副猪嗜血杆菌TbpA对仔猪的免疫效力评价

摘要

The aim of this study was to investigate the immune efficacy of the transferrin-binding protein A of HPS and to lay a foundation for research and development of new vaccine.The piglets were immunized with the inactivated whole cell vaccine from HPS serotype 13 and recombinant protein TbpA(0.5 and 0.25 mg · 4 mL-1).The immunization was conducted at week 0,2,4 and then challenged with HPSLJ3 (7 LDs0).Serum antibody (IgG) and cytokines (IL-5,IL-10,IFN-γ,TNF-α) levels were measured by ELISA and pathological examination was performed.Results were as follows:Immunization and challenge assay demonstrated the recombinant protein TbpA could induce high levels of antibody (IgG) and cytokines.The protective efficacy of the inactivated whole cell and TbpA (0.5 mg · 4mL-1) vaccines was 100％.There was a significant difference between the pathological changes and the control group.TbpA can stimulate the humoral and cellular immunity,and produce powerful immune protection.These results suggested that TbpA is a potential candidate for developing a novel HPS vaccine.%本研究旨在了解副猪嗜血杆菌(H PS)转铁结合蛋白A(TbpA)对仔猪的免疫保护性,从而为HPS新型疫苗的研发奠定基础.采用HPS血清型13型灭活全菌体以及浓度分别为0.5、0.25 mg· 4mL-1的重组TbpA,经3次间隔期均为14d的免疫后,检测仔猪抗体(IgG)水平及细胞因子(IL-5、IL-10、IFN-γ、TNF-α)水平;以相同血清型菌株7 LD50剂量,腹腔攻毒,检查病理学变化及其免疫保护率.结果显示:HPS的重组TbpA能诱导仔猪产生较高水平的特异性抗体IgG,并使细胞因子显著升高.重组TbpA和灭活全菌体在免疫后均能使仔猪获得免疫保护,其中0.5 mg·4 mL-1TbpA和灭活全菌体的免疫保护率均为100％,组织切片病理变化与攻毒对照组之间差异明显.HPS的TbpA能激发仔猪的体液免疫和细胞免疫,产生较强的免疫保护力,可以作为一种新的疫苗候选抗原.