Live imaging of remyelination after antibody-mediated demyelination in an ex-vivo model for immune mediated CNS damage

Mononuclear cell infiltrates, deposits of immunoglobulin and complement as well as demyelination and axonal damage are neuropathological hallmarks of Multiple Sclerosis (MS) lesions. An involvement of antibodies is further suggested by the presence of oligoclonal immunoglobulins in the cerebrospinal fluid of almost all MS patients. However, which mechanisms are most relevant for de- and remyelination and axonal loss in MS lesions is poorly understood.To characterize the regenerative abilities of demyelinated CNS tissue, we utilized murine organotypic cerebellar slice cultures expressing GFP in oligodendrocytes. The addition of a demyelinating monoclonal antibody specific for myelin oligodendrocyte glycoprotein and complement induced complete myelin destruction and oligodendrocyte loss, as demonstrated by confocal live imaging and staining for different myelin proteins. After removal of antibodies and complement we visualized the stages of remyelination, presumably originating from proliferating oligodendrocyte precursor cells and guided by morphologically intact appearing axons.Allowing for the detailed live imaging of de- and remyelination in an ex vivo situation closely resembling the three dimensional cytoarchitecture of the CNS, we provide a useful experimental system for the evaluation of new therapeutic strategies to enhance remyelination and repair in MS.