Arayan Lauren Togonon, Huy Tran Xuan Ngoc, Reyes Alisha Wehdnesday Bernardo, Hop Huynh Tan, Son Vu Hai, Min WonGi, Lee Hu Jang, Kim Suk
Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju 52828, Republic of Korea.
J Microbiol Biotechnol. 2019 Feb 28;29(2):330-338. doi: 10.4014/jmb.1811.10066.
Chronic infection with intracellular () in livestock remains as a major problem worldwide. Thus, the search for an ideal vaccine is still ongoing. In this study, we evaluated the protective efficacy of a combination of recombinant proteins; superoxide dismutase (rSodC), riboflavin synthase subunit beta (rRibH), nucleoside diphosphate kinase (rNdk), 50S ribosomal protein (rL7/L12) and malate dehydrogenase (rMDH), cloned and expressed into a pMal vector system and DH5α, respectively, and further purified and applied intraperitoneally into BALB/c mice. After first immunization and two boosters, mice were infected intraperitoneally (IP) with 5 × 10 CFU of virulent 544. Spleens were harvested and bacterial loads were evaluated at two weeks post-infection. Results revealed that this combination showed significant reduction in bacterial colonization in the spleen with a log protection unit of 1.31, which is comparable to the average protection conferred by the widely used live attenuated vaccine RB51. Cytokine analysis exhibited enhancement of cell-mediated immune response as IFN-γ is significantly elevated while IL-10, which is considered beneficial to the pathogen's survival, was reduced compared to control group. Furthermore, both titers of IgG1 and IgG2a were significantly elevated at three and four-week time points from first immunization. In summary, our in vivo data revealed that vaccination with a combination of five different proteins conferred a heightened host response to infection through cell-mediated immunity which is desirable in the control of intracellular pathogens. Thus, this combination might be considered for further improvement as a potential candidate vaccine against infection.
家畜细胞内（）的慢性感染在全球范围内仍然是一个主要问题。因此，寻找理想疫苗的工作仍在继续。在本研究中，我们评估了重组蛋白组合的保护效果；超氧化物歧化酶（rSodC）、核黄素合酶亚基β（rRibH）、核苷二磷酸激酶（rNdk）、50S核糖体蛋白（rL7/L12）和苹果酸脱氢酶（rMDH），它们分别克隆并表达于pMal载体系统和DH5α中，进一步纯化后腹腔注射到BALB/c小鼠体内。首次免疫和两次加强免疫后，小鼠腹腔内（IP）感染5×10 CFU的强毒株544。在感染后两周收获脾脏并评估细菌载量。结果显示，该组合使脾脏中的细菌定植显著减少，对数保护单位为1.31，这与广泛使用的减毒活疫苗RB51所提供的平均保护效果相当。细胞因子分析表明，细胞介导的免疫反应增强，因为与对照组相比，IFN-γ显著升高，而被认为有利于病原体存活的IL-10降低。此外，从首次免疫后的第三周和第四周时间点起，IgG1和IgG2a的滴度均显著升高。总之，我们的体内数据表明，用五种不同蛋白质的组合进行疫苗接种可通过细胞介导的免疫增强宿主对感染的反应，这在控制细胞内病原体方面是可取的。因此，这种组合可作为抗感染潜在候选疫苗考虑进一步改进。
