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Johnson DM, Khakhum N, Wang M, Warner NL, Jokinen JD, Comer JE, Lukashevich IS. Pathogenic and Apathogenic Strains of Lymphocytic Choriomeningitis Virus Have Distinct Entry and Innate Immune Activation Pathways. Viruses 2024; 16:635. [PMID: 38675975 PMCID: PMC11053560 DOI: 10.3390/v16040635] [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: 03/12/2024] [Revised: 04/08/2024] [Accepted: 04/18/2024] [Indexed: 04/28/2024] Open
Abstract
Lymphocytic choriomeningitis virus (LCMV) and Lassa virus (LASV) share many genetic and biological features including subtle differences between pathogenic and apathogenic strains. Despite remarkable genetic similarity, the viscerotropic WE strain of LCMV causes a fatal LASV fever-like hepatitis in non-human primates (NHPs) while the mouse-adapted Armstrong (ARM) strain of LCMV is deeply attenuated in NHPs and can vaccinate against LCMV-WE challenge. Here, we demonstrate that internalization of WE is more sensitive to the depletion of membrane cholesterol than ARM infection while ARM infection is more reliant on endosomal acidification. LCMV-ARM induces robust NF-κB and interferon response factor (IRF) activation while LCMV-WE seems to avoid early innate sensing and failed to induce strong NF-κB and IRF responses in dual-reporter monocyte and epithelial cells. Toll-like receptor 2 (TLR-2) signaling appears to play a critical role in NF-κB activation and the silencing of TLR-2 shuts down IL-6 production in ARM but not in WE-infected cells. Pathogenic LCMV-WE infection is poorly recognized in early endosomes and failed to induce TLR-2/Mal-dependent pro-inflammatory cytokines. Following infection, Interleukin-1 receptor-associated kinase 1 (IRAK-1) expression is diminished in LCMV-ARM- but not LCMV-WE-infected cells, which indicates it is likely involved in the LCMV-ARM NF-κB activation. By confocal microscopy, ARM and WE strains have similar intracellular trafficking although LCMV-ARM infection appears to coincide with greater co-localization of early endosome marker EEA1 with TLR-2. Both strains co-localize with Rab-7, a late endosome marker, but the interaction with LCMV-WE seems to be more prolonged. These findings suggest that LCMV-ARM's intracellular trafficking pathway may facilitate interaction with innate immune sensors, which promotes the induction of effective innate and adaptive immune responses.
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Affiliation(s)
- Dylan M. Johnson
- Center for Predictive Medicine for Biodefense and Emerging Infectious Diseases, Louisville, KY 94202, USA (I.S.L.)
- Department of Microbiology and Immunology, University of Louisville Health Sciences Center, Louisville, KY 94202, USA
- Galveston National Laboratory, Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77550, USA; (N.K.); (J.E.C.)
- Sandia National Laboratories, Department of Biotechnology & Bioengineering, Livermore, CA 94550, USA
| | - Nittaya Khakhum
- Galveston National Laboratory, Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77550, USA; (N.K.); (J.E.C.)
| | - Min Wang
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 94202, USA;
| | - Nikole L. Warner
- Center for Predictive Medicine for Biodefense and Emerging Infectious Diseases, Louisville, KY 94202, USA (I.S.L.)
- Department of Microbiology and Immunology, University of Louisville Health Sciences Center, Louisville, KY 94202, USA
| | - Jenny D. Jokinen
- Center for Predictive Medicine for Biodefense and Emerging Infectious Diseases, Louisville, KY 94202, USA (I.S.L.)
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 94202, USA;
| | - Jason E. Comer
- Galveston National Laboratory, Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77550, USA; (N.K.); (J.E.C.)
| | - Igor S. Lukashevich
- Center for Predictive Medicine for Biodefense and Emerging Infectious Diseases, Louisville, KY 94202, USA (I.S.L.)
