scholarly journals The Glycoprotein of the Live-Attenuated Junin Virus Vaccine Strain Induces Endoplasmic Reticulum Stress and Forms Aggregates prior to Degradation in the Lysosome

2020 ◽  
Vol 94 (8) ◽  
Author(s):  
John T. Manning ◽  
Nadya E. Yun ◽  
Alexey V. Seregin ◽  
Takaaki Koma ◽  
Rachel A. Sattler ◽  
...  

ABSTRACT Argentine hemorrhagic fever is a potentially lethal disease that is caused by Junin virus (JUNV). There are currently around 5 million individuals at risk of infection within regions of endemicity in Argentina. The live attenuated vaccine strain Candid #1 (Can) is approved for use in regions of endemicity and has substantially decreased the number of annual Argentine hemorrhagic fever (AHF) cases. The glycoprotein (GPC) gene is primarily responsible for attenuation of the Can strain, and we have shown that the absence of an N-linked glycosylation motif in the subunit G1 of the glycoprotein complex of Can, which is otherwise present in the wild-type pathogenic JUNV, causes GPC retention in the endoplasmic reticulum (ER). Here, we show that Can GPC aggregates in the ER of infected cells, forming incorrect cross-chain disulfide bonds, which results in impaired GPC processing into G1 and G2. The GPC fails to cleave into its G1 and G2 subunits and is targeted for degradation within lysosomes. Cells infected with the wild-type Romero (Rom) strain do not produce aggregates that are observed in Can infection, and the stress on the ER remains minimal. While the mutation of the N-linked glycosylation motif (T168A) is primarily responsible for the formation of aggregates, other mutations within G1 that occurred earlier in the passage history of the Can strain also contribute to aggregation of the GPC within the ER. IMPORTANCE The development of vaccines and therapeutics to combat viral hemorrhagic fevers remains a top priority within the Implementation Plan of the U.S. Department of Health and Human Services Public Health Emergency Medical Countermeasures Enterprise. The Can strain, derived from the pathogenic XJ strain of JUNV, has been demonstrated to be both safe and protective against AHF. While the vaccine strain is approved for use in regions of endemicity within Argentina, the mechanisms of Can attenuation have not been elucidated. A better understanding of the viral genetic determinants of attenuation will improve our understanding of the mechanisms contributing to disease pathogenesis and provide critical information for the rational design of live attenuated vaccine candidates for other viral hemorrhagic fevers.

2015 ◽  
Vol 89 (16) ◽  
pp. 8428-8443 ◽  
Author(s):  
Jessica Y. Rathbun ◽  
Magali E. Droniou ◽  
Robert Damoiseaux ◽  
Kevin G. Haworth ◽  
Jill E. Henley ◽  
...  

ABSTRACTCertain members of theArenaviridaefamily are category A agents capable of causing severe hemorrhagic fevers in humans. Specific antiviral treatments do not exist, and the only commonly used drug, ribavirin, has limited efficacy and can cause severe side effects. The discovery and development of new antivirals are inhibited by the biohazardous nature of the viruses, making them a relatively poorly understood group of human pathogens. We therefore adapted a reverse-genetics minigenome (MG) rescue system based on Junin virus, the causative agent of Argentine hemorrhagic fever, for high-throughput screening (HTS). The MG rescue system recapitulates all stages of the virus life cycle and enables screening of small-molecule libraries under biosafety containment level 2 (BSL2) conditions. The HTS resulted in the identification of four candidate compounds with potent activity against a broad panel of arenaviruses, three of which were completely novel. The target for all 4 compounds was the stage of viral entry, which positions the compounds as potentially important leads for future development.IMPORTANCEThe arenavirus family includes several members that are highly pathogenic, causing acute viral hemorrhagic fevers with high mortality rates. No specific effective treatments exist, and although a vaccine is available for Junin virus, the causative agent of Argentine hemorrhagic fever, it is licensed for use only in areas where Argentine hemorrhagic fever is endemic. For these reasons, it is important to identify specific compounds that could be developed as antivirals against these deadly viruses.


