  
Cytidine Deaminase ◽  
Marginal Zone Lymphoma ◽  
Immunoglobulin G4 ◽  
Intensity Index ◽  
Activation Induced Cytidine Deaminase ◽  
Systemic Disorder ◽  
Lymphoplasmacytic Infiltration ◽  
Ophthalmic Disease

Immunoglobulin G4-related disease (IgG4-RD) is a systemic disorder characterized by tissue fibrosis and intense lymphoplasmacytic infiltration, causing progressive organ dysfunction. Activation-induced cytidine deaminase (AID), a deaminase normally expressed in activated B-cells in germinal centers, edits ribonucleotides to induce somatic hypermutation and class switching of immunoglobulin. While AID expression is strictly controlled under physiological conditions, chronic inflammation has been noted to induce its upregulation to propel oncogenesis. We examined AID expression in IgG4-related ophthalmic disease (IgG4-ROD; n = 16), marginal zone lymphoma with IgG4-positive cells (IgG4+ MZL; n = 11), and marginal zone lymphoma without IgG4-positive cells (IgG4- MZL; n = 12) of ocular adnexa using immunohistochemical staining. Immunohistochemistry revealed significantly higher AID-intensity index in IgG4-ROD and IgG4+ MZL than IgG4- MZL (p < 0.001 and = 0.001, respectively). The present results suggest that IgG4-RD has several specific causes of AID up-regulation in addition to inflammation, and AID may be a driver of oncogenesis in IgG4-ROD to IgG4+ MZL.

Sign in / Sign up

Export Citation Format

Share Document