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 94202, USA;
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Greczmiel U, Oxenius A. The Janus Face of Follicular T Helper Cells in Chronic Viral Infections. Front Immunol 2018; 9:1162. [PMID: 29887868 PMCID: PMC5982684 DOI: 10.3389/fimmu.2018.01162] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 05/09/2018] [Indexed: 12/28/2022] Open
Abstract
Chronic infections with non-cytopathic viruses constitutively expose virus-specific adaptive immune cells to cognate antigen, requiring their numeric and functional adaptation. Virus-specific CD8 T cells are compromised by various means in their effector functions, collectively termed T cell exhaustion. Alike CD8 T cells, virus-specific CD4 Th1 cell responses are gradually downregulated but instead, follicular T helper (TFH) cell differentiation and maintenance is strongly promoted during chronic infection. Thereby, the immune system promotes antibody responses, which bear less immune-pathological risk compared to cytotoxic and pro-inflammatory T cell responses. This emphasis on TFH cells contributes to tolerance of the chronic infection and is pivotal for the continued maturation and adaptation of the antibody response, leading eventually to the emergence of virus-neutralizing antibodies, which possess the potential to control the established chronic infection. However, sustained high levels of TFH cells can also result in a less stringent B cell selection process in active germinal center reactions, leading to the activation of virus-unspecific B cells, including self-reactive B cells, and to hypergammaglobulinemia. This dispersal of B cell help comes at the expense of a stringently selected virus-specific antibody response, thereby contributing to its delayed maturation. Here, we discuss these opposing facets of TFH cells in chronic viral infections.
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Affiliation(s)
- Ute Greczmiel
- Institute of Microbiology, ETH Zürich, Zürich, Switzerland
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Moreno H, Grande-Pérez A, Domingo E, Martín V. Arenaviruses and lethal mutagenesis. Prospects for new ribavirin-based interventions. Viruses 2012; 4:2786-805. [PMID: 23202505 PMCID: PMC3509673 DOI: 10.3390/v4112786] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 10/17/2012] [Accepted: 10/25/2012] [Indexed: 01/05/2023] Open
Abstract
Lymphocytic choriomeningitis virus (LCMV) has contributed to unveil some of the molecular mechanisms of lethal mutagenesis, or loss of virus infectivity due to increased mutation rates. Here we review these developments, and provide additional evidence that ribavirin displays a dual mutagenic and inhibitory activity on LCMV that can be relevant to treatment designs. Using 5-fluorouracil as mutagenic agent and ribavirin either as inhibitor or mutagen, we document an advantage of a sequential inhibitor-mutagen administration over the corresponding combination treatment to achieve a low LCMV load in cell culture. This advantage is accentuated in the concentration range in which ribavirin acts mainly as an inhibitor, rather than as mutagen. This observation reinforces previous theoretical and experimental studies in supporting a sequential inhibitor-mutagen administration as a possible antiviral design. Given recent progress in the development of new inhibitors of arenavirus replication, our results suggest new options of ribavirin-based anti-arenavirus treatments.
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Affiliation(s)
- Héctor Moreno
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Campus de Cantoblanco 28049, Madrid, Spain; (H.M.); (E.D.)
| | - Ana Grande-Pérez
- Área de Genética, Facultad de Ciencias, Campus de Teatinos, Universidad de Málaga, 29071, Málaga, Spain;
| | - Esteban Domingo
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), Campus de Cantoblanco 28049, Madrid, Spain; (H.M.); (E.D.)
