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Bostedt L, Fénéant L, Leske A, Holzerland J, Günther K, Waßmann I, Bohn P, Groseth A. Alternative translation contributes to the generation of a cytoplasmic subpopulation of the Junín virus nucleoprotein that inhibits caspase activation and innate immunity. J Virol 2024; 98:e0197523. [PMID: 38294249 PMCID: PMC10878266 DOI: 10.1128/jvi.01975-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 01/03/2024] [Indexed: 02/01/2024] Open
Abstract
The highly pathogenic arenavirus, Junín virus (JUNV), expresses three truncated alternative isoforms of its nucleoprotein (NP), i.e., NP53kD, NP47kD, and NP40kD. While both NP47kD and NP40kD have been previously shown to be products of caspase cleavage, here, we show that expression of the third isoform NP53kD is due to alternative in-frame translation from M80. Based on this information, we were able to generate recombinant JUNVs lacking each of these isoforms. Infection with these mutants revealed that, while all three isoforms contribute to the efficient control of caspase activation, NP40kD plays the predominant role. In contrast to full-length NP (i.e., NP65kD), which is localized to inclusion bodies, where viral RNA synthesis takes place, the loss of portions of the N-terminal coiled-coil region in these isoforms leads to a diffuse cytoplasmic distribution and a loss of function in viral RNA synthesis. Nonetheless, NP53kD, NP47kD, and NP40kD all retain robust interferon antagonistic and 3'-5' exonuclease activities. We suggest that the altered localization of these NP isoforms allows them to be more efficiently targeted by activated caspases for cleavage as decoy substrates, and to be better positioned to degrade viral double-stranded (ds)RNA species that accumulate in the cytoplasm during virus infection and/or interact with cytosolic RNA sensors, thereby limiting dsRNA-mediated innate immune responses. Taken together, this work provides insight into the mechanism by which JUNV leverages apoptosis during infection to generate biologically distinct pools of NP and contributes to our understanding of the expression and biological relevance of alternative protein isoforms during virus infection.IMPORTANCEA limited coding capacity means that RNA viruses need strategies to diversify their proteome. The nucleoprotein (NP) of the highly pathogenic arenavirus Junín virus (JUNV) produces three N-terminally truncated isoforms: two (NP47kD and NP40kD) are known to be produced by caspase cleavage, while, here, we show that NP53kD is produced by alternative translation initiation. Recombinant JUNVs lacking individual NP isoforms revealed that all three isoforms contribute to inhibiting caspase activation during infection, but cleavage to generate NP40kD makes the biggest contribution. Importantly, all three isoforms retain their ability to digest double-stranded (ds)RNA and inhibit interferon promoter activation but have a diffuse cytoplasmic distribution. Given the cytoplasmic localization of both aberrant viral dsRNAs, as well as dsRNA sensors and many other cellular components of innate immune activation pathways, we suggest that the generation of NP isoforms not only contributes to evasion of apoptosis but also robust control of the antiviral response.
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Affiliation(s)
- Linus Bostedt
- Laboratory for Arenavirus Biology, Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Lucie Fénéant
- Laboratory for Arenavirus Biology, Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Anne Leske
- Laboratory for Arenavirus Biology, Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Julia Holzerland
- Laboratory for Arenavirus Biology, Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Karla Günther
- Laboratory for Arenavirus Biology, Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Irke Waßmann
- Laboratory for Arenavirus Biology, Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Patrick Bohn
- Laboratory for Arenavirus Biology, Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Allison Groseth
- Laboratory for Arenavirus Biology, Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
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2
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Lee M, Koma T, Iwasaki M, Urata S. [South American Hemorrhagic Fever viruses and the cutting edge of the vaccine and antiviral development]. Uirusu 2022; 72:7-18. [PMID: 37899233 DOI: 10.2222/jsv.72.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2023]
Abstract
South American Hemorrhagic Fever is caused by the Arenavirus, which belong to the Family Arenaviridae, genus mammarenavirus, infection at South America. South American Hemorrhagic Fever includes 1. Argentinian Hemorrhagic fever caused by Junin virus, 2. Brazilian hemorrhagic fever caused by Sabia virus, 3. Venezuelan Hemorrhagic fever caused by Guanarito virus, 4. Bolivian Hemorrhagic fever caused by Machupo virus, and 5. Unassigned hemorrhagic fever caused by Chapare virus. These viruses are classified in New World (NW) Arenavirus, which is different from Old World Arenavirus (ex. Lassa virus), based on phylogeny, serology, and geographic differences. In this review, the current knowledge of the biology and the development of the vaccines and antivirals of NW Arenaviruses which cause South American Hemorrhagic Fever will be described.