2019 ◽  
Vol 93 (15) ◽  
Author(s):  
Julieta S. Roldán ◽  
Nélida A. Candurra ◽  
María I. Colombo ◽  
Laura R. Delgui

ABSTRACTJunín virus (JUNV), a member of the familyArenaviridae, is the etiological agent of Argentine hemorrhagic fever (AHF), a potentially deadly endemic-epidemic disease affecting the population of the most fertile farming land of Argentina. Autophagy is a degradative process with a crucial antiviral role; however, several viruses subvert the pathway to their benefit. We determined the role of autophagy in JUNV-infected cells by analyzing LC3, a cytoplasmic protein (LC3-I) that becomes vesicle membrane associated (LC3-II) upon induction of autophagy. Cells overexpressing enhanced green fluorescent protein (EGFP)-LC3 and infected with JUNV showed an increased number of LC3 punctate structures, similar to those obtained after starvation or bafilomycin A1 treatment, which leads to autophagosome induction or accumulation, respectively. We also monitored the conversion of LC3-I to LC3-II, observing LC3-II levels in JUNV-infected cells similar to those observed in starved cells. Additionally, we kinetically studied the number of LC3 dots after JUNV infection and found that the virus activated the pathway as early as 2 h postinfection (p.i.), whereas the UV-inactivated virus did not induce the pathway. Cells subjected to starvation or pretreated with rapamycin, a pharmacological autophagy inductor, enhanced virus yield. Also, we assayed the replication capacity of JUNV in Atg5 knockout or Beclin 1 knockdown cells (both critical components of the autophagic pathway) and found a significant decrease in JUNV replication. Taken together, our results constitute the first study indicating that JUNV infection induces an autophagic response, which is functionally required by the virus for efficient propagation.IMPORTANCEMammalian arenaviruses are zoonotic viruses that cause asymptomatic and persistent infections in their rodent hosts but may produce severe and lethal hemorrhagic fevers in humans. Currently, there are neither effective therapeutic options nor effective vaccines for viral hemorrhagic fevers caused by human-pathogenic arenaviruses, except the vaccine Candid no. 1 against Argentine hemorrhagic fever (AHF), licensed for human use in areas of endemicity in Argentina. Since arenaviruses remain a severe threat to global public health, more in-depth knowledge of their replication mechanisms would improve our ability to fight these viruses. Autophagy is a lysosomal degradative pathway involved in maintaining cellular homeostasis, representing powerful anti-infective machinery. We show, for the first time for a member of the familyArenaviridae, a proviral role of autophagy in JUNV infection, providing new knowledge in the field of host-virus interaction. Therefore, modulation of virus-induced autophagy could be used as a strategy to block arenavirus infections.


2020 ◽  
Vol 94 (19) ◽  
Author(s):  
Chengjin Ye ◽  
Juan Carlos de la Torre ◽  
Luis Martínez-Sobrido

