Human myelin basic protein specific T cell lines display differential cytotoxicity against astrocytes, but are consistently cytotoxic against monocytes.

In experimental allergic encephalomyelitis (EAE) myelin basic protein (MBP) specific T cells differ in their encephalitogenic potential. To investigate the functional diversity of human MBP specific T cell lines, we analysed their cytotoxic activity against human astrocytes and monocytes. Five out of 14 MBP specific T cell lines killed astrocytes in the presence of MBP. Nevertheless, all lines lysed blood derived monocytes. T cell lines that lysed astrocytes efficiently in the presence of MBP, recognized peptide aa 80-99/86-105 in context with HLA-DRB5 * 0101, peptide aa 50-69/61-83 in context with HLA-DRB1 * 1501 and peptides aa 139-153, and aa 148-162 in context with HLA-DRB1 * 0101. There was no correlation of MBP-mediated lysis of astrocytes with TCR-Vbeta usage, HLA-restriction and the production of tumor-necrosis-factor-alpha (TNF-alpha), lymphotoxin (LT) and interferon-gamma (IFN-gamma). Different lysis of astrocytes, however, revealed a functional heterogeneity of MBP specific T cells, which was not observed by using monocytes as targets.