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Han L, Song S, Feng H, Ma J, Wei W, Si F. A roadmap for developing Venezuelan equine encephalitis virus (VEEV) vaccines: Lessons from the past, strategies for the future. Int J Biol Macromol 2023:125514. [PMID: 37353130 DOI: 10.1016/j.ijbiomac.2023.125514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 06/16/2023] [Accepted: 06/20/2023] [Indexed: 06/25/2023]
Abstract
Venezuelan equine encephalitis (VEE) is a zoonotic infectious disease caused by the Venezuelan equine encephalitis virus (VEEV), which can lead to severe central nervous system infections in both humans and animals. At present, the medical community does not possess a viable means of addressing VEE, rendering the prevention of the virus a matter of paramount importance. Regarding the prevention and control of VEEV, the implementation of a vaccination program has been recognized as the most efficient strategy. Nevertheless, there are currently no licensed vaccines or drugs available for human use against VEEV. This imperative has led to a surge of interest in vaccine research, with VEEV being a prime focus for researchers in the field. In this paper, we initially present a comprehensive overview of the current taxonomic classification of VEEV and the cellular infection mechanism of the virus. Subsequently, we provide a detailed introduction of the prominent VEEV vaccine types presently available, including inactivated vaccines, live attenuated vaccines, genetic, and virus-like particle vaccines. Moreover, we emphasize the challenges that current VEEV vaccine development faces and suggest urgent measures that must be taken to overcome these obstacles. Notably, based on our latest research, we propose the feasibility of incorporation codon usage bias strategies to create the novel VEEV vaccine. Finally, we prose several areas that future VEEV vaccine development should focus on. Our objective is to encourage collaboration between the medical and veterinary communities, expedite the translation of existing vaccines from laboratory to clinical applications, while also preparing for future outbreaks of new VEEV variants.
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Affiliation(s)
- Lulu Han
- Institute of Animal Science and Veterinary Medicine, Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Agricultural Genetics and Breeding, Shanghai Engineering Research Center of Breeding Pig, Shanghai 201106, China; Huaihe Hospital of Henan University, Clinical Medical College of Henan University, Kai Feng 475000, China
| | - Shuai Song
- Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Key Laboratory of Livestock Disease Prevention of Guangdong Province, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, Guangzhou 510640, PR China
| | - Huilin Feng
- Kaifeng Key Laboratory of Infection and Biological Safety, School of Basic Medical Sciences of Henan University, Kai Feng 475000, China
| | - Jing Ma
- Huaihe Hospital of Henan University, Clinical Medical College of Henan University, Kai Feng 475000, China
| | - Wenqiang Wei
- Kaifeng Key Laboratory of Infection and Biological Safety, School of Basic Medical Sciences of Henan University, Kai Feng 475000, China.
| | - Fusheng Si
- Institute of Animal Science and Veterinary Medicine, Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Agricultural Genetics and Breeding, Shanghai Engineering Research Center of Breeding Pig, Shanghai 201106, China.
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Kehn-Hall K, Bradfute SB. Understanding host responses to equine encephalitis virus infection: implications for therapeutic development. Expert Rev Anti Infect Ther 2022; 20:1551-1566. [PMID: 36305549 DOI: 10.1080/14787210.2022.2141224] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
INTRODUCTION Venezuelan, eastern, and western equine encephalitis viruses (VEEV, EEEV, and WEEV) are mosquito-borne New World alphaviruses that cause encephalitis in equids and humans. These viruses can cause severe disease and death, as well as long-term severe neurological symptoms in survivors. Despite the pathogenesis and weaponization of these viruses, there are no approved therapeutics for treating infection. AREAS COVERED In this review, we describe the molecular pathogenesis of these viruses, discuss host-pathogen interactions needed for viral replication, and highlight new avenues for drug development with a focus on host-targeted approaches. EXPERT OPINION Current approaches have yielded some promising therapeutics, but additional emphasis should be placed on advanced development of existing small molecules and pursuit of pan-encephalitic alphavirus drugs. More research should be conducted on EEEV and WEEV, given their high lethality rates.
