Preferential survival of an MBP-specific T cell clone in an HLA-DR2 multiple sclerosis patient

Anti-myelin basic protein (MBP) autoreactive T cells play a key role in the pathogenesis of multiple sclerosis. Thus, we applied the Immunoscope strategy to cerebrospinal fluid (CSF) and peripheral blood lymphocytes (PBLs) of an HLA-DR2 patient. Both compartments showed major expansion for the V(beta)13S5 chain, which was associated in peripheral blood with significant proliferation of PBLs in response to MBP and the 84-102 HLA-DR2-restricted peptide. Sequencing revealed a unique nucleotide sequence in the CSF that gives rise to the amino acid sequence V(beta)13S5-RPGQGDQETQ-J(beta)2.5 if translated. This CDR3 sequence had already been reported to be reactive against the 84-102 peptide. This specific sequence was not detected in PBLs on day 0, whereas it was readily detectable on day 6 culture samples. Thus, cell culture may lead to enrichment in a T cell clone identified as autoreactive.