State Key Laboratory for Zoonotic Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun 130062, China.
State Key Laboratory for Zoonotic Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun 130062, China; Panjin Center for Inspection and Testing, Panjin 124000, China.
Vet Microbiol. 2023 Mar;278:109661. doi: 10.1016/j.vetmic.2023.109661. Epub 2023 Jan 16.
Avian Angara disease caused by fowl adenovirus serotype 4 (FAdV-4) has spread widely and brought economic losses to the poultry industry in some countries. Effective vaccines for Angara disease control are currently lacking. In this study, four capsid proteins (hexon, penton, fiber1 and fiber2) from FAdV-4 were selected, and their optimal efficient antigenic epitopes predicted by bioinformatics software were tandemly linked with the flexible linker GGGGS. Based on their amino acid sequences, the DNA sequences for the genes encoding the multiantigen epitope tandem proteins (MAETPs) FAdV4:F1, FAdV4:P, FAdV4:F2 and FAdV4:H were chemosynthesized and then ligated by T4 ligases at the cleavage sites of restriction endonucleases to construct DNAs encoding the multilinked fusion recombinant proteins (MLFRPs) used as protective antigens from avian Angara disease. These genes ligated into the expression vector pET-28a were successfully expressed using the Escherichia coli prokaryotic expression system to prepare five kinds of MLFRPs (FAdV4:F1-P-F2-H, FAdV4:F1-F2-P-H, FAdV4:F1-F2-H-P, FAdV4:F1-P-H-F2 and FAdV4:F1-H-F2-P) for use to immunize chicks. FAdV-4 was injected into MLFRP-immunized chickens, and the challenge protection rate was evaluated. FAdV4:F1-P-F2-H produced the best protection against FAdV-4, with a single immunization resulting in a 100 % protection rate, followed by FAdV4:F1-F2-P-H (83.33 %) and FAdV4:F1-F2-H-P (66.67 %). FAdV4:F1-P-H-F2 and FAdV4:F1-H-F2-P were not able to induce a good immune protection effect after one immunization. However, all of the MLFRPs were capable of protecting the host from FAdV-4 infection after two immunizations. In conclusion, these MLFRPs generated based on capsid proteins of FAdV-4 are promising candidate subunit vaccines against Angara disease.
禽腺病毒 4 型（FAdV-4）引起的安卡拉病在一些国家广泛传播，给家禽业造成了经济损失。目前缺乏用于安卡拉病控制的有效疫苗。在本研究中，选择了 FAdV-4 的四个衣壳蛋白（六邻体、五邻体、纤维 1 和纤维 2），并通过生物信息学软件预测其最佳有效的抗原表位，然后将它们与柔性接头 GGGGS 串联。基于它们的氨基酸序列，化学合成了编码多抗原表位串联蛋白（MAETPs）FAdV4：F1、FAdV4：P、FAdV4：F2 和 FAdV4：H 的基因序列，并通过 T4 连接酶在限制性内切酶的切割位点上将它们连接起来，构建了编码用于禽安卡拉病保护的多连接融合重组蛋白（MLFRP）的 DNA。将这些基因连接到表达载体 pET-28a 中，使用大肠杆菌原核表达系统成功表达了五种 MLFRP（FAdV4：F1-P-F2-H、FAdV4：F1-F2-P-H、FAdV4：F1-F2-H-P、FAdV4：F1-P-H-F2 和 FAdV4：F1-H-F2-P），用于免疫小鸡。将 FAdV-4 注射到 MLFRP 免疫的鸡中，评估其攻毒保护率。FAdV4：F1-P-F2-H 对 FAdV-4 的保护效果最好，单次免疫的保护率为 100%，其次是 FAdV4：F1-F2-P-H（83.33%）和 FAdV4：F1-F2-H-P（66.67%）。FAdV4：F1-P-H-F2 和 FAdV4：F1-H-F2-P 单次免疫不能诱导良好的免疫保护效果。然而，所有的 MLFRP 在两次免疫后都能够保护宿主免受 FAdV-4 感染。总之，基于 FAdV-4 衣壳蛋白生成的这些 MLFRP 是预防安卡拉病的有前途的候选亚单位疫苗。