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Affiliation(s)
- Kylene Kehn-Hall
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA.,Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Tech, Blacksburg, VA, USA
| | - Steven B Bradfute
- Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
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Members of Venezuelan Equine Encephalitis complex entry into host cells by clathrin-mediated endocytosis in a pH-dependent manner. Sci Rep 2022; 12:14556. [PMID: 36008558 PMCID: PMC9411563 DOI: 10.1038/s41598-022-18846-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 08/22/2022] [Indexed: 01/20/2023] Open
Abstract
Pixuna virus (PIXV) and Río Negro virus (RNV) are mosquito-borne alphaviruses belonging to the Venezuelan Equine Encephalitis (VEE) complex, which includes pathogenic epizootic and enzootic subtypes responsible for life-threatening diseases in equines. Considering that the first steps in viral infection are crucial for the efficient production of new progeny, the aim of this study was to elucidate the early events of the replication cycle of these two viruses. To this end, we used chemical inhibitors and the expression of dominant-negative constructs to study the dependence of clathrin and endosomal pH on PIXV and RNV internalization mechanisms. We demonstrated that both viruses are internalized primarily via clathrin-mediated endocytosis, where the low pH in endosomes is crucial for viral replication. Contributing knowledge regarding the entry route of VEE complex members is important to understand the pathogenesis of these viruses and also to develop new antiviral strategies.
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Lucas CJ, Davenport BJ, Carpentier KS, Tinega AN, Morrison TE. Two Conserved Phenylalanine Residues in the E1 Fusion Loop of Alphaviruses Are Essential for Viral Infectivity. J Virol 2022; 96:e0006422. [PMID: 35416719 PMCID: PMC9093095 DOI: 10.1128/jvi.00064-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 03/13/2022] [Indexed: 11/20/2022] Open
Abstract
Alphaviruses infect cells by a low pH-dependent fusion reaction between viral and host cell membranes that is mediated by the viral E1 glycoprotein. Most reported alphavirus E1 sequences include two phenylalanines (F87 and F95) in the fusion loop, yet the role of these residues in viral infectivity remains to be defined. Following introduction of wild type (WT), E1-F87A, and E1-F95A chikungunya virus (CHIKV) RNA genomes into cells, viral particle production was similar in magnitude. However, CHIKV E1-F87A and E1-F95A virions displayed impaired infectivity compared with WT CHIKV particles. Although WT, E1-F87A, and E1-F95A particles bound cells with similar efficiencies, E1-F87A and E1-F95A particles were unable to undergo fusion and entry into cells. Introduction of an F95A mutation in the E1 fusion loop of Mayaro virus or Venezuelan equine encephalitis virus also resulted in poorly infectious virions. We further tested whether an E1-F87A or E1-F95A mutation could be incorporated into a live-attenuated vaccine strain, CHIKV 181/25, to enhance vaccine safety. Infection of immunocompromised Ifnar1-/- and Irf3-/-Irf5-/-Irf7-/- mice with 181/25E1-F87A or 181/25E1-F95A resulted in 0% mortality, compared with 100% mortality following 181/25 infection. Despite this enhanced attenuation, surviving Ifnar1-/- and Irf3-/-Irf5-/-Irf7-/- mice were protected against virulent virus re-challenge. Moreover, single-dose immunization of WT mice with either 181/25, 181/25E1-F87A, or 181/25E1-F95A elicited CHIKV-specific antibody responses and protected against pathogenic CHIKV challenge. These studies define a critical function for residues E1-F87 and E1-F95 in alphavirus fusion and entry into target cells and suggest that incorporation of these mutations could enhance the safety of live-attenuated alphavirus vaccine candidates. IMPORTANCE Alphaviruses are human pathogens that cause both debilitating acute and chronic musculoskeletal disease and potentially fatal encephalitis. In this study, we determined that two highly conserved phenylalanine residues in the alphavirus E1 glycoprotein are required for fusion of viral and host cell membranes and viral entry into target cells. We further demonstrated that mutation of these phenylalanines results in a substantial loss of viral virulence but not immunogenicity. These data enhance an understanding of the viral determinants of alphavirus entry into host cells and could contribute to the development of new antivirals targeting these conserved phenylalanines or new live-attenuated alphavirus vaccines.
