scholarly journals Rab5 and Rab11 Are Required for Clathrin-Dependent Endocytosis of Japanese Encephalitis Virus in BHK-21 Cells

2017 ◽  
Vol 91 (19) ◽  
Author(s):  
Chun-Chun Liu ◽  
Yun-Na Zhang ◽  
Zhao-Yao Li ◽  
Jin-Xiu Hou ◽  
Jing Zhou ◽  
...  

ABSTRACT During infection Japanese encephalitis virus (JEV) generally enters host cells via receptor-mediated clathrin-dependent endocytosis. The trafficking of JEV within endosomes is controlled by Rab GTPases, but which Rab proteins are involved in JEV entry into BHK-21 cells is unknown. In this study, entry and postinternalization of JEV were analyzed using biochemical inhibitors, RNA interference, and dominant negative (DN) mutants. Our data demonstrate that JEV entry into BHK-21 cells depends on clathrin, dynamin, and cholesterol but not on caveolae or macropinocytosis. The effect on JEV infection of dominant negative (DN) mutants of four Rab proteins that regulate endosomal trafficking was examined. Expression of DN Rab5 and DN Rab11, but not DN Rab7 and DN Rab9, significantly inhibited JEV replication. These results were further tested by silencing Rab5 or Rab11 expression before viral infection. Confocal microscopy showed that virus particles colocalized with Rab5 or Rab11 within 15 min after virus entry, suggesting that after internalization JEV moves to early and recycling endosomes before the release of the viral genome. Our findings demonstrate the roles of Rab5 and Rab11 on JEV infection of BHK-21 cells through the endocytic pathway, providing new insights into the life cycle of flaviviruses. IMPORTANCE Although Japanese encephalitis virus (JEV) utilizes different endocytic pathways depending on the cell type being infected, the detailed mechanism of its entry into BHK-21 cells is unknown. Understanding the process of JEV endocytosis and postinternalization will advance our knowledge of JEV infection and pathogenesis as well as provide potential novel drug targets for antiviral intervention. With this objective, we used systematic approaches to dissect this process. The results show that entry of JEV into BHK-21 cells requires a low-pH environment and that the process occurs through dynamin-, actin-, and cholesterol-dependent clathrin-mediated endocytosis that requires Rab5 and Rab11. Our work provides a detailed picture of the entry of JEV into BHK-21 cells and the cellular events that follow.

Viruses ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 630 ◽  
Author(s):  
Jichen Niu ◽  
Ya Jiang ◽  
Hao Xu ◽  
Changjing Zhao ◽  
Guodong Zhou ◽  
...  

Japanese encephalitis virus (JEV) is a mosquito-borne Flavivirus, the leading cause of viral-induced encephalitis. Several host molecules have been identified as the JEV attachment factor; however, the molecules involved in JEV entry remain poorly understood. In the present study, we demonstrate that TIM-1 is important for efficient infection by JEV. Firstly, three TIM-1 variants (V1, V2, and V3) were cloned from A549 cells, and we revealed that only ectopically TIM-1 V2 expression in 293T cells significantly promotes JEV attachment, entry and infection. Point mutation of phosphatidylserine (Ptdser) binding pocket in the TIM-1 IgV domain dampened JEV entry, indicating that TIM-1-mediated JEV infection is Ptdser-dependent. Furthermore, we found the cytoplasmic domain of TIM-1 is also required for enhancing JEV entry. Additionally, knock down of TIM-1 expression in A549 cells impaired JEV entry and infection, but not attachment, suggesting that additional factors exist in A549 cells that allow the virus to bind. In conclusion, our findings demonstrate that TIM-1 promotes JEV infection as an entry cofactor, and the polymorphism of TIM-1 is associated with JEV susceptibility to host cells.


Pathogens ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 111 ◽  
Author(s):  
Filgueira ◽  
Lannes

Japanese encephalitis virus (JEV) is an emerging flavivirus of the Asia-Pacific region. More than two billion people live in endemic or epidemic areas and are at risk of infection. Recently, the first autochthonous human case was recorded in Africa, and infected birds have been found in Europe. JEV may spread even further to other continents. The first section of this review covers established and new information about the epidemiology of JEV. The subsequent sections focus on the impact of JEV on humans, including the natural course and immunity. Furthermore, new concepts are discussed about JEV’s entry into the brain. Finally, interactions of JEV and host cells are covered, as well as how JEV may spread in the body through latently infected immune cells and cell-to-cell transmission of virions or via other infectious material, including JEV genomic RNA.