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 08036 Barcelona, Spain
| | - Verónica Martín
- Centro de Investigación en Sanidad Animal (CISA), Carretera de Algete a El Casar s/n, 28130 Valdeolmos, Madrid, Spain;
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Targeting the proteolytic processing of the viral glycoprotein precursor is a promising novel antiviral strategy against arenaviruses. J Virol 2010; 84:573-84. [PMID: 19846507 DOI: 10.1128/jvi.01697-09] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A crucial step in the arenavirus life cycle is the biosynthesis of the viral envelope glycoprotein (GP) responsible for virus attachment and entry. Processing of the GP precursor (GPC) by the cellular proprotein convertase site 1 protease (S1P), also known as subtilisin-kexin-isozyme 1 (SKI-1), is crucial for cell-to-cell propagation of infection and production of infectious virus. Here, we sought to evaluate arenavirus GPC processing by S1P as a target for antiviral therapy using a recently developed peptide-based S1P inhibitor, decanoyl (dec)-RRLL-chloromethylketone (CMK), and the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV). To control for off-target effects of dec-RRLL-CMK, we employed arenavirus reverse genetics to introduce a furin recognition site into the GPC of LCMV. The rescued mutant virus grew to normal titers, and the processing of its GPC critically depended on cellular furin, but not S1P. Treatment with the S1P inhibitor dec-RRLL-CMK resulted in specific blocking of viral spread and virus production of LCMV. Combination of the protease inhibitor with ribavirin, currently used clinically for treatment of human arenavirus infections, resulted in additive drug effects. In cells deficient in S1P, the furin-dependent LCMV variant established persistent infection, whereas wild-type LCMV underwent extinction without the emergence of S1P-independent escape variants. Together, the potent antiviral activity of an inhibitor of S1P-dependent GPC cleavage, the additive antiviral effect with ribavirin, and the low probability of emergence of S1P-independent viral escape variants make S1P-mediated GPC processing by peptide-derived inhibitors a promising strategy for the development of novel antiarenaviral drugs.
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Martín V, Abia D, Domingo E, Grande-Pérez A. An interfering activity against lymphocytic choriomeningitis virus replication associated with enhanced mutagenesis. J Gen Virol 2009; 91:990-1003. [PMID: 20007356 DOI: 10.1099/vir.0.017053-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Previous studies have documented that, in the presence of the mutagenic base analogue 5-fluorouracil (FU), lymphocytic choriomeningitis virus (LCMV) that persisted in BHK-21 cells decreased its infectivity to a larger extent than intracellular viral RNA levels, prior to virus extinction. This observation, together with in silico simulations, led to the proposal of the lethal defection model of virus extinction. This model suggests the participation of defective-interfering genomes in the loss of infectivity by increased mutagenesis. Since LCMV naturally produces defective-interfering particles, it was important to show that a capacity to interfere is produced in association with FU treatment. Here, we document that BHK-21 cells persistently infected with LCMV grown in the presence of FU, but not in its absence, generated an interfering activity that suppressed LCMV infectivity. Interference was specific for LCMV and was sensitive to UV irradiation and its activity was dose- and time-dependent. The interfering preparations produced positive LCMV immunofluorescence and viral particles seen by electron microscopy when used to infect cells, despite some preparations being devoid of detectable infectivity. Interference did not involve significant increases of mutant spectrum complexity, as predicted by the lethal defection model. The results provide support for a specific interference associated with LCMV when the virus replicates in the presence of FU. The excess of interference relative to that observed in the absence of FU is necessary for LCMV extinction.
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Affiliation(s)
- Verónica Martín
- Centro de Biología Molecular 'Severo Ochoa' (CSIC-UAM), C/ Nicolás Cabrera, 1, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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Arenavirus genetic diversity and its biological implications. INFECTION GENETICS AND EVOLUTION 2009; 9:417-29. [PMID: 19460307 PMCID: PMC7106275 DOI: 10.1016/j.meegid.2009.03.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2009] [Revised: 03/13/2009] [Accepted: 03/13/2009] [Indexed: 12/15/2022]
Abstract
The Arenaviridae family currently comprises 22 viral species, each of them associated with a rodent species. This viral family is important both as tractable experimental model systems to study acute and persistent infections and as clinically important human pathogens. Arenaviruses are enveloped viruses with a bi-segmented negative-strand RNA genome. The interaction with the cellular receptor and subsequent entry into the host cell differs between Old World and New World arenavirus that use α-dystoglycan or human transferring receptor 1, respectively, as main receptors. The recent development of reverse genetic systems for several arenaviruses has facilitated progress in understanding the molecular biology and cell biology of this viral family, as well as opening new approaches for the development of novel strategies to combat human pathogenic arenaviruses. On the other hand, increased availability of genetic data has allowed more detailed studies on the phylogeny and evolution of arenaviruses. As with other riboviruses, arenaviruses exist as viral quasispecies, which allow virus adaptation to rapidly changing environments. The large number of different arenavirus host reservoirs and great genetic diversity among virus species provide the bases for the emergence of new arenaviruses potentially pathogenic for humans.