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Affiliation(s)
- Cormac J. Lucas
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Bennett J. Davenport
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Kathryn S. Carpentier
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Alex N. Tinega
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Thomas E. Morrison
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
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Hasan SS, Dey D, Singh S, Martin M. The Structural Biology of Eastern Equine Encephalitis Virus, an Emerging Viral Threat. Pathogens 2021; 10:pathogens10080973. [PMID: 34451437 PMCID: PMC8400090 DOI: 10.3390/pathogens10080973] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/21/2021] [Accepted: 07/28/2021] [Indexed: 11/16/2022] Open
Abstract
Alphaviruses are arboviruses that cause arthritis and encephalitis in humans. Eastern Equine Encephalitis Virus (EEEV) is a mosquito-transmitted alphavirus that is implicated in severe encephalitis in humans with high mortality. However, limited insights are available into the fundamental biology of EEEV and residue-level details of its interactions with host proteins. In recent years, outbreaks of EEEV have been reported mainly in the United States, raising concerns about public safety. This review article summarizes recent advances in the structural biology of EEEV based mainly on single-particle cryogenic electron microscopy (cryoEM) structures. Together with functional analyses of EEEV and related alphaviruses, these structural investigations provide clues to how EEEV interacts with host proteins, which may open avenues for the development of therapeutics.
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Affiliation(s)
- S. Saif Hasan
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 108 N. Greene Street, Baltimore, MD 21201, USA; (D.D.); (S.S.); (M.M.)
- Center for Biomolecular Therapeutics, University of Maryland School of Medicine, 9600 Gudelsky Drive, Rockville, MD 20850, USA
- University of Maryland Marlene and Stewart Greenebaum Cancer Center, University of Maryland Medical Center, 22. S. Greene St., Baltimore, MD 21201, USA
- Correspondence:
| | - Debajit Dey
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 108 N. Greene Street, Baltimore, MD 21201, USA; (D.D.); (S.S.); (M.M.)
| | - Suruchi Singh
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 108 N. Greene Street, Baltimore, MD 21201, USA; (D.D.); (S.S.); (M.M.)
| | - Matthew Martin
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 108 N. Greene Street, Baltimore, MD 21201, USA; (D.D.); (S.S.); (M.M.)
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Somiya M, Kuroda S. Real-Time Luminescence Assay for Cytoplasmic Cargo Delivery of Extracellular Vesicles. Anal Chem 2021; 93:5612-5620. [PMID: 33759512 DOI: 10.1021/acs.analchem.1c00339] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Extracellular vesicles (EVs) have been considered to deliver biological cargos between cells and mediate intercellular communication and potential drug delivery carriers. However, the mechanisms that underlie the biological process of EV uptake and cytoplasmic cargo release in recipient cells are largely unknown. Quantitative and real-time assays for the assessment of cargo delivery efficiency inside recipient cells have not been feasible. In this study, we developed an EV cargo delivery (EVCD) assay using a split luciferase called a NanoBiT system. Recipient cells expressing LgBiT, a large subunit of luciferase, emit luminescence when EV cargo proteins fused with a small luminescence tag (HiBiT tag) that can complement LgBiT are delivered to the cytoplasm of recipient cells. Using the EVCD assay, the cargo delivery efficiency of EVs could be quantitatively measured in real time. This assay was highly sensitive in detecting a single event of cargo delivery per cell. We found that modification of EVs with a virus-derived fusogenic protein significantly enhanced the cytoplasmic cargo delivery; however, in the absence of a fusogenic protein, the cargo delivery efficiency of EVs was below the threshold of the assay. The EVCD assay could assess the effect of entry inhibitors on EV cargo delivery. Furthermore, using a luminescence microscope, the cytoplasmic cargo delivery of EVs was directly visualized in living cells. This assay could reveal the biological mechanism of the cargo delivery processes of EVs.
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Affiliation(s)
- Masaharu Somiya
- Department of Biomolecular Science and Reaction, The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Shun'ichi Kuroda
- Department of Biomolecular Science and Reaction, The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
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De Caluwé L, Ariën KK, Bartholomeeusen K. Host Factors and Pathways Involved in the Entry of Mosquito-Borne Alphaviruses. Trends Microbiol 2020; 29:634-647. [PMID: 33208275 DOI: 10.1016/j.tim.2020.10.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 11/17/2022]
Abstract
Chikungunya virus (CHIKV) is an arthropod-borne virus that has re-emerged recently and has spread to previously unaffected regions, resulting in millions of infections worldwide. The genus Alphavirus, in the family Togaviridae, contains several members with a similar potential for epidemic emergence. In order for CHIKV to replicate in targeted cell types it is essential for the virus to enter these cells. In this review, we summarize our current understanding of the versatile and promiscuous steps in CHIKV binding and entry into human and mosquito host cells. We describe the different entry pathways, receptors, and attachment factors so far described for CHIKV and other mosquito-borne alphaviruses and discuss them in the context of tissue tropism and potential therapeutic targeting.
