PATHOGENESIS OF ALEUTIAN DISEASE VIRUS INFECTION

本项目的范围是研究水貂感染 水貂阿留申病细小病毒（ADV）。 过去一年 我们已经开始利用链- 特异性原位分子杂交。 理由是基于 ADV DNA的复制形式（RFs）含有“+” 有义核酸链，而病毒体DNA在很大程度上是“-”， 道理啊 因此，有意义的探针将优先定义 复制位点，而“+”有义探针将另外 描绘出病毒被隔离的地点。 我们应用 这些探针在原位杂交到目前为止对ADV感染 组织培养细胞的体外培养和新生水貂组织切片， ADV间质性肺炎 在整个允许体外 感染后，双链RF定位于细胞核。 病毒体 DNA和衣壳蛋白被发现在细胞核的早期， 感染，但后来转移到细胞质。 的 放射自显影颗粒明显定位于感染的 细胞，ADV抗原阳性细胞数为 与病毒DNA阳性相同，这表明在这种情况下， 允许系统，所有含有病毒DNA的细胞也表达 病毒蛋白 在ADV感染的新生水貂中， ADV主要分布于肺组织。 RF和ADV抗原 主要存在于产生表面活性剂的肺泡 II型细胞，并且模式与观察到的 组织培养细胞 这一观察结果表明，新生儿 肺炎由ADV的直接细胞病变感染引起， II型细胞，随后的肺细胞耗竭 表面活性 在其他器官中也发现了病毒DNA，但 链特异性探针使得有可能显示大部分这种 DNA代表被吞噬细胞隔离的病毒 淋巴网状系统的组成部分。 病毒体DNA，ADV 在组织学正常者中， 肾小球这些感染的新生儿，提示早期形式的 完整病毒体参与的免疫复合物肾炎。

The scope of this project is the study of infections of mink with the Aleutian disease of mink parvovirus (ADV). In the past year we have begun the analysis of ADV infections utilizing strand- specific in situ molecular hybridization. The rationale is based on the fact that replicative forms of ADV DNA (RFs) contain "+" sense nucleic acid strands, whereas virion DNA is largely "-" in sense. Thus, probes that are "-" in sense will preferentially define sites of replication, whereas "+" sense probes will in addition delineate sites where virus is being sequestered. We have applied these probes in in situ hybridization to date on ADV infected tissue culture cells in vitro and on sections of newborn mink with ADV interstitial pneumonitis. Throughout permissive in vitro infection, duplex RFs were localized to the cell nuclei. Virion DNA and capsid proteins were found in the nuclei early in infection, but were later translocated to the cytoplasm. The autoradiographic grains were clearly localized over the infected cells, and the number of cells positive for ADV antigen was the same as that positive for viral DNA, suggesting that in this permissive system, all cells containing viral DNA also expressed viral proteins. In ADV infected neonatal mink, cells replicating ADV were found primarily in the lung. RFs and ADV antigens were found predominantly in the surfactant producing alveolar type II cells, and the pattern was similar to that observed for the tissue culture cells. This observation suggested that the neonatal pneumonitis results from a direct cytopathic infection by ADV of the type II cells, with subsequent depletion of pulmonary surfactant. Viral DNA was also found in other organs, but the strand specific probes made it possible to show that most of this DNA represented virus that was being sequestered in phagocytic elements of the lymphoreticular system. Virion DNA, ADV antigen and mink IgG were found in the histologically normal glomeruli of these infected neonates, suggesting an early form of immune complex nephritis in which intact virions participated.