2014 ◽  
Vol 95 (1) ◽  
pp. 71-79 ◽  
Author(s):  
Sankar Bhattacharyya ◽  
Utsav Sen ◽  
Sudhanshu Vrati

Japanese encephalitis virus (JEV) infection-induced encephalitis causes extensive death or long-term neurological damage, especially among children, in south and south-east Asia. Infection of mammalian cells has shown induction of an unfolded protein response (UPR), presumably leading to programmed cell death or apoptosis of the host cells. UPR, a cellular response to accumulation of unfolded or misfolded proteins in the endoplasmic reticulum (ER) lumen, is initiated by three ER-lumen-resident sensors (PERK, IRE1 and ATF6), and involves transcriptional and translational regulation of the expression of several genes. The sensor IRE1 possesses an intrinsic RNase activity, activated through homo-dimerization and autophosphorylation during UPR. Activated IRE1 performs cytoplasmic cleavage of Xbp1u transcripts, thus facilitating synthesis of XBP1S transcription factor, in addition to cleavage of a cohort of cellular transcripts, the later initiating the regulated IRE1-dependent decay (RIDD) pathway. In this study, we report the initiation of the RIDD pathway in JEV-infected mouse neuroblastoma cells (Neuro2a) and its effect on viral infection. Activation of the RIDD pathway led to degradation of known mouse cell target transcripts without showing any effect on JEV RNA despite the fact that both when biochemically purified showed significant enrichment in ER membrane-enriched fractions. Additionally, inhibition of the IRE1 RNase activity by STF083010, a specific drug, diminished viral protein levels and reduced the titre of the virus produced from infected Neuro2a cells. The results present evidence for the first report of a beneficial effect of RIDD activation on the viral life cycle.


Virology ◽  
1996 ◽  
Vol 217 (1) ◽  
pp. 220-229 ◽  
Author(s):  
LI-KUANG CHEN ◽  
CHING-LEN LIAO ◽  
CHING-GONG LIN ◽  
SZU-CHIA LAI ◽  
CHIU-I LIU ◽  
...  

Pathogens ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 68 ◽  
Author(s):  
Sang-Im Yun ◽  
Young-Min Lee

Japanese encephalitis virus (JEV), a mosquito-borne zoonotic flavivirus, is an enveloped positive-strand RNA virus that can cause a spectrum of clinical manifestations, ranging from mild febrile illness to severe neuroinvasive disease. Today, several killed and live vaccines are available in different parts of the globe for use in humans to prevent JEV-induced diseases, yet no antivirals are available to treat JEV-associated diseases. Despite the progress made in vaccine research and development, JEV is still a major public health problem in southern, eastern, and southeastern Asia, as well as northern Oceania, with the potential to become an emerging global pathogen. In viral replication, the entry of JEV into the cell is the first step in a cascade of complex interactions between the virus and target cells that is required for the initiation, dissemination, and maintenance of infection. Because this step determines cell/tissue tropism and pathogenesis, it is a promising target for antiviral therapy. JEV entry is mediated by the viral glycoprotein E, which binds virions to the cell surface (attachment), delivers them to endosomes (endocytosis), and catalyzes the fusion between the viral and endosomal membranes (membrane fusion), followed by the release of the viral genome into the cytoplasm (uncoating). In this multistep process, a collection of host factors are involved. In this review, we summarize the current knowledge on the viral and cellular components involved in JEV entry into host cells, with an emphasis on the initial virus-host cell interactions on the cell surface.


2018 ◽  
Vol 92 (22) ◽  
Author(s):  
Xuchen Zheng ◽  
Hao Zheng ◽  
Wu Tong ◽  
Guoxin Li ◽  
Tao Wang ◽  
...  

ABSTRACT The Japanese encephalitis virus (JEV) envelope (E) protein, as one of mediators of virus entry into host cells, plays a critical role in determining virulence. The Glu-to-Lys mutation of residue 138 in E protein (E138) plays an important role in attenuating JEV vaccine strain SA14-14-2. However, it is not clear how E138 attenuates JEV. Here, we demonstrate that the Glu-to-Arg mutation of E138 also determines the attenuation of JEV strain 10S3. Likewise, for its parent strain (HEN0701), a virulence strain, the mutations of E138 are responsible for virulence alteration. Furthermore, we demonstrated that mutations of alkaline residues in E138 contributed to the attenuation of neurovirulence; in contrast, mutations of acidic residues enhanced the neurovirulence of the strains. Moreover, acidity in residue E47 had a similar effect on neurovirulence. Furthermore, the alkaline E138 residue enhanced susceptibility to heparin inhibition in vitro and limited JEV diffusion in mouse brain. These results suggest that the acidity/alkalinity of the E138 residue plays an important role in neurovirulence determination. IMPORTANCE The E protein is the only glycoprotein in mature JEV, and it plays an important role in viral neurovirulence. E protein mutations attenuate JEV neurovirulence through unclear mechanisms. Here, we discovered that E138 is a predominant determinant of JEV neurovirulence. We demonstrated that the alkalinity/acidity of E138 determines JEV neurovirulence. These data contribute to the characterization of the E protein and the rational development of novel JEV vaccines.


