Liu Jinlin, Chen Yan, Hu Linlin, Bei Weicheng, Chen Huanchun
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
Sheng Wu Gong Cheng Xue Bao. 2010 Mar;26(3):305-10.
Actinobacillus pleuropneumoniae (A. pleuropneumoniae), the causative agent of porcine contagious pleuropneumonia (PCP), is a significant pathogen of the world pig industry, vaccination is potentially an effective tool for the prevention of PCP. The purpose of present study was to enhance the immunogenicity of A. pleuropneumoniae live vaccine strain HB04C- (serovar 7), which was unable to express ApxIA, and to develop effective multivalent vaccines for the respiratory pathogens based on the attenuated A. pleuropneumoniae. We introduced a shuttle vector containing intact apxIA gene into HB04C-, generating HB04C2, an A. pleuropneumoniae serovar 7 live attenuated vaccine strain co-expressing ApxIA. Then we investigated the biological characteristics of HB04C2. We found that the shuttle vector expressing ApxIA was stable in HB04C2, and the growth ability of HB04C2 was not affected by the shuttle vector. We observed that HB04C2 elicited detectable antibodies against ApxIA and ApxIIA when it was administrated intratracheally as a live vaccine in pigs, and all immunized pigs were protected from heterologous virulent A. pleuropneumoniae (serovar 1) challenge. In conclusion, we demonstrated that A. pleuropneumoniae live vaccine could be used as a vector for expression of heterologous antigens.
猪胸膜肺炎放线杆菌（A. pleuropneumoniae）是猪传染性胸膜肺炎（PCP）的病原体，是世界养猪业的重要病原菌，疫苗接种可能是预防PCP的有效工具。本研究的目的是增强无法表达ApxIA的猪胸膜肺炎放线杆菌活疫苗株HB04C-（血清型7）的免疫原性，并基于减毒的猪胸膜肺炎放线杆菌开发针对呼吸道病原体的有效多价疫苗。我们将含有完整apxIA基因的穿梭载体导入HB04C-，构建了HB04C2，这是一株共表达ApxIA的猪胸膜肺炎放线杆菌血清型7活疫苗株。然后我们研究了HB04C2的生物学特性。我们发现表达ApxIA的穿梭载体在HB04C2中稳定，且HB04C2的生长能力不受穿梭载体影响。我们观察到，当HB04C2作为活疫苗经气管内接种给猪时，能诱导出针对ApxIA和ApxIIA的可检测抗体，且所有免疫猪均能抵抗异源强毒猪胸膜肺炎放线杆菌（血清型1）的攻击。总之，我们证明了猪胸膜肺炎放线杆菌活疫苗可作为表达异源抗原的载体。