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Affiliation(s)
- Lien De Caluwé
- Virology Unit, Biomedical Sciences, Institute of Tropical Medicine Antwerp, Antwerp, Belgium
| | - Kevin K Ariën
- Virology Unit, Biomedical Sciences, Institute of Tropical Medicine Antwerp, Antwerp, Belgium; Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium.
| | - Koen Bartholomeeusen
- Virology Unit, Biomedical Sciences, Institute of Tropical Medicine Antwerp, Antwerp, Belgium.
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Scroggs SLP, Andrade CC, Chinnasamy R, Azar SR, Schirtzinger EE, Garcia EI, Arterburn JB, Hanley KA, Rossi SL. Old Drugs with New Tricks: Efficacy of Fluoroquinolones to Suppress Replication of Flaviviruses. Viruses 2020; 12:v12091022. [PMID: 32933138 PMCID: PMC7551155 DOI: 10.3390/v12091022] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/10/2020] [Accepted: 09/11/2020] [Indexed: 02/06/2023] Open
Abstract
Repurposing FDA-approved compounds could provide the fastest route to alleviate the burden of disease caused by flaviviruses. In this study, three fluoroquinolones, enoxacin, difloxacin and ciprofloxacin, curtailed replication of flaviviruses Zika (ZIKV), dengue (DENV), Langat (LGTV) and Modoc (MODV) in HEK-293 cells at low micromolar concentrations. Time-of-addition assays suggested that enoxacin suppressed ZIKV replication at an intermediate step in the virus life cycle, whereas ciprofloxacin and difloxacin had a wider window of efficacy. A129 mice infected with 1 × 105 plaque-forming units (pfu) ZIKV FSS13025 (n = 20) or phosphate buffered saline (PBS) (n = 11) on day 0 and treated with enoxacin at 10 mg/kg or 15 mg/kg or diluent orally twice daily on days 1–5 did not differ in weight change or virus titer in serum or brain. However, mice treated with enoxacin showed a significant, five-fold decrease in ZIKV titer in testes relative to controls. Mice infected with 1 × 102 pfu ZIKV (n = 13) or PBS (n = 13) on day 0 and treated with 15 mg/kg oral enoxacin or diluent twice daily pre-treatment and days 1–5 post-treatment also did not differ in weight and viral load in the serum, brain, and liver, but mice treated with enoxacin showed a significant, 2.5-fold decrease in ZIKV titer in testes relative to controls. ZIKV can be sexually transmitted, so reduction of titer in the testes by enoxacin should be further investigated.
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Affiliation(s)
- Stacey L. P. Scroggs
- Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA; (C.C.A.); (E.E.S.); (E.I.G.); (K.A.H.)
- Biology of Vector-Borne Viruses Section, Laboratory of Virology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA
- Correspondence:
| | - Christy C. Andrade
- Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA; (C.C.A.); (E.E.S.); (E.I.G.); (K.A.H.)
- Department of Biology, Gonzaga University, Spokane, WA 99258, USA
| | - Ramesh Chinnasamy
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003, USA; (R.C.); (J.B.A.)
| | - Sasha R. Azar
- Institute for Translational Sciences, The University of University of Texas Medical Branch, Galveston, TX 77555, USA;
| | - Erin E. Schirtzinger
- Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA; (C.C.A.); (E.E.S.); (E.I.G.); (K.A.H.)
- Arthropod-borne Animal Diseases Research Unit, United States Department of Agriculture, Agricultural Research Service, Manhattan, KS 66506, USA
| | - Erin I. Garcia
- Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA; (C.C.A.); (E.E.S.); (E.I.G.); (K.A.H.)
- Science News, Washington, DC 20036, USA
| | - Jeffrey B. Arterburn
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003, USA; (R.C.); (J.B.A.)
| | - Kathryn A. Hanley
- Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA; (C.C.A.); (E.E.S.); (E.I.G.); (K.A.H.)
