CD206 is a macrophage mannose receptor involved in variety of autoimmune and inflammatory diseases. This study aimed to identify the pathogenic role of CD206 in a herpes simplex virus (HSV) induced Behcet's disease (BD) mouse model. CD206 positive cells were detected in peripheral blood mononuclear cells and quantified by flow cytometry. Levels of cytokines were measured by ELISA. CD206 was found to be down-regulated both in vitro (10(-6)M) and in vivo (200mug/mouse) after treatment with N-acetylgalactosamine (GalNAc), a ligand for CD206. The down-regulation of CD206 was correlated with improvement in BD symptoms. Colchicine (2mug/mouse) or pentoxifylline (400mug/mouse) treated mice displayed improvement in BD symptoms with fewer CD206 positive cells. The prevalence of CD206-positive cells differed between ligand-responsive and non-responsive BD mice. Inhibition of CD206 was associated with down-regulated serum level of interleukin-17 in GalNAc-treated BD mice. These results suggest that the expression of CD206 is correlated with HSV-induced BD symptoms in mice, implicating that CD206 might have a pathogenic role in BD.