Protection against the toxic effects of Loxosceles intermedia spider venom elicited by mimotope peptides
Protection against the toxic effects of Loxosceles intermedia spider venom elicited by mimotope peptides
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DOI：
10.1016/j.vaccine.2011.08.065
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发表时间：
2011-10-19
期刊：
影响因子：
5.5
通讯作者：
Chavez-Olortegui, C.
中科院分区：
文献类型：
--
作者：
de Moura, J.;Felicori, L.;Chavez-Olortegui, C.
Loxosceles intermedia (Li) 蜘蛛的毒液会导致皮肤损伤和其他临床表现。我们之前报道过单克隆抗体LimAb7可以中和粗锂毒液的皮肤坏死活性。在这项研究中，我们观察到该抗体可识别毒液皮肤坏死部分 (DNF) 中的多种蛋白质，包括 LiD1。识别这种中和抗体的表位可以帮助设计用于产生治疗血清或疫苗接种方法的免疫原。为此，使用 SPOT 技术合成了两组覆盖 LiD1 完整氨基酸序列的 25 聚体和 15 聚体重叠肽。 LimAb7 无法识别其中任何一个，表明该表位是不连续的。然后，对四个肽噬菌体展示文库的筛选产生了四个可能的表位模拟物，然而，它们与 LiD1 序列没有表现出任何明显的相似性。这些模拟表位与 LiD1 的 3D 模型一起，通过 MIOP 生物信息学工具来预测 LimAb7 识别的假定表位区域（LiD1 的残基 C197、Y224、W225、T226、D228、K229、R230、T232 和 Y248）。该分析和丙氨酸扫描实验的结果突出显示了在不同 SMases D 的活性位点中发现的一些残基（例如 W225 和 D228），这些残基可能对 LiD1 酶活性很重要。最后，唯一通过 SPOT 与 LimAb7 相互作用的模拟表位 NCNKNDHLFACW 及其类似物 NSNKNDHLFASW 被用作兔子的免疫原。由此产生的抗体可以中和粗锂毒液诱导的一些生物效应，证明模拟表位诱导的针对中间锂毒液的保护作用。由爱思唯尔有限公司出版
The venom of Loxosceles intermedia (Li) spiders is responsible for cutaneous lesions and other clinical manifestations. We previously reported that the monoclonal antibody LimAb7 can neutralize the dermonecrotic activity of crude Li venom. In this study, we observed that this antibody recognizes several proteins from the venom dermonecrotic fraction (DNF), including LiD1. Identifying the epitope of such a neutralizing antibody could help designing immunogens for producing therapeutic sera or vaccination approaches. To this aim, two sets of 25- and 15-mer overlapping peptides that cover the complete amino acid sequence of LiD1 were synthesized using the SPOT technique. None of them was recognized by LimAb7, suggesting that the epitope is discontinuous. Then, the screening of four peptide phage-display libraries yielded four possible epitope mimics that, however, did not show any obvious similarity with the LiD1 sequence. These mimotopes, together with a 3D model of LiD1, were used to predict with the MIMOP bioinformatic tool the putative epitope region (residues C197, Y224, W225, T226, D228, K229, R230, T232 and Y248 of LiD1) recognized by LimAb7. This analysis and the results of alanine-scanning experiments highlighted a few residues (such as W225 and D228) that are found in the active site of different SMases D and that may be important for LiD1 enzymatic activity. Finally, the only mimotope NCNKNDHLFACW that interacts with LimAb7 by SPOT and its analog NSNKNDHLFASW were used as immunogens in rabbits. The resulting antibodies could neutralize some of the biological effects induced by crude Li venom, demonstrating a mimotope-induced protection against L. intermedia venom. Published by Elsevier Ltd.