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Affiliation(s)
- Meion Lee
- National Research Center for the Control and Prevention of Infectious Diseases (CCPID), Nagasaki University
- Department of Cell Regulation, Graduate School of Biomedical Sciences, Nagasaki University
| | - Takaaki Koma
- Department of Microbiology, Graduate School of Medicine, Tokushima University
| | - Masaharu Iwasaki
- Laboratory of Emerging Viral Diseases, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University
| | - Shuzo Urata
- National Research Center for the Control and Prevention of Infectious Diseases (CCPID), Nagasaki University
- Department of Emerging Infectious Diseases, Institute of Tropical Medicine (NEKKEN), Nagasaki University
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3
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Brisse M, Huang Q, Rahman M, Di D, Liang Y, Ly H. RIG-I and MDA5 Protect Mice From Pichinde Virus Infection by Controlling Viral Replication and Regulating Immune Responses to the Infection. Front Immunol 2021; 12:801811. [PMID: 34925387 PMCID: PMC8677829 DOI: 10.3389/fimmu.2021.801811] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 11/17/2021] [Indexed: 12/28/2022] Open
Abstract
RIG-I and MDA5 are major cytoplasmic innate-immune sensor proteins that recognize aberrant double-stranded RNAs generated during virus infection to activate type 1 interferon (IFN-I) and IFN-stimulated gene (ISG) expressions to control virus infection. The roles of RIG-I and MDA5 in controlling replication of Pichinde virus (PICV), a mammarenavirus, in mice have not been examined. Here, we showed that MDA5 single knockout (SKO) and RIG-I/MDA5 double knockout (DKO) mice are highly susceptible to PICV infection as evidenced by their significant reduction in body weights during the course of the infection, validating the important roles of these innate-immune sensor proteins in controlling PICV infection. Compared to the wildtype mice, SKO and DKO mice infected with PICV had significantly higher virus titers and lower IFN-I expressions early in the infection but appeared to exhibit a late and heightened level of adaptive immune responses to clear the infection. When a recombinant rPICV mutant virus (rPICV-NPmut) that lacks the ability to suppress IFN-I was used to infect mice, as expected, there were heightened levels of IFN-I and ISG expressions in the wild-type mice, whereas infected SKO and DKO mice showed delayed mouse growth kinetics and relatively low, delayed, and transient levels of innate and adaptive immune responses to this viral infection. Taken together, our data suggest that PICV infection triggers activation of immune sensors that include but might not be necessarily limited to RIG-I and MDA5 to stimulate effective innate and adaptive immune responses to control virus infection in mice.
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Affiliation(s)
- Morgan Brisse
- Biochemistry, Molecular Biology and Biophysics Graduate Program, College of Veterinary Medicine, University of Minnesota, Twin Cities, MN, United States
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Twin Cities, MN, United States
| | - Qinfeng Huang
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Twin Cities, MN, United States
| | - Mizanur Rahman
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Twin Cities, MN, United States
| | - Da Di
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Twin Cities, MN, United States
| | - Yuying Liang
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Twin Cities, MN, United States
| | - Hinh Ly
- Biochemistry, Molecular Biology and Biophysics Graduate Program, College of Veterinary Medicine, University of Minnesota, Twin Cities, MN, United States
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Twin Cities, MN, United States
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4
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Mateer EJ, Maruyama J, Card GE, Paessler S, Huang C. Lassa Virus, but Not Highly Pathogenic New World Arenaviruses, Restricts Immunostimulatory Double-Stranded RNA Accumulation during Infection. J Virol 2020; 94:e02006-19. [PMID: 32051278 PMCID: PMC7163147 DOI: 10.1128/jvi.02006-19] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 02/09/2020] [Indexed: 12/14/2022] Open
Abstract
