Alpha-amylase functions as a salivary gland-specific self T cell epitope in patients with Sjögren's syndrome.
Alpha-amylase functions as a salivary gland-specific self T cell epitope in patients with Sjögren's syndrome.
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α-淀粉酶在干燥综合征患者中充当唾液腺特异性自身 T 细胞表位。
DOI：
10.3892/ijmm.3.5.485
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发表时间：
1999
影响因子：
5.4
通讯作者：
T. Sumida
中科院分区：
文献类型：
--
作者：
I. Matsumoto;T. Maeda;Y. Takemoto;Y. Hashimoto;F. Kimura;I. Iwamoto;Y. Saito;K. Nishioka;T. Sumida
对干燥综合征（SS）患者唇唾液腺浸润性T细胞上的T细胞受体（TCR）的分析表明，在主要组织相容性复合体（MHC）的背景下，细胞通过抗原刺激而扩增。为阐明SS患者唇腺浸润T细胞识别的自身抗原，以T细胞TCR的抗原识别区TCR-CDR 3为探针，采用West-Western方法从人唇腺cDNA文库中筛选抗原。13个cDNA克隆被检测到与TCR-CDR 3区结合的蛋白。其中之一是人α-淀粉酶唾液前体（AA 54 -407），表明α-淀粉酶可能是唾液腺特异性自身抗原。为了检查α-淀粉酶是否作为唇唾液腺中的抗原，将来自11名SS患者的PBL与α-淀粉酶或唾液α-淀粉酶的9种不同合成氨基酸一起孵育。TCR的SSCP分析清楚地显示，在11例SS患者中的3例（27%）的唇唾液腺中观察到α-淀粉酶反应性T细胞。这些发现支持α-淀粉酶作为唾液腺特异性T细胞表位发挥作用并诱导SS自身免疫的可能性。
Analyses of T cell receptors (TCR) on T cells infiltrating labial salivary glands of patients with Sjögren's syndrome (SS) indicate that the cells expand by antigen stimulation in context of major histocompatibility complex (MHC). To elucidate the autoantigens recognized by T cells infiltrating in labial salivary glands from patients with SS, proteins derived from human salivary gland cDNA libraries were screened by West-Western method using TCR-CDR3 probe, which is antigen recognition region of TCR on T cells. 13 cDNA clones were detected as proteins binding to TCR-CDR3 region. One was a human alpha-amylase salivary precursor (AA54-407), suggesting that alpha-amylase might be a salivary gland-specific autoantigen. To examine whether alpha-amylase acts as an antigen in labial salivary glands, PBL from 11 patients with SS were incubated with 9 different synthetic amino acids of alpha-amylase or salivary alpha-amylase. SSCP analysis on TCR clearly showed that alpha-amylase reactive T cells were observed in labial salivary glands from 3 of 11 patients with SS (27%). These findings support the possibility that alpha-amylase functions as a salivary gland-specific T cell epitope and induces autoimmunity in SS.