Communication of CD8 T cells with mononuclear phagocytes in multiple sclerosis.

Objective: CD8 T cells are the most prevailing lymphocyte population in inflammatory lesions of patients with multiple sclerosis (MS) but it is not even known whether they are merely passive bystanders or actively communicate with other cells in the brain. To identify their potential interaction partners, we analyzed CD8 T cells that contained vectorially oriented cytotoxic granules and analyzed the areas to which the granules pointed.

Methods: We stained cryo-sections of active MS lesions of an index patient with antibodies to CD8 and perforin, searched for vectorially oriented perforin granules, and isolated target areas opposing the granules and control areas by laser-microdissection.