The arenaviruses Lassa virus (LASV), Junín virus (JUNV), and Machupo virus (MACV) can cause severe and fatal diseases in humans. Although these pathogens are closely related, the host immune responses to these virus infections differ remarkably, with direct implications for viral pathogenesis. LASV infection is immunosuppressive, with a very low-level interferon response. In contrast, JUNV and MACV infections stimulate a robust interferon (IFN) response in a retinoic acid-inducible gene I (RIG-I)-dependent manner and readily activate protein kinase R (PKR), a known host double-stranded RNA (dsRNA) sensor. In response to infection with RNA viruses, host nonself RNA sensors recognize virus-derived dsRNA as danger signals and initiate innate immune responses. Arenavirus nucleoproteins (NPs) contain a highly conserved exoribonuclease (ExoN) motif, through which LASV NP has been shown to degrade virus-derived immunostimulatory dsRNA in biochemical assays. In this study, we for the first time present evidence that LASV restricts dsRNA accumulation during infection. Although JUNV and MACV NPs also have the ExoN motif, dsRNA readily accumulated in infected cells and often colocalized with dsRNA sensors. Moreover, LASV coinfection diminished the accumulation of dsRNA and the IFN response in JUNV-infected cells. The disruption of LASV NP ExoN with a mutation led to dsRNA accumulation and impaired LASV replication in minigenome systems. Importantly, both LASV NP and RNA polymerase L protein were required to diminish the accumulation of dsRNA and the IFN response in JUNV infection. For the first time, we discovered a collaboration between LASV NP ExoN and L protein in limiting dsRNA accumulation. Our new findings provide mechanistic insights into the differential host innate immune responses to highly pathogenic arenavirus infections.IMPORTANCE Arenavirus NPs contain a highly conserved DEDDh ExoN motif, through which LASV NP degrades virus-derived, immunostimulatory dsRNA in biochemical assays to eliminate the danger signal and inhibit the innate immune response. Nevertheless, the function of NP ExoN in arenavirus infection remains to be defined. In this study, we discovered that LASV potently restricts dsRNA accumulation during infection and minigenome replication. In contrast, although the NPs of JUNV and MACV also harbor the ExoN motif, dsRNA readily formed during JUNV and MACV infections, accompanied by IFN and PKR responses. Interestingly, LASV NP alone was not sufficient to limit dsRNA accumulation. Instead, both LASV NP and L protein were required to restrict immunostimulatory dsRNA accumulation. Our findings provide novel and important insights into the mechanism for the distinct innate immune response to these highly pathogenic arenaviruses and open new directions for future studies.
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Affiliation(s)
- Elizabeth J Mateer
- Department of Pathology, Galveston National Laboratory and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
| | - Junki Maruyama
- Department of Pathology, Galveston National Laboratory and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
| | - Galen E Card
- Department of Pathology, Galveston National Laboratory and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
| | - Slobodan Paessler
- Department of Pathology, Galveston National Laboratory and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
| | - Cheng Huang
- Department of Pathology, Galveston National Laboratory and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
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Mantlo E, Bukreyeva N, Maruyama J, Paessler S, Huang C. Potent Antiviral Activities of Type I Interferons to SARS-CoV-2 Infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2020:2020.04.02.022764. [PMID: 32511327 PMCID: PMC7239057 DOI: 10.1101/2020.04.02.022764] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
The historical outbreak of COVID-19 disease not only constitutes a global public health crisis, but also has a devastating social and economic impact. The disease is caused by a newly identified coronavirus, Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2). There is an urgent need to identify antivirals to curtail the COVID-19 pandemic. Herein, we report the remarkable sensitivity of SARS-CoV-2 to recombinant human interferons α and β (IFNα/β). Treatment with IFN-α or IFN-β at a concentration of 50 international units (IU) per milliliter drastically reduce viral titers by 3.4 log or 4.5 log, respectively in Vero cells. The EC50 of IFN-α and IFN-β treatment is 1.35 IU/ml and 0.76 IU/ml, respectively, in Vero cells. These results suggested that SARS-CoV-2 is more sensitive to many other human pathogenic viruses, including the SARS-CoV. Overall, our results demonstrate the potent efficacy of human Type I IFN in suppressing SARS-CoV-2 replication, a finding which could inform future treatment options for COVID-19.
