Host-pathogen interactions are highly complex,involving large dynamic changes in gene expression during infection. These interactions are fundamental to understanding anti-infection immunity of hosts, as well as the p...Host-pathogen interactions are highly complex,involving large dynamic changes in gene expression during infection. These interactions are fundamental to understanding anti-infection immunity of hosts, as well as the pathogenesis of pathogens. For bacterial pathogens interacting with animal hosts, timeresolved dual RNA-seq of infected tissue is difficult to perform due to low pathogen load in infected tissue. In this study, an acute infection model of Larimichthys crocea infected by Pseudomonas plecoglossicida was established. The spleens of infected fish exhibited typical symptoms, with a maximum bacterial load at two days post-injection(dpi). Time-resolved dual RNA-seq of infected spleens was successfully applied to study hostpathogen interactions between L. crocea and P.plecoglossicida. The spleens of infected L. crocea were subjected to dual RNA-seq, and transcriptome data were compared with those of noninfected spleens or in vitro cultured bacteria. Results showed that pathogen-host interactions were highly dynamically regulated, with corresponding fluctuations in host and pathogen transcriptomes during infection. The expression levels of many immunogenes involved in cytokine-cytokine receptor,Toll-like receptor signaling, and other immunerelated pathways were significantly up-regulated during the infection period. Furthermore, metabolic processes and the use of oxygen in L. crocea were strongly affected by P. plecoglossicida infection. The WGCNA results showed that the metabolic process was strongly related to the entire immune process.For P. plecoglossicida, the expression levels of motility-related genes and flagellum assemblyrelated genes were significantly up-regulated. The results of this study may help to elucidate the interactions between L. crocea and P.plecoglossicida.展开更多
Pseudomonas plecoglossicida is the pathogen responsible for visceral white spot disease in large yellow croaker(Larimichthys crocea)and orangespotted grouper(Epinephelus coioides).Previously,RNA sequencing showed that...Pseudomonas plecoglossicida is the pathogen responsible for visceral white spot disease in large yellow croaker(Larimichthys crocea)and orangespotted grouper(Epinephelus coioides).Previously,RNA sequencing showed that P.plecoglossicida flgK gene expression was significantly up-regulated in orange-spotted grouper spleens during infection.To explore the role of flgK in P.plecoglossicida pathogenicity,RNA interference(RNAi)was performed to silence the P.plecoglossicida flgK gene,and the mutant(flgK-RNAi strain)with the best silencing efficiency(89.40%)was chosen for further study.Results showed that flgK gene silencing significantly attenuated P.plecoglossicida motility,adhesion,and biofilm formation.Compared to those fish infected with the wild-type strain of P.plecoglossicida,orange-spotted grouper infected with the flgK-RNAi strain showed a 55%increase in the survival rate and a one-day delay in time of first death,with fewer pathogens in the spleen and fewer white spots on the spleen surface.RNAi of flgK significantly affected the transcriptome and metabolome of the spleen in infected orange-spotted grouper.Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis showed that the C-type lectin receptor signaling pathway was the most significantly changed immune-related pathway and the mitogen-activated protein kinase(MAPK)signaling pathway was related to multiple immunerelated pathways.Furthermore,arginine biosynthesis and glycerophospholipid metabolism were the most significantly changed metabolism-related pathways.These findings suggest that flgK is a virulence gene of P.plecoglossicida.Furthermore,flgK appears to be involved in the regulation of motility,adhesion,and biofilm formation in P.plecoglossicida,as well as in the regulation of inflammatory and immune responses of orange-spotted grouper to P.plecoglossicida infection.展开更多
杀香鱼假单胞菌是大黄鱼内脏白点病的致病菌,感染该菌常会导致养殖大黄鱼很高的死亡率和严重的经济损失。病原株NB2011编码典型的Ⅲ型分泌系统,可能是该菌重要的毒力因子,ExsA是控制此分泌系统表达的重要调控蛋白。为确认ExsA在NB2011...杀香鱼假单胞菌是大黄鱼内脏白点病的致病菌,感染该菌常会导致养殖大黄鱼很高的死亡率和严重的经济损失。病原株NB2011编码典型的Ⅲ型分泌系统,可能是该菌重要的毒力因子,ExsA是控制此分泌系统表达的重要调控蛋白。为确认ExsA在NB2011致病过程中的作用,开发有效疫苗,实验采用双交换同源重组法构建了ExsA内部序列被卡那霉素基因替换的突变株,检测突变株与野生株对鼠巨噬细胞J774的黏附、内化和胞内增殖特性,并比较对大黄鱼的毒力变化,同时,通过透射电子显微镜观察人工感染后大黄鱼内脏组织的病理变化。研究表明,巨噬细胞对突变株的内化率降低,内化的细菌在12 h内被清除,野生株在内化后虽然一段时间内数量稍有下降,12~24 h期间数量急剧上升;突变株对大黄鱼的96 h LD_(50)为2.59×10~7/mL,比野生株高数百倍;电镜切片中未观察到组织内有菌体的存在,表明突变株的毒力明显减弱,可以作为弱毒疫苗的开发对象。展开更多
