Anti-class II MHC antibodies prevent and treat EAE without APC depletion.

We have demonstrated that a murine IgG1 anti-class II major histocompatibility complex (MHC) antibody (OX6) is able both to prevent and treat experimental autoimmune encephalomyelitis (EAE) in the Biozzi AB/H mouse. We have confirmed that this antibody is poorly cytotoxic, allowing mechanisms of action other than depletion of antigen-presenting cells (APC) to be assessed. Despite its effect on disease, OX6 administration does not prevent priming of T cells in the draining lymph node, implying an alternative mechanism for regulation of the autoimmune disease process.