The EBVCS2 monoclonal antibody reacts with human CD23, a 45 kDa type II transmembrane
glycoprotein. CD23 is expressed on mature B cells, mantle zone B cells, follicular dendritic
cells and at low levels on T, NK, langerhans cells and platelets. Expression of CD23 is
upregulated upon B cell activation, and soluble forms of the antigen have been reported to
be biologically active. CD23 is a low affinity receptor for IgE and is thought to play a role
in the regulation of IgE response and B cell activation. CD21 and the alpha subunit of CD11b
and CD11c bind to CD23.