Liver stellate cells suppress dendritic cells through IL-10.

Liver allografts can be spontaneously accepted across an MHC class I disparity, the mechanism of which is still not known. Since the liver has a large amount of immature dendritic cells, these elements may contribute to transplant acceptance. However, the reason why liver dendritic cells are immature status is unknown. In this study, bone marrow-derived dendritic cell progenitors were cocultured with liver stellate cells, which produce the immunosuppressive cytokines IL-10 and TGF-beta. The results revealed that dendritic cells cocultured with liver stellate cells express low levels of costimulatory molecules with decreased allostimulatory capacity. Addition of anti-IL-10 antibody to the culture media to neutralize IL-10 effects reversed the allostimulatory function of dendritic cells cocultured with stellate cells. In conclusion, liver dendritic cells are conditioned by stellate cells to maintain an immature status, which may contribute to the low immunity of liver. One of the mechanisms that stellate cells may influence dendritic cells is through IL-10.