CD23/FcεRII: Signaling and Clinical Implication

Abstract

CD23 is an activation antigen expressed by various human hematopoietic cells, tissular epithelial cells and represents the major low affinity receptor for IgE (FcεRII). In its membrane and soluble forms, CD23 has multiple ligands that enable this molecule to trigger various functions in human and murine cells. In this issue, we discussed the intracellular signaling events induced by soluble CD23 and the ligand involved in each target cell. Signal transduction through surface CD23 ligation is linked to cyclic nucleotides and nitric oxide (NO) pathways in various human cells and in rat macrophages. Recent in vivo data suggest a regulatory role for these signals during various human physiopathological situations such as hemopoiesis, anti-tumoral defense, inflammation, allergy, microbicidal activity of macrophages and eosinophils, skin diseases, and HIV infection.

Key Words:

• CD23
• IgE
• Nitric oxide
• cAMP
• Transduction
• Inflammation