The experiments are nicely designed, the results are overall very convincing and well described. My only issue with the manuscript relates to Figure 2. 1. The levels of IL-10 produced are quite low, and it would be important to state what the limit of detection for the ELISA was. If it was in the range of 5 pg/ml, then measurements of mRNA by qRT-PCR would be more informative. 2. The FACS data in Fig. 2C show an increased fraction of IFNg+ DC in absence of IL-10. IFNg production from myeloid cells has been controversial. Therefore, the DC identity of the IFNg+ cells needs to be checked; this requires showing the gating strategy, and in addition should be corroborated by excluding non-DC cell types typically producing IFNg (NK, NKT and T cells) by co-staining with appropriate lineage-specific antibodies. In the legend to Fig. 2, the source of the cells (spleen?) and the gating strategy for the CD11c+ DC is not described.