College of Animal Science and Technology, Zhejiang Agriculture and Forestry University, Hangzhou 311300, China.
College of Animal Science and Technology, Zhejiang Agriculture and Forestry University, Hangzhou 311300, China.
Fish Shellfish Immunol. 2018 Apr;75:8-16. doi: 10.1016/j.fsi.2018.01.040. Epub 2018 Jan 31.
Diphthamide biosynthesis protein 7 (Dph7) is a vital protein for diphthamide biosynthesis in archaea and eukaryotes. The 1143 bp cDNA sequence of Dph7 was cloned from the gills of Marsupenaeus japonicus using RT-PCR and RACE. Data showed that Dph7 was highly expressed in the gills and digestive gland of M. japonicus. Furthermore, the expression of dph7 was induced by infection with white spot syndrome virus (WSSV). When Dph7 was knocked down, immune genes such as toll, prophenoloxidase (proPO), p53, tumor necrosis factor-α (TNF-α) and signal transducer and activator of transcription (STAT) were significantly down-regulated (P < 0.01) in hemocytes. First, we demonstrated that Dph7 is very important in the progression of WSSV infection and that the time of death for WSSV-infected shrimp was significantly advanced following RNAi targeting of Dph7. We also investigated the effect of Dph7 on apoptosis rate in M. japonicas and found that Dph7-dsRNA treatment caused lower levels of apoptosis in hemocytes, both in the disease-free group and the WSSV group. Knock-down of Dph7 affected the activity of both phenoloxidase (PO) and superoxide dismutase (SOD), and total hemocyte count (THC) after infection with WSSV, indicating that Dph7 plays a regulatory role in the immunological reaction of shrimp in response to WSSV infection. Thus, we conclude that Dph7 may promote the anti-WSSV immune response of shrimp by regulating apoptosis, SOD and PO activity, and can influence the progression of WSSV infection.
二氢嘧啶酶生物合成蛋白 7（Dph7）是古菌和真核生物中二氢嘧啶酶生物合成的关键蛋白。采用 RT-PCR 和 RACE 技术，从日本对虾（Marsupenaeus japonicus）的鳃中克隆得到长度为 1143bp 的 cDNA 序列。数据表明，Dph7 在日本对虾的鳃和消化腺中高表达。此外，Dph7 的表达可被白斑综合征病毒（WSSV）感染诱导。当 Dph7 被敲低时，血细胞中免疫基因如 toll、酚氧化酶原（proPO）、p53、肿瘤坏死因子-α（TNF-α）和信号转导与转录激活因子（STAT）的表达显著下调（P<0.01）。首先，我们证明了 Dph7 在 WSSV 感染的进展过程中非常重要，并且在靶向 Dph7 的 RNAi 处理后，WSSV 感染虾的死亡时间明显提前。我们还研究了 Dph7 对日本对虾细胞凋亡率的影响，发现 Dph7-dsRNA 处理导致血细胞中凋亡水平降低，无论是在无病组还是在 WSSV 组。Dph7 的敲低影响了酚氧化酶（PO）和超氧化物歧化酶（SOD）的活性以及总血细胞计数（THC），在 WSSV 感染后，表明 Dph7 在虾对 WSSV 感染的免疫反应中发挥调节作用。因此，我们得出结论，Dph7 可能通过调节凋亡、SOD 和 PO 活性以及影响 WSSV 感染的进程来促进虾的抗 WSSV 免疫反应。
