NEUTROPHIL RECRUITMENT IN CLOSTRIDIUM-DIFFICILE TOXIN-A ENTERITIS IN THE RABBIT
NEUTROPHIL RECRUITMENT IN CLOSTRIDIUM-DIFFICILE TOXIN-A ENTERITIS IN THE RABBIT
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DOI：
10.1172/jci117080
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发表时间：
1994-03-01
影响因子：
15.9
通讯作者：
POTHOULAKIS, C
中科院分区：
文献类型：
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作者：
KELLY, CP;BECKER, S;POTHOULAKIS, C
中性粒细胞浸润是艰难梭菌相关肠炎和结肠炎的一个显著特征。本研究的目的是研究中性粒细胞募集和中性粒细胞介导的组织损伤在艰难梭菌毒素a诱导的肠炎中的重要性。使用纯化的h -3毒素A进行的竞争性结合实验表明，在兔中性粒细胞（k - d7 × 10(-8) M）上存在一类中等亲和力受体。百日毒和不可水解的GTP类似物GTPgamma S均抑制h -3-毒素A的结合（分别抑制56%和65%），表明兔中性粒细胞毒素A受体与G蛋白连接。毒素A对体外中性粒细胞迁移具有剂量依赖性（25 ~ 200 μ g/ml），且该功能效应对百日咳毒素敏感（抑制69%）。R15.7（一种针对白细胞粘附分子CD18的阻断性单克隆抗体）处理中性粒细胞，可在体外抑制毒素a刺激的中性粒细胞迁移85%。通过组织学检查和回肠组织髓过氧化物酶水平测定，R15.7预处理家兔体内毒素a暴露回肠袢也能阻止中性粒细胞浸润。此外，R15.7对毒素a暴露的回肠袢的液体分泌（65%）、甘露醇渗透性（66%）和组织学损伤有显著的抑制作用。抗cd18 （R15.7）对霍乱毒素肠毒性无抑制作用。这些数据表明艰难梭菌毒素A是一种促炎毒素，其肠毒性作用在很大程度上依赖于中性粒细胞的募集。
Neutrophil infiltration is a prominent feature of Clostridium difficile-associated enteritis and colitis. The aim of this study was to examine the importance of neutrophil recruitment and neutrophil-mediated tissue damage in C. difficile toxin A-induced enteritis. Competitive binding experiments using purified H-3-toxin A demonstrated the presence of a single class of medium affinity receptors on rabbit neutrophils (K-d 7 X 10(-8) M). Pertussis toxin and the nonhydrolyzable GTP analog GTPgamma S both inhibited H-3-toxin A binding (by 56 and 65%, respectively), indicating that the rabbit neutrophil toxin A receptor is G protein linked. Toxin A elicited a dose-dependent (25-200 mu g/ml) stimulation of neutrophil migration in vitro, and this functional effect was also pertussis toxin sensitive (69% inhibition). Treatment of neutrophils with R15.7, a blocking monoclonal antibody to the leukocyte adhesion molecule CD18, inhibited toxin A-stimulated neutrophil migration by 85% in vitro. Pretreatment of rabbits with R15.7 also prevented neutrophil infiltration of toxin A-exposed ileal loops in vivo as determined by histologic examination and by ileal tissue myeloperoxidase levels. Furthermore, R15.7 effected a substantial inhibition of fluid secretion (by 65%), mannitol permeability (by 66%), and histologic damage in toxin A-exposed ileal loops. Anti-CD18 (R15.7) had no inhibitory effect on cholera toxin enterotoxicity. These data demonstrate that C. difficile toxin A is a proinflammatory toxin whose enterotoxic effects are substantially dependent upon neutrophil recruitment.