College of Veterinary Medicine, Shandong Agricultural University, Tai'an 271018, China.
Delicious Food Co. Ltd, Weifang 262216, China.
Vaccine. 2017 Dec 4;35(48 Pt B):6685-6690. doi: 10.1016/j.vaccine.2017.10.019. Epub 2017 Oct 18.
The hypervariable antigenicity and immunosuppressive features of avian leukosis virus subgroup J (ALV-J) has led to great challenges to develop effective vaccines. Epitope vaccine will be a perspective trend. Previously, we identified a variant antigenic neutralizing epitope in hypervariable region 1 (hr1) of ALV-J, N-LRDFIA/E/TKWKS/GDDL/HLIRPYVNQS-C. BLAST analysis showed that the mutation of A, E, T and H in this epitope cover 79% of all ALV-J strains. Base on this data, we designed a multi-variant epitope ensemble vaccine comprising the four mutation variants linked with glycine and serine. The recombinant multi-variant epitope gene was expressed in Escherichia coli BL21. The expressed protein of the variant multi-variant epitope gene can react with positive sera and monoclonal antibodies of ALV-J, while cannot react with ALV-J negative sera. The multi-variant epitope vaccine that conjugated Freund's adjuvant complete/incomplete showed high immunogenicity that reached the titer of 1:64,000 at 42 days post immunization and maintained the immune period for at least 126 days in SPF chickens. Further, we demonstrated that the antibody induced by the variant multi-variant ensemble epitope vaccine recognized and neutralized different ALV-J strains (NX0101, TA1, WS1, BZ1224 and BZ4). Protection experiment that was evaluated by clinical symptom, viral shedding, weight gain, gross and histopathology showed 100% chickens that inoculated the multi-epitope vaccine were well protected against ALV-J challenge. The result shows a promising multi-variant epitope ensemble vaccine against hypervariable viruses in animals.
禽白血病病毒 J 亚群（ALV-J）的高变异性抗原性和免疫抑制特征给开发有效疫苗带来了巨大挑战。表位疫苗将是一个有前景的趋势。以前，我们在 ALV-J 的高变区 1（hr1）中鉴定了一个变异的抗原中和表位，N-LRDFIA/E/TKWKS/GDDL/HLIRPYVNQS-C。BLAST 分析表明，该表位中的 A、E、T 和 H 突变覆盖了所有 ALV-J 株的 79%。基于这些数据，我们设计了一种由 4 个突变变体与甘氨酸和丝氨酸连接组成的多变异表位集合疫苗。该重组多变异表位基因在大肠杆菌 BL21 中表达。变异多变异表位基因的表达蛋白可与 ALV-J 的阳性血清和单克隆抗体反应，而不能与 ALV-J 阴性血清反应。与弗氏佐剂完全/不完全缀合的多变异表位疫苗在免疫后 42 天达到 1:64000 的效价，在 SPF 鸡中至少保持 126 天的免疫期。此外，我们证明了由变异多变异集合表位疫苗诱导的抗体识别和中和了不同的 ALV-J 株（NX0101、TA1、WS1、BZ1224 和 BZ4）。通过临床症状、病毒脱落、体重增加、大体和组织病理学评估的保护实验表明，接种多表位疫苗的鸡 100%得到保护，免受 ALV-J 攻击。结果表明，针对动物高变异性病毒的多变异表位集合疫苗具有广阔的应用前景。