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Site 1 protease is required for proteolytic processing of the glycoproteins of the South American hemorrhagic fever viruses Junin, Machupo, and Guanarito. J Virol 2008; 82:6045-51. [PMID: 18400865 DOI: 10.1128/jvi.02392-07] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The cellular proprotein convertase site 1 protease (S1P) has been implicated in the proteolytic processing of the glycoproteins (GPs) of Old World arenaviruses. Here we report that S1P is also involved in the processing of the GPs of the genetically more-distant South American hemorrhagic fever viruses Guanarito, Machupo, and Junin. Efficient cleavage of Guanarito virus GP, whose protease recognition sites deviate from the reported S1P consensus sequence, indicates a broader specificity of S1P than anticipated. Lack of GP processing of Junin virus dramatically reduced production of infectious virus and prevented cell-to-cell propagation. Infection of S1P-deficient cells resulted in viral persistence over several weeks without the emergence of escape variants able to use other cellular proteases for GP processing.
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Rojek JM, Spiropoulou CF, Campbell KP, Kunz S. Old World and clade C New World arenaviruses mimic the molecular mechanism of receptor recognition used by alpha-dystroglycan's host-derived ligands. J Virol 2007; 81:5685-95. [PMID: 17360738 PMCID: PMC1900301 DOI: 10.1128/jvi.02574-06] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
alpha-Dystroglycan (DG) is an important cellular receptor for extracellular matrix (ECM) proteins and also serves as the receptor for Old World arenaviruses Lassa fever virus (LFV) and lymphocytic choriomeningitis virus (LCMV) and clade C New World arenaviruses. In the host cell, alpha-DG is subject to a remarkably complex pattern of O glycosylation that is crucial for its interactions with ECM proteins. Two of these unusual sugar modifications, protein O mannosylation and glycan modifications involving the putative glycosyltransferase LARGE, have recently been implicated in arenavirus binding. Considering the complexity of alpha-DG O glycosylation, our present study was aimed at the identification of the specific O-linked glycans on alpha-DG that are recognized by arenaviruses. As previously shown for LCMV, we found that protein O mannosylation of alpha-DG is crucial for the binding of arenaviruses of distinct phylogenetic origins, including LFV, Mobala virus, and clade C New World arenaviruses. In contrast to the highly conserved requirement for O mannosylation, more generic O glycans present on alpha-DG are dispensable for arenavirus binding. Despite the critical role of O-mannosyl glycans for arenavirus binding under normal conditions, the overexpression of LARGE in cells deficient in O mannosylation resulted in highly glycosylated alpha-DG that was functional as a receptor for arenaviruses. Thus, modifications by LARGE but not O-mannosyl glycans themselves are most likely the crucial structures recognized by arenaviruses. Together, the data demonstrate that arenaviruses recognize the same highly conserved O-glycan structures on alpha-DG involved in ECM protein binding, indicating a strikingly similar mechanism of receptor recognition by pathogen- and host-derived ligands.
