Adenosine deaminase 2 (ADA2)

Adenosine deaminase 2 (ADA2) is an extracellular enzyme that converts adenosine and 2'-deoxyadenosine to inosine, influencing purine metabolism and immune responses[1][3]. ADA2 is secreted predominantly by antigen-presenting cells and its activity regulates macrophage differentiation, balances pro- and anti-inflammatory macrophage populations, and stimulates monocyte-dependent CD4^+^ T cell proliferation independently of its enzymatic function[1][2]. Genetic deficiency of ADA2 leads to abnormal inflammation, particularly affecting the blood vessels (vasculitis), and is characterized by increased pro-inflammatory macrophage activity and immune system abnormalities. ADA2 structure reveals several domains unique to the ADGF family, essential for its growth factor function and dimerization. Unlike ADA1, which is intracellular, ADA2 acts in the extracellular space and participates directly in cell surface receptor interactions and extracellular signaling[1][3][4]. Therapeutically, ADA2 is an emerging target in rare immunological diseases, lymphoproliferative disorders, and infection, but current drugs lack ADA2-specificity, posing safety challenges[3].

Other names

Adenosine deaminase CECR1ADGF (Adenosine deaminase growth factor)CECR1 (Cat eye syndrome critical region protein 1)IDGFLPANSNEDSVAIHSCat eye syndrome chromosome region candidate 1

Inhibition of enzymatic activity (deaminase inhibition: blocks adenosine to inosine conversion); Immunomodulation (drugs may either suppress or enhance immune responses via macrophage and lymphocyte effects); Anticancer action (potential via modulating ADA2 activity in lymphoma/neoplasia)