CD23. also known as FcεRII, is a type II transmembrane glycoprotein that functions as the low-affinity receptor for immunoglobulin E (IgE). It is primarily expressed on B lymphocytes, eosinophils, follicular dendritic cells, and certain epithelial cells. CD23 plays a dual role in immune regulation: it modulates IgE synthesis by interacting with IgE-containing immune complexes and participates in antigen presentation, cytokine release, and cell adhesion. Its soluble form (sCD23), generated via proteolytic cleavage, acts as a pleiotropic cytokine influencing inflammatory and allergic responses.
CD23 antibodies are critical tools for studying IgE-mediated immune pathways and related diseases, such as asthma, allergic rhinitis, and atopic dermatitis. In research, these antibodies help characterize CD23 expression patterns, receptor-ligand interactions, and downstream signaling mechanisms. Therapeutically, CD23-targeting monoclonal antibodies (e.g., lumiliximab) have been explored for conditions involving dysregulated IgE production or B-cell malignancies, though clinical success remains limited. Recent studies also highlight CD23's role in autoimmune disorders and viral infections, broadening its research relevance. Antibodies against CD23 are available in various formats (monoclonal, polyclonal) and are widely used in techniques like flow cytometry, Western blotting, and immunohistochemistry to dissect its functional contributions in health and disease.