State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, China; Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Meishan Campus, Ningbo University, Ningbo, 315832, China.
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, China; Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Meishan Campus, Ningbo University, Ningbo, 315832, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Meishan Campus, Ningbo University, Ningbo, 315832, China.
Fish Shellfish Immunol. 2020 Apr;99:176-183. doi: 10.1016/j.fsi.2020.01.063. Epub 2020 Feb 1.
Large yellow croaker (Larimichthys crocea, LYC) aquaculture is being threatened by intensive infectious diseases. Relevant studies have focused on LYC immune responses to infection. By contrast, little is known how and to what extent the gut microbiota responds to infection. Here, we explored the interactions between LYC immune responses and gut bacterial communities during Pseudomonas plecoglossicida infection. P. plecoglossicida successfully colonized into LYC gut microbiota, resulting in an increasing mortality rate. Relative gene expressions of pro-inflammatory cytokines (TNF-α1, TNF-α2 and IL-1β) and anti-inflammatory cytokine (IL-10) were consistently and significantly induced by P. plecoglossicida infection, whereas non-specific immune enzymes activities were only enhanced at the early infection stages. P. plecoglossicida infection caused an irreversible disruption in the gut microbiota, of which infection and hours post infection constrained 16.2% and 5.6% variations, respectively. In addition, top 18 discriminatory taxa that were responsible for the difference between treatments were identified, whose abundances were significantly associated with the immune activities of LYC. Using a structural equation modeling (SEM), we found that gut bacterial communities were primarily governed by the conjointly direct (-0.33) and indirect (0) effects of infection, which subsequently affect host immune responses. Our results suggest that an irreversible dysbiosis in gut microbiota could be the causality of increasing mortality. To our knowledge, this is the first study to provide an integrated overview among pathogen infection, immune response and gut microbiota of LYC.
大黄鱼（Larimichthys crocea，LYC）养殖业正受到传染性疾病的严重威胁。相关研究主要集中在 LYC 对感染的免疫反应上。相比之下，人们对肠道微生物群如何以及在多大程度上对感染作出反应知之甚少。在这里，我们探讨了在感染假单胞菌（Pseudomonas plecoglossicida）期间 LYC 免疫反应和肠道细菌群落之间的相互作用。假单胞菌成功定植在 LYC 肠道微生物群中，导致死亡率不断上升。促炎细胞因子（TNF-α1、TNF-α2 和 IL-1β）和抗炎细胞因子（IL-10）的相对基因表达水平被假单胞菌感染持续且显著诱导，而非特异性免疫酶活性仅在早期感染阶段增强。假单胞菌感染导致肠道微生物群发生不可逆转的破坏，其中感染和感染后 5 小时分别解释了 16.2%和 5.6%的变异。此外，鉴定出了 18 个负责处理间差异的主要鉴别分类群，其丰度与 LYC 的免疫活性显著相关。通过结构方程模型（SEM），我们发现肠道细菌群落主要受到感染的直接（-0.33）和间接（0）共同作用的影响，而间接作用则会影响宿主的免疫反应。我们的研究结果表明，肠道微生物群的不可逆转失调可能是死亡率增加的原因。据我们所知，这是首次对大黄鱼病原体感染、免疫反应和肠道微生物群进行综合研究。
