TCR V GENE USAGE IN HUMAN AUTOIMMUNE DISEASE AND TCR-TARGETED THERAPY A v r a h a m Ben-Nun, Department of Cell Biology, The Weizmann Institute of Science, Rehovot 76100. Israel We investigated T cell receptor (TCR) Vet and V~ gene usage by antigen-specific T !ymphocytes potentially pathogenic in multiple sclerosis (MS) and by non-antigen-specific T cells infiltrating thyroids of patients with autoimmune thyroiditls. About 30 well-characterized CD4 + T cell clones specific to myelin basic protein (MBP) were isolated from 5 MS patients and analyzed for their utilization TCR Vet and Vp genes, eDNA from these clones and a set of 18 V¢ gene family-specific and 19 VI~ gene family- specific primers were utilized to amplify by PCR their Wan~ribed TCR Va and V[~ genes. The results demonstrated a diverse Va and V[~ gane usage by MBP-specific clones from different MS patients. In contrast, a restricted Va and V[~ gene usage was displayed by MBP-specific clones of the same MS patient. However, the predominant Va and V 0 genes varied among MBP-specific clones from different patients with no clear association to MBP-epitope specificity or HLA-restricting elements. The restricted usage of TCR Va and V/~ genes by potentially pathogenic T lymphocytes suggests that both Vet and V{~ TCR elements can be used as targets for intervention with specific antibodies as an approach to therapy. However, the predominant Va and V[~ genes would have to be determined for each patient. T cells infiltrating the thyroids in autoimmune thyroiditis, when compared to peripheral blood, demonstrated marked restriction in TCR Va gene utilization, in spite of the fact that these T cells were not specific to thyroid antigens. However, the predominant Va genes used differed from patient to patient, with no clear disease-related preference. These studies support the concept of restricted TCR heterogeneity in autoimmune thyroid disease and point to the primacy ofT cells in the etiology of autoimmune tinyoid dysfunction. In contrast to the Va restriction, these T cells demonstrated a widespread usage of V[~ gane utilization, similar to the peripheral blood cells. Thus selective accumulation of T cells was demonstrated in autoimmune thyroiditis, based on their Vet gene usage. Such a selective accumulation may be secondary to the presence of superantigeus. These findings and the possibility of TCR-targeted therapy in autoimmune disease will be presented.

T CELL RECEPTOR USAGE IN BRAINS OF MULTIPLE SCLEROSIS PATIENTS. CORRELATION WITH HLA CLASS H MOLECULAR PHENOTYPE J R Oksenberg, M A Panzara , M Sherri t , A Begovich, El Erlieh, CCA B e r n a r d and L Steinman. Dept of Neurology & Neurological Sciences, Stanford University, Stanford CA 94305; Dept of Human Genetics, Cetus Corp., Emeryville CA 94608; Neuroi~muno!ogy Lab, LaTrobe University, Bundnora, Australia. The identification of activated T cells in the brains of individuals affected with mnltiple sclerosis (MS) suggests that these cells are important in the pathogenesis of the disease, In an attempt to elucidate the nature of the lymphocyte infiltration, a blind study was performed using the polymerase chain reaction method to specifically amplify T cell receptor Vc~ and V[3 rearranged sequences from transcripts derived from MS and control brain autopsy samples. Upon decoding, there was a complete correlation between the presence of TCR transcripts mid MS. No transcripts were det~'~ted in any of the control brains. The number of different TCR transcripts has a range of 0-9 for Vc~ (mean of 4.4- + 2.8 out of lg tested TCR families), and 2-13 for V[3 (mean of 7± 3.4 out of 21 tested TCR families). Different rearranged TCRs were observed in different patients, probably reflecting different genetic backgrounds. Seven patients were HLA-DR2Dw2, DRBI 1501, DQAI 0102, DQBI 0602,DPBI 0401. In all these brain samples, rearranged V1~5.2 transcripts were detected, compared to 2/8 MS brains without this molecular phenotype. TCR VI~6 was found in 6/7, compared to 3]8 MS brains with other phenotypes. The~ results imply that TCR V gene usage in MS brain may be restricted and that particular V beta genes may be preferentially rearranged in certain HLA I~piotypes like HLA-DR2Dw2 which is associated with increased susceptibility to MS in Caucasoid populations. Our findings might have therapeutic implications, given the success of reversing or preventing experimental allergic encephalomyelitis, the putative animal model for MS, with reagents targeting TCR V genes or MHC class 11 molecules.