title: Specificity of human T cell clones reactive to immunodominant epitopes of myelin basic protein.
abstract: Several recently discovered lines of evidence support the involvement of myelin basic protein (BP)-specific T cells in multiple sclerosis (MS). To identify potentially relevant immunodominant T cell epitopes, human BP (Hu-BP)-reactive T cell lines were selected from MS and normal donors and tested for reactivity to cleavage fragments and synthetic peptides of Hu-BP. The MS T cell lines responded to more Hu-BP epitopes than did normal lines, showing biased recognition of the N terminal half of the molecule, and one region in the C terminal half, suggesting increased sensitization to BP. The MS lines also differed from normal lines in their decreased percentage of CD8+ T cells. One hundred nine T cell clones isolated from these lines confirmed the reactivity pattern of the lines but did not reflect the mixed phenotype, since all but three clones tested were CD4+. T cell clones from HLA-DR2 homozygous donors responded to a variety of epitopes, indicating that this molecule was permissive in its ability to restrict T cell responses. Other epitopes, including the immunodominant 149-170 sequence, were restricted by several different major histocompatibility complex (MHC) molecules from both MS and normal donors. T cell receptor (TCR) V gene products could be identified on six of 38 clones tested using monoclonal antibodies. From one HLA-DR2 homozygous donor, four of eight clones utilized V beta 5.2 in response to different BP epitopes, providing initial support for the preferential use of a limited set of V region genes in the human response to BP. Preferential TCR V gene use in MS patients would provide the rationale to regulate selectively BP-reactive T cells through immunity directed at the TCR and thus test for the first time the hypothesis that BP-reactive T cells play a critical role in the pathogenesis of MS.
authors.affiliation: Department of Neuroimmunology Research, Veterans Affairs Medical Center, Portland, OR 97201.
authors.forename: Y K
authors.initials: YK
authors.lastname: Chou
authors.forename: P
authors.initials: P
authors.lastname: Henderikx
authors.forename: M
authors.initials: M
authors.lastname: Vainiene
authors.forename: R
authors.initials: R
authors.lastname: Whitham
authors.forename: D
authors.initials: D
authors.lastname: Bourdette
authors.forename: C H
authors.initials: CH
authors.lastname: Chou
authors.forename: G
authors.initials: G
authors.lastname: Hashim
authors.forename: H
authors.initials: H
authors.lastname: Offner
authors.forename: A A
authors.initials: AA
authors.lastname: Vandenbark
mesh_terms: D000328:Adult; D000368:Aged; D002999:Clone Cells; D000939:Epitopes; D005260:Female; D005796:Genes; D015802:HLA-DR2 Antigen / Q000276:immunology; D006801:Humans; D016056:Immunodominant Epitopes / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000276:immunology; D004676:Myelin Basic Protein / Q000276:immunology*; D011948:Receptors, Antigen, T-Cell / Q000235:genetics; D012016:Reference Values; D013601:T-Lymphocytes / Q000276:immunology* / Q000502:physiology
chemical_list: D000939:Epitopes; D015802:HLA-DR2 Antigen; D016056:Immunodominant Epitopes; D004676:Myelin Basic Protein; D011948:Receptors, Antigen, T-Cell