The properties of human CD40-activated B cells as antigen-presenting cells are not affected by PGE2

Tumor vaccination represents a promising immuno-therapeutic strategy incancer. However, the inherent ability of many tumors to evade immune responsesby suppression of immune cell function represents a major barrier. Prostaglandin E2(PGE2) has been shown to be a critical tumor-derived immunosuppressive factor.It affects a broad range of immune cells including T cells, macrophages and dendriticcells (DCs). CD40-activated B cells are being studied as a potential alternativeto DCs as antigen-presenting cells for immunotherapy. So far, it is not knownwhether PGE2 affects their antigen presenting capacity. We, therefore, investigatedthe influence of PGE2 on the phenotype, migratory potential and antigen-presentingfunction of CD40-activated human B cells. Here, we demonstrate that the immunostimulatoryproperties of CD40-activated B cells are not affected by PGE2. These results supportthe use of CD40-activated B cells as cellular adjuvants, especially in settingswhere PGE2 is present in the tumor microenvironment.