Studies on the development of diagnosis for infectious diseases among laboratory rodents

1.用大肠杆菌表达汉滩病毒、首尔病毒和多布拉瓦病毒的N蛋白。coli和杆状病毒系统。两种系统的重组蛋白均能产生足够量的重组蛋白，并保持了与真实病毒相似的抗原性。结论：1.本实验条件下制备的ELISA抗原具有较好的应用价值. N端缺失50个氨基酸的截短N蛋白降低了与异源血清型抗体的交叉反应性。因此，将该截短抗原作为血清分型抗原，经常规中和试验确定，该截短抗原可用于中国和俄罗斯远东地区病人和啮齿动物血清的ELISA分型.小鼠肝炎病毒N蛋白基因在酵母系统中表达，培养72小时表达量最高。但其抗原性较低，不适合作为ELISA抗原.从日本分离株（OQ 28株）和原型株（WE株）中克隆了淋巴细胞性脉络丛脑膜炎（LCM）病毒N蛋白的cDNA。将全长cDNA、C端cDNA和中央区cDNA分别转染COS细胞。尽管它们可以表达重组蛋白，但表达的抗原量太小，不适用于ELISA。5。表达LCM病毒N蛋白的重组杆状病毒由日本国立传染病研究所提供。重组杆状病毒感染的SF-9细胞和Tm 5细胞分别适用于IFA抗原和ELISA抗原。通过IFA和ELISA检测了来自日本1，117个动物设施的共计9，840份小鼠血清的LCM病毒抗体。根据这些结果，建议先用ELISA进行筛查，然后用IFA进行确认。

1. Nucleocapsid (N) proteins of Hantaan, Seoul and Dobrava viruses were expressed by E. coli and baculovirus systems. The recombinant proteins by both systems produced enough amount of recombinant proteins and retained the anti genicity similar to those of authentic viruses. They are considered to be a ble to apply for ELISA antigen.2. The truncated N proteins which lacked 50 amino acids at N-terminal reduced the cross reactivity to antibody to heterologous serotypes. Therefore, the truncated antigens were applied as serotyping antigen.The ELISA with the truncated antigen able to serotype of patient and rodent sera from China and Far Eastern part of Russia as determined by ordinary neutralization test.3. Mouse hepatitis virus N protein gene was expressed by yeast system of which maximum expression was observed at 72 hours after culture. However, the antigenicity was too low to apply for ELISA antigen.4. cDNA of N protein of lymphocytic choriomeningitis (LCM) virus were cloned from Japanese isolate (strain OQ28) and prototype strain (strain WE). The cDNAs of full length, C-terminal region and central region were independently transfected to COS cells. Although they could express recombinant proteins, amount of antigen expressed was too small to apply to ELISA.5. Recombinant baculovirus expressing LCM virus N protein was provided from National Institute of Infectious Diseases Japan. Both the recombinant baculovirus infected SF-9 cells and Tm5 cells were found to be applicable for IFA antigen and ELISA antigen, respectively. A total of 9,840 mouse sera from 1,117 animal facility in Japan were tested for LCM virus antibody by IFA and ELISA. From these results, screening with ELISA followed by confirmation by IFA was recommended.