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Affiliation(s)
- Emily Mantlo
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Natalya Bukreyeva
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Junki Maruyama
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Slobodan Paessler
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Cheng Huang
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
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6
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Comparison of the Innate Immune Responses to Pathogenic and Nonpathogenic Clade B New World Arenaviruses. J Virol 2019; 93:JVI.00148-19. [PMID: 31270228 DOI: 10.1128/jvi.00148-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 06/28/2019] [Indexed: 12/25/2022] Open
Abstract
The New World (NW) arenaviruses are a diverse group of zoonotic viruses, including several causative agents of severe hemorrhagic fevers in humans. All known human-pathogenic NW arenaviruses belong to clade B, where they group into sublineages with phylogenetically closely related nonpathogenic viruses, e.g., the highly pathogenic Junin (JUNV) and Machupo viruses with the nonpathogenic Tacaribe virus (TCRV). Considering the close genetic relationship of nonpathogenic and pathogenic NW arenaviruses, the identification of molecular determinants of virulence is of great importance. The host cell's innate antiviral defense represents a major barrier for zoonotic infection. Here, we performed a side-by-side comparison of the innate immune responses against JUNV and TCRV in human cells. Despite similar levels of viral replication, infection with TCRV consistently induced a stronger type I interferon (IFN-I) response than JUNV infection did. Transcriptome profiling revealed upregulation of a largely overlapping set of interferon-stimulated genes in cells infected with TCRV and JUNV. Both viruses were relatively insensitive to IFN-I treatment of human cells and induced similar levels of apoptosis in the presence or absence of an IFN-I response. However, in comparison to JUNV, TCRV induced stronger activation of the innate sensor double-strand RNA-dependent protein kinase R (PKR), resulting in phosphorylation of eukaryotic translation initiation factor eIF2α. Confocal microscopy studies revealed similar subcellular colocalizations of the JUNV and TCRV viral replication-transcription complexes with PKR. However, deletion of PKR by CRISPR/Cas9 hardly affected JUNV but promoted TCRV multiplication, providing the first evidence for differential innate recognition and control of pathogenic and nonpathogenic NW arenaviruses by PKR.IMPORTANCE New World (NW) arenaviruses are a diverse family of emerging zoonotic viruses that merit significant attention as important public health problems. The close genetic relationship of nonpathogenic NW arenaviruses with their highly pathogenic cousins suggests that few mutations may be sufficient to enhance virulence. The identification of molecular determinants of virulence of NW arenaviruses is therefore of great importance. Here we undertook a side-by-side comparison of the innate immune responses against the highly pathogenic Junin virus (JUNV) and the related nonpathogenic Tacaribe virus (TCRV) in human cells. We consistently found that TCRV induces a stronger type I interferon (IFN-I) response than JUNV. Transcriptome profiling revealed an overlapping pattern of IFN-induced gene expression and similar low sensitivities to IFN-I treatment. However, the double-stranded RNA (dsRNA)-dependent protein kinase R (PKR) contributed to the control of TCRV, but not JUNV, providing the first evidence for differential innate recognition and control of JUNV and TCRV.
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7
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Brisse ME, Ly H. Hemorrhagic Fever-Causing Arenaviruses: Lethal Pathogens and Potent Immune Suppressors. Front Immunol 2019; 10:372. [PMID: 30918506 PMCID: PMC6424867 DOI: 10.3389/fimmu.2019.00372] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 02/14/2019] [Indexed: 12/22/2022] Open
Abstract
Hemorrhagic fevers (HF) resulting from pathogenic arenaviral infections have traditionally been neglected as tropical diseases primarily affecting African and South American regions. There are currently no FDA-approved vaccines for arenaviruses, and treatments have been limited to supportive therapy and use of non-specific nucleoside analogs, such as Ribavirin. Outbreaks of arenaviral infections have been limited to certain geographic areas that are endemic but known cases of exportation of arenaviruses from endemic regions and socioeconomic challenges for local control of rodent reservoirs raise serious concerns about the potential for larger outbreaks in the future. This review synthesizes current knowledge about arenaviral evolution, ecology, transmission patterns, life cycle, modulation of host immunity, disease pathogenesis, as well as discusses recent development of preventative and therapeutic pursuits against this group of deadly viral pathogens.
