Functional characterization of mouse spinal cord infiltrating CD8+ lymphocytes

Understanding the immunopathogenesis of neuroimmunological diseases of the CNS requires a robust method for isolating and characterizing the immune effector cells that infiltrate the spinal cord in animal models. We have developed a simple and rapid isolation method that produces high yields of spinal cord infiltrating leukocytes from a single demyelinated spinal cord and which maintains high surface expression of key immunophenotyping antigens. Using this method and the Theiler's virus model of chronic demyelination, we report the presence of spinal cord infiltrating acute effector CD8(+) lymphocytes that are CD45(hi)CD44(lo)CD62L(-) and a population of spinal cord infiltrating target effector memory CD8(+) lymphocytes that are CD45(hi)CD44(hi)CD62L(-). These cells respond robustly to ex vivo stimulation by producing interferon gamma but do not exhibit specificity for Theiler's virus in a cytotoxicity assay. We conclude that target-derived lymphocytes in a mouse model of chronic spinal cord demyelination may have unique functional specificities.