AICDA

AICDA (Activation-Induced Cytidine Deaminase) is a gene that encodes an enzyme crucial for the adaptive immune response. This enzyme is primarily expressed in B cells and is essential for the processes of somatic hypermutation and class switch recombination, which are vital for the diversification of antibodies.

Function

AICDA is responsible for the deamination of cytidine to uridine in DNA, a process that introduces mutations in the immunoglobulin genes of B cells. This activity is central to somatic hypermutation, which increases the diversity of antibodies and enhances the ability of the immune system to recognize a wide array of antigens. Additionally, AICDA is involved in class switch recombination, a mechanism that changes the immunoglobulin class (or isotype) of an antibody, allowing it to mediate different immune functions.

Clinical Significance

Mutations in the AICDA gene can lead to Hyper-IgM syndrome, a condition characterized by elevated levels of IgM antibodies and a lack of other antibody classes. This results in increased susceptibility to infections. AICDA is also implicated in the development of certain lymphomas and autoimmune diseases, where its activity may lead to inappropriate mutations and chromosomal translocations.

Research and Applications

AICDA is a target of interest in cancer research and gene therapy. Understanding its role in antibody diversification has implications for vaccine development and the treatment of autoimmune diseases. Researchers are exploring ways to modulate AICDA activity to enhance immune responses or prevent pathological mutations.

Also see

• B cell
• Somatic hypermutation
• Class switch recombination
• Immunoglobulin
• Hyper-IgM syndrome