Alvarez-Torres Daniel, Podadera Ana M, Bejar Julia, Bandin Isabel, Alonso M Carmen, Garcia-Rosado Esther
Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071, Málaga, Spain.
Departamento de Genética, Facultad de Ciencias, Universidad de Málaga, 29071, Málaga, Spain.
Vet Res. 2016 Jan 8;47:3. doi: 10.1186/s13567-015-0299-4.
Senegalese sole is susceptible to marine VHSV isolates but is not affected by freshwater isolates, which may indicate differences regarding virus-host immune system interaction. IFN I induces an antiviral state in fish, stimulating the expression of genes encoding antiviral proteins (ISG). In this study, the stimulation of the Senegalese sole IFN I by VHSV infections has been evaluated by the relative quantification of the transcription of several ISG (Mx, Isg15 and Pkr) after inoculation with marine (pathogenic) and freshwater (non-pathogenic) VHSV isolates. Compared to marine VHSV, lower levels of RNA of the freshwater VHSV induced transcription of ISG to similar levels, with the Isg15 showing the highest fold induction. The protective role of the IFN I system was evaluated in poly I:C-inoculated animals subsequently challenged with VHSV isolates. The cumulative mortality caused by the marine isolate in the control group was 68%, whereas in the poly I:C-stimulated group was 5%. The freshwater VHSV isolate did not cause any mortality. Furthermore, viral RNA fold change and viral titers were lower in animals from the poly I:C + VHSV groups than in the controls. The implication of the IFN I system in the protection observed was confirmed by the transcription of the ISG in animals from the poly I:C + VHSV groups. However, the marine VHSV isolate exerts a negative effect on the ISG transcription at 3 and 6 h post-inoculation (hpi), which is not observed for the freshwater isolate. This difference might be partly responsible for the virulence shown by the marine isolate.
塞内加尔鳎对海洋型病毒性出血性败血症病毒（VHSV）分离株敏感，但不受淡水型分离株影响，这可能表明在病毒与宿主免疫系统相互作用方面存在差异。I型干扰素（IFN I）可在鱼类中诱导抗病毒状态，刺激编码抗病毒蛋白（ISG）的基因表达。在本研究中，通过接种海洋型（致病性）和淡水型（非致病性）VHSV分离株后，对几种ISG（Mx、Isg15和Pkr）转录的相对定量，评估了VHSV感染对塞内加尔鳎IFN I的刺激作用。与海洋型VHSV相比，淡水型VHSV诱导ISG转录的RNA水平较低，但能达到相似水平，其中Isg15的诱导倍数最高。在随后用VHSV分离株攻击的聚肌胞苷酸（poly I:C）接种动物中评估了IFN I系统的保护作用。海洋型分离株在对照组中引起的累积死亡率为68%，而在聚肌胞苷酸刺激组中为5%。淡水型VHSV分离株未导致任何死亡。此外，聚肌胞苷酸+VHSV组动物的病毒RNA变化倍数和病毒滴度低于对照组。聚肌胞苷酸+VHSV组动物中ISG的转录证实了IFN I系统在观察到的保护作用中的意义。然而，海洋型VHSV分离株在接种后3小时和6小时（hpi）对ISG转录产生负面影响，而淡水型分离株未观察到这种情况。这种差异可能部分解释了海洋型分离株所表现出的毒力。
