RT Journal Article SR Electronic T1 Detection of GAD65-Specific T-Cells by Major Histocompatibility Complex Class II Tetramers in Type 1 Diabetic Patients and At-Risk Subjects JF Diabetes JO Diabetes FD American Diabetes Association SP 1375 OP 1382 DO 10.2337/diabetes.51.5.1375 VO 51 IS 5 A1 Reijonen, Helena A1 Novak, Erik J. A1 Kochik, Sharon A1 Heninger, Anne A1 Liu, Andrew W. A1 Kwok, William W. A1 Nepom, Gerald T. YR 2002 UL http://diabetes.diabetesjournals.org/content/51/5/1375.abstract AB Soluble HLA-DR401 or -DR404 tetramers containing a peptide corresponding to an immunodominant epitope from human GAD65 were used to analyze peripheral blood T-cells of newly diagnosed type 1 diabetic patients and at-risk subjects. Peripheral blood mononuclear cells were expanded on antigen-presenting cells presenting GAD65 peptide and subsequently activated with specific plate-bound class II-peptide monomers. T-cell activation defined in flow cytometry by CD4high and/or CD25 markers were observed in all type 1 diabetic patients and some at-risk subjects, but not in normal control subjects. The activated T-cells stained positive with tetramers containing the GAD65 epitope 555-567. Tetramer-positive cells were CD4high T-cells with high avidity for an immunodominant GAD65 T-cell epitope. Phenotyping of T-cells utilizing HLA class II tetramers provides a new tool to characterize the autoimmune response in type 1 diabetes.