Winocur D H, Videla C, Laguens R, Carballal G
Departamento de Microbiología, Facultad de Medicina, Universidad de Buenos Aires, Argentina.
Rev Argent Microbiol. 1990 Jul-Sep;22(3):150-4.
Infection of newborn immunocompetent (nu/+) mice with the XJ prototype strain of Junin virus, etiological agent of Argentine Hemorrhagic Fever, produces a lethal meningo-encephalitis due to cellular immune response. The same strain inoculated into athymic (nu/nu) mice produces an asymptomatic persistent infection. The purpose of this work was to determine the nu/nu mice response when infected with XJCl3, an attenuated Junin virus strain, since this strain behaves differently to the pathogenic prototype in various experimental hosts and humans. Fifty five suckling nu/nu mice and 45 nu/+ were inoculated intracerebrally with 10(3) PFU of the XJCl3 strain. Twenty nu/nu and 20 nu/+ were kept as uninoculated controls. Similar percentages of mortality were recorded for nu/nu and nu/+ infected animals (86 and 87%). In contrast, no morbi-mortality was detected in control animals which were kept in the same animal room. High virus titers were detected in brains and lungs of infected nu/nu at 7, 14, 21 and 70 days post-infection(pi). Virus titers in blood were 1 log lower than those found in organs. Immunohistochemical studies of brains showed viral antigen in the cytoplasm of cortical neurons at 21 and 70 days pi. An interstitial pneumonitis was detected in lungs of infected nu/nu at 7 and 21 days pi, while no lesions were observed in brains and spleens. Results show that the XJl3 strain behaves in a very different way in newborn nu/nu mice as the XJ prototype strain. Further studies are necessary to determine the pathogenic mechanisms involved.
阿根廷出血热的病原体胡宁病毒XJ原型株感染新生免疫功能正常（nu/+）小鼠，会因细胞免疫反应引发致命性脑膜脑炎。将同一毒株接种到无胸腺（nu/nu）小鼠体内会产生无症状持续性感染。这项研究的目的是确定nu/nu小鼠感染减毒胡宁病毒株XJCl3后的反应，因为该毒株在各种实验宿主和人类中与致病性原型株的表现不同。55只乳鼠nu/nu和45只nu/+小鼠脑内接种10³ PFU的XJCl3毒株。20只nu/nu和20只nu/+小鼠作为未接种对照。nu/nu和nu/+感染动物的死亡率相似（分别为86%和87%）。相比之下，在同一动物房饲养的对照动物未检测到发病死亡情况。在感染后7、14、21和70天，在感染的nu/nu小鼠的脑和肺中检测到高病毒滴度。血液中的病毒滴度比器官中的低1个对数。脑的免疫组织化学研究显示，在感染后21天和70天，皮质神经元细胞质中有病毒抗原。在感染后7天和21天，在感染的nu/nu小鼠的肺中检测到间质性肺炎，而在脑和脾中未观察到病变。结果表明，XJl3毒株在新生nu/nu小鼠中的表现与XJ原型株非常不同。需要进一步研究以确定其中涉及的致病机制。
