Serum IL-10 from systemic lupus erythematosus patients suppresses the differentiation and function of monocyte-derived dendritic cells

The role played by cytokines,other than interferon(IFN)-α,in the differentiation and function of dendritic cells(DCs) in systemic lupus erythematosus(SLE),remains unclear.Serum interleukin-10(IL-10) levels are generally elevated in SLE patients,which might modulate the differentiation of DCs.In this study,DCs were induced from monocytes either by transendothelial trafficking or by culture with granulocyte-macrophage colony-stimulating factor(GM-CSF) + IL-4 + tumor necrosis factor(TNF)-α.Both systems were used to investigate the effects of elevated serum IL-10 level on DC differentiation in SLE patients.The results showed that monocyte-derived DCs induced by either SLE serum or exogenous IL-10 reduced the expression of human leukocyte antigen(HLA)-DR and CD80,decreased IL-12p40 level,and increased IL-10 level,and exhibited an impaired capacity to stimulate allogenic T-cell proliferation.These results indicate that serum IL-10 may be involved in the pathogenesis of SLE by modulating the differentiation and function of DCs.