title: In vitro stimulation with glutamic acid decarboxylase (GAD65) leads to an oligoclonal response of peripheral T-cells in an IDDM patient.
abstract: The enzyme glutamic acid decarboxylase (GAD65) is a major autoantigen in insulin-dependent diabetes mellitus (IDDM). To study T-cell reactivity towards GAD, peripheral blood leucocytes from seven patients with IDDM and five control subjects were stimulated in vitro with recombinant GAD. All diabetics studied were heterozygous for diabetes-associated HLA alleles, i.e. HLA-DRB1*03,*04-DQB1 *0302,*0201. A single IDDM subject (no. GAD65.05) revealed a strong response against GAD65. After stimulation, his T-cell receptor beta (TCRBV) usage was found to be oligoclonal. The sequence analysis of the putative peptide binding region of the T-cell receptor (CDR3 region) of 37 GAD-reactive T-cell clones revealed no common CDR3 motif. The stimulation of GAD-reactive T-cells could be inhibited with anti-class II monoclonal antibodies, indicating a class II restricted T-cell response. In addition, GAD65-responsive T-cells revealed a Th1 cytokine response pattern. The author's data suggest that GAD-reactive T-cells of Th1 phenotype can be obtained after in vitro stimulation of peripheral blood leucocytes from an HLA-DRB1*03/*04 heterozygous IDDM patient. The lack of a common CDR3 motif suggests the absence of an immunodominant T-cell epitope in that patient, or may indicate receptor repertoire spreading of peripheral T-lymphocytes.
authors.affiliation: Medizinische Klinik, Universität Ulm, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Weiss
authors.forename: B J
authors.initials: BJ
authors.lastname: Manfras
authors.forename: D
authors.initials: D
authors.lastname: Terjung
authors.forename: T
authors.initials: T
authors.lastname: Eiermann
authors.forename: A
authors.initials: A
authors.lastname: Wölpl
authors.forename: C
authors.initials: C
authors.lastname: Löliger
authors.forename: P
authors.initials: P
authors.lastname: Kühnl
authors.forename: B O
authors.initials: BO
authors.lastname: Boehm
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002478:Cells, Cultured; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology*; D015329:Gene Rearrangement, T-Lymphocyte; D005968:Glutamate Decarboxylase / Q000378:metabolism*; D006801:Humans; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000096:biosynthesis / Q000235:genetics; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D008222:Lymphokines; D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell; D015375:Receptors, Interleukin-2; D005968:Glutamate Decarboxylase