We have investigated the T cell receptor (TCR) repertoire in the inflammatory infiltrates of T line-transferred experimental autoimmune encephalomyelitis (EAE) of the Lewis rats. Using a panel of TCR V beta-specific monoclonal antibodies (mAbs) and immunocytochemistry, we studied the nature of the T cells entering the central nervous system (CNS) after transfer of either myelin basic protein (MBP)-reactive, or MBP-reactive but non-encephalitogenic T cell lines. All the MBP-specific T cell lines predominantly used the V beta 8.2 TCR chain. T cell lines specific for the tuberculin purified protein derivative (PPD), using TCR V genes different from V beta 8.2, served as controls. We first studied the time course of T cells entering the CNS. In all recipient rats, small, but significant numbers of alpha beta-TCR-expressing infiltrate cells appeared in the CNS within the first 24 h after T cell transfer. In animals injected with either type of MBP-reactive T cells, the early infiltrate cells were preferentially located within the parenchyma of the spinal cord, while in PDD T line-injected rats, the lymphocytes were mostly found in the meninges. TCR V beta gene usage was examined on the peak of clinical disease. Six days after T cell transfer, the TCR repertoire used by infiltrating lymphocytes in general seemed to be highly diverse. None of the V beta isotypes examined (i.e. V beta 8.2, V beta 8.5 or V beta 10) was used by a major population of the alpha beta-TCR-positive T cells.(ABSTRACT TRUNCATED AT 250 WORDS)