Saccharomyces boulardii protease inhibits Clostridium difficile toxin A effects in the rat ileum
Saccharomyces boulardii protease inhibits Clostridium difficile toxin A effects in the rat ileum
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DOI：
10.1128/iai.64.12.5225-5232.1996
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发表时间：
1996-12-01
影响因子：
3.1
通讯作者：
Pothoulakis, C
中科院分区：
文献类型：
--
作者：
Castagliuolo, I;LaMont, JM;Pothoulakis, C
布拉囊酵母是一种非致病性酵母菌，对艰难梭菌腹泻和结肠炎有较好的治疗作用。布拉氏酵母菌对C.艰难梭菌毒素A可能是通过释放一种蛋白酶来抑制肠道对这种毒素的受体（C，Pothoulakis，C，P，Kelly，M，A，Joshi，N，Gao，C，J，O'Keane，I，Castagliuolo和J，T，拉蒙，Gastroenterology 104：1108-1115，1993），本研究的目的是纯化和表征这种蛋白酶S，通过SephadexG-50和Octyl-Sepharose凝胶过滤部分纯化了布拉氏酵母蛋白酶。在大鼠体内回肠袢中检测布拉氏酵母蛋白酶对大鼠回肠分泌、上皮通透性和响应毒素A的形态学的影响，纯化的S.用部分纯化的蛋白酶预处理大鼠回肠刷状缘（BE）膜，可使BE膜与毒素A受体的特异性结合降低26%;部分纯化的蛋白酶在体外消化毒素A分子，可使BE膜与毒素A受体的特异性结合降低42%;毒素A、vith S、布拉氏蛋白酶预孵育抑制回肠分泌（46%抑制率，P < 0.01），甘露醇通透性（74%抑制率，P < 0.01），以及毒素A引起的组织损伤。布拉氏菌蛋白酶通过蛋白水解毒素和抑制毒素A与BE受体的结合来抑制艰难梭菌毒素A的肠道效应。布拉氏酵母菌在人类艰难梭菌感染中发挥保护作用。
Sacckaromyces boulardii, a nonpathogenic yeast, is effective in treating some patients with Clostridium difficile diarrhea and colitis, We have previously reported that S. boulardii inhibits rat ileal secretion in response to C. difficile toxin A possibly by releasing a protease that digests the intestinal receptor for this toxin (C, Pothoulakis, C, P, Kelly, M, A, Joshi, N, Gao, C, J, O'Keane, I, Castagliuolo, and J, T, LaMont, Gastroenterology 104: 1108-1115, 1993), The aim of this study was to purify and characterize this protease, S, boulardii protease was partially purified by gel filtration on Sephadex G-50 and octyl-Sepharose, The effect of S, boulardii protease on rat ileal secretion, epithelial permeability, and morphology in response to toxin A was examined in rat ileal loops in vivo, Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified S. boulardii protease revealed a major band at 54 kDa, Pretreatment of rat ileal brush border (BE) membranes with partially purified protease reduced specific toxin A receptor binding (by 26%), Partially purified protease digested the toxin A molecule and significantly reduced its binding to BE membranes in vitro (by 42%), Preincubation of toxin A,vith S, boulardii protease inhibited ileal secretion (46% inhibition, P < 0.01), mannitol permeability (74% inhibition, P < 0.01), and histologic damage caused by toxin A, Thus, S. boulardii protease inhibits the intestinal effects of C, difficile toxin A by proteolysis of the toxin and inhibition of toxin A binding to its BE receptor, Our results may be relevant to the mechanism by which S. boulardii exerts its protective effects in C, difficile infection in humans.