HOMING OF T-CELLS TO THE CENTRAL-NERVOUS-SYSTEM THROUGHOUT THE COURSEOF RELAPSING EXPERIMENTAL AUTOIMMUNE ENCEPHALOMYELITIS IN THY-1 CONGENIC MICE

Chronic relapsing experimental allergic encephalomyelitis (EAE) was in duced in Thy- 1. 1 congenic SJL/J mice by the adoptive transfer of mye lin basic protein (MBP)-responsive lymph node cells from Thy-1.2 SJL/J mice. The Thy-1 congenic mouse strain was constructed on the SJL (Thy -1.2) background by the initial cross with the AKR (Thy-1.1) strain an d does not reject Thy-1.2+ T cells. Quantitative immunocytochemical an alysis of the central nervous system (CNS) of Thy-1.1 recipients showe d preferential trafficking of Thy-1.2+ T cells to the meninges and whi te matter, beginning prior to onset of clinical signs. At 7 days post- transfer (dpt), Thy-1.2+ donor cells constituted 2.5% of the infiltrat ing cells and reached peak values (ca. 10%) during the first attack. A t later stages (up to ten relapses), Thy-1.2+ T cells constituted 2-5% of the infiltrate. In control mice injected with irrelevant antigen-s timulated Thy-1.2+ T cells, only the occasional Thy-1.2+ T cell could be demonstrated up to 14 dpt. This is the first study showing unequivo cally the presence of MBP-stimulated, adoptively transferred T cells w ithin the CNS of recipients throughout the course of EAE, particularly during later relapsing stages. These results indicate that the persis tent presence of antigen-specific T cells may be required for the recr uitment of non-CNS antigen-responsive immune cells.