新城疫病毒La Sota株热损伤靶点的初步分析

Analysis on Thermal Damage Sites of La Sota Strain of Newcastle Disease Virus

为探索新城疫病毒不耐热毒株La Sota热损伤靶点,以期为新型耐热疫苗研发提供理论依据,试验通过检测加热前后La Sota株的吸附及内化功能,考察纤突蛋白HN和F活性变化情况,以及核衣壳完整性,综合分析新城疫病毒热损伤靶点。结果显示:37℃加热24 h后F蛋白活性首先受损,表现为内化功能显著下降(0.01<P<0.05),56℃加热15 min后HN和F蛋白活性几乎丧失,表现为吸附及内化功能均极显著下降(P<0.01);高温加热后,病毒核衣壳完整性显著降低,病毒粒子破损且失去纤突结构,表现为吸附及内化功能极显著下降(P<0.01)。研究表明,La Sota株热损伤靶点与加热温度和时间密切相关:中温下(≤56℃)病毒热损伤靶点主要在HN和F蛋白,高温下(≥80℃)病毒热损伤靶点为纤突蛋白和核衣壳;纤突蛋白的热敏感性高于核衣壳,且F蛋白受损早于HN蛋白。

In order to explore the thermal damage sites of La Sota strain of Newcastle disease virus(NDV)that facilitate new-type thermostable vaccine development,the function changes of virus adsorption and internalization of La Sota strain before and after heat treatment were studied to explored the activity change of the envelope proteins HN and F of NDV,and further to find out the damage site of viral structure.The results showed that F protein was firstly damaged after heating for 24 h at 37℃,which showed a significant decline in internalization(0.01<P<0.05).After heating at 56℃for 15 min,the activities of HN and F protein were almost lost,showing a remarkable decrease in both adsorption and internalization functions(P<0.01).When exposed into the high temperature,the virus nucleocapsid was damaged,and the viral fibrous structure was totally destroyed,while adsorp-tion and internalization functions were significantly reduced(P<0.01).It was demonstrated that the thermal damage sites of NDV was related to temperature and heating time.The primary thermal damage site of NDV was only HN and F proteins under a mild temperature(below 56℃),while the damage site was the viral envelope protein and nucleocapsid at high temperature(over 80℃).The envelope protein was more thermal-labile than nucleocapsid,and F protein was damaged earlier than HN protein.