2020 ◽  
Author(s):  
Xiaolong Zhou ◽  
Qiongyu Yuan ◽  
Chen Zhang ◽  
Zhenglie Dai ◽  
Chengtao Du ◽  
...  

Abstract Background: Japanese encephalitis virus is a mosquito-borne neurotropic flavivirus that causes acute viral encephalitis in humans. Pigs are crucial amplifier host of JEV. Recently, increasing evidences have shown that long non-coding RNAs (lncRNAs) play important roles in virus infection. Methods: The JEV proliferation was evaluated after overexpression or knockdown of lncRNA-NONSUST006715.1 using western blotting and reverse-transcription polymerase chain reaction (RT-PCR). C-C chemokine receptor type 1 (CCR1) was found to regulate the expression of lncRNA-NONSUST006715.1 by inhibitors screen. The expression of lncRNA-NONSUST006715.1 was detected using RT-PCR after overexpression or knockdown of transcription factor SP1. In addition, the enrichments of transcription factor SP1 on the promoter of lncRNA-NONSUST006715.1 were analyzed by chromatin immunoprecipitation. Results: In this study, we demonstrated that swine lncRNA-NONSUST006715.1 could suppress JEV proliferation in PK-15 cells. We also found that CCR1 inhibited the expression of lncRNA-NONSUST006715.1 via the transcription factor SP1. In addition, knockdown of CCR1 could upregulated the expression of SP1 and lncRNA-NONSUST006715.1, resulting in resistance to JEV proliferation. Conclusions: These findings illustrate the importance of lncRNAs in virus proliferation, and reveal how this virus regulates lncRNAs in host cells to promote its proliferation.


2020 ◽  
Author(s):  
Xiaolong Zhou ◽  
Qiongyu Yuan ◽  
Chen Zhang ◽  
Zhenglie Dai ◽  
Chengtao Du ◽  
...  

Abstract Background: Japanese encephalitis virus is a mosquito-borne neurotropic flavivirus that causes acute viral encephalitis in humans. Pigs are crucial amplifier host of JEV. Recently, long non-coding RNAs have received increasing attention for their antiviral function. Methods: LncRNA-NONSUST006715.1 was overexpression or knockdown using western blotting and reverse-transcription polymerase chain reaction (RT-PCR) to detect the effect of lncRNA on JEV proliferation. CCR1 was found to regulate the expression of lncRNA-NONSUST006715.1 by inhibitors screen. Transcription factor SP1 was overexpression or knockdown using RT-PCR to detect the influence of SP1 on the expression of lncRNA. In addition, the enrichments of transcription factor SP1 on the promoter of lncRNA-NONSUST006715.1 were analyzed by Chromatin immunoprecipitation.Results: In this study, we demonstrated a new function of lncRNA-NONSUST006715.1, the inhibition of JEV proliferation in PK-15 cells. We found that C-C chemokine receptor type 1 inhibited the expression of lncRNA-NONSUST006715.1 via the transcription factor SP1. Knockdown of CCR1 could upregulated the expression of SP1 and lncRNA-NONSUST006715.1, resulting in resistance to JEV proliferation. Conclusions: These findings illustrate the importance of lncRNAs in virus proliferation, and reveal how this virus regulates lncRNAs in host cells to promote its proliferation.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Xiaolong Zhou ◽  
Qiongyu Yuan ◽  
Chen Zhang ◽  
Zhenglie Dai ◽  
Chengtao Du ◽  
...  

Abstract Background Japanese encephalitis virus is a mosquito-borne neurotropic flavivirus that causes acute viral encephalitis in humans. Pigs are crucial amplifier host of JEV. Recently, increasing evidence has shown that long non-coding RNAs (lncRNAs) play important roles in virus infection. Methods JEV proliferation was evaluated after overexpression or knockdown of lncRNA-SUSAJ1 using western blotting and reverse-transcription polymerase chain reaction (RT-PCR). C–C chemokine receptor type 1 (CCR1) was found to regulate the expression of lncRNA-SUSAJ1 by inhibitors screen. The expression of lncRNA-SUSAJ1 was detected using RT-PCR after overexpression or knockdown of transcription factor SP1. In addition, the enrichments of transcription factor SP1 on the promoter of lncRNA-SUSAJ1 were analyzed by chromatin immunoprecipitation. Results In this study, we demonstrated that swine lncRNA-SUSAJ1 could suppress JEV proliferation in PK-15 cells. We also found that CCR1 inhibited the expression of lncRNA-SUSAJ1 via the transcription factor SP1. In addition, knockdown of CCR1 could upregulated the expression of SP1 and lncRNA-SUSAJ1, resulting in resistance to JEV proliferation. Conclusions These findings illustrate the importance of lncRNAs in virus proliferation, and reveal how this virus regulates lncRNAs in host cells to promote its proliferation.


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