Levicán-Asenjo Jorge, Soto-Rifo Ricardo, Aguayo Francisco, Gaggero Aldo, Leon Oscar
Programa de Virología, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile.
J Fish Dis. 2019 Jul;42(7):1035-1046. doi: 10.1111/jfd.13009. Epub 2019 May 2.
We have previously shown that infectious pancreatic necrosis virus (IPNV) enters the embryo cell line CHSE-214 by macropinocytosis. In this study, we have extended our investigation into SHK-1 cells, a macrophage-like cell line derived from the head kidney of Atlantic salmon, the most economically important host of IPNV. We show that IPNV infection stimulated fluid uptake in SHK-1 cells above the constitutive macropinocytosis level. In addition, upon infection of SHK-1 cells, IPNV produced several changes in actin dynamics, such as protrusions and ruffles, which are important features of macropinocytosis. We also observed that the Na+/H+ pump inhibitor EIPA blocked IPNV infection. On the other hand, IPNV entry was independent of clathrin, a possibility that could not be ruled out in CHSE 214 cells. In order to determine the possible role of accessory factors on the macropinocytic process, we tested several inhibitors that affect components of transduction pathways. While pharmacological intervention of PKI3, PAK-1 and Rac1 did not affect IPNV infection, inhibition of Ras and Rho GTPases as well as Cdc42 resulted in a partial decrease in IPNV infection. Further studies will be required to determine the signalling pathway involved in the macropinocytosis-mediated entry of IPNV into its target cells.
我们之前已经表明，传染性胰腺坏死病毒（IPNV）通过巨胞饮作用进入胚胎细胞系CHSE - 214。在本研究中，我们将调查扩展至SHK - 1细胞，这是一种源自大西洋鲑鱼头肾的巨噬细胞样细胞系，而大西洋鲑是IPNV在经济上最重要的宿主。我们发现IPNV感染会刺激SHK - 1细胞的液体摄取，使其高于组成型巨胞饮作用水平。此外，在感染SHK - 1细胞后，IPNV会引起肌动蛋白动力学的多种变化，如突起和褶皱，这些都是巨胞饮作用的重要特征。我们还观察到Na+/H+泵抑制剂EIPA可阻断IPNV感染。另一方面，IPNV的进入不依赖网格蛋白，而在CHSE 214细胞中这种可能性无法排除。为了确定辅助因子在巨胞饮过程中的可能作用，我们测试了几种影响转导途径成分的抑制剂。虽然对PKI3、PAK - 1和Rac1的药物干预不影响IPNV感染，但抑制Ras和Rho GTP酶以及Cdc42会导致IPNV感染部分减少。需要进一步研究来确定巨胞饮作用介导IPNV进入其靶细胞所涉及的信号通路。
