Immune maturation of human monocyte-derived dendritic cells induced by angiotensinⅡ / 中国病理生理杂志

ABSTRACT

AIM:To investigate the effects of angiotensin II ( Ang II) on the immune maturation and the oxi-dized low-density lipoprotein (Ox-LDL)-uptaking capacity of human monocyte-derived dendritic cells (DCs).METH-ODSHuman peripheral blood mononuclear cells were isolated by density gradient centrifugation , and the monocytes were purified by positive selection with anti-CD14 magnetic beads.After cultured with rhGM-CSF (100 μg/L) and rhIL-4 (50μg/L) for 5 d, the monocytes differentiated into immature DCs .On the 6th day of the culture, the cells were treated with various concentration levels of Ang II or pretreated with losartan .The immunophenotypic expression of HLA-DR and CD83 was analyzed by flow cytometry .The secretion levels of IL-12 and IFN-γin the culture supernatants were measured by ELISA.Furthermore, DCs were incubated with DiI-labelled Ox-LDL.The DiI-Ox-LDL-incorporated fraction was investiga-ted by flow cytometry .The mRNA expression of 3 scavenger receptors , scavenger receptor A ( SR-A) , CD36 and lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1), was examined by real-time PCR.RESULTS: Ang II induced the maturation of human monocyte-derived DCs, stimulated the expression of CD83 and HLA-DR, and promoted the secre-tion of IL-12 and IFN-γ, which were suppressed by losartan .Furthermore, Ang II increased the Ox-LDL-uptaking capacity of DCs, which was partially reduced by losartan .The incubation of DCs with Ang II enhanced the mRNA expression of LOX-1 in a dose-dependent manner , which was reduced by losartan .However, the expression of SR-A and CD36 was not changed .CONCLUSION:Ang II promotes the immune maturation of human monocyte-derived DCs and increases the up-take of Ox-LDL probably through the up-regulation of LOX-1 expression.