title: Activation and control of pathogenic T cells in OSP/claudin-11-induced EAE in SJL/J mice are dominated by their focused recognition of a single epitopic residue (OSP58M).
abstract: Oligodendrocyte-specific protein (OSP)/claudin-11 has been recently implicated in multiple sclerosis pathophysiology. Yet, the pathogenic autoimmunity against OSP has been poorly investigated. We previously showed that OSP-induced experimental autoimmune encephalomyelitis (EAE) and optic neuritis in SJL/J mice are primarily associated with CD4+ T cells reactive against OSP55-80. Dissecting the fine epitope specificity to the level of epitopic residues recognized by OSP-specific encephalitogenic T cells revealed their focused recognition of OSP58M. Accordingly, OSP58M predicted by computer modeling to be a major TCR contact residue shared by the three nonameric core epitopes within OSP55-80, albeit at different MHC-II pockets, was experimentally determined as the primary TCR contact residue crucial for activation and control of encephalitogenic T cells reactive against OSP55-80 or against recombinant OSP. Ala substitution of OSP58M impaired the functional TCR recognition/activation of pathogenic OSP-reactive T cells. Accordingly, the non-stimulatory/non-encephalitogenic pOSP55-58A-66 analogue not only treated EAE induced by pOSP55-80 but also effectively reversed EAE induced by whole OSP. Thus, the selection/activation and control of OSP-pathogenic T cells in H-2(s) mice appeared to be dominated by their predetermined focused recognition of OSP58M. Such a focused recognition by OSP-pathogenic T cells, despite their extensive TCR heterogeneity (Kaushansky, N., Zhong, M. C., Kerlero de Rosbo, N., Hoeftberger, R., Lassmann, H. and Ben-Nun, A. 2006. Epitope specificity of autoreactive T and B cells associated with experimental autoimmune encephalomyelitis and optic neuritis induced by oligodendrocyte-specific protein in SJL/J mice. J. Immunol. 177:7364), may impact profoundly on peripheral self-tolerance to OSP and on altered peptide ligand-mediated immune-specific modulation of the recently described OSP-related autoimmune pathogenesis.
authors.affiliation: Department of Immunology, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Nathali
authors.initials: N
authors.lastname: Kaushansky
authors.forename: Miriam
authors.initials: M
authors.lastname: Eisenstein
authors.forename: Joseph H
authors.initials: JH
authors.lastname: Oved
authors.forename: Avraham
authors.initials: A
authors.lastname: Ben-Nun
mesh_terms: D020816:Amino Acid Motifs / Q000276:immunology*; D000818:Animals; D001324:Autoantigens / Q000276:immunology / Q000378:metabolism*; D002460:Cell Line; D057167:Claudins; D016207:Cytokines / Q000378:metabolism; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D018984:Epitopes, T-Lymphocyte / Q000737:chemistry; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D006801:Humans; D007108:Immune Tolerance; D007114:Immunization; D008213:Lymphocyte Activation; D051379:Mice; D008958:Models, Molecular; D009103:Multiple Sclerosis / Q000276:immunology; D009419:Nerve Tissue Proteins / Q000276:immunology / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding / Q000276:immunology; D037182:T-Cell Antigen Receptor Specificity; D013601:T-Lymphocytes / Q000378:metabolism* / Q000473:pathology
chemical_list: D001324:Autoantigens; D057167:Claudins; C492354:Cldn11 protein, mouse; D016207:Cytokines; D018984:Epitopes, T-Lymphocyte; D000949:Histocompatibility Antigens Class II; D009419:Nerve Tissue Proteins; D010455:Peptides