Yang Xi, Cheng Yu-Ting, Tan Mei-Fang, Zhang Hua-Wei, Liu Wan-Quan, Zou Geng, Zhang Liang-Sheng, Zhang Chun-Yan, Deng Si-Min, Yu Lei, Hu Xue-Ying, Li Lu, Zhou Rui
State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.
Institute of Veterinary Pathology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.
Infect Immun. 2015 Jul;83(7):2836-43. doi: 10.1128/IAI.03101-14. Epub 2015 Apr 27.
To reduce the need for antibiotics in animal production, alternative approaches are needed to control infection. We hypothesized that overexpression of native defensin genes will provide food animals with enhanced resistance to bacterial infections. In this study, recombinant porcine beta-defensin 2 (PBD-2) was overexpressed in stably transfected PK-15 porcine kidney cells. PBD-2 antibacterial activities against Actinobacillus pleuropneumoniae, an important respiratory pathogen causing porcine contagious pleuropneumonia, were evaluated on agar plates. Transgenic pigs constitutively overexpressing PBD-2 were produced by a somatic cell cloning method, and their resistance to bacterial infection was evaluated by direct or cohabitation infection with A. pleuropneumoniae. Recombinant PBD-2 peptide that was overexpressed in the PK-15 cells showed antibacterial activity against A. pleuropneumoniae. PBD-2 was overexpressed in the heart, liver, spleen, lungs, kidneys, and jejunum of the transgenic pigs, which showed significantly lower bacterial loads in the lungs and reduced lung lesions after direct or cohabitation infection with A. pleuropneumoniae. The results demonstrate that transgenic overexpression of PBD-2 in pigs confers enhanced resistance against A. pleuropneumoniae infection.
为减少动物生产中抗生素的使用需求，需要采用替代方法来控制感染。我们假设天然防御素基因的过表达将使食用动物增强对细菌感染的抵抗力。在本研究中，重组猪β-防御素2（PBD-2）在稳定转染的PK-15猪肾细胞中过表达。在琼脂平板上评估了PBD-2对胸膜肺炎放线杆菌（一种引起猪传染性胸膜肺炎的重要呼吸道病原体）的抗菌活性。通过体细胞克隆方法培育出持续过表达PBD-2的转基因猪，并通过直接感染或与胸膜肺炎放线杆菌同居感染来评估它们对细菌感染的抵抗力。在PK-15细胞中过表达的重组PBD-2肽对胸膜肺炎放线杆菌显示出抗菌活性。PBD-2在转基因猪的心脏、肝脏、脾脏、肺、肾脏和空肠中过表达，在直接感染或与胸膜肺炎放线杆菌同居感染后，这些猪的肺部细菌载量显著降低，肺部病变减少。结果表明，猪中PBD-2的转基因过表达赋予了对胸膜肺炎放线杆菌感染更强的抵抗力。