基金the National Natural Science Foundation of China(31672694,31972836)Fujian Provincial Special Fund for Marine and Fishery Protection and Development(MCZ[2019]062)。
文摘Host-pathogen interactions are highly complex,involving large dynamic changes in gene expression during infection. These interactions are fundamental to understanding anti-infection immunity of hosts, as well as the pathogenesis of pathogens. For bacterial pathogens interacting with animal hosts, timeresolved dual RNA-seq of infected tissue is difficult to perform due to low pathogen load in infected tissue. In this study, an acute infection model of Larimichthys crocea infected by Pseudomonas plecoglossicida was established. The spleens of infected fish exhibited typical symptoms, with a maximum bacterial load at two days post-injection(dpi). Time-resolved dual RNA-seq of infected spleens was successfully applied to study hostpathogen interactions between L. crocea and P.plecoglossicida. The spleens of infected L. crocea were subjected to dual RNA-seq, and transcriptome data were compared with those of noninfected spleens or in vitro cultured bacteria. Results showed that pathogen-host interactions were highly dynamically regulated, with corresponding fluctuations in host and pathogen transcriptomes during infection. The expression levels of many immunogenes involved in cytokine-cytokine receptor,Toll-like receptor signaling, and other immunerelated pathways were significantly up-regulated during the infection period. Furthermore, metabolic processes and the use of oxygen in L. crocea were strongly affected by P. plecoglossicida infection. The WGCNA results showed that the metabolic process was strongly related to the entire immune process.For P. plecoglossicida, the expression levels of motility-related genes and flagellum assemblyrelated genes were significantly up-regulated. The results of this study may help to elucidate the interactions between L. crocea and P.plecoglossicida.
基金supported by the National Natural Science Foundation of China(31972836)Natural Science Foundation of Fujian Province(2021J01828)Open Fund of Fujian Province Key Laboratory of Special Aquatic Formula Feed(TMKJZ2101)。
文摘Pseudomonas plecoglossicida is the pathogen responsible for visceral white spot disease in large yellow croaker(Larimichthys crocea)and orangespotted grouper(Epinephelus coioides).Previously,RNA sequencing showed that P.plecoglossicida flgK gene expression was significantly up-regulated in orange-spotted grouper spleens during infection.To explore the role of flgK in P.plecoglossicida pathogenicity,RNA interference(RNAi)was performed to silence the P.plecoglossicida flgK gene,and the mutant(flgK-RNAi strain)with the best silencing efficiency(89.40%)was chosen for further study.Results showed that flgK gene silencing significantly attenuated P.plecoglossicida motility,adhesion,and biofilm formation.Compared to those fish infected with the wild-type strain of P.plecoglossicida,orange-spotted grouper infected with the flgK-RNAi strain showed a 55%increase in the survival rate and a one-day delay in time of first death,with fewer pathogens in the spleen and fewer white spots on the spleen surface.RNAi of flgK significantly affected the transcriptome and metabolome of the spleen in infected orange-spotted grouper.Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis showed that the C-type lectin receptor signaling pathway was the most significantly changed immune-related pathway and the mitogen-activated protein kinase(MAPK)signaling pathway was related to multiple immunerelated pathways.Furthermore,arginine biosynthesis and glycerophospholipid metabolism were the most significantly changed metabolism-related pathways.These findings suggest that flgK is a virulence gene of P.plecoglossicida.Furthermore,flgK appears to be involved in the regulation of motility,adhesion,and biofilm formation in P.plecoglossicida,as well as in the regulation of inflammatory and immune responses of orange-spotted grouper to P.plecoglossicida infection.
文摘杀香鱼假单胞菌是大黄鱼内脏白点病的致病菌,感染该菌常会导致养殖大黄鱼很高的死亡率和严重的经济损失。病原株NB2011编码典型的Ⅲ型分泌系统,可能是该菌重要的毒力因子,ExsA是控制此分泌系统表达的重要调控蛋白。为确认ExsA在NB2011致病过程中的作用,开发有效疫苗,实验采用双交换同源重组法构建了ExsA内部序列被卡那霉素基因替换的突变株,检测突变株与野生株对鼠巨噬细胞J774的黏附、内化和胞内增殖特性,并比较对大黄鱼的毒力变化,同时,通过透射电子显微镜观察人工感染后大黄鱼内脏组织的病理变化。研究表明,巨噬细胞对突变株的内化率降低,内化的细菌在12 h内被清除,野生株在内化后虽然一段时间内数量稍有下降,12~24 h期间数量急剧上升;突变株对大黄鱼的96 h LD_(50)为2.59×10~7/mL,比野生株高数百倍;电镜切片中未观察到组织内有菌体的存在,表明突变株的毒力明显减弱,可以作为弱毒疫苗的开发对象。