| | - Shannan L. Rossi
- Department of Pathology, The University of Texas Medical Branch, Galveston, TX 77555, USA;
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Using genetic variation in Aedes aegypti to identify candidate anti-dengue virus genes. BMC Infect Dis 2019; 19:580. [PMID: 31272403 PMCID: PMC6611004 DOI: 10.1186/s12879-019-4212-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 06/23/2019] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Transcriptomic profiling has generated extensive lists of genes that respond to viral infection in mosquitoes. These gene lists contain two types of genes; (1) those that are responsible for the insect's natural antiviral defense mechanisms, including some known innate immunity genes, and (2) genes whose change in expression may occur simply as a result of infection. As genetic modification tools for mosquitoes continue to improve, the opportunities to make refractory insects via allelic replacement or delivery of small RNAs that alter gene expression are expanding. Therefore, the ability to identify which genes in transcriptional profiles may have immune function has increasing value. Arboviruses encounter a range of mosquito tissues and physiologies as they traverse from the midgut to the salivary glands. While the midgut is well-studied as the primary tissue barrier, antiviral genes expressed in the subsequent tissues of the carcass offer additional candidates for second stage intervention in the mosquito body. METHODS Mosquito lines collected recently from field populations exhibit natural genetic variation for dengue virus susceptibility. We sought to use a modified full-sib breeding design to identify mosquito families that varied in their dengue viral load in their bodies post infection. RESULTS By delivering virus intrathoracically, we bypassed the midgut and focused on whole body responses in order to evaluate carcass-associated refractoriness. We tested 25 candidate genes selected for their appearance in multiple published transcriptional profiles and were able to identify 12 whose expression varied with susceptibility in the genetic families. CONCLUSIONS This method, using natural genetic variation, offers a simple means to screen and reduce candidate gene lists prior to carrying out more labor-intensive functional studies. The extracted RNA from the females across the families represents a storable resource that can be used to screen subsequent candidate genes in the future. The aspect of vector competence being assessed could be varied by focusing on different tissues or time points post infection.
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Elmogy M, Mohamed AA, Tufail M, Uno T, Takeda M. Molecular and functional characterization of the American cockroach, Periplaneta americana, Rab5: the first exopterygotan low molecular weight ovarian GTPase during oogenesis. INSECT SCIENCE 2018; 25:751-764. [PMID: 28548451 DOI: 10.1111/1744-7917.12485] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 03/22/2017] [Accepted: 04/19/2017] [Indexed: 06/07/2023]
Abstract
The small Rab GTPases are key regulators of membrane vesicle trafficking. Ovaries of Periplaneta americana (Linnaeus) (Blattodea: Blattidae) have small molecular weight GTP/ATP-binding proteins during early and late vitellogenic periods of oogenesis. However, the identification and characterization of the detected proteins have not been yet reported. Herein, we cloned a cDNA encoding Rab5 from the American cockroach, P. americana, ovaries (PamRab5). It comprises 796 bp, encoding a protein of 213 amino acid residues with a predicted molecular weight of 23.5 kDa. PamRab5 exists as a single-copy gene in the P. americana genome, as revealed by Southern blot analysis. An approximate 2.6 kb ovarian mRNA was transcribed especially at high levels in the previtellogenic ovaries, detected by Northern blot analysis. The muscle and head tissues also showed high levels of PamRab5 transcript. PamRab5 protein was localized, via immunofluorescence labeling, to germline-derived cells of the oocytes, very early during oocyte differentiation. Immunoblotting detected a ∼25 kDa signal as a membrane-associated form revealed after application of detergent in the extraction buffer, and 23 kDa as a cytosolic form consistent with the predicted molecular weight from amino acid sequence in different tissues including ovary, muscles and head. The PamRab5 during late vitellogenic periods is required to regulate the endocytotic machinery during oogenesis in this cockroach. This is the first report on Rab5 from a hemimetabolan, and presents an inaugural step in probing the molecular premises of insect oocyte endocytotic trafficking important for oogenesis and embryonic development.
