Maas Alexander, Jacobsen Ilse D, Meens Jochen, Gerlach Gerald-F
Institut fuer Mikrobiologie, Zentrum fuer Infektionsmedizin, Stiftung Tierärztliche Hochschule Hannover, Bischofsholer Damm 15, 30173 Hannover, Germany.
Infect Immun. 2006 Jul;74(7):4124-32. doi: 10.1128/IAI.00133-06.
Vaccination against Actinobacillus pleuropneumoniae is hampered by the lack of vaccines inducing reliable cross-serotype protection. In contrast, pigs surviving natural infection are at least partially protected from clinical symptoms upon reinfection with any serotype. Thus, we set out to construct an attenuated A. pleuropneumoniae live vaccine allowing the differentiation of vaccinated from infected animals (the DIVA concept) by successively deleting virulence-associated genes. Based on an A. pleuropneumoniae serotype 2 prototype live negative marker vaccine (W. Tonpitak, N. Baltes, I. Hennig-Pauka, and G.-F. Gerlach, Infect. Immun. 70:7120-7125, 2002), genes encoding three enzymes involved in anaerobic respiration and the ferric uptake regulator Fur were deleted, resulting in a highly attenuated sixfold mutant; this mutant was still able to colonize the lower respiratory tract and induced a detectable immune response. Upon a single aerosol application, this mutant provided significant protection from clinical symptoms upon heterologous infection with an antigenically distinct A. pleuropneumoniae serotype 9 challenge strain and allowed the serological discrimination between infected and vaccinated groups.
缺乏能诱导可靠交叉血清型保护的疫苗阻碍了胸膜肺炎放线杆菌疫苗接种。相比之下，自然感染存活的猪在再次感染任何血清型时至少能部分免受临床症状影响。因此，我们着手构建一种减毒的胸膜肺炎放线杆菌活疫苗，通过依次删除毒力相关基因，实现区分接种动物和感染动物（即鉴别诊断概念）。基于胸膜肺炎放线杆菌血清型2原型活阴性标记疫苗（W. 通皮塔克、N. 巴尔特斯、I. 亨尼希 - 保卡和G.-F. 格拉赫，《感染与免疫》70:7120 - 7125，2002年），删除了编码参与无氧呼吸的三种酶和铁摄取调节蛋白Fur的基因，得到高度减毒的六重突变体；该突变体仍能定殖于下呼吸道并诱导可检测到的免疫反应。单次气溶胶接种后，该突变体在受到抗原性不同的胸膜肺炎放线杆菌血清型9攻击菌株的异源感染时，能显著保护动物免受临床症状影响，并能在血清学上区分感染组和接种组。
