Soluble CD40 ligand induces expression of CD25 and CD23 in resting human tonsillar B lymphocytes.

In this report, we describe the dose-dependent increase in both CD25 and CD23 levels on resting human B cells in response to CD40 ligation, as mediated by soluble CD40 ligand (sCD40L) or anti-CD40 antibody. In combination with interleukin (IL)-4, sCD40L had limited additive effects on CD25 expression, but significantly enhanced CD23 expression on tonsillar B cells. Interferon-gamma (IFN-gamma) exerted no inhibitory effect upon increases in CD25 or CD23 driven by CD40 ligation with sCD40L or anti-CD40 antibody. These data suggest that the induction of CD25 and CD23 genes by IL-4 is mediated, at least in part, by an IFN-gamma-sensitive component, whereas gene activation driven via CD40 ligation involves signaling pathways which are not sensitive to IFN-gamma.