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Affiliation(s)
- Morgan E Brisse
- Biochemistry, Molecular Biology, and Biophysics Graduate Program, University of Minnesota, St. Paul, MN, United States.,Department of Veterinary and Biomedical Sciences, University of Minnesota, St. Paul, MN, United States
| | - Hinh Ly
- Department of Veterinary and Biomedical Sciences, University of Minnesota, St. Paul, MN, United States
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8
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Madu IG, Files M, Gharaibeh DN, Moore AL, Jung KH, Gowen BB, Dai D, Jones KF, Tyavanagimatt SR, Burgeson JR, Korth MJ, Bedard KM, Iadonato SP, Amberg SM. A potent Lassa virus antiviral targets an arenavirus virulence determinant. PLoS Pathog 2018; 14:e1007439. [PMID: 30576397 PMCID: PMC6322784 DOI: 10.1371/journal.ppat.1007439] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 01/07/2019] [Accepted: 10/25/2018] [Indexed: 11/25/2022] Open
Abstract
Arenaviruses are a significant cause of hemorrhagic fever, an often-fatal disease for which there is no approved antiviral therapy. Lassa fever in particular generates high morbidity and mortality in West Africa, where the disease is endemic, and a recent outbreak in Nigeria was larger and more geographically diverse than usual. We are developing LHF-535, a small-molecule viral entry inhibitor that targets the arenavirus envelope glycoprotein, as a therapeutic candidate for Lassa fever and other hemorrhagic fevers of arenavirus origin. Using a lentiviral pseudotype infectivity assay, we determined that LHF-535 had sub-nanomolar potency against the viral envelope glycoproteins from all Lassa virus lineages, with the exception of the glycoprotein from the LP strain from lineage I, which was 100-fold less sensitive than that of other strains. This reduced sensitivity was mediated by a unique amino acid substitution, V434I, in the transmembrane domain of the envelope glycoprotein GP2 subunit. This position corresponds to the attenuation determinant of Candid#1, a live-attenuated Junín virus vaccine strain used to prevent Argentine hemorrhagic fever. Using a virus-yield reduction assay, we determined that LHF-535 potently inhibited Junín virus, but not Candid#1, and the Candid#1 attenuation determinant, F427I, regulated this difference in sensitivity. We also demonstrated that a daily oral dose of LHF-535 at 10 mg/kg protected mice from a lethal dose of Tacaribe virus. Serial passage of Tacaribe virus in LHF-535-treated Vero cells yielded viruses that were resistant to LHF-535, and the majority of drug-resistant viruses exhibited attenuated pathogenesis. These findings provide a framework for the clinical development of LHF-535 as a broad-spectrum inhibitor of arenavirus entry and provide an important context for monitoring the emergence of drug-resistant viruses. Lassa fever is a viral hemorrhagic fever disease that is transmitted to humans primarily through contact with the urine or feces of infected rodents. The disease is endemic in West Africa, and an unusually large outbreak occurred in Nigeria in early 2018. The case fatality rate was 25% among confirmed cases, underscoring the need for an effective antiviral therapy. Here, we evaluated the small-molecule drug LHF-535, which targets the arenavirus envelope glycoprotein, for broad-spectrum activity against Lassa viruses of different lineages and related arenaviruses that cause hemorrhagic fever diseases in South America. We also selected for LHF-535-resistant viruses and characterized their genotype and phenotype. Using a combination of surrogate systems and wild-type viruses, we determined that all tested Lassa virus strains and New World hemorrhagic fever arenaviruses were sensitive to LHF-535. Sensitivity to the drug was modulated by specific amino acid changes in the viral envelope glycoprotein, and the majority of emerging drug-resistant viruses were attenuated for virulence. Similarly, the live-attenuated vaccine strain for Argentine hemorrhagic fever was also resistant to LHF-535. These findings indicate that LHF-535 targets a viral virulence determinant, the mutation of which may result in the emergence of drug-resistant viruses, but with reduced capacity for virulence.
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Affiliation(s)
- Ikenna G. Madu
- Kineta, Inc., Seattle, Washington, United States of America
| | - Megan Files
- Kineta, Inc., Seattle, Washington, United States of America
| | - Dima N. Gharaibeh
- SIGA Technologies, Inc., Corvallis, Oregon, United States of America
| | - Amy L. Moore
- SIGA Technologies, Inc., Corvallis, Oregon, United States of America
| | - Kie-Hoon Jung
- Institute for Antiviral Research, Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, Utah, United States of America
| | - Brian B. Gowen
- Institute for Antiviral Research, Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, Utah, United States of America
| | - Dongcheng Dai
- SIGA Technologies, Inc., Corvallis, Oregon, United States of America
| | - Kevin F. Jones
- SIGA Technologies, Inc., Corvallis, Oregon, United States of America
| | | | - James R. Burgeson
- SIGA Technologies, Inc., Corvallis, Oregon, United States of America
| | | | | | | | - Sean M. Amberg
- Kineta, Inc., Seattle, Washington, United States of America
- * E-mail:
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9
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Mateer EJ, Paessler S, Huang C. Visualization of Double-Stranded RNA Colocalizing With Pattern Recognition Receptors in Arenavirus Infected Cells. Front Cell Infect Microbiol 2018; 8:251. [PMID: 30087859 PMCID: PMC6066581 DOI: 10.3389/fcimb.2018.00251] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 07/03/2018] [Indexed: 12/20/2022] Open
Abstract
An important step in the initiation of the innate immune response to virus infection is the recognition of non-self, viral RNA, including double-stranded RNA (dsRNA), by cytoplasmic pattern recognition receptors (PRRs). For many positive-sense RNA viruses and DNA viruses, the production of viral dsRNA, and the interaction of viral dsRNA and PRRs are well characterized. However, for negative-sense RNA viruses, viral dsRNA was thought to be produced at low to undetectable levels and PRR recognition of viral dsRNA is still largely unclear. In the case of arenaviruses, the nucleocaspid protein (NP) has been identified to contain an exoribonuclease activity that preferentially degrades dsRNA in biochemical studies. Nevertheless, pathogenic New World (NW) arenavirus infections readily induce an interferon (IFN) response in a RIG-I dependent manner, and also activate the dsRNA-dependent Protein Kinase R (PKR). To better understand the innate immune response to pathogenic arenavirus infection, we used a newly identified dsRNA-specific antibody that efficiently detects viral dsRNA in negative-sense RNA virus infected cells. dsRNA was detected in NW arenavirus infected cells colocalizing with virus NP in immunofluorescence assay. Importantly, the dsRNA signals also colocalized with cytoplasmic PRRs, namely, PKR, RIG-I and MDA-5, as well as with the phosphorylated, activated form of PKR in infected cells. Our data clearly demonstrate the PRR recognition of dsRNA and their activation in NW arenavirus infected cells. These findings provide new insights into the interaction between NW arenaviruses and the host innate immune response.
