title: Evidence for in vivo primed and expanded autoreactive T cells as a specific feature of patients with type 1 diabetes.
abstract: Identifying beta cell autoantigen-reactive T cells that are involved in the pathogenesis of type 1 diabetes has been troublesome for many laboratories. Disease-relevant autoreactive T cells should be in vivo Ag experienced. The aim of this study was to test this hypothesis and then use this principle as a strategy for identifying diabetes-relevant autoreactive T cells. In this study, a CSFE dilution assay was used to detect glutamic acid decarboxylase 65 (GAD65)- and insulin-responsive T cells and HLA-0201*-GAD65(114-122) pentamers were used to detect CD8(+) GAD-responsive T cells in memory CD45RO(+) and naive CD45RO(-) cell populations from patients with type 1 diabetes and healthy control subjects. T cell proliferative history was evaluated by flow cytometry telomere length measurement. CD4(+) and CD8(+) T cells specific for GAD65 and insulin were present in patients with type 1 diabetes and control subjects. Within the naive CD45RO(-) cells, CD4(+) and CD8(+) T cell responses were similar between patients and controls. Within the memory CD45RO(+) cells, CD4(+) T cell responses against whole GAD65 and insulin and HLA-0201*-GAD65(114-122) pentamer-positive CD8(+) T cells were found in patients with type 1 diabetes, but not in control subjects (p < 0.05 for all). Responding cells from the CD45RO(+) T cell population had substantially shorter telomere lengths than responding cells from the CD45RO(-) cell population. Diabetes-specific autoreactive T cells in the circulation have uniquely undergone sustained in vivo proliferation and differentiation into memory T cells. Prior selection of these cells is possible and is a way to identify diabetes-relevant target Ags and epitopes.
authors.affiliation: Telethon-Juvenile Diabetes Research Foundation Center for Beta Cell Replacement, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Monti
authors.forename: Miriam
authors.initials: M
authors.lastname: Scirpoli
authors.forename: Andrea
authors.initials: A
authors.lastname: Rigamonti
authors.forename: Anya
authors.initials: A
authors.lastname: Mayr
authors.forename: Annika
authors.initials: A
authors.lastname: Jaeger
authors.forename: Riccardo
authors.initials: R
authors.lastname: Bonfanti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Chiumello
authors.forename: Anette G
authors.initials: AG
authors.lastname: Ziegler
authors.forename: Ezio
authors.initials: E
authors.lastname: Bonifacio
mesh_terms: D000293:Adolescent; D000328:Adult; D001324:Autoantigens / Q000276:immunology*; D002454:Cell Differentiation / Q000276:immunology*; D002478:Cells, Cultured; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D005260:Female; D005452:Fluoresceins; D005968:Glutamate Decarboxylase / Q000378:metabolism; D006801:Humans; D007156:Immunologic Memory / Q000276:immunology; D007201:Indicator Dilution Techniques; D007328:Insulin / Q000378:metabolism; D017493:Leukocyte Common Antigens / Q000276:immunology; D008297:Male; D010641:Phenotype; D012307:Risk Factors; D013388:Succinimides; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology*; D016615:Telomere / Q000235:genetics
chemical_list: C087165:5-(6)-carboxyfluorescein diacetate succinimidyl ester; D001324:Autoantigens; D005452:Fluoresceins; D007328:Insulin; D013388:Succinimides; D017493:Leukocyte Common Antigens; D005968:Glutamate Decarboxylase; C401141:glutamate decarboxylase 2