Multiple Sclerosis: Lymphocyte Responses to CNS Antigens

In multiple sclerosis (MS), T lymphocytes are observed in the perivascular cuffs1 and increased numbers of activated T cells are detected in cerebrospinal fluid (CSF) samples from some MS patients,2 suggesting an ongoing immune response. T cells are clearly involved in experimental allergic encephalomyelitis (EAE) for demyelinating disease can be induced in SJL mice after adoptively transferring cloned T cells reactive to the encephalitogenic region of myelin basic protein.3 Thus a role for T cells in the pathogenesis of MS has been proposed. Although the origin and specificity of these autoimmune T cells remains obscure, recent reports suggest that CD2+ T cells rapidly migrate from the peripheral blood into the central nervous system (CNS).4 The peripheral blood might therefore be useful for monitoring the ongoing pathological process within the CNS.