Tanshinone ⅡA Inhibits Dendritic Cell-mediated Adaptive Immunity: Potential Role in Anti-atherosclerotic Activity

Objective：Antigen-presenting cells such as monocytes and dendritic cells（DCs） stimulate T-ceil proliferation and activation during adaptive immunity.This cellular interaction plays a role in the growth of atherosclerotic plaques.Tanshinone ⅡA（TSN） had been shown to decrease the growth of atherosclerotic lesions.We therefore investigated the ability of TSN to inhibit human monocyte-derived DCs and their T-cellstimulatory capacity.Methods：DCs derived from human monocytes cultured with recombinant human interieukin（IL）-4 and recombinant human granulocyte-macrophage colony-stimulating factor were co-cultured with TSN and lipopolysaccharide for 48 h.Phosphate-buffered saline was used as a negative control.Activation markers and the capacity of DCs for endocytosis were measured by flow cytometry,and proinflammatory cytokines were measured by enzyme-linked immunosorbent assays.DCs were co-cultured with lymphocytes to measure T-cell proliferation and IL-2 secretion by mixed lymphocyte reactions.Results：TSN dose-dependently attenuated DC expression of costimulatory molecules（CD86）,and decreased expression of major histocompatibility complex class I（human loukocyte antigen-DR） and adhesion molecules（CD54）.Moreover,TSN reduced secretion of the proinflammatory cytokines IL-12 and IL-1 by human DCs,and restored the capacity for endocytosis.Finally,TSN-preincubated DCs showed a reduced capacity to stimulate T-cell proliferation and cytokine secretion.Conclusions：TSN inhibits DC maturation and decreases the expression of proinflammatory cytokines,while impairing their capacity to stimulate T-cell proliferation and cytokine secretion.These effects may contribute to the influence of TSN on the progression of atherosclerotic lesions.

Tanshinone II A inhibits dendritic cell-mediated adaptive immunity: Potential role in anti-atherosclerotic activity

dendritic cells immunity atherosclerosis tanshinone ⅡA