A trivalent Apx-fusion protein delivered by E-coli outer membrane vesicles induce protection against Actinobacillus pleuropneumoniae of serotype 1 and 7 challenge in a murine model

作者：Xu, Kui; Zhao, Qin; Wen, Xintian; Wu, Rui; Wen, Yiping; Huang, Xiaobo; Huang, Yong; Yan, Qigui; Han, Xinfeng; Ma, Xiaoping; Chang, Yung-Fu^*; Cao, Sanjie^*

来源：PLos One, 2018, 13(1): e0191286.

DOI：10.1371/journal.pone.0191286

• VACCINES
• DETERMINANT
• BIOGENESIS
• LEUKOTOXIN
• VIRULENCE
• RESPONSES
• BACTERIA
• IMMUNITY
• GAMMA
• GENE

Actinobacillus pleuropneumoniae (APP) causes serious economic losses in the swine industry, and is the etiologic agent of porcine pleuropneumonia. In this study we have engineered a trivalent Apx fusion protein enclosed in outer membrane vesicles (Apxr-OMV) and studied its immunoprotective efficacy against APP serotypes 1 and 7 challenge in mice. The results showed that the IgG levels in the Apxr-OMVs immune group were significantly higher than those of the negative control (P < 0.05). Up-regulation of both Th1 (IFN-gamma, IL-2) and Th2 (IL-4) cytokines were detected in splenocytes of Apxr-OMVs immune group. The survival rates 87.5% and 62.5% were observed against APP strain 1516 of serotype 7 and APP strain 2701 of serotype 1 in the groups of Apxr-OMVs immune group, respectively. Histopathological lesions of the pulmonary structure alveoli were found to be minimal in APXOMV group challenged with APP serotypes 1 and 7. These results strongly indicated that engineered OMVs could effectively induce specific humoral or cellular immune responses. Moreover, Apxr-OMVs used as novel vaccine provides cross-protective immunity against different serotype 1 and 7 of APP infection in a mouse model. In contrast, the OMV-empty and PBS as negative controls or inactivated strain of APP-2701 and APP-1516 as positive controls for the animal study cannot provide protection or cross-protection.

• 出版日期2018-1-26
• 单位四川农业大学