DCs were derived by incubating purified human monocytes with granulocyte macrophage colony stimulating factor (GM-CSF) and IL-4. DCs were pre-incubated with or without PQS and stimulated by oxidized low density lipoprotein (ox-LDL). Expression of DCs membrane molecules (CD40, CD86, CD1a, HLA-DR) and endocytotic ability were analyzed by FACS, cytokines (IL-12 and TNF-伪) were measured by ELISA. Nuclear factor (NF)-魏B signaling pathway was determined by Western blotting, and RT-PCR. NF-魏B activation was quantified by ELISA.
PQS reduced ox-LDL induced immunophenotypic expressions (CD40, CD1a, CD86, and HLA-DR) and cytokine secretions (IL-12 and TNF-伪), and improved endocytotic ability of DCs. These above phenomena were accompanied by decreased protein expression and binding activity of nuclear localized c-Rel subunit.
Our study suggested that PQS inhibited ox-LDL induced immune maturation of DCs in vitro, which might be in part mediated by NF-魏B signal transduction pathway.