ABSTRACT The New World mammarenavirus Tacaribe virus (TCRV) has been isolated from fruit bats, mosquitoes, and ticks, whereas all other known New World mammarenaviruses are maintained in rodents. TCRV has not been linked to human disease, but it has been shown to protect against Argentine hemorrhagic fever-like disease in marmosets infected with the New World mammarenavirus Junín virus (JUNV), indicating the potential of TCRV as a live-attenuated vaccine for the treatment of Argentine hemorrhagic fever. Implementation of TCRV as a live-attenuated vaccine or a vaccine vector would be facilitated by the establishment of reverse genetics systems for the genetic manipulation of the TCRV genome. In this study, we developed, for the first time, reverse genetics approaches for the generation of recombinant TCRV (rTCRV). We successfully rescued a wild-type (WT) rTCRV (a trisegmented form of TCRV expressing two reporter genes [r3TCRV]) and a bisegmented TCRV expressing a single reporter gene from a bicistronic viral mRNA (rTCRV/GFP). These reverse genetics approaches represent an excellent tool to investigate the biology of TCRV and to explore its potential use as a live-attenuated vaccine or a vaccine vector for the treatment of other viral infections. Notably, we identified a 39-nucleotide (nt) deletion (Δ39) in the noncoding intergenic region (IGR) of the viral large (L) segment that is required for optimal virus multiplication. Accordingly, an rTCRV containing this 39-nt deletion in the L-IGR (rTCRV/Δ39) exhibited decreased viral fitness in cultured cells, suggesting the feasibility of using this deletion in the L-IGR as an approach to attenuate TCRV, and potentially other mammarenaviruses, for their implementation as live-attenuated vaccines or vaccine vectors. IMPORTANCE To date, no Food and Drug Administration (FDA)-approved vaccines are available to combat hemorrhagic fever caused by mammarenavirus infections in humans. Treatment of mammarenavirus infections is limited to the off-label use of ribavirin, which is partially effective and associated with significant side effects. Tacaribe virus (TCRV), the prototype member of the New World mammarenaviruses, is nonpathogenic in humans but able to provide protection against Junín virus (JUNV), the causative agent of Argentine hemorrhagic fever, demonstrating the feasibility of using TCRV as a live-attenuated vaccine vector for the treatment of JUNV and potentially other viral infections. Here, we describe for the first time the feasibility of generating recombinant TCRV (rTCRV) using reverse genetics approaches, which paves the way to study the biology of TCRV and also its potential use as a live-attenuated vaccine or a vaccine vector for the treatment of mammarenavirus and/or other viral infections in humans.


Virology ◽  
2007 ◽  
Vol 367 (2) ◽  
pp. 275-287 ◽  
Author(s):  
Christopher L. Parks ◽  
Theresa Latham ◽  
Adriana Cahill ◽  
Robert E. O'Neill ◽  
Christopher J. Passarotti ◽  
...  

1998 ◽  
Vol 177 (2) ◽  
pp. 277-283 ◽  
Author(s):  
Julio I. Maiztegui ◽  
Kelly T. McKee, Jr. ◽  
Julio G. Barrera Oro ◽  
Lee H. Harrison ◽  
Paul H. Gibbs ◽  
...  

1983 ◽  
Vol 12 (4) ◽  
pp. 273-280 ◽  
Author(s):  
Mercedes C. Weissenbacher ◽  
Marta S. Sabattini ◽  
María M. Avila ◽  
Patricia M. Sangiorgio ◽  
María R. F. De Sensi ◽  
...  

Author(s):  
Галина Компанец ◽  
Galina Kompanets

This paper includes review of innovative methods of monitoring of activity of natural foci of epidemically important for Russian Federation such viral infections as hemorrhagic fever with renal syndrome (HFRS) and Crimean-Congo hemorrhagic fever (CCHF), and the analysis of probability to control such «exotic» infections, as Denge fever and severe fever with thrombocytopenia syndrome (SFTS).


2016 ◽  
Vol 52 (1) ◽  
pp. 51-56
Author(s):  
Jarosław Piszczyk

Viral hemorrhagic fevers (VHFs) represent a group of similar clinical entities contagious constitutional diseases, caused by four different types of RNA viruses: Flaviviridae, Bunyaviridae, Arenaviridae i Filoviridae. These diseases proceed with high fever and damage of the circulatory system leading to homeostasis disorders, commonly accompanied by symptoms of hemorrhagic diathesis. VHFs are typically transmitted through infection vectors (mosquito) or through direct physical contact with infectious material. West Nile fever is the disease which is caused by West Nile virus from the Flaviviridae family. It begins flu-like symptoms, then it appears maculopapular rash and lymphadenopathy. At the most cases the symptoms retreat idiopathically. This disease can proceed as West Nile Neurological Disease in 1% of infected. The article presents three diseases, which can be present in tropical climate such as: Ebola hemorrhagic fever, dengue hemorrhagic fever, West Nile fever.


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