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Affiliation(s)
| | | | - Cheng Huang
- Department of Pathology and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, United States
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10
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Xia H, Luo H, Shan C, Muruato AE, Nunes BTD, Medeiros DBA, Zou J, Xie X, Giraldo MI, Vasconcelos PFC, Weaver SC, Wang T, Rajsbaum R, Shi PY. An evolutionary NS1 mutation enhances Zika virus evasion of host interferon induction. Nat Commun 2018; 9:414. [PMID: 29379028 PMCID: PMC5788864 DOI: 10.1038/s41467-017-02816-2] [Citation(s) in RCA: 200] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 12/29/2017] [Indexed: 12/12/2022] Open
Abstract
Virus-host interactions determine an infection outcome. The Asian lineage of Zika virus (ZIKV), responsible for the recent epidemics, has fixed a mutation in the NS1 gene after 2012 that enhances mosquito infection. Here we report that the same mutation confers NS1 to inhibit interferon-β induction. This mutation enables NS1 binding to TBK1 and reduces TBK1 phosphorylation. Engineering the mutation into a pre-epidemic ZIKV strain debilitates the virus for interferon-β induction; reversing the mutation in an epidemic ZIKV strain invigorates the virus for interferon-β induction; these mutational effects are lost in IRF3-knockout cells. Additionally, ZIKV NS2A, NS2B, NS4A, NS4B, and NS5 can also suppress interferon-β production through targeting distinct components of the RIG-I pathway; however, for these proteins, no antagonistic difference is observed among various ZIKV strains. Our results support the mechanism that ZIKV has accumulated mutation(s) that increases the ability to evade immune response and potentiates infection and epidemics.
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Affiliation(s)
- Hongjie Xia
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Huanle Luo
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Chao Shan
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Antonio E Muruato
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Bruno T D Nunes
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
- Department of Arbovirology and Hemorrhagic Fevers, Evandro Chagas Institute, Ministry of Health, Ananindeua, Pará State, Brazil
| | - Daniele B A Medeiros
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
- Department of Arbovirology and Hemorrhagic Fevers, Evandro Chagas Institute, Ministry of Health, Ananindeua, Pará State, Brazil
| | - Jing Zou
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Xuping Xie
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Maria Isabel Giraldo
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Pedro F C Vasconcelos
- Department of Arbovirology and Hemorrhagic Fevers, Evandro Chagas Institute, Ministry of Health, Ananindeua, Pará State, Brazil
- Department of Pathology, Pará State University, Belém, Brazil
| | - Scott C Weaver
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, 77555, USA
- Institute for Human Infections & Immunity, University of Texas Medical Branch, Galveston, TX, 77555, USA
- Institute for Translational Science, University of Texas Medical Branch, Galveston, TX, 77555, USA
- Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX, 77555, USA
- Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA
| | - Tian Wang
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, 77555, USA
- Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX, 77555, USA
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Ricardo Rajsbaum
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, 77555, USA
- Institute for Human Infections & Immunity, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Pei-Yong Shi
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA.
- Institute for Human Infections & Immunity, University of Texas Medical Branch, Galveston, TX, 77555, USA.
- Institute for Translational Science, University of Texas Medical Branch, Galveston, TX, 77555, USA.
- Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX, 77555, USA.
- Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA.
- Department of Phamarcology & Toxicology, University of Texas Medical Branch, Galveston, TX, 77555, USA.
