Tabata H, Kanai T, Yoshizumi H, Nishiyama S, Fujimoto S, Matsuda I, Yasukawa M, Matsushita S, Nishimura Y
Department of Neuroscience and Immunology, Kumamoto University Graduate School of Medical Sciences, Japan.
Hum Immunol. 1998 Sep;59(9):549-60. doi: 10.1016/s0198-8859(98)00050-0.
To investigate autoimmunity to glutamic acid decarboxylase (GAD) 65 in Japanese patients with insulin-dependent diabetes mellitus (IDDM, type I diabetes), we established seven CD4+ T-cell clones, by stimulating peripheral blood mononuclear cells (PBMC) of six IDDM patients, using a mixture of overlapping human GAD65 peptides. No GAD65 autoreactive T-cell clones were evidenced in four healthy controls. Specificities of T-cell clones were as follows: (a) two clones specific to GAD65 p111-131 (residue 111 to 131) + DR53 (DRB40103); (b) one clone specific to GAD65 p413-433 + DR1 (DRB10101); (c) two clones specific to GAD65 p200-217 + either DR9 (DRB10901) or DR8 (DRB10802); and (d) two clones specific to GAD65 p368-388 + DP2 (DPA101 or 0201-DPB10201). Two DR53-restricted and one DR1-restricted T-cell clones, responded to a recombinant human GAD65 protein, and showed cytotoxicity against B lymphoblastoid cell lines pre-pulsed with the peptides. Six T-cell clones exhibited the Th1-like phenotype. Interestingly, two DR53-restricted T-cell clones killed a Fas-deficient B lymphoblastoid cell line, thereby indicating that cytotoxicity was not completely dependent on a Fas-Fas ligand interaction. Thus, the T-cell epitopes were mapped in a limited portion of GAD65 protein, with a tendency to be restricted by disease-associated HLA-DR, but not DQ molecules.
为了研究日本胰岛素依赖型糖尿病（IDDM，I型糖尿病）患者对谷氨酸脱羧酶（GAD）65的自身免疫性，我们通过用重叠的人GAD65肽混合物刺激6例IDDM患者的外周血单个核细胞（PBMC），建立了7个CD4 + T细胞克隆。在4名健康对照中未发现GAD65自身反应性T细胞克隆。T细胞克隆的特异性如下：（a）两个克隆对GAD65 p111 - 131（第111至131位氨基酸）+ DR53（DRB4 * 0103）具有特异性；（b）一个克隆对GAD65 p413 - 433 + DR1（DRB1 * 0101）具有特异性；（c）两个克隆对GAD65 p200 - 217 + DR9（DRB1 * 0901）或DR8（DRB1 * 0802）具有特异性；（d）两个克隆对GAD65 p368 - 388 + DP2（DPA1 * 01或0201 - DPB1 * 0201）具有特异性。两个受DR53限制和一个受DR1限制的T细胞克隆对重组人GAD65蛋白有反应，并对预先用肽脉冲处理的B淋巴母细胞系表现出细胞毒性。六个T细胞克隆表现出Th1样表型。有趣的是，两个受DR53限制的T细胞克隆杀死了一个Fas缺陷的B淋巴母细胞系，从而表明细胞毒性并不完全依赖于Fas - Fas配体相互作用。因此，T细胞表位定位于GAD65蛋白的有限部分，倾向于受疾病相关的HLA - DR而非DQ分子限制。
