Immunophenotype of murine splenic B cells activated with CpG, lipopolysaccharide (LPS), anti-CD40, or combinations of these compared to mature dendritic cells (DCs). Freshly isolated CD19+ B cells were cultured with CpG, LPS, anti-CD40 or combinations. After a 2-day culture, B cells were harvested and analysed for expression of major histocompatibility complex (MHC) class II molecules, CD86, CD80, CD54, OX40L, and 4-1BBL by flow cytometry. As a control, LPS-stimulated, bone-marrow-derived DCs were used. Bars in the histograms indicate the areas beyond background. Representative data from three individual experiments are shown.