P. yoelii lysates, but not whole P. yoelii -infected erythrocytes, induce DC maturation in vitro. (A) Bone marrow-derived DC were incubated with whole RBC (red), whole P. yoelii-iRBC (black), lysates of RBC (orange), or lysates of iRBC (purple).Ratio of red blood cell (RBC):DC was 30:1, an amount of lysate equivalent to a 30:1 ratio of whole parasites/DC was added to DC. Surface expression of maturation-associated receptors and MHC was determined by FACS after 24 h or 48 h. (B) DC derived from wt (circles) or MyD88-deficient (squares) mice were incubated with lysates of RBC (black symbols) or P. yoelii-iRBC (white symbols) at the indicated ratios of RBC:DC. The ratio indicates the amount of RBC or iRBC from which the lysate was derived. Expression of CD86 was determined by FACs after 24 h.