Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, Hubei, 430079, China.
Sci Rep. 2020 Feb 11;10(1):2343. doi: 10.1038/s41598-020-58968-7.
Actinobacillus pleuropneumoniae is an important veterinary pathogen that causes porcine pleuropneumonia. Lipoproteins of bacterial pathogens play pleiotropic roles in the infection process. In addition, many bacterial lipoproteins are antigenic and immunoprotective. Therefore, characterization of lipoproteins is a promising strategy for identification of novel vaccine candidates or diagnostic markers. We cloned 58 lipoproteins from A. pleuropneumoniae JL03 (serovar 3) and expressed them in Escherichia coli. Five proteins with strong positive signals in western blotting analysis were used to immunize mice. These proteins elicited significant antibody responses, and three of them (APJL_0922, APJL_1380 and APJL_1976) generated efficient immunoprotection in mice against lethal heterologous challenge with A. pleuropneumoniae 4074 (serovar 1), both in the active and passive immunization assays. Then immunogenicity of these three lipoproteins (APJL_0922, APJL_1380 and APJL_1976) were further tested in pigs. Results showed that these proteins elicited considerable humoral immune responses and effective protective immunity against virulent A. pleuropneumoniae challenge. Our findings suggest that these three novel lipoproteins could be potential subunit vaccine candidates.
副猪嗜血杆菌是一种重要的兽医病原体，可引起猪传染性胸膜肺炎。细菌病原体的脂蛋白在感染过程中发挥多种作用。此外，许多细菌脂蛋白具有抗原性和免疫保护作用。因此，脂蛋白的特性分析是鉴定新型疫苗候选物或诊断标志物的有前途的策略。我们从副猪嗜血杆菌 JL03（血清型 3）中克隆了 58 种脂蛋白，并在大肠杆菌中表达。Western blot 分析中具有强阳性信号的 5 种蛋白被用于免疫小鼠。这些蛋白引起了明显的抗体反应，其中 3 种（APJL_0922、APJL_1380 和 APJL_1976）在主动和被动免疫试验中对致死性异源攻毒的副猪嗜血杆菌 4074（血清型 1）均产生了有效的免疫保护。然后在猪中进一步测试了这三种脂蛋白（APJL_0922、APJL_1380 和 APJL_1976）的免疫原性。结果表明，这些蛋白引起了相当大的体液免疫反应，并对强毒副猪嗜血杆菌的攻击具有有效的保护作用。我们的研究结果表明，这三种新型脂蛋白可能是潜在的亚单位疫苗候选物。
