Accumulating evidence suggests that the Th1 immune response induced by various antigens such as oxidized low density lipoprotein (ox-LDL) and heat shock proteins (HSPs) play a key role in the process of atherosclerosis.1 Dendritic cells (DCs) are the most potent antigen-presenting cells (APCs) in the body with the unique ability to initiate a primary immune response to certain antigens by the activation of "naive" T cells.2 The maturation of DC with the upregulation of costimulatory molecules such as CD83,CD40,CD86,and major histocompatibility complex (MHC) class molecules such as human leukocyte antigen (HLA)-DR,is required for DC to activate T cells.