抗禽传染性支气管炎病毒多肽疫苗EpiA免疫原性研究

The Immune Response Against Avian Infectious Bronchitis Virus Induced by Multi-epitope Based Peptide Vaccines

设计基于B细胞表位和T细胞表位的禽传染性支气管炎病毒(IBV)多肽疫苗EpiA,并利用基因工程重组技术将EpiA在大肠杆菌中表达、纯化。ELISA和Western blot法验证其免疫原性后,将重组蛋白配以弗氏佐剂免疫鸡,并以灭活苗、GST和PBS为试验对照组。细胞免疫效应采用流式细胞仪(FACS)对免疫鸡外周血中CD4+,CD8+T淋巴细胞进行计数,IBV特异性抗体采用ELISA法进行检测,并进行攻毒试验。结果显示,成功设计了多肽疫苗EpiA:ELISA和Western blot证明所表达的融合蛋白能与标准IBV阳性血清产生特异性抗原-抗体反应,而且该融合蛋白能有效激发鸡体特异性体液和细胞免疫,与对照组差异显著(P≤0.01)。攻毒试验表明,多肽疫苗保护率可达73%,大肠杆菌生物合成重组抗IBV多肽疫苗将为IBV疫苗研究制备提供了新的途径。

The peptide vaccine was designed based on B cell and T cell epitope of IBV, and the multiepitope based peptide vaccine was expressed in E. coli fused with glutathione S-transferase （GST）. ELISA and Western blot analysis showed that purified fusion proteins （EpiA） had an excellent immune activity with chicken anti-IBV serum. The expressed fusion proteins were purified and emulsified with Freund adjuvant. Vaccination twice at an interval of 2 weeks with the emulsified the fusion proteins elicited anti-IBV specific antibodies and specific cellular responses and 73% of the vaccinated chickens were protected against mortality. The use of a biosynthesis system instead of peptide synthesis provided a new way to prepare muhi-epitope based peptide vaccine.