title: Autoreactive human T-cell receptor initiates insulitis and impaired glucose tolerance in HLA DR4 transgenic mice.
abstract: A human T-cell receptor (TcR) derived from an autoreactive T-cell specific for GAD65, from a subject at high risk for autoimmune diabetes, was introduced into HLA-DR4 transgenic mice. The source of TcR was a CD4(+) T(H)1(+) T-cell clone which responded to an immunodominant epitope of the human islet protein GAD65, an epitope shared with both GAD65 and GAD67 in the mouse. The resulting HLA-DR4/GAD-TcR transgenic mice on a Rag2(o/o)/I-Ab(o/o)/B6 background exhibited a CD4(+) infiltrate into pancreatic islets that correlated with a loss of insulin in infiltrated islets. These mice also exhibited a subclinical impaired tolerance to exogenously fed glucose as assayed by an intraperitoneal glucose tolerance test. T cells containing the GAD65/67 (555-567) responsive TcR undergo strong negative selection as evidenced by a 10-fold lower thymocyte cellularity compared to non-TcR transgenic mice, and clonotype peripheral T cells represented approximately 1% of CD4(+) T cells in Rag2 sufficient mice. Upon in vitro stimulation, GAD65/67 555-567 responsive T cells secrete interferon-gamma, minimal interleukin (IL)-2 and tumor necrosis factor-alpha, and no IL-4, IL-5, IL-10, or IL-17, consistent with a T(H)1 profile. These data demonstrate that CD4(+) T cells specific for a naturally processed epitope within GAD can specifically home to pancreatic islets and lead to impaired islet beta-cell function in diabetes-associated HLA-DR4 transgenic mice on the relatively non-autoimmune C57BL/6 background. The relatively slow progression and patchy insulitis are reminiscent of the chronic pre-clinical phase similar to a majority of human at-risk subjects, and models these indolent features of human T1D.
authors.affiliation: Department of Diabetes, Benaroya Research Institute, 1201 Ninth Avenue, Seattle, WA 98101, USA. jgebe@benaroyaresearch.org
authors.forename: John A
authors.initials: JA
authors.lastname: Gebe
authors.forename: Kellee A
authors.initials: KA
authors.lastname: Unrath
authors.forename: Betty B
authors.initials: BB
authors.lastname: Yue
authors.forename: Tom
authors.initials: T
authors.lastname: Miyake
authors.forename: Ben A
authors.initials: BA
authors.lastname: Falk
authors.forename: Gerald T
authors.initials: GT
authors.lastname: Nepom
mesh_terms: D000818:Animals; D001324:Autoantigens / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology*; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D005434:Flow Cytometry; D005968:Glutamate Decarboxylase / Q000276:immunology*; D015804:HLA-DR4 Antigen / Q000235:genetics*; D006801:Humans; D007515:Islets of Langerhans / Q000276:immunology* / Q000473:pathology; D051379:Mice; D008822:Mice, Transgenic; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*
chemical_list: D001324:Autoantigens; D018984:Epitopes, T-Lymphocyte; D015804:HLA-DR4 Antigen; D011948:Receptors, Antigen, T-Cell; D005968:Glutamate Decarboxylase; C401141:glutamate decarboxylase 2