Inactivated vaccines are often applied with adjuvants in commercial fish farming. Although some mineral or non-mineral oil adjuvants show efficient improvement with inactivated vaccines, but sometimes bring side effects such as tissue adhesion and granulomatous lesion at the injection site. CpG ODN is a novel type of soluble adjuvant which has been proved to possess excellent advantages in fish vaccine development. In this study, we designed a tandem sequence of CpG ODN synthesized in plasmid pcDNA 3.1, and an inactivated Vibrio anguillarum vaccine developed in our previous work was chosen for determining the efficiency of the CpG-riched plasmids (pCpG) as an adjuvant. Results showed that pCpG we designed can offer higher immunoprotection with the vaccine. Interestingly, even below the minimum immune dosage of the vaccine, a high RPS of 84% was observed once the vaccine was administrated with the pCpG. Serum specific antibody titer, superoxide dismutase and total protein were enhanced and some immune genes related to both innate and adaptive immune response were upregulated, implying an effective auxiliary function of the pCpG. Totally, our study suggested that the pCpG is a potential and available adjuvant for turbot vaccine development.

中文翻译：

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富含CpG的质粒作为疫苗佐剂可降低大菱t（Scophthalmus maximus L.）中灭活的鳗弧菌弧菌疫苗的抗原剂量。

灭活疫苗通常与佐剂一起用于商业鱼类养殖。尽管某些矿物油或非矿物油佐剂对灭活疫苗显示出有效的改善，但有时会在注射部位带来副作用，例如组织粘连和肉芽肿性病变。CpG ODN是新型的可溶性佐剂，已被证明在鱼疫苗开发中具有优异的优势。在这项研究中，我们设计了在质粒pcDNA 3.1中合成的CpG ODN的串联序列，并选择了我们先前工作中开发的灭活的鳗弧菌疫苗来确定富含CpG的质粒（pCpG）作为佐剂的效率。结果表明，我们设计的pCpG可以为疫苗提供更高的免疫保护作用。有趣的是，即使低于疫苗的最低免疫剂量，疫苗与pCpG一起使用后，可观察到84％的高RPS。血清特异性抗体滴度，超氧化物歧化酶和总蛋白得到增强，与先天性和适应性免疫反应相关的一些免疫基因被上调，这意味着pCpG具有有效的辅助功能。总体而言，我们的研究表明，pCpG是一种潜在的且可利用的佐剂，可用于开发菱turbo疫苗。