Toma Andréa, Haddouk Samy, Briand Jean-Paul, Camoin Luc, Gahery Hanne, Connan Francine, Dubois-Laforgue Danielle, Caillat-Zucman Sophie, Guillet Jean-Gérard, Carel Jean-Claude, Muller Sylviane, Choppin Jeannine, Boitard Christian
Institut National de la Santé et de la Recherche Médicale U561, Hôpital Cochin-Saint Vincent de Paul, Université Paris V, 75014 Paris, France.
Proc Natl Acad Sci U S A. 2005 Jul 26;102(30):10581-6. doi: 10.1073/pnas.0504230102. Epub 2005 Jul 19.
Proinsulin is a key autoantigen in type 1 diabetes. Evidence in the mouse has underscored the importance of the insulin B chain region in autoimmunity to pancreatic beta cells. In man, a majority of proteasome cleavage sites are predicted by proteasome cleavage algorithms within this region. To study CD8+ T cell responses to the insulin B chain and adjacent C peptide, we selected 8- to 11-mer peptides according to proteasome cleavage patterns obtained by digestion of two peptides covering proinsulin residues 28 to 64. We studied their binding to purified HLA class I molecules and their recognition by T cells from diabetic patients. Peripheral blood mononuclear cells from 17 of 19 recent-onset and 12 of 13 long-standing type 1 diabetic patients produced IFN-gamma in response to proinsulin peptides as shown by using an ELISPOT assay. In most patients, the response was against several class I-restricted peptides. Nine peptides were recognized within the proinsulin region covering residues 34 to 61. Four yielded a high frequency of recognition in HLA-A1 and -B8 patients. Three peptides located in the proinsulin region 41-51 were shown to bind several HLA molecules and to be recognized in a high percentage of diabetic patients.
胰岛素原是1型糖尿病中的关键自身抗原。小鼠实验证据强调了胰岛素B链区域在针对胰腺β细胞自身免疫中的重要性。在人类中，该区域内的大多数蛋白酶体切割位点可通过蛋白酶体切割算法预测。为了研究CD8 + T细胞对胰岛素B链和相邻C肽的反应，我们根据对覆盖胰岛素原28至64位残基的两种肽进行消化所获得的蛋白酶体切割模式，选择了8至11聚体肽。我们研究了它们与纯化的HLA I类分子的结合以及糖尿病患者T细胞对它们的识别。如通过ELISPOT分析所示，19例近期发病的1型糖尿病患者中的17例以及13例长期患病患者中的12例的外周血单个核细胞对胰岛素原肽产生了γ干扰素。在大多数患者中，反应针对几种I类限制性肽。在覆盖34至61位残基的胰岛素原区域内识别出9种肽。其中4种在HLA - A1和 - B8患者中具有高识别频率。位于胰岛素原区域41 - 51的3种肽显示与几种HLA分子结合，并在高比例的糖尿病患者中被识别。