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Affiliation(s)
- Jillian M Rojek
- Molecular and Integrative Neurosciences Department, The Scripps Research Institute, 10550 N. Torrey Pines Rd., La Jolla, CA 92037, USA
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Bui HH, Botten J, Fusseder N, Pasquetto V, Mothe B, Buchmeier MJ, Sette A. Protein sequence database for pathogenic arenaviruses. Immunome Res 2007; 3:1. [PMID: 17288609 PMCID: PMC1803765 DOI: 10.1186/1745-7580-3-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2006] [Accepted: 02/08/2007] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Arenaviruses are a family of rodent-borne viruses that cause several hemorrhagic fevers. These diseases can be devastating and are often lethal. Herein, to aid in the design and development of diagnostics, treatments and vaccines for arenavirus infections, we have developed a database containing protein sequences from the seven pathogenic arenaviruses (Junin, Guanarito, Sabia, Machupo, Whitewater Arroyo, Lassa and LCMV). RESULTS The database currently contains a non-redundant set of 333 protein sequences which were manually annotated. All entries were linked to NCBI and cited PubMed references. The database has a convenient query interface including BLAST search. Sequence variability analyses were also performed and the results are hosted in the database. CONCLUSION The database is available at http://epitope.liai.org:8080/projects/arena and can be used to aid in studies that require proteomic information from pathogenic arenaviruses.
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Affiliation(s)
- Huynh-Hoa Bui
- La Jolla Institute for Allergy and Immunology, Division of Vaccine Discovery, 9420 Athena Circle, La Jolla, CA 92037, USA
| | - Jason Botten
- The Scripps Research Institute, Molecular & Integrative Neurosciences Department, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Nicolas Fusseder
- La Jolla Institute for Allergy and Immunology, Division of Vaccine Discovery, 9420 Athena Circle, La Jolla, CA 92037, USA
| | - Valerie Pasquetto
- La Jolla Institute for Allergy and Immunology, Division of Vaccine Discovery, 9420 Athena Circle, La Jolla, CA 92037, USA
| | - Bianca Mothe
- California State University, Department of Biology, San Marcos, CA 92096, USA
| | - Michael J Buchmeier
- The Scripps Research Institute, Molecular & Integrative Neurosciences Department, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Alessandro Sette
- La Jolla Institute for Allergy and Immunology, Division of Vaccine Discovery, 9420 Athena Circle, La Jolla, CA 92037, USA
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Sevilla N, de la Torre JC. Arenavirus diversity and evolution: quasispecies in vivo. Curr Top Microbiol Immunol 2006; 299:315-35. [PMID: 16568904 PMCID: PMC7120374 DOI: 10.1007/3-540-26397-7_11] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Arenaviruses exist as viral quasispecies due to the high mutation rates of the low-fidelity viral RNA-dependent RNA polymerase (RdRp). This genomic heterogeneity is advantageous to the population, allowing for adaptation to rapidly changing environments that present varying types and degrees of selective pressure. The significant variation in biological properties observed among lymphocytic choriomeningitis virus (LCMV) strains, the prototypic arenavirus, indicates to what extent a quasispecies dynamics may play a role in arenavirus adaptability and pathogenesis. Several aspects of arenavirus variability and its contribution to pathogenesis will be discussed.
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Affiliation(s)
- N Sevilla
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049 Madrid, Spain.
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Grande-Pérez A, Gómez-Mariano G, Lowenstein PR, Domingo E. Mutagenesis-induced, large fitness variations with an invariant arenavirus consensus genomic nucleotide sequence. J Virol 2005; 79:10451-9. [PMID: 16051837 PMCID: PMC1182645 DOI: 10.1128/jvi.79.16.10451-10459.2005] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2005] [Accepted: 05/09/2005] [Indexed: 11/20/2022] Open
Abstract
Enhanced mutagenesis may result in RNA virus extinction, but the molecular events underlying this process are not well understood. Here we show that 5-fluorouracil (FU)-induced mutagenesis of the arenavirus lymphocytic choriomeningitis virus (LCMV) resulted in preextinction populations whose consensus genomic nucleotide sequence remained unaltered. Furthermore, fitness recovery passages in the absence of FU, or alternate virus passages in the presence and absence of FU, led to profound differences in the capacity of LCMV to produce progeny, without modification of the consensus genomic sequence. Molecular genetic analysis failed to produce evidence of hypermutated LCMV genomes. The results suggest that low-level mutagenesis to enrich the viral population with defector, interfering genomes harboring limited numbers of mutations may mediate the loss of infectivity that accompanies viral extinction.
