Myelin oligodendrocyte glycoprotein has a dual role in T cell autoimmunity against central nervous system myelin

BACKGROUND: Myelin oligodendrocyte glycoprotein (MOG) is a candidate primary target of the autoimmune attack on the central nervous system (CNS) in multiple sclerosis (MS). However, the physiological function of MOG has been unclear for a long time. OBJECTIVE: We propose that MOG has a central role in the regulation of tolerance and autoimmunity. CONCLUSION: The interaction of MOG with DC-SIGN, an innate antigen receptor of myeloid antigen-presenting cells (m-APCs), present inside the CNS (microglia) or in draining lymph nodes (dendritic cells; DCs), keeps these cells in an immature/tolerogenic state. We postulate that this tolerogenic mechanism may be disturbed in MS by unknown factors.