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Peña Cárcamo JR, Morell ML, Vázquez CA, Vatansever S, Upadhyay AS, Överby AK, Cordo SM, García CC. The interplay between viperin antiviral activity, lipid droplets and Junín mammarenavirus multiplication. Virology 2018; 514:216-229. [DOI: 10.1016/j.virol.2017.10.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 10/10/2017] [Accepted: 10/12/2017] [Indexed: 01/09/2023]
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12
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Highly Pathogenic New World Arenavirus Infection Activates the Pattern Recognition Receptor Protein Kinase R without Attenuating Virus Replication in Human Cells. J Virol 2017; 91:JVI.01090-17. [PMID: 28794024 DOI: 10.1128/jvi.01090-17] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 08/01/2017] [Indexed: 02/07/2023] Open
Abstract
The arenavirus family consists of several highly pathogenic viruses, including the Old World (OW) arenavirus Lassa fever virus (LASV) and the New World (NW) Junin virus (JUNV) and Machupo virus (MACV). Host response to infection by these pathogenic arenaviruses is distinct in many aspects. JUNV and MACV infections readily induce an interferon (IFN) response in human cells, while LASV infection usually triggers an undetectable or weak IFN response. JUNV induces an IFN response through RIG-I, suggesting that the host non-self RNA sensor readily detects JUNV viral RNAs (vRNAs) during infection and activates IFN response. Double-stranded-RNA (dsRNA)-activated protein kinase R (PKR) is another host non-self RNA sensor classically known for its vRNA recognition activity. Here we report that infection with NW arenaviruses JUNV and MACV, but not OW LASV, activated PKR, concomitant with elevated phosphorylation of the translation initiation factor α subunit of eukaryotic initiation factor 2 (eIF2α). Host protein synthesis was substantially suppressed in MACV- and JUNV-infected cells but was only marginally reduced in LASV-infected cells. Despite the antiviral activity known for PKR against many other viruses, the replication of JUNV and MACV was not impaired but was slightly augmented in wild-type (wt) cells compared to that in PKR-deficient cells, suggesting that PKR or PKR activation did not negatively affect JUNV and MACV infection. Additionally, we found an enhanced IFN response in JUNV- or MACV-infected PKR-deficient cells, which was inversely correlated with virus replication.IMPORTANCE The detection of viral RNA by host non-self RNA sensors, including RIG-I and MDA5, is critical to the initiation of the innate immune response to RNA virus infection. Among pathogenic arenaviruses, the OW LASV usually does not elicit an interferon response. However, the NW arenaviruses JUNV and MACV readily trigger an IFN response in a RIG-I-dependent manner. Here, we demonstrate for the first time that pathogenic NW arenaviruses JUNV and MACV, but not the OW arenavirus LASV, activated the dsRNA-dependent PKR, another host non-self RNA sensor, during infection. Interestingly, the replication of JUNV and MACV was not restricted but was rather slightly augmented in the presence of PKR. Our data provide new evidence for a distinct interplay between host non-self RNA sensors and pathogenic arenaviruses, which also provides insights into the pathogenesis of arenaviruses and may facilitate the design of vaccines and treatments against arenavirus-caused diseases.
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Abstract
Hemorrhagic fevers caused by viruses were identified in the late 1950s in South America. These viruses have existed in their hosts, the New World rodents, for millions of years. Their emergence as infectious agents in humans coincided with changes in the environment and farming practices that caused explosions in their host rodent populations. Zoonosis into humans likely occurs because the pathogenic New World arenaviruses use human transferrin receptor 1 to enter cells. The mortality rate after infection with these viruses is high, but the mechanism by which disease is induced is still not clear. Possibilities include direct effects of cellular infection or the induction of high levels of cytokines by infected sentinel cells of the immune system, leading to endothelia and thrombocyte dysfunction and neurological disease. Here we provide a review of the ecology and molecular and cellular biology of New World arenaviruses, as well as a discussion of the current animal models of infection. The development of animal models, coupled with an improved understanding of the infection pathway and host response, should lead to the discovery of new drugs for treating infections.
