Mitea C, Havenaar R, Drijfhout J Wouter, Edens L, Dekking L, Koning F
Department of Immunohematology and Blood Transfusion, E3-Q, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands.
Gut. 2008 Jan;57(1):25-32. doi: 10.1136/gut.2006.111609. Epub 2007 May 9.
Coeliac disease is caused by an immune response to gluten. As gluten proteins are proline rich they are resistant to enzymatic digestion in the gastrointestinal tract, a property that probably contributes to the immunogenic nature of gluten.
This study determined the efficiency of gluten degradation by a post-proline cutting enzyme, Aspergillus niger prolyl endoprotease (AN-PEP), in a dynamic system that closely mimics the human gastrointestinal tract (TIM system).
Two experiments were performed. In the first, a slice of bread was processed in the TIM system with and without co-administration of AN-PEP. In the second, a standard fast food menu was used. Samples of the digesting meals were taken from the stomach, duodenum, jejunum and ileum compartments at time zero until 4 hours after the start of the experiment. In these samples the levels of immunogenic peptides from gliadins and glutenins were assessed by monoclonal antibody-based competition assays, Western blot analysis and proliferation T-cell assays.
AN-PEP accelerated the degradation of gluten in the stomach compartment to such an extent that hardly any gluten reached the duodenum compartment.
AN-PEP is capable of accelerating the degradation of gluten in a gastrointestinal system that closely mimics in-vivo digestion. This implies that the co-administration of AN-PEP with a gluten-containing meal might eliminate gluten toxicity, thus offering patients the possibility of abandoning (occasionally) their strict gluten-free diet.
乳糜泻由对麸质的免疫反应引起。由于麸质蛋白富含脯氨酸,它们在胃肠道中对酶消化具有抗性,这一特性可能导致了麸质的免疫原性。
本研究在一个紧密模拟人类胃肠道的动态系统(TIM系统)中,测定了一种脯氨酸切割后酶——黑曲霉脯氨酰内肽酶(AN-PEP)对麸质的降解效率。
进行了两项实验。第一项实验中,在TIM系统中对一片面包进行处理,分别添加和不添加AN-PEP。第二项实验中,使用了一份标准快餐菜单。在实验开始后0小时至4小时期间,从胃、十二指肠、空肠和回肠隔室采集正在消化的食物样本。通过基于单克隆抗体的竞争测定、蛋白质印迹分析和增殖T细胞测定,评估这些样本中麦醇溶蛋白和麦谷蛋白免疫原性肽的水平。
AN-PEP极大地加速了胃隔室中麸质的降解,以至于几乎没有麸质到达十二指肠隔室。
AN-PEP能够在一个紧密模拟体内消化的胃肠系统中加速麸质的降解。这意味着将AN-PEP与含麸质餐一起服用可能消除麸质毒性,从而为患者提供(偶尔)放弃严格无麸质饮食的可能性。