Characterization of two putative Dichelobacter nodosus footrot vaccine antigens identifies the first lysozyme inhibitor in the genus
Characterization of two putative Dichelobacter nodosus footrot vaccine antigens identifies the first lysozyme inhibitor in the genus
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DOI：
10.1038/s41598-019-46506-z
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发表时间：
2019-07-11
影响因子：
4.6
通讯作者：
Christodoulides, Myron
中科院分区：
文献类型：
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作者：
Humbert, Maria Victoria;Jackson, Alexandra;Christodoulides, Myron
革兰氏阴性厌氧细菌节瘤叉蹄菌（Dichelobacterium nodosus，Dn）引起反刍动物的腐蹄病，这是一种使人衰弱且高度传染性的疾病，其导致蹄坏死和农业中的重大经济损失。用与多种重组菌毛蛋白混合的粗全细胞疫苗接种可以在物种特异性爆发期间提供保护，但是含有广泛交叉保护性抗原的亚单位疫苗是期望的。我们研究了两个D。结节虫候选疫苗抗原。巨噬细胞增殖增强因子Dn-MIP（DNO_0012，DNO_RS00050）和粘附素复合物蛋白Dn-ACP（DNO_0725，DNO_RS06795）在170 D中高度保守。在https://pubmlst.org/dnodosus/database上找到了结节菌分离物。我们描述了存在两个同源的ACP结构域在DN-ACP与有效的C型溶菌酶抑制剂功能，和同源性的DN-MIP其他假定的细胞表面和膜锚定的MIP毒力因子。用重组蛋白与多种佐剂免疫小鼠，诱导出识别D.结节状的值得注意的是，用菌毛全细胞Footvax疫苗免疫诱导了抗DN-ACP和抗DN-MIP抗体。尽管所有佐剂都诱导了高滴度的抗体应答，但只有rDn-ACP-基拉和rDn-ACP-Al（OH）（3）的抗血清在体外显著阻止了rDn-ACP蛋白对溶菌酶活性的抑制。因此，特别是掺入rDn-ACP的疫苗可以通过使正常的先天免疫溶菌酶功能能够帮助细菌清除而有助于保护。
The Gram-negative anaerobic bacterium Dichelobacter nodosus (Dn) causes footrot in ruminants, a debilitating and highly contagious disease that results in necrotic hooves and significant economic losses in agriculture. Vaccination with crude whole-cell vaccine mixed with multiple recombinant fimbrial proteins can provide protection during species-specific outbreaks, but subunit vaccines containing broadly cross-protective antigens are desirable. We have investigated two D. nodosus candidate vaccine antigens. Macrophage Infectivity Potentiator Dn-MIP (DNO_0012, DNO_RS00050) and Adhesin Complex Protein Dn-ACP (DNO_0725, DNO_RS06795) are highly conserved amongst similar to 170 D. nodosus isolates in the https://pubmlst.org/dnodosus/database. We describe the presence of two homologous ACP domains in Dn-ACP with potent C-type lysozyme inhibitor function, and homology of Dn-MIP to other putative cell-surface and membrane-anchored MIP virulence factors. Immunization of mice with recombinant proteins with a variety of adjuvants induced antibodies that recognised both proteins in D. nodosus. Notably, immunization with fimbrial-whole-cell Footvax vaccine induced anti-Dn-ACP and anti-Dn-MIP antibodies. Although all adjuvants induced high titre antibody responses, only antisera to rDn-ACP-QuilA and rDn-ACP-Al(OH)(3) significantly prevented rDn-ACP protein from inhibiting lysozyme activity in vitro. Therefore, a vaccine incorporating rDn-ACP in particular could contribute to protection by enabling normal innate immune lysozyme function to aid bacterial clearance.