Abstract:
Mycoplasma synoviae (MS) is a primary avian pathogen prevalent worldwide that causes airsacculitis and synovitis in birds. Vaccination is recommended as the most cost-effective strategy in the control of MS infection. Novel alternative vaccines are needed for eradicating and controlling MS infection in flocks. DnaK, enolase, elongation factor Tu (EF-Tu), MSPB, NADH oxidase and LP78 are the major immunogenic antigens of MS and are promising targets for subunit vaccine candidates. In the present study, genes encoding DnaK, enolase, EF-Tu, MSPB, LP78, and NADH oxidase were cloned and expressed in Escherichia coli. Enzyme-linked immunosorbent assay showed that the six recombinant proteins were recognized by convalescent sera, indicating that they were expressed during infection. Two injections of the six subunit vaccines induced a robust antibody response and increased the concentrations of IFN-γ and IL-4, especially rEnolase and rEF-Tu. The proliferation of peripheral blood lymphocytes was enhanced in all of the immunized groups. Chickens immunized with rEnolase, rEF-Tu, rLP78, and rMSPB conferred significant protection against MS infection, as indicated by significantly lower DNA copies in the trachea, lower scores of air sac lesions, and lesser tracheal mucosal thickness than that in the challenge control. Especially, rEnolase provided the best protective efficacy, followed by rEF-Tu, rMSPB, and rLP78. Our finds demonstrate that the subunit vaccines and bacterin can only reduce the lesions caused by MS infection, but not prevent colonization of the organism. Our findings may contribute to the development of novel vaccine agents against MS infection.
摘要:
滑膜支原体(MS)是世界范围内流行的主要禽类病原体,可引起鸟类的呼吸道炎和滑膜炎。建议将疫苗接种作为控制MS感染的最具成本效益的策略。需要新的替代疫苗来根除和控制鸡群中的MS感染。DnaK,烯醇化酶,延伸率Tu(EF-Tu),MSPB,NADH氧化酶和LP78是MS的主要免疫原性抗原,并且是亚单位疫苗候选物的有希望的靶标。在本研究中,编码DnaK的基因,烯醇化酶,EF-Tu,MSPB,克隆了LP78和NADH氧化酶并在大肠杆菌中表达。酶联免疫吸附试验表明,6种重组蛋白均被恢复期血清识别,表明它们在感染期间表达。6个亚单位疫苗的两次注射诱导了强烈的抗体应答并增加了IFN-γ和IL-4的浓度,尤其是rEnolase和rEF-Tu。所有免疫组的外周血淋巴细胞增殖均增强。用rEnolase免疫的鸡,rEF-Tu,rLP78和rMSPB对MS感染具有重要的保护作用,气管中的DNA拷贝明显较低,气囊病变评分较低,气管粘膜厚度小于攻击对照。尤其是,rEnolase提供了最好的保护功效,其次是rEF-Tu,rMSPB,rLP78我们的发现表明,亚单位疫苗和菌苗只能减少MS感染引起的病变,但不能阻止生物体的定殖。我们的发现可能有助于开发针对MS感染的新型疫苗制剂。