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Affiliation(s)
- Mohamed Elmogy
- Department of Entomology, Faculty of Science, Cairo University, Orman, Giza, Egypt
| | - Amr A Mohamed
- Department of Entomology, Faculty of Science, Cairo University, Orman, Giza, Egypt
| | - Muhammad Tufail
- Department of Plant Protection, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia
- Graduate School of Agricultural Science, Kobe University, Nada-ku, Kobe, Japan
| | - Tomohide Uno
- Laboratory of Biological Chemistry, Faculty of Agriculture, Department of Biofunctional Chemistry, Kobe University, Nada-ku, Hyogo, Japan
| | - Makio Takeda
- Graduate School of Agricultural Science, Kobe University, Nada-ku, Kobe, Japan
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Lundberg L, Carey B, Kehn-Hall K. Venezuelan Equine Encephalitis Virus Capsid-The Clever Caper. Viruses 2017; 9:E279. [PMID: 28961161 PMCID: PMC5691631 DOI: 10.3390/v9100279] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 09/23/2017] [Accepted: 09/26/2017] [Indexed: 01/13/2023] Open
Abstract
Venezuelan equine encephalitis virus (VEEV) is a New World alphavirus that is vectored by mosquitos and cycled in rodents. It can cause disease in equines and humans characterized by a febrile illness that may progress into encephalitis. Like the capsid protein of other viruses, VEEV capsid is an abundant structural protein that binds to the viral RNA and interacts with the membrane-bound glycoproteins. It also has protease activity, allowing cleavage of itself from the growing structural polypeptide during translation. However, VEEV capsid protein has additional nonstructural roles within the host cell functioning as the primary virulence factor for VEEV. VEEV capsid inhibits host transcription and blocks nuclear import in mammalian cells, at least partially due to its complexing with the host CRM1 and importin α/β1 nuclear transport proteins. VEEV capsid also shuttles between the nucleus and cytoplasm and is susceptible to inhibitors of nuclear trafficking, making it a promising antiviral target. Herein, the role of VEEV capsid in viral replication and pathogenesis will be discussed including a comparison to proteins of other alphaviruses.
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Affiliation(s)
- Lindsay Lundberg
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA 20110, USA.
| | - Brian Carey
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA 20110, USA.
| | - Kylene Kehn-Hall
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA 20110, USA.
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Lin J, Wang C, Zhang L, Wang T, Zhang J, Liang W, Li C, Qian G, Ouyang Y, Guo K, Zhang Y. Rab5 Enhances Classical Swine Fever Virus Proliferation and Interacts with Viral NS4B Protein to Facilitate Formation of NS4B Related Complex. Front Microbiol 2017; 8:1468. [PMID: 28848503 PMCID: PMC5550665 DOI: 10.3389/fmicb.2017.01468] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 07/20/2017] [Indexed: 11/13/2022] Open
Abstract
Classical swine fever virus (CSFV) is a fatal pig pestivirus and causes serious financial losses to the pig industry. CSFV NS4B protein is one of the most important viral replicase proteins. Rab5, a member of the small Rab GTPase family, is involved in infection and replication of numerous viruses including hepatitis C virus and dengue virus. Until now, the effects of Rab5 on the proliferation of CSFV are poorly defined. In the present study, we showed that Rab5 could enhance CSFV proliferation by utilizing lentivirus-mediated constitutive overexpression and eukaryotic plasmid transient overexpression approaches. On the other hand, lentivirus-mediated short hairpin RNA knockdown of Rab5 dramatically inhibited virus production. Co-immunoprecipitation, glutathione S-transferase pulldown and laser confocal microscopy assays further confirmed the interaction between Rab5 and CSFV NS4B protein. In addition, intracellular distribution of NS4B-Red presented many granular fluorescent signals (GFS) in CSFV infected PK-15 cells. Inhibition of basal Rab5 function with Rab5 dominant negative mutant Rab5S34N resulted in disruption of the GFS. These results indicate that Rab5 plays a critical role in facilitating the formation of the NS4B related complexes. Furthermore, it was observed that NS4B co-localized with viral NS3 and NS5A proteins in the cytoplasm, suggesting that NS3 and NS5A might be components of the NS4B related complex. Taken together, these results demonstrate that Rab5 positively modulates CSFV propagation and interacts with NS4B protein to facilitate the NS4B related complexes formation.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Yanming Zhang
- College of Veterinary Medicine, Northwest A&F UniversityYangling, China
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Rabies virus co-localizes with early (Rab5) and late (Rab7) endosomal proteins in neuronal and SH-SY5Y cells. Virol Sin 2017. [PMID: 28634871 DOI: 10.1007/s12250-017-3968-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Rabies virus (RABV) is a highly neurotropic virus that follows clathrin-mediated endocytosis and pH-dependent pathway for trafficking and invasion into endothelial cells. Early (Rab5, EEA1) and late (Rab7, LAMP1) endosomal proteins play critical roles in endosomal sorting, maturity and targeting various molecular cargoes, but their precise functions in the early stage of RABV neuronal infection remain elusive. In this study, the relationship between enigmatic entry of RABV with these endosomal proteins into neuronal and SH-SY5Y cells was investigated. Immunofluorescence, TCID50 titers, electron microscopy and western blotting were carried out to determine the molecular interaction of the nucleoprotein (N) of RABV with early or late endosomal proteins in these cell lines. The expression of N was also determined by down-regulating Rab5 and Rab7 in both cell lines through RNA interference. The results were indicative that N proficiently colocalized with Rab5/EEA1 and Rab7/LAMP1 in both cell lines at 24 and 48 h post-infection, while N titers significantly decreased in early infection of RABV. Down-regulation of Rab5 and Rab7 did not inhibit N expression, but it prevented productive infection via blocking the normal trafficking of RABV in a low pH environment. Ultrathin sections of cells studied by electron microscope also verified the close association of RABV with Rab5 and Rab7 in neurons. From the data it was concluded that primary entry of RABV strongly correlates with the kinetics of Rab-proteins present on early and late vesicles, which provides helpful clues to explain the early events of RABV in nerve cells.
