Immunogenic properties of the surface layer precursor of Clostridium difficile and vaccination assays in animal models
Immunogenic properties of the surface layer precursor of Clostridium difficile and vaccination assays in animal models
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DOI：
10.1016/j.anaerobe.2015.10.010
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发表时间：
2016-02-01
期刊：
影响因子：
2.3
通讯作者：
Pechine, S.
中科院分区：
文献类型：
--
作者：
Bruxelle, J. -F.;Mizrahi, A.;Pechine, S.
艰难梭菌是一种引起肠道炎症的机会性病原体，通常与抗生素引起的肠道生态失调有关。已经确定了几个毒力因素在肠道定植中起关键作用。表层蛋白由高分子量SlpA （HMW-SLP）和低分子量SlpA （LMW-SLP）两种蛋白组成，是艰难梭菌表面最丰富的蛋白。这两种蛋白来源于cwp84介导的单个前体蛋白SIpA的裂解。在这项研究中，我们在仓鼠和小鼠模型中评估了从产毒艰难梭菌菌株（630）中提取的重组SIpA前体的免疫原性，以及它作为疫苗抗原与霍乱毒素作为佐剂共同给药的保护作用。首先，我们证实了SlpA在人体内的免疫原性。采用ELISA法对难辨梭菌感染患者血清进行分析。CDI患者比健康患者有更多的SlpA抗体，证实了该蛋白在发病过程中的免疫原性。然后，在常规仓鼠和小鼠中进行直肠疫苗接种试验。接种前后分别采集动物血清，采用ELISA法进行分析。此外，在小鼠模型中，接种疫苗后取样粪便，用ELISA检测针对SIpA的IgA。在两种模型中，攻毒后通过粪便细菌计数评估肠道定植。用SlpA和霍乱毒素作为佐剂的直肠内疫苗接种在小鼠和仓鼠中诱导了局部和全身的体液免疫反应，这可能是小鼠体内艰难梭菌定植的微弱减少和在致死仓鼠模型中观察到的部分保护的原因。(C) 2015 Elsevier Ltd.版权所有。
Clostridium difficile is an opportunistic pathogen causing gut inflammation generally associated with an intestinal dysbiosis due to antibiotics. Several virulence factors have been identified as playing a key role in gut colonization. The surface-layer proteins, comprised of two proteins, the high molecular weight SlpA (HMW-SLP) and the low molecular weight SlpA (LMW-SLP), are the most abundant proteins on the C difficile surface. These two proteins are derived from the Cwp84-mediated cleavage of a single precursor protein SIpA. In this study, we assessed the immunogenic properties of a recombinant SIpA precursor derived from a toxigenic C difficile strain (630) and its protective effect as a vaccine antigen co-administered with the cholera toxin as an adjuvant in both hamster and mouse models.First, we confirmed the immunogenicity of SlpA in humans. Sera from patients with C difficile infection were analyzed by ELISA. Patients with CDI have a greater number of SlpA antibodies than healthy patients, confirming the immunogenicity of this protein during the pathogenic process. Then, rectal vaccination assays were performed in both conventional hamsters and mice. The animals' sera were sampled before and after vaccination, and were analyzed by ELISA. In addition, in the mouse model, feces were sampled after vaccination and IgA directed against SIpA were detected by ELISA. In both models, the intestinal colonization was evaluated by fecal bacterial count after challenge. Intra-rectal vaccination with SlpA and cholera toxin as an adjuvant induced a local and systemic humoral immune response in mice and hamsters potentially responsible for the weak decrease of C difficile colonization in mice and the partial protection observed in a lethal-hamster model. (C) 2015 Elsevier Ltd. All rights reserved.