Live recombinant Lactococcuslactis expressing avian hepatitis virus ORF2 protein: Immunoprotection against homologous virus challenge in chickens
Live recombinant Lactococcuslactis expressing avian hepatitis virus ORF2 protein: Immunoprotection against homologous virus challenge in chickens
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表达禽肝炎病毒 ORF2 蛋白的活重组乳酸乳球菌：对鸡同源病毒攻击的免疫保护
DOI：
10.1016/j.vaccine.2018.01.003
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发表时间：
2018-02-14
期刊：
影响因子：
5.5
通讯作者：
Zhou, En-Min
中科院分区：
文献类型：
--
作者：
Wang, Dian;Zhang, Yue;Zhou, En-Min
禽戊型肝炎病毒（avianhepatitisingE virus，aHEV）是引起鸡肝炎-脾肿大综合征的病原体。到目前为止，还没有商业疫苗可用于预防aHEV感染。在本研究中，使用pTX 8048载体构建了三种重组乳酸乳球菌NZ 9000实验活疫苗，其表达胞质、分泌和细胞壁锚定形式的aHEV截短的ORF 2蛋白，其跨越氨基酸249-606（Delta ORF 2），并进行表征。每只鸡用三种aHEV ORF 2活疫苗中的一种（实验组）或仅含空载体的活疫苗（对照组）以两周间隔免疫三次。然后用aHEV攻击两组，并进行评价以比较免疫应答和免疫原性效果。试验组血清IgG水平、胆汁和空肠灌洗液中分泌型伊加（sigA）水平以及肝脏和脾脏中IL-2和IFN-γ mRNA表达水平均显著高于对照组。同时，攻毒后血清和粪便病毒载量显着低于对照组的实验鸡。此外，在感染后第7天（PI），血清中的乳糖脱氢酶（LDH）水平显着高于对照组比实验鸡。此外，在感染后第28天，在对照组肝脏和脾脏中观察到明显的大体病理学病变和典型的aHEV感染的组织病理学变化，而在实验组中仅观察到中度病理学变化。本研究结果表明，以乳酸乳杆菌NZ 9000为载体的aHEV免疫原性抗原口服疫苗能有效地控制鸡的aHEV感染。(C)2018爱思唯尔有限公司版权所有
Avian hepatitis E virus (aHEV) is a pathogen associated with hepatitis-splenomegaly syndrome in chickens. To date, no commercial vaccine is available for preventing aHEV infection. In this study, three recombinant LactococcuslactisNZ9000experimental live vaccines expressing cytoplasmic, secreted, and cell wall-anchored forms of aHEV truncated ORF2 protein spanning amino acids 249-606 (Delta ORF2) were constructed using pTX8048 vector and characterized. Each chicken was immunized three times at two-week intervals with one of the three live aHEV ORF2 vaccines (experimental group) or with live vaccine containing empty vector only (control group). Both groups were then challenged with aHEV and evaluated to compare immune responses and immunogenic effects. Serum IgG levels, secretory IgA (sigA) levels in bile and jejunal lavage fluid, and mRNA expression levels oflL-2 and IFN-gamma in liver and spleen were significantly higher in experimental chickens than in controls. Meanwhile, post-challenge serum and fecal virus loads were significantly lower in experimental chickens versus controls. Moreover, on day 7 post infection (PI), serum lactose dehydrogenase (LDH) levels were significantly higher in controls than experimental chickens. Furthermore, at day 28 PI, obvious gross pathological lesions and histopathological changes typical for aHEV infection were observed in control livers and spleens, with only moderate pathological changes observed in the experimental group. The results of this study collectively demonstrate that an oral vaccineusing L.lactisNZ9000 as a delivery vector for aHEV immunogenic antigen could effectively control aHEV infection of chickens. (C) 2018 Elsevier Ltd. All rights reserved.