Standifer Nathan E, Ouyang Qin, Panagiotopoulos Constadina, Verchere C Bruce, Tan Rusung, Greenbaum Carla J, Pihoker Catherine, Nepom Gerald T
Benaroya Research Institute at Virginia Mason, 1201 Ninth Ave., Room 260, Seattle WA, 98101, USA.
Diabetes. 2006 Nov;55(11):3061-7. doi: 10.2337/db06-0066.
Cytotoxic T-lymphocytes (CTLs) are considered to be essential for beta-cell destruction in type 1 diabetes. However, few islet-associated peptides have been demonstrated to activate autoreactive CTLs from type 1 diabetic subjects. In an effort to identify novel epitopes, we used matrix-assisted algorithms to predict peptides of glial fibrillary acidic protein (GFAP), prepro-islet amyloid polypeptide (ppIAPP), and islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP) that likely bind to HLA-A0201 with a strong affinity and contain a COOH-terminal proteasomal cleavage site. Seven peptides stabilized HLA-A0201 expression in binding assays and were used to stimulate peripheral blood mononuclear cells and were evaluated for granzyme B secretion. We found that 5 of 13 type 1 diabetic subjects and 4 of 6 antibody-positive relatives exhibited greater numbers of granzyme B-secreting cells in response to at least one putative epitope compared with healthy control subjects. The most prevalent responses in antibody-positive and type 1 diabetic subjects were to ppIAPP(9-17). Other peptides recognized by type 1 diabetic or antibody-positive subjects included GFAP(143-151), IGRP(152-160), and GFAP(214-222). These data implicate peptides of ppIAPP, GFAP, and IGRP as CTL epitopes for a heterogenous CD8(+) T-cell response in type 1 subjects and antibody-positive relatives.
细胞毒性T淋巴细胞（CTLs）被认为在1型糖尿病的β细胞破坏中起关键作用。然而，很少有胰岛相关肽被证明能激活1型糖尿病患者的自身反应性CTLs。为了确定新的表位，我们使用矩阵辅助算法预测胶质纤维酸性蛋白（GFAP）、胰岛淀粉样多肽前体（ppIAPP）和胰岛特异性葡萄糖-6-磷酸酶催化亚基相关蛋白（IGRP）的肽段，这些肽段可能与HLA-A0201具有高亲和力结合且含有COOH末端蛋白酶体切割位点。在结合试验中，7种肽稳定了HLA-A0201的表达，并用于刺激外周血单个核细胞，并评估颗粒酶B的分泌。我们发现，与健康对照相比，13名1型糖尿病患者中的5名和6名抗体阳性亲属中的4名对至少一种假定表位产生了更多分泌颗粒酶B的细胞。抗体阳性和1型糖尿病患者中最普遍的反应是针对ppIAPP(9-17)。1型糖尿病或抗体阳性患者识别的其他肽包括GFAP(143-151)、IGRP(152-160)和GFAP(214-222)。这些数据表明，ppIAPP、GFAP和IGRP的肽段是1型患者和抗体阳性亲属中异质性CD8(+)T细胞反应的CTL表位。
