title: Regulatory T cells in experimental allergic encephalomyelitis. I. Frequency and specificity analysis in normal and immune rats of a T cell subset that inhibits disease.
abstract: We have shown previously that administration of myelin basic protein (MBP)-reactive T cells to naive Lewis rats induces not only autoimmune encephalomyelitis (EAE) but also a near total resistance to subsequent disease. By isolating the effector cells that are responsible for the resistance, we demonstrated that disease protection paralleled with increased numbers of a CD8+ regulatory T cell (RTC) subset and that co-injection of this RTC subset with encephalitogenic T cells aborted the pathogenic activity of the latter cells. Here, we show that a radio-sensitive splenic population of RTC also exists in naive rats that can be recruited and activated to inhibit the onset of secondary episodes of adoptive EAE. In co-transfer experiments, this protective RTC subpopulation can be isolated to neutralize the pathogenic activity of stimulatory MBP-reactive T cells in vivo. We show that the frequency of RTC with specificity for MBP-reactive T cells in naive rats is two orders of magnitude higher than the frequency of MBP-specific precursors, the activity of RTC increases substantially with age and RTC frequencies increase as a consequence of immunization with MBP-reactive cells lines. In specificity studies, we show that RTC isolated from naive rats and RTC from animals primed with one MBP-reactive cell line show cross-reactive responses to a variety of different MBP-reactive T cell lines. However, following repeated stimulation with a given MBP line, these RTC display a more limited, clonotypic response to the selecting line and assume a uniform CD8 phenotype. Finally, functional studies with RTC indicate that proliferative and lytic specificities do not necessarily correlate and that activated rat RTC are especially lytic for a Fas-sensitive murine cell line.
authors.affiliation: Department of Neurology and the Center for Neuroimmunology, University of Alabama at Birmingham, 35294, USA.
authors.forename: D
authors.initials: D
authors.lastname: Sun
authors.forename: J N
authors.initials: JN
authors.lastname: Whitaker
authors.forename: D B
authors.initials: DB
authors.lastname: Wilson
mesh_terms: D019264:Adoptive Transfer; D000367:Age Factors; D000818:Animals; D001327:Autoimmune Diseases / Q000517:prevention & control; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002999:Clone Cells; D003602:Cytotoxicity, Immunologic; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000276:immunology* / Q000517:prevention & control; D008213:Lymphocyte Activation; D004676:Myelin Basic Protein / Q000276:immunology; D051381:Rats; D011917:Rats, Inbred Lew; D013154:Spleen / Q000166:cytology / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000528:radiation effects; D013601:T-Lymphocytes / Q000276:immunology* / Q000528:radiation effects; D014916:Whole-Body Irradiation
chemical_list: D004676:Myelin Basic Protein