Doosti Mohammad, Nassiri Mohammadreza, Nasiri Khadijeh, Tahmoorespur Mojtaba, Zibaee Saeed
Department of Animal Science, Ferdowsi University of Mashhad, Mashhad, Iran.
Recombinant Proteins Research Group, Research Institute of Biotechnology, Ferdowsi University of Mashhad, Mashhad, Iran.
Iran J Basic Med Sci. 2019 Mar;22(3):302-309. doi: 10.22038/ijbms.2019.31972.7683.
The results of studies on vaccine development for foot-and-mouth disease (FMD) virus show that the use of inactivated vaccines for FMD virus is not completely effective. Novel vaccinations based on immuno-dominant epitopes have been shown to induce immune responses. Furthermore, for safety of immunization, access to efficient adjuvants against FMD virus seems to be critical.
In this study, we produced epitope recombinant vaccines from the VP1 protein of the FMD virus for serotype O of Iran. Constructs were included polytope (tandem-repeat multiple-epitope), polytope coupled with interleukin-2 (polytope-IL 2) as a molecular adjuvant and IL-2. Three expression vectors were constructed and expressed in BL21 (DE3). To evaluate whether these recombinant vaccines induce immune responses, BALB/c mice were injected with the recombinant vaccines and their immune responses were compared with a negative control group. The humoral and cellular immune responses were measured by ELISA.
The results showed that IL-2 co-expressed or co-inoculated with Polytope protein enhances the immune effect of multiple epitope recombinant vaccine against FMD virus. The results of total immunoglobulin G (IgG), IgG1, and IgG2a levels and secretion of interferon gamma (IFN-γ), IL-4 and IL-10 revealed that there were significant differences between negative control group and other injected mice with the recombinant vaccines (0.05).
Observations indicated that the epitope recombinant plasmid of the VP1 protein co-expressed or co-inoculated with IL-2 was effective in inducing an enhanced immune response. Therefore, IL-2 can be recommended as a potential adjuvant for epitope recombinant vaccine of the VP1 protein from FMD virus.
口蹄疫（FMD）病毒疫苗研发研究结果表明，使用FMD病毒灭活疫苗并不完全有效。基于免疫显性表位的新型疫苗已被证明可诱导免疫反应。此外，为确保免疫安全性，获得高效的FMD病毒佐剂似乎至关重要。
在本研究中，我们从伊朗O型FMD病毒的VP1蛋白制备了表位重组疫苗。构建体包括多表位（串联重复多表位）、与白细胞介素-2偶联的多表位（多表位-IL 2）作为分子佐剂以及IL-2。构建了三种表达载体并在BL21（DE3）中表达。为评估这些重组疫苗是否能诱导免疫反应，将重组疫苗注射到BALB/c小鼠体内，并将其免疫反应与阴性对照组进行比较。通过酶联免疫吸附测定法（ELISA）测量体液免疫和细胞免疫反应。
结果表明，与多表位蛋白共表达或共接种的IL-2增强了多表位重组疫苗对FMD病毒的免疫效果。总免疫球蛋白G（IgG）、IgG1和IgG2a水平以及干扰素γ（IFN-γ）、IL-4和IL-10分泌水平的结果显示，阴性对照组与其他注射重组疫苗的小鼠之间存在显著差异（P<0.05）。
观察结果表明，与IL-2共表达或共接种的VP1蛋白表位重组质粒在诱导增强免疫反应方面有效。因此，IL-2可被推荐作为FMD病毒VP1蛋白表位重组疫苗的潜在佐剂。
