A, Splenocytes were harvested from IOE-infected IL-18Rα-/- and WT mice on day 3 p.i., and the expression levels of CD40 and MHCII costimulatory molecules on CD11c+ dendritic cells were analyzed by flow cytometry. B, Bone marrow derived dendritic cells (BMDCs) were isolated from WT and IL-18Rα-/- mice and were propagated in vitro. Cells were either left unstimulated or infected with IOE at MOI of 5: 1 for 24 hours. Histogram show different maturation markers; MHC-I, MHC-II, CD80, CD86, and CD40 on CD11c+ BMDCs from naive (filled line), WT (solid line) and IL-18Rα-/- (dotted line). C, TNF-α and IL-6 production in culture supernatant of IOE-infected BMDCs from WT and IL-18Rα-/-. Uninfected BMDCs from WT mice was used as negative controls. In vivo experiments showing results from four mice/ group, and similar results were obtained in three independent experiments. In vitro data are representative from one of three different experiments with similar results.