A permanent rat T cell line that mediates experimental allergic neuritis in the Lewis rat <i>in vivo</i>.

A rat T cell line of the "helper" phenotype (W3/25-positive, OX 8-negative) has been derived from Lewis rats inoculated with P2 protein isolated from bovine PNS myelin. The line LiP2/A is exquisitely specific for P2 protein, exhibiting no reactivity to bovine basic protein or to PPD. In addition to responding strongly to the intact P2 protein, the line cells show some response to a synthetic peptide containing the neuritogenic amino acid sequence of P2 protein (SP-B, residues 66-78). Intravenous inoculation of naive rats with as few as 10(4) activated LiP2/A cells leads to the onset of mild clinical signs of experimental allergic neuritis. Higher doses of cells lead to more severe clinical disease. Histologic examination of clinically ill animals confirmed the disease as EAN. The pathologic lesions were confined to the PNS and spared the central nervous system. The lesions consisted of marked perivascular cuffs and infiltrates of inflammatory cells associated with marked degenerative changes--demyelination and some axonal degeneration.