CD40-B and DCs express GFP after mRNA electroporation. (A) CD40-B or matured, monocyte-derived DCs from healthy donors or adult or pediatric cancer patients were electroporated with FluMP mRNA or GFP mRNA and analyzed by flow cytometry for expression of GFP and HLA-DR 12 hours after electroporation. Upper panels, healthy donor; middle panels, 58-year-old patient with hormone-independent prostate cancer; bottom panel, (CD40-B only) 17-month-old patient with neuroblastoma. Percentages shown indicate transfection efficiency. (B) Day 14 CD40-B and resting peripheral B cells from pediatric patients were analyzed by flow cytometry for cell surface expression of CD19, CD23, HLA-DR, CD86, CD54, CD3, CD4, and CCR7. Similar results were obtained for 4 healthy donors, 2 adult patients, and 4 pediatric patients.