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Ahmad W, Li Y, Guo Y, Wang X, Duan M, Guan Z, Liu Z, Zhang M. Rabies virus co-localizes with early (Rab5) and late (Rab7) endosomal proteins in neuronal and SH-SY5Y cells. Virol Sin 2017. [PMID: 28634871 DOI: 10.1007/s12250-017-3968-959:665-677,2010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023] Open
Abstract
Rabies virus (RABV) is a highly neurotropic virus that follows clathrin-mediated endocytosis and pH-dependent pathway for trafficking and invasion into endothelial cells. Early (Rab5, EEA1) and late (Rab7, LAMP1) endosomal proteins play critical roles in endosomal sorting, maturity and targeting various molecular cargoes, but their precise functions in the early stage of RABV neuronal infection remain elusive. In this study, the relationship between enigmatic entry of RABV with these endosomal proteins into neuronal and SH-SY5Y cells was investigated. Immunofluorescence, TCID50 titers, electron microscopy and western blotting were carried out to determine the molecular interaction of the nucleoprotein (N) of RABV with early or late endosomal proteins in these cell lines. The expression of N was also determined by down-regulating Rab5 and Rab7 in both cell lines through RNA interference. The results were indicative that N proficiently colocalized with Rab5/EEA1 and Rab7/LAMP1 in both cell lines at 24 and 48 h post-infection, while N titers significantly decreased in early infection of RABV. Down-regulation of Rab5 and Rab7 did not inhibit N expression, but it prevented productive infection via blocking the normal trafficking of RABV in a low pH environment. Ultrathin sections of cells studied by electron microscope also verified the close association of RABV with Rab5 and Rab7 in neurons. From the data it was concluded that primary entry of RABV strongly correlates with the kinetics of Rab-proteins present on early and late vesicles, which provides helpful clues to explain the early events of RABV in nerve cells.
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Affiliation(s)
- Waqas Ahmad
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
- Section of Epidemiology and Public Health, College of Veterinary and Animal Sciences, Jhang, 35200, Pakistan
| | - Yingying Li
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Yidi Guo
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Xinyu Wang
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Ming Duan
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Zhenhong Guan
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Zengshan Liu
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Maolin Zhang
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, 130062, China.
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15
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Najjar K, Erazo-Oliveras A, Brock DJ, Wang TY, Pellois JP. An l- to d-Amino Acid Conversion in an Endosomolytic Analog of the Cell-penetrating Peptide TAT Influences Proteolytic Stability, Endocytic Uptake, and Endosomal Escape. J Biol Chem 2016; 292:847-861. [PMID: 27923812 DOI: 10.1074/jbc.m116.759837] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 12/05/2016] [Indexed: 12/12/2022] Open
Abstract
Cell-penetrating peptides (CPPs) are well established as delivery agents for otherwise cell-impermeable cargos. CPPs can also theoretically be used to modulate intracellular processes. However, their susceptibility to proteolytic degradation often limits their utility in these applications. Previous studies have explored the consequences for cellular uptake of converting the residues in CPPs from l- to d-stereochemistry, but conflicting results have been reported and specific steps en route to intracellular activity have not been explored. Here we use dimeric fluorescence TAT as a model CPP to explore the broader consequences of l- to d-stereochemical conversion. We show that inversion of chirality provides protease resistance without altering the overall mode of cellular entry, a process involving endocytic uptake followed by endosomal escape and cytosolic access. However, whereas inversion of chirality reduces endocytic uptake, the d-peptide, once in the endosome, is significantly more prone to escape than its l-counterpart. Moreover, the d-peptide is retained in the cytosol of cells for several days, whereas the l-peptide is degraded within hours. Notably, while the l-peptide is relatively innocuous to cells, the d-peptide exerts a prolonged anti-proliferative activity. Together, our results establish connections between chirality, protease resistance, cellular penetration, and intracellular activity that may be useful for the development of future delivery agents with improved properties.
