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More MS news articles for March 2004

Ex vivo detection of myelin basic protein-reactive T cells in multiple sclerosis and controls using specific TCR oligonucleotide probes

Eur J Immunol. 2004 Mar;34(3):870-81
Hong J, Zang YC, Li S, Rivera VM, Zhang JZ.
Department of Neurology and Baylor-Methodist Multiple Sclerosis Center, Baylor College of Medicine, Houston, USA.

T cell reactivity to candidate myelin autoantigens, such as myelin basic protein (MBP), may play an important role in the pathogenesis of multiple sclerosis (MS).

Although MBP-reactive T cellshave been found to undergo in vivo activation in patients with MS, their true precursor frequency in MS is unknown as current frequency analysis is commonly based on the T cell functional responses to MBP.

In this study, we developed a TCR sequence-based ex vivo detection system using colony hybridization with oligonucleotide probes specific for CDR3 of selected T cell clones for the analysis of true T cell precursor frequency in PBMC.

The results revealed that the precursor frequency of five independent T cell clones recognizing the immunodominant MBP(83-99) region was found to be in the range of 1.6x10(-4) in total T cells in three HLA-DR2 patients with MS compared to that of 0.25x10(-4) in HLA-DR2 healthy individuals.

The observed frequency of MBP(83-99)-reactive T cells in MS patients was considerably higher than those measured in parallel by cell culture-based analysis (2.3x10(-6)) or by enzyme-linked immunospot assay (3.9x10(-5)) in the same peripheral blood mononuclear cell specimens.

Furthermore, the study showed that MBP(83-99)-reactive T cells detected ex vivo belonged to CD45RA(+), CD25(+) and CD95(-) T cell subsets as evidenced by preferential expression of specific TCR transcripts in these cell fractions.