College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an 271018, China.
China Animal Health and Epidemiology Center, Qingdao 266032, China.
Viruses. 2022 Sep 24;14(10):2115. doi: 10.3390/v14102115.
Chicken infectious anemia (CIA) is an immunosuppressive disease caused by chicken infectious anemia virus (CIAV) that poses a great threat to the poultry industry worldwide. At present, vaccination is an important way to prevent and control CIA. Apart from a CIAV-attenuated vaccine used in clinical practice, the research and development of a genetically engineered vaccine has good prospects. However, it is difficult to induce a strong protective effect with a single subunit vaccine or DNA vaccine. Therefore, the goal of this study is to develop and evaluate a DNA prime/protein boost vaccine strategy for defense against CIAV infection and spread. In this study, the recombinant proteins of CIAV VP1 and VP2 were prepared using an () expression system, and the eukaryotic expression plasmid pBud-VP1-VP2 was constructed. Subsequently, the effects of the DNA prime/protein boost strategy on antibody production and cellular immunity response were measured. The results showed that combined vaccination could induce a higher antibody titer than those of a DNA vaccine or subunit vaccine alone. In addition, spleen lymphocyte index (SI) and IL-2, IL-4, and IFN-γ levels were also significant in chickens the received the combined vaccination. To further investigate the protective effect of DNA prime/protein boost vaccination, a CIAV challenge experiment was carried out. The results showed that infection with CIAV reduced the hematocrit value (Hct) and thymus index, while vaccination recovered this reduction, and the combined immunization group was the least affected by CIAV infection. Furthermore, the CIAV viral load in the combined immunization group was the lowest, indicating that the combined immunization could provide a better protective efficacy. In conclusion, the DNA prime and recombinant protein boost vaccination can be used as an important anti-CIAV strategy, which can induce both enhanced cellular and humoral immunity responses in chickens and provide a new avenue for CIAV prevention and control.
鸡传染性贫血病（CIA）是由鸡传染性贫血病毒（CIAV）引起的一种免疫抑制性疾病，对全球家禽业构成巨大威胁。目前，接种疫苗是预防和控制 CIA 的重要手段。除了在临床实践中使用的 CIAV 减毒疫苗外，基因工程疫苗的研究和开发前景良好。然而，单一亚单位疫苗或 DNA 疫苗很难诱导出强烈的保护作用。因此，本研究旨在开发和评估一种 DNA 初免/蛋白加强疫苗策略，以防御 CIAV 感染和传播。在本研究中，使用（）表达系统制备了 CIAV VP1 和 VP2 的重组蛋白，并构建了真核表达质粒 pBud-VP1-VP2。随后，测量了 DNA 初免/蛋白加强策略对抗体产生和细胞免疫应答的影响。结果表明，联合免疫接种可诱导比 DNA 疫苗或亚单位疫苗单独接种更高的抗体滴度。此外，接受联合免疫接种的鸡的脾淋巴细胞指数（SI）和 IL-2、IL-4 和 IFN-γ 水平也显著升高。为了进一步研究 DNA 初免/蛋白加强免疫接种的保护效果，进行了 CIAV 攻毒实验。结果表明，CIAV 感染降低了红细胞压积（Hct）和胸腺指数，而接种可恢复这种降低，联合免疫组受 CIAV 感染的影响最小。此外，联合免疫组 CIAV 病毒载量最低，表明联合免疫接种可提供更好的保护效果。综上所述，DNA 初免和重组蛋白加强免疫接种可作为一种重要的抗 CIAV 策略，可诱导鸡增强细胞和体液免疫应答，并为 CIAV 的预防和控制提供新途径。
