Functional properties of myelin oligodendrocyte glycoprotein-reactive T cells in multiple sclerosis patients and controls

Autoimmune T-cell reactivity to myelin components may be implicated in the initiation or maintenance of the inflammation leading to myelin destruction in multiple sclerosis (MS). Myelin oligodendrocyte glycoprotein (MOG), a quantitatively minor myelin protein, is an important candidate autoantigen in MS. We studied T-cell responses to recombinant MOG (extracellular domain, rMOG) and a panel of four peptides within this domain (amino acids 1-22, 34-56, 64-86 and 74-96) in MS patients and healthy controls (NS). Frequency analysis of T cells reactive to rMOG as measured by IFN-gamma ELISPOT did not reveal significant differences between MS patients and controls. MOG-reactive T-cell lines and clones (TCL/TCC) were generated by stimulating PBMC of four MS patients and three healthy subjects with a cocktail of the four MOG peptides. The functional properties of 50 MOG peptide-reactive TCL/TCC obtained were studied. All TCL were TCR alpha beta+CD4+ and 20 TCL showed reactivity to MOG peptides 1-22, 13 to 34-56, 1 to 64-86 and 16 to 74-96. No significant differences in peptide recognition were observed between MS patients and controls. The T-cell receptor (TCR) hypervariable regions of MOG-reactive TCL/TCC showed a heterogeneous usage of various TCR V(-D)-J elements. The data provide no evidence for clonal expansions within the MOG-reactive T-cell repertoire of the two study groups. Intracellular cytokine analysis demonstrated predominantly Th1-TCC (IFN-gamma+/IL-4-) in MS patients, while most MOG-reactive TCC of control subjects had a mixed Th0/Th1 phenotype. Furthermore, the MS-derived MOG-reactive TCC produced...