Functional analysis of neutralizing antibodies against Clostridium perfringens epsilon-toxin
Functional analysis of neutralizing antibodies against Clostridium perfringens epsilon-toxin
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DOI：
10.1128/iai.01643-06
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发表时间：
2007-04-01
影响因子：
3.1
通讯作者：
Cover, Timothy L.
中科院分区：
文献类型：
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作者：
McClain, Mark S.;Cover, Timothy L.
产气荚膜梭状芽胞杆菌毒素引起严重的，通常是致命的疾病（肠毒血症），其特征是心脏、肺、肾和脑水肿。在这项研究中，我们检测了两种中和性单克隆抗体对产气荚膜荚膜杆菌毒素的活性。这两种抗体抑制了epsilon-毒素对培养MDCK细胞的细胞毒性，并抑制了毒素在细胞质膜上形成孔的能力，结果表明，用膜内染色剂7-氨基放线菌素d染色细胞。利用抗体竞争酶联免疫吸附试验（ELISA）、肽阵列和突变毒素分析，我们绘制了其中一种中和单克隆抗体识别的表位，氨基酸134至145。抗体竞争ELISA和突变毒素分析表明，第二中和单克隆抗体也识别靠近该区域的表位。氨基酸134至145组成的区域重叠了一个两亲环，对应于毒素的假定膜插入域。鉴定这些中和抗体识别的表位是开发可用于对抗epsilon毒素影响的治疗剂的重要的第一步。
The Clostridium perfringens epsilon-toxin causes a severe, often fatal illness (enterotoxemia) characterized by cardiac, pulmonary, kidney, and brain edema. In this study, we examined the activities of two neutralizing monoclonal antibodies against the C. perfringens epsilon-toxin. Both antibodies inhibited epsilon-toxin cyto- toxicity towards cultured MDCK cells and inhibited the ability of the toxin to form pores in the plasma membranes of cells, as shown by staining cells with the membrane-impermeant dye 7-aminoactinomycin D. Using an antibody competition enzyme-linked immunosorbent assay (ELISA), a peptide array, and analysis of mutant toxins, we mapped the epitope recognized by one of the neutralizing monoclonal antibodies to amino acids 134 to 145. The antibody competition ELISA and analysis of mutant toxins suggest that the second neutralizing monoclonal antibody also recognizes an epitope in close proximity to this region. The region comprised of amino acids 134 to 145 overlaps an amphipathic loop corresponding to the putative membrane insertion domain of the toxin. Identifying the epitopes recognized by these neutralizing antibodies constitutes an important first step in the development of therapeutic agents that could be used to counter the effects of the epsilon-toxin.