Targeted infection of endothelial cells by avian influenza virus A/FPV/Rostock/34 (H7N1) in chicken embryos
Targeted infection of endothelial cells by avian influenza virus A/FPV/Rostock/34 (H7N1) in chicken embryos
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DOI：
10.1128/jvi.74.17.8018-8027.2000
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发表时间：
2000-09-01
影响因子：
5.4
通讯作者：
Klenk, HD
中科院分区：
文献类型：
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作者：
Feldmann, A;Schäfer, MKH;Klenk, HD
对高致病性禽流感病毒A/FPV/Rostock/34(H7N1)(FPV)在11日龄鸡胚胎中的组织嗜性和感染传播进行了分析。原位杂交结果表明，该病毒引起的全身性感染仅限于所有器官的内皮细胞。用FPV的重组体和非致病性禽流感A/chick/德国/N/49(H10N7)株的研究表明，亲内皮性与FPV血凝素(EW)有关。为了进一步分析决定亲内皮性的因素，从鸡组织中克隆了透明质酸激活蛋白水解酶Furin。鸡胚中广泛表达呋喃西林等原蛋白转换酶，提示HA的蛋白水解性激活不是限制内皮细胞感染的原因。为了确定病毒受体在胚胎组织中的表达，用凝集素结合法对α2，3和α2，6连接的神经氨酸进行了组织化学分析。这些受体存在于内皮细胞和几个上皮细胞上，但不存在于内皮细胞周围的组织中。最后，我们分析了病毒在内皮细胞中成熟的极性，用激光共聚焦扫描显微镜对培养的人内皮细胞的研究表明，EIA特异性地针对这些细胞的顶面，而胚胎组织的电子显微镜显示病毒成熟也发生在发光侧。综上所述，这些观察结果表明，鸡胚中的鸡瘟病毒的亲内皮性一方面是由HA的高切割能力决定的，它介导病毒进入血管系统，另一方面是由限制性受体表达和极芽生长决定的，后者防止感染扩散到内皮周围的组织。
The tissue tropism and spread of infection of the highly pathogenic avian influenza virus A/FPV/Rostock/34 (H7N1) (FPV) were analyzed in 11-day-old chicken embryos, As shown by in situ hybridization, the virus caused generalized infection that was strictly confined to endothelial cells in all organs, Studies with reassortants of FPV and the apathogenic avian strain A/chick/Germany/N/49 (H10N7) revealed that endotheliotropism was linked to FPV hemagglutinin (EW). To further analyze the factors determining endotheliotropism, the HA-activating protease furin was cloned from chicken tissue. Ubiquitous expression of furin and other proprotein convertases in the chick embryo indicated that proteolytic activation of HA was not responsible for restriction of infection to the endothelium. To determine the expression of virus receptors in embryonic tissues, histochemical analysis of alpha 2,3- and alpha 2,6-linked neuraminic acid was carried out by Lectin-binding assays. These receptors were found on endothelial tells and on several epithelial cells, but not on tissues surrounding endothelia. Finally, we analyzed the polarity of virus maturation in endothelial cells, Studies on cultured human endothelial cells employing confocal laser scanning microscopy revealed that EIA is specifically targeted to the apical surface of these cells, and electron microscopy of embryonic tissues showed that virus maturation occurs also at the luminar side. Taken together, these observations indicate that endotheliotropism of FPV in the chicken embryo is determined, on one hand, by the high cleavability of HA, which mediates virus entry into the vascular system, and, on the other hand, by restricted receptor expression and polar budding, which prevent spread of infection into tissues surrounding endothelia.