Chemokine expression by central nervous system resident cells and infiltrating neutrophils during experimental autoimmune encephalomyelitis in the BALB/c mouse

The active role of chemokines in the central nervous system (CNS) during th e pathogenesis of experimental autoimmune encephalomyelitis (EAE) has been clearly established. In this study the expression pattern of several chemok ines and cytokines was elucidated using reverse transcription-PCR and immun ohistochemistry in a recently established EAE model of the BALB/c mouse tha t is characterized by CNS infiltration of polymorphonuclear neutrophils. El evated mRNA levels of the chemokines MIP-1 alpha, MIP-2 and MCP-1 were dete cted in the CNS of diseased mice, whereas no chemokine expression could be measured in asymptomatic mice. Activated astrocytes were shown to be the ma in source of MIP-1 alpha and MIP-2 before and during cellular CNS infiltrat ion. Among the infiltrating immune cells the neutrophils secreted MIP-1 alp ha and MCP-1. These results suggest involvement of ordered chemokine expres sion during the process of neutrophil attraction into the CNS, which may pl ay an important role in the initiation and perpetuation of autoimmune CNS i nflammation in the BALB/c mouse. This is the first EAE model to describe CN S expression of the C-X-C chemokine MIP-2, corresponding to an observed neu trophil accumulation in the CNS.