PDF(Pubmed)
Abstract：
Clinical avian coccidiosis is typically caused by coinfection with several Eimeria species. Recombinant protein and DNA vaccines have shown promise in controlling coccidiosis. On this basis, DNA vaccines that encode multiple epitopes from different Eimeria species may provide broad protection against coinfections. In this study, we designed a fusion gene fragment, 14EGT, that contained concentrated T-cell epitopes from four common antigens of Eimeria species (14-3-3, elongation factor 2, glyceraldehyde-3-phosphate dehydrogenase, and transhydrogenase). The multiepitope DNA vaccine pVAX1-14EGT and recombinant protein vaccine pET-32a-14EGT (r14EGT) were then created based on the 14EGT fragment. Subsequently, cellular and humoral immune responses were measured in vaccinated chickens. Vaccination-challenge trials were also conducted, where the birds were vaccinated with the 14EGT preparations and later exposed to single or multiple Eimeria species to evaluate the protective efficacy of the vaccines. According to the results, vaccination with 14EGT preparations effectively increased the proportions of CD4+ and CD8+ T cells and the levels of Th1 and Th2 hallmark cytokines. The levels of serum IgG antibodies were also significantly increased. Animal vaccination trials revealed alleviated enteric lesions, weight loss, and oocyst output compared to those of the control groups. The preparations were found to be moderately effective against single Eimeria species, with the anticoccidial index (ACI) ranging from 160 to 180. However, after challenge with multiple Eimeria species, the protection provided by the 14EGT preparations was not satisfactory, with ACI values of 142.18 and 146.41. Collectively, the results suggest that a multiepitope vaccine that encodes the T-cell epitopes of common antigens derived from Eimeria parasites could be a potential and effective strategy to control avian coccidiosis.
摘要：
临床禽球虫病通常是由几种艾美球虫的共感染引起的。重组蛋白和DNA疫苗已显示出控制球虫病的前景。在此基础上,编码来自不同艾美球虫物种的多个表位的DNA疫苗可以提供针对共感染的广泛保护。在这项研究中,我们设计了一个融合基因片段，14EGT,包含来自艾美球虫物种的四种常见抗原的浓缩T细胞表位（14-3-3，延伸因子2，甘油醛-3-磷酸脱氢酶，和转运酶)。然后基于14EGT片段产生多表位DNA疫苗pVAX1-14EGT和重组蛋白疫苗pET-32a-14EGT(r14EGT)。随后，在接种疫苗的鸡中测量细胞和体液免疫应答。还进行了疫苗接种-攻击试验，其中鸟类接种了14EGT制剂，然后暴露于单个或多个艾美球虫物种，以评估疫苗的保护效力。根据结果,用14EGT制剂接种疫苗有效地增加了CD4+和CD8+T细胞的比例以及Th1和Th2标志细胞因子的水平。血清IgG抗体水平也显著升高。动物疫苗接种试验显示肠损伤减轻,减肥,和卵囊输出与对照组相比。发现该制剂对单一的艾美球虫物种具有中等效果，抗球虫指数（ACI）在160到180之间。然而,在挑战多种艾美球虫物种后，14EGT制剂提供的保护不令人满意，ACI值为142.18和146.41。总的来说，结果表明,编码艾美球虫寄生虫常见抗原T细胞表位的多表位疫苗可能是控制禽球虫病的潜在和有效策略.