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Affiliation(s)
- Nicolás Sarute
- Department of Microbiology and Immunology, University of Illinois College of Medicine at Chicago, Chicago, Illinois 60612; ,
| | - Susan R Ross
- Department of Microbiology and Immunology, University of Illinois College of Medicine at Chicago, Chicago, Illinois 60612; ,
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14
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Abstract
Mammalian arenaviruses are zoonotic viruses that cause asymptomatic, persistent infections in their rodent hosts but can lead to severe and lethal hemorrhagic fever with bleeding and multiorgan failure in human patients. Lassa virus (LASV), for example, is endemic in several West African countries, where it is responsible for an estimated 500,000 infections and 5,000 deaths annually. There are currently no FDA-licensed therapeutics or vaccines available to combat arenavirus infection. A hallmark of arenavirus infection (e.g., LASV) is general immunosuppression that contributes to high viremia. Here, we discuss the early host immune responses to arenavirus infection and the recently discovered molecular mechanisms that enable pathogenic viruses to suppress host immune recognition and to contribute to the high degree of virulence. We also directly compare the innate immune evasion mechanisms between arenaviruses and other hemorrhagic fever-causing viruses, such as Ebola, Marburg, Dengue, and hantaviruses. A better understanding of the immunosuppression and immune evasion strategies of these deadly viruses may guide the development of novel preventative and therapeutic options.
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Affiliation(s)
- Bjoern Meyer
- Department of Veterinary and Biomedical Sciences, University of Minnesota, Twin Cities, Saint Paul, Minnesota, USA
| | - Hinh Ly
- Department of Veterinary and Biomedical Sciences, University of Minnesota, Twin Cities, Saint Paul, Minnesota, USA
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15
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Highly Pathogenic New World and Old World Human Arenaviruses Induce Distinct Interferon Responses in Human Cells. J Virol 2015; 89:7079-88. [PMID: 25926656 DOI: 10.1128/jvi.00526-15] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 04/21/2015] [Indexed: 12/20/2022] Open
Abstract
UNLABELLED The arenavirus family includes several important pathogens that cause severe and sometimes fatal diseases in humans. The highly pathogenic Old World (OW) arenavirus Lassa fever virus (LASV) is the causative agent of Lassa fever (LF) disease in humans. LASV infections in severe cases are generally immunosuppressive without stimulating interferon (IFN) induction, a proinflammatory response, or T cell activation. However, the host innate immune responses to highly pathogenic New World (NW) arenaviruses are not well understood. We have previously shown that the highly pathogenic NW arenavirus, Junin virus (JUNV), induced an IFN response in human A549 cells. Here, we report that Machupo virus (MACV), another highly pathogenic NW arenavirus, also induces an IFN response. Importantly, both pathogenic NW arenaviruses, in contrast to the OW highly pathogenic arenavirus LASV, readily elicited an IFN response in human primary dendritic cells and A549 cells. Coinfection experiments revealed that LASV could potently inhibit MACV-activated IFN responses even at 6 h after MACV infection, while the replication levels of MACV and LASV were not affected by virus coinfection. Our results clearly demonstrated that although all viruses studied herein are highly pathogenic to humans, the host IFN responses toward infections with the NW arenaviruses JUNV and MACV are quite different from responses to infections with the OW arenavirus LASV, a discovery that needs to be further investigated in relevant animal models. This finding might help us better understand various interplays between the host immune system and highly pathogenic arenaviruses as well as distinct mechanisms underlying viral pathogenesis. IMPORTANCE Infections of humans with the highly pathogenic OW LASV are accompanied by potent suppression of interferon or proinflammatory cytokine production. In contrast, infections with the highly pathogenic NW arenavirus JUNV are associated with high levels of IFNs and cytokines in severe and fatal cases. Arenaviruses initially target macrophages and dendritic cells, which are potent IFN/cytokine-producers. In human macrophages, JUNV reportedly does not trigger IFN responses. We here demonstrated that JUNV activated IFN responses in human dendritic cells. MACV, another highly pathogenic NW arenavirus, also activated IFN responses. LASV did not induce detectable IFN responses, in spite of higher replication levels, and blocked the MACV-triggered IFN response in a coinfection assay. Although these viruses are highly pathogenic to humans, our study highlights distinct innate immune responses to infections with the NW arenaviruses JUNV and MACV and to infection with the OW arenavirus LASV and provides important insights into the virus-host interaction and pathogenesis.
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Human Plasmacytoid Dendritic Cells Elicited Different Responses after Infection with Pathogenic and Nonpathogenic Junin Virus Strains. J Virol 2015; 89:7409-13. [PMID: 25926646 DOI: 10.1128/jvi.01014-15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 04/22/2015] [Indexed: 12/24/2022] Open
Abstract
The arenavirus Junin virus (JUNV) is the etiologic agent of Argentine hemorrhagic fever. We characterized the JUNV infection of human peripheral blood-derived plasmacytoid dendritic cells (hpDC), demonstrating that hpDC are susceptible to infection with the C#1 strain (attenuated) and even more susceptible to infection with the P (virulent) JUNV strain. However, hpDC elicited different responses in terms of viability, activation, maturation, and cytokine expression after infection with both JUNV strains.
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