Effects of L. infantum infection on BMDC CD40 and CD86 costimulatory molecule expression. A: BMDCs plated at 2 × 106 cells/well were infected with L. infantum promastigotes in a 10:1 (parasites/cell) ratio for 4 hours. Cells were immediately recovered or left in culture for an additional 24 hours after the end of the infection. As a control, BDMCs were stimulated with 1 μg/ml LPS for 4 and 24 hours. The mRNA levels were assessed by qPCR for CD40 and CD86. Gene expression is indicated as mean log2 values of fold changes relative to untreated cells. B: BMDCs were treated with 1 μg/ml LPS or pretreated for 1 hour with LPS and then infected with L. infantum promastigotes in a 10:1 (parasites/cell) ratio, (LPS → Infection). After 4 hours of culture, cells were harvested, and the CD40 and CD86 mRNA levels were assessed by qPCR. Gene expression is indicated as mean log2 values of fold changes relative to LPS-treated cells. C: Cells were infected, treated with 1 μg/ml LPS or pretreated during 1 hour with LPS and then infected (LPS → Infection). After 24 hours, the surface expression of CD40 and CD86 was measured on gated CD11c+ cells by flow cytometry. As negative control, cells were incubated in RPMIc (DCs) for a similar time. Each value represents the mean ± SD from three independent experiments. **P < 0.01.