Guo Longjun, Niu Junwei, Yu Haidong, Gu Weihong, Li Ren, Luo Xiaolei, Huang Mingming, Tian Zhijun, Feng Li, Wang Yue
State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China.
State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
J Virol. 2014 Sep;88(18):10448-58. doi: 10.1128/JVI.01117-14. Epub 2014 Jun 25.
As a consequence of their effects on ectodomain shedding, members of the A disintegrin and metalloprotease (ADAM) family have been implicated in the control of various cellular processes. Although ADAM family members are also involved in cancer, inflammation, and other pathologies, it is unclear whether they affect porcine reproductive and respiratory syndrome virus (PRRSV) infection. Here, we demonstrate for the first time that inhibition of ADAM17 enhances PRRSV entry in Marc-145 and porcine alveolar macrophages (PAMs). We also demonstrate that the inhibition of ADAM17 upregulates membrane CD163 expression, a putative PRRSV receptor that is exogenously expressed in BHK-21 and endogenously expressed in Marc-145 and PAMs. Furthermore, overexpression of ADAM17 induced downregulation of CD163 expression and a reduction in PRRSV infection, whereas ablation of ADAM17 expression using specific small interfering RNA resulted in upregulation of CD163 expression with a corresponding increase in PRRSV infection. These ADAM17-mediated effects were confirmed with PRRSV nonpermissive BHK-21 cells transfected with CD163 cDNA. Overall, these findings indicate that ADAM17 downregulates CD163 expression and hinders PRRSV entry. Hence, downregulation of ADAM17 particular substrates may be an additional component of the anti-infection defenses.
ADAM17 is one of the important membrane-associated metalloproteases that mediate various cellular events, as well as inflammation, cancer, and other pathologies. Here, we investigate for the first time the role of the metalloprotease ADAM17 in PRRSV infection. By using inhibitor and genetic modification methods, we demonstrate that ADAM17 negatively regulate PRRSV entry by regulating its substrate(s). More specifically, ADAM 17 mediates the downregulation of the PRRSV cellular receptor CD163. The reduction in CD163 expression represents another component of the anti-infection response initiated by ADAM17.
由于其对胞外域脱落的影响，解整合素和金属蛋白酶（ADAM）家族成员已被认为参与多种细胞过程的调控。尽管ADAM家族成员也与癌症、炎症及其他病理状况有关，但它们是否影响猪繁殖与呼吸综合征病毒（PRRSV）感染尚不清楚。在此，我们首次证明抑制ADAM17可增强PRRSV进入Marc-145细胞和猪肺泡巨噬细胞（PAM）的能力。我们还证明抑制ADAM17可上调膜CD163的表达，CD163是一种假定的PRRSV受体，在BHK-21细胞中外源表达，在Marc-145细胞和PAM细胞中内源表达。此外，ADAM17的过表达导致CD163表达下调及PRRSV感染减少，而使用特异性小干扰RNA敲除ADAM17表达则导致CD163表达上调，同时PRRSV感染相应增加。用CD163 cDNA转染的PRRSV非允许性BHK-21细胞证实了这些ADAM17介导的效应。总体而言，这些发现表明ADAM17下调CD163表达并阻碍PRRSV进入。因此，下调ADAM17的特定底物可能是抗感染防御的一个额外组成部分。
ADAM17是介导各种细胞事件以及炎症、癌症和其他病理状况的重要膜相关金属蛋白酶之一。在此，我们首次研究金属蛋白酶ADAM17在PRRSV感染中的作用。通过使用抑制剂和基因修饰方法，我们证明ADAM17通过调节其底物负调控PRRSV进入。更具体地说，ADAM17介导PRRSV细胞受体CD163的下调。CD163表达的降低代表了ADAM17引发的抗感染反应的另一个组成部分。
