Aim To investigate the effect of peroxisome proliferator-activated receptors α(PPARα)agonist fenofibrate on the immune maturation of monocyte-derived dendritic cell(DC) induced by oxidized low-density lipoprotein(ox-LDL). Methods Monocytes were purified(over 98%) using Anti-CD14 microbeads. After cultured with DC Cellgro medium containing recombinated human granulocytemacrophage colony stimulating factor(rhGM-CSF)(100 μg/L) and recombinated human interleukin-4(rhIL-4)(20 μg/L) for 5 days,monocytes were derived into immature DC.Human monocyte-derived DC were incubated with fenofibrate(100 μmol/L) for 24 hours,and subsequently stimulated with ox-LDL(50 mg/L)for another 48 hours. The immunophenotypic expressions(CD1a,CD40,CD86,and HLA-DR) were analyzed by FACS and endocytosis function by FITC-dextran,and the cytokines secretions of culture supernatants(IL-12,IL-10,TNF-α) were measured with enzyme-linked immunosorbent assay(ELISA). Results Fenofibrate reduced ox-LDL induced immunophenotypic expressions of DC(CD1a: 68.80%±5.89% vs 46.50%±11.39%,p<0.05;CD40: 72.97%±10.38% vs 56.76%±11.16%,p<0.05;CD86: 79.82%±22.07% vs 65.74%±9.94%,p<0.05;HLA-DR: 83.24%±6.60%vs 60.72%±11.85%,p<0.05).Ox-LDL inhibited the endocytosis of DC,which was partly prevented by fenofibrate(83.12%±3.10% vs 57.78%±23.28%,p<0.05);fenofibrate attenuated ox-LDL induced cytokine secretions of DC(IL-12: 106.7±20.7 ng/L vs 64.9±18.5 ng/L,p<0.05;TNFα: 50.3±9.9 ng/L vs 26.0±8.8 ng/L,p<0.05;IL-10: 66.1±2.6 ng/L vs 33.4±13.4 ng/L,p<0.05). Conclusion PPARαagonist fenofibrate partly inhibits ox-LDL induced immune maturation of DC,through which it may play an anti-atherosclerosis effect.