Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran.
Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran.
BMC Vet Res. 2019 Nov 8;15(1):402. doi: 10.1186/s12917-019-2074-7.
Designing a potent recombinant vaccine, using the appropriate subunits with the greatest effect on stimulating the immune system, especially in the case of intracellular pathogens such as gram negative Brucella Melitensis bacteria, is of great importance. In this study, three repeats of 27 amino acids of the immunogenic epitope derived from OMP31 antigen (3E) from the Brucella melitensis, in a protective manner against Brucellosis have been used. To fortify the delivery system of recombinant antigens, IL-2 cytokine as a molecular adjuvant was fused to recombinant constructs. Recombinant proteins were evaluated for immunological studies in a mouse model (BALB/c).
The results showed that all recombinant proteins could stimulate the immune system to produce Th1 cytokines and antibodies in compare to the negative control treatments. 3E-IL2 and then OMP31-IL2 proteins stimulated higher levels of IFN-γ and IL-2 compared to the other treatments (p < 0.05). Also, the results indicated that experimental treatments produced a higher level of IgG2a isotype than IgG1 isotype. In addition, the findings of the experiment showed that the presence of chemical adjuvant (IFA) along with molecular adjuvant can play a significant role in stimulating the immune system. After determining the potency of recombinant structures, their efficacy in stimulating the immune system were also evaluated. B. melitensis M16 strain was used to challenge 30 days after last immunization. The microbial load of the splenocyte in the treatments receiving chimeric proteins were significantly lower. Also, Wright serological test confirmed that these treatments had the lowest agglutination rate, as well as the positive treatment, while in the negative treatments in excess of blood serum dilutions, agglutination rate were more than 2 + .
3E-IL2 treatment showed the best performance compared to other recombinant proteins and could be considered as the suitable candidate for further research on the production of recombinant vaccine against Brucella.
设计一种有效的重组疫苗，使用对刺激免疫系统最有效的适当亚单位，特别是对于革兰氏阴性布鲁氏菌等细胞内病原体，非常重要。在这项研究中，使用了源自布鲁氏菌 OMP31 抗原的免疫原性表位的 3 个重复 27 个氨基酸（3E），以保护性方式抵抗布鲁氏菌病。为了增强重组抗原的传递系统，将 IL-2 细胞因子作为分子佐剂融合到重组构建体中。在小鼠模型（BALB/c）中评估了重组蛋白的免疫学研究。
结果表明，与阴性对照处理相比，所有重组蛋白都能刺激免疫系统产生 Th1 细胞因子和抗体。与其他处理相比，3E-IL2 然后 OMP31-IL2 蛋白刺激产生更高水平的 IFN-γ 和 IL-2（p<0.05）。此外，结果表明实验处理产生的 IgG2a 同型高于 IgG1 同型。此外，实验结果表明，化学佐剂（IFA）与分子佐剂一起存在可以在刺激免疫系统方面发挥重要作用。在确定重组结构的效力后，还评估了它们刺激免疫系统的功效。在最后一次免疫后 30 天用布鲁氏菌 M16 菌株挑战。在接受嵌合蛋白治疗的脾细胞中微生物负荷显着降低。此外，Wright 血清学试验证实，这些处理的凝集率最低，与阳性处理一样，而在阴性处理中，血清稀释度超过 2+，凝集率更高。
与其他重组蛋白相比，3E-IL2 处理表现出最佳性能，可被视为进一步研究针对布鲁氏菌的重组疫苗生产的合适候选物。
