Antigen-specific T cell trafficking into the central nervous system

The initiation step of cell-mediated immune responses in the central nervous system (CNS) involves the trafficking of the antigen-specific T cells into the blain. To study this trafficking, we developed an in vivo system for studying antigen-specific responses in the CNS. In this assay, T cell receptor (TCR) transgenic mice having 95% of T cells specific for a defined antigen-pigeon cytochrome c (PCC) were cannulated intraventricularly for PCC antigen infusion and cerebrospinal fluid (CSF) sampling. Upon PCC infusion into the CNS, the number of alpha/beta TCR+ V beta 3(+) Mac1(-) cells in the CSF was characterized. We found that infusion of antigen into the CSF induced an increased number of antigen-specific T cells in the CNS and activation of antigen-specific T cells in the peripheral blood. Hence, the drainage of CNS antigen into the periphery might play an important role in sustaining autoimmune reactivity in CNS inflammatory diseases. (C) 2000 Elsevier Science B.V. All rights reserved.