多杀性巴氏杆菌转铁结合蛋白TbpA的原核表达及免疫原性

Protective efficacy of recombinant transferrin-binding protein A of bovine Pasteurella multocida serogroup A in mice model

为研究多杀性巴氏杆菌转铁结合蛋白TbpA的免疫原性,本试验利用PCR从牛源A型多杀性巴氏杆菌HB01基因组中扩增了TbpA的编码基因tbpA,并将其克隆至原核表达载体pET-30α(+)上,转化至大肠杆菌BL21中进行诱导表达。SDS-PAGE检测结果显示,rTbpA蛋白成功表达。Western blot证实该蛋白能够与抗多杀性巴氏杆菌HB01血清发生阳性反应。将rTbpA免疫小鼠后,分别于免疫后14,28 d采血,利用ELISA试验检测血清中的抗体滴度,结果显示血清中的抗rTbpA蛋白的IgG抗体显著升高(P<0.05)。感染试验结果显示,免疫rTbpA蛋白能够保护70%的小鼠抵抗多杀性巴氏杆菌的致死性攻击,并且病理切片结果表明,免疫小鼠的肺部损伤相对于对照组小鼠显著降低。本试验为筛选新型的多杀性巴氏杆菌免疫原性蛋白提供依据。

To investigate the protective efficacy of the recombinant transferrin-binding protein A(rTbpA)of bovine Pasteurella multocida serogroup A,the TbpA coding gene tbpA harboured in the genome of P.multocida HB01 was amplified and cloned into the prokaryotic expression plasmid pET-30α(+),transformed into E.coli BL21.After induction,the TbpA was successfully expressed in E.coli.Western blot demonstrated that the rTbpA displayed a positive reaction to the anti-P.multocida HB01 serum.The ELISA titers of rTbpA antigen specific IgG in the serum from the mice vaccinated with rTbpA were significantly increased at the 14 th and 28 th day post-immunization(P<0.05).The rTbpA contributed a lot to the elimination of lung lesions resulted from homologous challenge and provided 70%protection to the bacteria infection mice.The TbpA could be used as an effective component of subunit vaccine against the infection of Pasteurella multocida in cattle and buffalo.