Recombinant flagellins with deletions in domains D1, D2, and D3: Characterization as novel immunoadjuvants
Recombinant flagellins with deletions in domains D1, D2, and D3: Characterization as novel immunoadjuvants
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DOI：
10.1016/j.vaccine.2018.12.009
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发表时间：
2019-01-21
期刊：
影响因子：
5.5
通讯作者：
Sirard, Jean Claude
中科院分区：
文献类型：
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作者：
Biedma, Marina E.;Cayet, Delphine;Sirard, Jean Claude
细菌鞭毛蛋白通过Toll样受体5（TLR 5）依赖性信号传导机制激活先天免疫系统并最终激活适应性免疫系统。鉴于TLR 5广泛分布于上皮细胞中，鞭毛蛋白目前正被开发为粘膜佐剂。来自肠道沙门氏菌的鞭毛蛋白FliC具有四个结构域：保守的D 0和D1结构域以及高变的D2和D3结构域。重组FliC（Delta 174-400）中D3的缺失和D2的部分缺失强烈地损害鞭毛蛋白的固有抗原性，但不影响TLR 5依赖性免疫刺激活性，即，促进对共同施用的抗原的先天应答和适应性应答的能力。在这里，我们描述了新的重组鞭毛蛋白的发展与各种缺失，包括所有的D2和D3，和部分的D1。大多数的重组分子保守的α-螺旋的二级结构，是耐热变性的天然蛋白质。尽管重组鞭毛蛋白在体外触发TLR 5的能力显著不同，但在向小鼠鼻内施用2 μ g鞭毛蛋白后，大多数重组鞭毛蛋白在体内产生等同的TLR 5依赖性先天免疫应答。一致地，重组鞭毛蛋白也是用于引发对外源抗原卵清蛋白的抗体应答的有价值的呼吸道佐剂，尽管其内在抗原性与天然鞭毛蛋白相比降低，并且与FliC（Delta 174-400）相比没有增加。我们的结果表明，FliC的D2和D1远端部分的额外缺失（Delta 174-400）不会影响抗原性，也不会显著改变免疫刺激佐剂活性。总之，本研究产生了一组新的重组鞭毛蛋白，其构成了用于疫苗接种的TLR 5依赖性候选佐剂的组合。(C)2018爱思唯尔有限公司版权所有。
Bacterial flagellin activates the innate immune system and ultimately the adaptive immune system through a Toll-like receptor 5 (TLR5)-dependent signaling mechanism. Given that TLR5 is widely distributed in epithelia, flagellin is currently being developed as a mucosal adjuvant. Flagellin FliC from Salmonella enterica has four domains: the conserved D0 and D1 domains and the hypervariable D2 and D3 domains. The deletion of D3 and partial deletion of D2 in the recombinant FliC(Delta 174-400) strongly impairs flagellin's intrinsic antigenicity but does not affect the TLR5-dependent immunostimulation activity, i.e., the capacity to promote innate responses and adaptive responses to co-administered antigens. Here, we describe the development of novel recombinant flagellins with various deletions encompassing all of D2 and D3, and part of D1. Most of the recombinant molecules conserved an alpha-helical secondary structure that was as resistant to heat denaturation as the native protein. Whereas the recombinant flagellins' ability to trigger TLR5 varied markedly in vitro, most gave equivalent in vivo TLR5-dependent innate immune responses following intranasal administration of 2 mu g of flagellin to mice. Concordantly, the recombinant flagellins were also valuable respiratory adjuvants for eliciting antibody responses to the foreign antigen ovalbumin, although their intrinsic antigenicity was decreased compared to the native flagellin and not increased compared to FliC(Delta 174-400). Our results show that the additional deletions of D2 and the distal part of D1 of FliC(Delta 174-400) does not impact on antigenicity and does not significantly modify the immunostimulatory adjuvant activity. Altogether, this study generated a novel set of recombinant flagellin that constitutes a portfolio of TLR5-dependent candidate adjuvants for vaccination. (C) 2018 Elsevier Ltd. All rights reserved.