Whole Plasmodium -infected red blood cells (iRBC) do not induce DC maturation in vitro. Bone marrow-derived DC were incubated for 24 h in different conditions. Ratio of red blood cell (RBC):DC is 30:1 unless specified otherwise. Expression of CD86 and CD40 analyzed by flow cytometry is expressed as fold-to-control (DC cultured alone). LPS (Salmonella typhimurium) and Zymosan (Saccharomyces cerevisiae) were used as positive controls for DC maturation. CD40 (A) and CD86 (B) expression after incubation with RBC or P. yoelii-iRBC at different ratios. (C) Expression of CD86 at 24 h of culture when DC were co-incubated with iRBC for a short time (3 h pulse) and then washed, or for the whole 24 h. Data correspond to the mean of triplicate samples ± standard deviation. Figures are representative of one out of three independent experiments.