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Affiliation(s)
- Ana Grande-Pérez
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain
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Abstract
Viral hemorrhagic fevers represent serious human public health problems causing devastating and often lethal disease. Several hemorrhagic fevers are caused by arenaviruses including Lassa fever virus (LFV) and the South American viral hemorrhagic fevers (SAHF). In recent years, increased air travel between Africa and other areas has led to the importation of LFV into the US, Europe, Japan, and Canada. This has raised awareness about arenaviruses as potential emerging viruses. Moreover, because of its severe morbidity and high mortality, and transmissibility from human to human, weaponized forms of LFV poses a real threat as agent of bioterrorism. No licensed vaccine is available in the US, and currently there is not efficacious therapy to treat these infections. Therefore, the importance of developing novel effective antiviral drugs to combat HF arenaviruses, for which the prototypic Arenavirus lymphocytic choriomeningitis virus (LCMV) provides us with an excellent model system. Recent findings have shown that LCMV multiplication both in cultured cells and in vivo is highly susceptible to the mutagenic agent 5-fluorouracil (FU). FU-mediated extinction of LCMV was associated with only modest increases in virus mutation frequencies, but did not significantly affect virus replication and transcription, or virus particle formation. These findings indicate that, as with other riboviruses, lethal mutagenesis is effective also against LCMV raising the possibility of using this novel antiviral strategy to combat pathogenic arenaviruses.
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Affiliation(s)
- Juan Carlos de la Torre
- Department of Neuropharmacology IMM-6, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
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Abstract
The successful replication of a viral pathogen in a host is a complex process involving many interactions. These interactions develop from the coevolution of pathogen and host and often lead to a species specificity of the virus that can make interspecies transmissions difficult. Nevertheless, viruses do sporadically cross species barriers into other host populations, including humans. In zoonotic infections, many of these interspecies transfer events are dead end, where transmission is confined only to the animal-to-human route but sometimes viruses adapt to enable spread from human to human. A pathogen must overcome many hurdles to replicate successfully in a foreign host. The viral pathogen must enter the host cell, replicate with the assistance of host factors, evade inhibitory host products, exit the first cell and move on to the next, and possibly leave the initial host and transmit to another. Each of these stages may require adaptive changes in the pathogen. Although the factors that influence each stage of the replication and transmission of most agents have not been resolved, the genomics of both hosts and pathogens are now at hand and we have begun to understand some of the molecular changes that enable some viruses to adapt to a new host.
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Affiliation(s)
- Richard Webby
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, 38105 Tennessee USA
| | - Erich Hoffmann
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, 38105 Tennessee USA
| | - Robert Webster
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, 38105 Tennessee USA
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Baranowski E, Ruiz-Jarabo CM, Pariente N, Verdaguer N, Domingo E. Evolution of cell recognition by viruses: a source of biological novelty with medical implications. Adv Virus Res 2004; 62:19-111. [PMID: 14719364 PMCID: PMC7119103 DOI: 10.1016/s0065-3527(03)62002-6] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The picture beginning to form from genome analyses of viruses, unicellular organisms, and multicellular organisms is that viruses have shared functional modules with cells. A process of coevolution has probably involved exchanges of genetic information between cells and viruses for long evolutionary periods. From this point of view present-day viruses show flexibility in receptor usage and a capacity to alter through mutation their receptor recognition specificity. It is possible that for the complex DNA viruses, due to a likely limited tolerance to generalized high mutation rates, modifications in receptor specificity will be less frequent than for RNA viruses, albeit with similar biological consequences once they occur. It is found that different receptors, or allelic forms of one receptor, may be used with different efficiency and receptor affinities are probably modified by mutation and selection. Receptor abundance and its affinity for a virus may modulate not only the efficiency of infection, but also the capacity of the virus to diffuse toward other sites of the organism. The chapter concludes that receptors may be shared by different, unrelated viruses and that one virus may use several receptors and may expand its receptor specificity in ways that, at present, are largely unpredictable.
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Affiliation(s)
- Eric Baranowski
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Centro de Investigación en Sanidad Animal (CISA-INIA), Madrid, Spain
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