树鼬对森林脑炎病毒的敏感性及发病机理的研究

Susceptibilty and Pathogenesis Study of Tupaia Belanger Yunalis to Experimental Infection with Russian Spring-Summer Encephalitis Virus

从云南新分离森林脑炎病毒(YH和T57)及东北株经脑内、皮下及腹腔感染成年中国云南树鼩,均发生病毒血症。持续时间为7—9天。抗体应答反应和病理改变程度成反比,病变轻的能产生较好的免疫应答。血凝抑制抗体、中和抗体和补体结合抗体分别于感染后的第5、7、13天出现,且血凝抑制抗体和中和抗体的升高呈正相关。经抗原定位研究发现,腹腔注射后48小时,各组织器官均能查到抗原,除中枢神经系统外,其它组织内病毒抗原消失都很快,随病毒血症的消失而转阴,中枢神经系统携带抗原可持续27天,且病变随病程的延长而加重,表现为充血、血管周围淋巴细胞呈套状浸润,局灶性出血,神经元变性,胶质细胞增生,轴索断裂等,说明靶器官是中枢神经系统。试验表明,成年中国云南树勉对森林脑炎病毒比较敏感,是森林脑炎病毒动物模型研究首选动物。

Chinese tupaia belangeri yunalises were infected with Russian spring summer encephalitis viruses (Dongbai, YH, T57 strains) by intracerebral, intraperitoneal and subcataneous route. All tupaia belangeri yunalies had viremia and lasted for 7—9 days. Immune response depended on pathogen which light pathological change induced good immune response HI antibody, neutralizing antibody and CF antibody were checked out on 5th, 7th and 13thday, respectively. The growth of both HI antibody and neutralizing antibody were positive relation. Brain mantlet brain neuropile, cerebellum, brain stem, spinal cord, Iymphoid node, Stomach, intestinum angustum, liver, spleen, lung, kidney and peritonaeum were examined by IFAT. The organs were negative with viremia gone off but the central nervous system. Pathological examination showed that pathological changes located in the central nervous systemt hyperaemia lymphoid leucocytes surrounded arround the blood vessel, hemorrhage in location, nerve cell denatured and necrosised, neuropongium cell hyperplasia and spinal nerve broke. It showed that central nervous system was the target organ. Cross-neutralization test showed that the virus to lead to the special pathological changes of tupaia belangeri yunalis was the inoculation material. The experimental results showed that Russian spring-summer encephalitis virus was sensitive to Chinese tupaia belangeri yunalis that is ideal animal model of RSSEV.