Transamidation of wheat flour inhibits the response to gliadin of intestinal T cells in celiac disease
Transamidation of wheat flour inhibits the response to gliadin of intestinal T cells in celiac disease
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DOI：
10.1053/j.gastro.2007.06.023
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发表时间：
2007-09-01
期刊：
影响因子：
29.4
通讯作者：
Rossi, Mauro
中科院分区：
文献类型：
--
作者：
Gianfrani, Carmen;Siciliano, Rosa A.;Rossi, Mauro
背景与目的：乳糜泻是以人类白细胞抗原DQ2/DQ8限制性肠谷蛋白特异性CD4(+)T细胞活化为特征的疾病。特别是，面筋在组织转谷氨酰胺酶的催化下脱酰胺后成为一种更好的T细胞抗原。到目前为止，唯一可用的治疗方法是坚持无麸质饮食。在这里，我们研究了一种新的酶策略，以预防性地消除面筋活性。方法：用质谱仪分析免疫优势的α-Ghadin多肽p56-68的酶修饰，并通过模拟研究模拟其与人类白细胞抗原-DQ2的结合。用微生物谷氨酰胺转氨酶和赖氨酸甲酯处理小麦粉，然后提取、消化和脱胺。从12例成人乳糜泻患者的活检标本中获得醇溶蛋白特异的肠道T细胞系(ITCL)，并在体外用不同的抗原制剂进行攻击。结果：组织转谷氨酰胺酶介导的p56-68赖氨酸或赖氨酸甲酯或醇溶蛋白在碱性条件下转酰胺化可抑制iTCL中干扰素-γ的表达，同时与DQ2的结合也减少，但未被取消。赖氨酸甲酯对醇溶蛋白活性的抑制作用尤为明显。值得注意的是，当用从经过微生物转谷氨酰胺酶和赖氨酸甲酯处理的面粉中提取的醇溶蛋白挑战iTCL时，反应被阻断。结论：用食品级酶和适当的胺供体对小麦面粉进行转酰胺化可以阻断T细胞介导的Ghadin活性。考虑到获得性免疫在乳糜泻中的关键作用，我们的研究结果强调了拟议的治疗方法在预防谷物中毒方面的潜力。
Background & Aims: Celiac disease is characterized by activation of HLA-DQ2/DQ8 -restricted intestinal gluten-specific CD4(+) T cells. in particular, gluten becomes a better T-cell antigen following deamidation catalyzed by tissue transglutaminase. To date, the only available therapy is represented by adherence to a gluten-free diet. Here, we examined a new enzyme strategy to preventively abolish gluten activity. MethodS: Enzyme modifications of the immunodominant alpha-ghadin peptide p56-68 were analyzed by mass spectrometry, and peptide binding to HLA-DQ2 was simulated by modeling studies. Wheat flour was treated with microbial transglutaminase and lysine methyl ester; ghadin was subsequently extracted, digested, and deamidated. Gliadin-specific intestinal T-cell lines (iTCLs) were generated from biopsy specimens from 12 adult patients with celiac disease and challenged in vitro with different antigen preparations. Results: Tissue transglutaminase-mediated transamidation with lysine or lysine methyl ester of p56-68 or gliadin in alkaline conditions inhibited the interferon gamma expression in iTCLs; also, binding to DQ2 was reduced but not abolished, as suggested by in silico analysis. Lysine methyl ester was particularly effective in abrogating the activity of gliadin. Notably, a block in the response was observed when iTCLs were challenged with gliadin extracted from flour pretreated with microbial transglutaminase and lysine methyl ester. Conclusions: Transamidation of wheat flour with a food-grade enzyme and an appropriate amine donor can be used to block the T cell.-mediated ghadin activity. Considering the crucial role of adaptive immunity in celiac disease, our findings highlight the potential of the proposed treatment to prevent cereal toxicity.