College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China.
Institute of special animal and plant sciences of CAAS, Changchun, Jilin, China.
Virulence. 2022 Dec;13(1):794-807. doi: 10.1080/21505594.2022.2063484.
The immunogenicity of Aha1, an OMP of mediating the adhesion of bacteria onto the mucosal surface of hosts has been established. In this study, recombinant vectors, pPG1 and pPG2, carrying a 1366 bp DNA fragment that was responsible for encoding the 49 kDa Aha1 from were constructed, respectively, then electroporated into a probiotic strain CC16 separately to generate two types of recombinants, pPG1-Aha1 (Lc-pPG1-Aha1) and -pPG2-Aha1 (Lc-pPG2-Aha1). Subsequently, these were orally administered into common carps to examine their immunogenicity. The expression and localization of the expressed Aha1 protein relative to the carrier was validated via Western blotting, flow cytometry, and immune fluorescence separately. The recombinant vaccines produced were shown high efficacies, stimulated higher level of antibodies and AKP, ACP, SOD, LZM, C3, C4 in serum in hosts. Immune-related gene expressions of cytokines including IL-10, IL-1β, TNF-α, IFN-γ in the livers, spleens, HK, and intestines were up-regulated significantly. Besides, a more potent phagocytosis response was observed in immunized fish, and higher survival rates were presented in immunized with Lc-pPG1-Aha1 (60%) and Lc-pPG2-Aha1 (50%) after re-infection with virulent strain . Moreover, the recombinant were shown a stronger propensity for survivability in the intestine in immunized fish. Taken together, the recombinant strains might be promising candidates for oral vaccination against infections in common carps.
Aha1 是 mediating 细菌黏附到宿主黏膜表面的一种 OMP，其免疫原性已得到证实。在本研究中，分别构建了携带负责编码 49 kDa Aha1 的 1366 bp DNA 片段的重组载体 pPG1 和 pPG2，然后分别电穿孔到益生菌株 CC16 中，生成两种重组体，pPG1-Aha1（Lc-pPG1-Aha1）和 -pPG2-Aha1（Lc-pPG2-Aha1）。随后，将这些重组体口服给予鲤鱼，以检测其免疫原性。通过 Western blot、流式细胞术和免疫荧光分别验证了表达的 Aha1 蛋白相对于载体的表达和定位。结果表明，重组疫苗具有高效性，能刺激宿主血清中抗体和 AKP、ACP、SOD、LZM、C3、C4 水平升高。肝脏、脾脏、HK 和肠道中的细胞因子（包括 IL-10、IL-1β、TNF-α、IFN-γ）的免疫相关基因表达显著上调。此外，在免疫鱼中观察到更强的吞噬反应，并且在经强毒力菌株再次感染后，用 Lc-pPG1-Aha1（60%）和 Lc-pPG2-Aha1（50%）免疫的鱼的存活率更高。此外，重组 在免疫鱼的肠道中具有更强的存活倾向。综上所述，重组 菌株可能是鲤鱼对抗 感染口服疫苗的有前途的候选者。
