Aeromonas salmonicida subsp. masoucida (ASM) is an important bacterial pathogen of salmonid fish, which can cause huge economic losses to the fish farming industry. In order to screen effective vaccine candidate proteins, four outer membrane proteins of ASM, including OmpA, OmpC, OmpK and OmpW, were selected and recombinantly expressed in Escherichia coli. The result of western blotting showed that these four recombinant proteins could be recognized by rainbow trout anti-ASM antibodies. The immune protective effects of the four rOMPs were also investigated, and the relative percentage survival (RPS) of rOmpA, rOmpC, rOmpK and rOmpW were 71.1%, 81.6%, 55.3% and 42.1%, respectively. The RPS of rOmpC was significantly higher than the other three rOMPs, so the immune responses of rainbow trout induced by rOmpC were further investigated. The results showed that vaccination with rOmpC could significantly induced the production of specific serum antibodies and proliferation of sIg + lymphocytes in peripheral blood. Meanwhile, RT-qPCR analysis showed that rOmpC could significantly enhance the expression of the MHC-II, TCR, CD4, CD8, IL-8 and IgM genes compared with the BSA immunized group. These results demonstrated that rOmpC could induce strong humoral immune response in rainbow trout and provided effective immune protection against ASM challenge, which indicated that OmpC is a promising vaccine candidate against Aeromonas salmonicida infection.

中文翻译：

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鲑鱼气单胞菌亚种的重组外膜蛋白C。masoucida，可能是虹鳟鱼（Oncorhynchus mykiss）的候选疫苗。

鲑气单胞菌亚种。毛毛纲（ASM）是鲑鱼的重要细菌病原体，可能对养鱼业造成巨大的经济损失。为了筛选有效的疫苗候选蛋白，选择了ASM的四种外膜蛋白，包括OmpA，OmpC，OmpK和OmpW，并在大肠杆菌中重组表达。蛋白质印迹的结果表明，这四个重组蛋白可以被虹鳟鱼抗ASM抗体识别。还研究了这四种rOMP的免疫保护作用，rOmpA，rOmpC，rOmpK和rOmpW的相对存活率（RPS）分别为71.1％，81.6％，55.3％和42.1％。rOmpC的RPS明显高于其他三个rOMP，因此需要进一步研究rOmpC诱导的虹鳟鱼的免疫反应。结果表明，接种rOmpC可以显着诱导特异性血清抗体的产生以及外周血sIg +淋巴细胞的增殖。同时，RT-qPCR分析显示，与BSA免疫组相比，rOmpC可以显着增强MHC-II，TCR，CD4，CD8，IL-8和IgM基因的表达。这些结果表明，rOmpC可以在虹鳟鱼中诱导强烈的体液免疫反应，并提供针对ASM攻击的有效免疫保护，这表明OmpC是针对鲑鱼气单胞菌感染的有希望的候选疫苗。RT-qPCR分析表明，与BSA免疫组相比，rOmpC可以显着增强MHC-II，TCR，CD4，CD8，IL-8和IgM基因的表达。这些结果表明，rOmpC可以在虹鳟鱼中诱导强烈的体液免疫反应，并提供针对ASM攻击的有效免疫保护，这表明OmpC是针对鲑鱼气单胞菌感染的有希望的候选疫苗。RT-qPCR分析表明，与BSA免疫组相比，rOmpC可以显着增强MHC-II，TCR，CD4，CD8，IL-8和IgM基因的表达。这些结果表明，rOmpC可以在虹鳟鱼中诱导强烈的体液免疫反应，并提供针对ASM攻击的有效免疫保护，这表明OmpC是针对鲑鱼气单胞菌感染的有希望的候选疫苗。