Pathology and Forensic Veterinary Medicine, Department of Pathobiology, University of Veterinary Medicine, Veterinärplatz 1, A-1210 Vienna, Austria.
Vet Microbiol. 2010 Sep 28;145(1-2):9-16. doi: 10.1016/j.vetmic.2010.02.030. Epub 2010 Mar 3.
Proventricular dilatation disease (PDD) of psittacine birds is caused by a number of different genotypes of a novel viral species, avian bornavirus (ABV). Here we present an in situ hybridization (ISH) procedure using digoxigenin-labeled RNA probes for localizing viral genomic and mRNA of ABV-2 and ABV-4 in tissues of affected birds. Out of eleven immunohistochemically positive birds ISH signals were only found in seven. Partial sequencing of the viral genome had shown that four of them were infected with ABV-2, two with ABV-4 and one had a mixed infection with ABV-2 and ABV-4. ISH signals were present in the brain, in the vegetative nerve system, glandular epithelia and smooth muscle cells of the intestinal tract and in cardiomyocytes. Hybridization signals for viral genome were more abundant than signals for mRNA. As the probes were not strictly genotype-specific, four of the birds had hybridization signals with both, the ABV-2 and ABV-4 probes. The signals achieved with the homologous probes were more intense and more abundant than those resulting from heterologous probes. Taken together, the results of this study show that ISH can be used as a tool for localizing ABV sequences in tissues of birds with PDD and confirm the causative role of ABVs by showing viral replication in affected tissues.
禽传染性腺胃炎（PDD）由多种新型病毒种的不同基因型引起，即禽传染性支气管炎病毒（ABV）。本文展示了一种原位杂交（ISH）技术，该技术使用地高辛标记的 RNA 探针，用于定位 ABV-2 和 ABV-4 在受感染鸟类组织中的基因组和 mRNA。在 11 只免疫组织化学阳性的鸟类中，只有 7 只发现了 ISH 信号。对病毒基因组的部分测序表明，其中 4 只感染了 ABV-2，2 只感染了 ABV-4，1 只同时感染了 ABV-2 和 ABV-4。ISH 信号存在于大脑、植物性神经系统、肠道的腺上皮和平滑肌细胞以及心肌细胞中。病毒基因组的杂交信号比 mRNA 信号更为丰富。由于探针并非严格的基因型特异性，因此有 4 只鸟类的 ABV-2 和 ABV-4 探针都出现了杂交信号。同源探针的信号比异源探针的信号更强烈、更丰富。综上所述，本研究结果表明，ISH 可用于定位 PDD 鸟类组织中的 ABV 序列，并通过显示受影响组织中的病毒复制，证实 ABV 具有致病作用。
