Seabass (Lates calcarifer) are high value fish occupying a market niche, and is susceptible to infection by pathogenic bacteria such as Vibriosis. In this study the effect of intraperitoneal administration of recombinant outer membrane protein (OMP) of inactivated cells vaccine; r-OmpK on hematological parameters for monitoring fish health and histopathological examination of seabass were investigated. The results revealed that r-OmpK affect some hematological parameters positively in juvenile bass. The r-OmpK vaccinated seabass showed mild histological alterations in the vital organs (spleen, kidney and intestine) when compared to PBS control groups. Further we sought to understand the mechanisms of molecular immunity of L. calcarifer against V. harveyi infection. We carried out an extensive analysis of the transcriptome of L. calcarifer head kidney upon vaccination trial with r-OmpK recombinant cell vaccine and challenged with V. harveyi pathogenic strain VH1. Average reads of 92.74 million and 116.17 million were obtained from head kidney of juvenile L. calcarifer immunized with phosphate buffered saline (PBS) and r-OmpK (10 ⁹ cfu/mL) recombinant cell vaccine, respectively. Also, the analysis revealed that a higher number of genes and pathways were regulated in response to infection with V. harveyi at 48 h post infection compared to the PBS controls. Based on the differential expressed genes (DEGs) around 0.31 % of total unigenes were differentially expressed between the two vaccinated groups. Protein-protein interaction analysis predicts glycolysis pathway, alanine, aspartate and glutamate metabolism pathway, pyruvate metabolism pathway, MAPK signaling pathway, metabolic pathways, insulin signaling pathway and focal adhesion pathway in head kidney of infected fish, which might be useful in understanding biological processes and further studies in the direction of pathways. We reported the novel immune-related signalling pathways, namely complement and coagulation cascades, chemokine signalling pathway, and toll-like receptor signalling pathway having great importance in immunity and anti-inflammation.

鲈鱼（Lates calcarifer）是一种高价值的鱼类，占据了市场空间，容易感染弧菌等病原菌。本次研究腹腔注射重组外膜蛋白（OMP）灭活细胞疫苗的效果；r-OmpK 对用于监测鱼类健康和鲈鱼组织病理学检查的血液学参数进行了研究。结果表明，r-OmpK 对幼鲈的一些血液学参数产生积极影响。与 PBS 对照组相比，r-OmpK 接种的鲈鱼在重要器官（脾、肾和肠）中显示出轻微的组织学改变。进一步我们试图了解L. calcarifer对V. harveyi的分子免疫机制感染。我们在用 r-OmpK 重组细胞疫苗进行疫苗接种试验后对L. calcarifer头肾的转录组进行了广泛分析，并用V. harveyi致病菌株 VH1 进行攻击。从用磷酸盐缓冲盐水（PBS）和r-OmpK（10 ⁹ cfu/mL）重组细胞疫苗免疫的幼体L. calcarifer的头肾分别获得了9274万和11617万的平均读数。此外，分析显示，在对哈维伊弧菌感染作出反应时，更多的基因和通路受到调控与 PBS 对照相比，感染后 48 小时。基于差异表达基因 (DEG)，大约 0.31% 的总 unigenes 在两个接种组之间差异表达。蛋白质-蛋白质相互作用分析预测受感染鱼头肾糖酵解途径、丙氨酸、天冬氨酸和谷氨酸代谢途径、丙酮酸代谢途径、MAPK信号通路、代谢通路、胰岛素信号通路和粘着斑通路，这可能有助于了解生物过程并在路径方向上​​进一步研究。我们报道了新的免疫相关信号通路，即补体和凝血级联、趋化因子信号通路和 Toll 样受体信号通路在免疫和抗炎方面具有重要意义。