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Affiliation(s)
- Kristina Najjar
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
| | - Alfredo Erazo-Oliveras
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
| | - Dakota J Brock
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
| | - Ting-Yi Wang
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
| | - Jean-Philippe Pellois
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
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16
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Erazo-Oliveras A, Najjar K, Truong D, Wang TY, Brock DJ, Prater AR, Pellois JP. The Late Endosome and Its Lipid BMP Act as Gateways for Efficient Cytosolic Access of the Delivery Agent dfTAT and Its Macromolecular Cargos. Cell Chem Biol 2016; 23:598-607. [PMID: 27161484 DOI: 10.1016/j.chembiol.2016.03.016] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 03/16/2016] [Accepted: 03/22/2016] [Indexed: 01/02/2023]
Abstract
Endosomal entrapment is a severely limiting bottleneck in the delivery of biologics into cells. The compound dfTAT was recently found to circumvent this problem by mediating endosomal leakage efficiently and without toxicity. Herein, we report on the mechanism of endosomal escape of this cell-penetrating peptide. By modulating the trafficking of the peptide within the endocytic pathway, we identify late endosomes as the organelles rendered leaky by dfTAT. We establish that dfTAT binds bis(monoacylglycero)phosphate (BMP), a lipid found in late endosomes, and that the peptide causes the fusion and leakage of bilayers containing BMP. Together, these data identify late endosomes as desirable gateways for cell penetration and BMP as a cellular factor that can be exploited for the development of future delivery agents.
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Affiliation(s)
- Alfredo Erazo-Oliveras
- Department of Biochemistry and Biophysics, Texas A&M University, 300 Olsen Boulevard, College Station, TX 77843, USA
| | - Kristina Najjar
- Department of Biochemistry and Biophysics, Texas A&M University, 300 Olsen Boulevard, College Station, TX 77843, USA
| | - Dat Truong
- Department of Biochemistry and Biophysics, Texas A&M University, 300 Olsen Boulevard, College Station, TX 77843, USA
| | - Ting-Yi Wang
- Department of Biochemistry and Biophysics, Texas A&M University, 300 Olsen Boulevard, College Station, TX 77843, USA
| | - Dakota J Brock
- Department of Biochemistry and Biophysics, Texas A&M University, 300 Olsen Boulevard, College Station, TX 77843, USA
| | - Austin R Prater
- Department of Biochemistry and Biophysics, Texas A&M University, 300 Olsen Boulevard, College Station, TX 77843, USA
| | - Jean-Philippe Pellois
- Department of Biochemistry and Biophysics, Texas A&M University, 300 Olsen Boulevard, College Station, TX 77843, USA; Department of Chemistry, Texas A&M University, 300 Olsen Boulevard, College Station, TX 77843, USA.
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17
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Dynamics of Chikungunya Virus Cell Entry Unraveled by Single-Virus Tracking in Living Cells. J Virol 2016; 90:4745-4756. [PMID: 26912616 DOI: 10.1128/jvi.03184-15] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 02/19/2016] [Indexed: 12/14/2022] Open
Abstract
UNLABELLED Chikungunya virus (CHIKV) is a rapidly emerging mosquito-borne human pathogen causing major outbreaks in Africa, Asia, and the Americas. The cell entry pathway hijacked by CHIKV to infect a cell has been studied previously using inhibitory compounds. There has been some debate on the mechanism by which CHIKV enters the cell: several studies suggest that CHIKV enters via clathrin-mediated endocytosis, while others show that it enters independently of clathrin. Here we applied live-cell microscopy and monitored the cell entry behavior of single CHIKV particles in living cells transfected with fluorescent marker proteins. This approach allowed us to obtain detailed insight into the dynamic events that occur during CHIKV entry. We observed that almost all particles fused within 20 min after addition to the cells. Of the particles that fused, the vast majority first colocalized with clathrin. The average time from initial colocalization with clathrin to the moment of membrane fusion was 1.7 min, highlighting the rapidity of the cell entry process of CHIKV. Furthermore, these results show that the virus spends a relatively long time searching for a receptor. Membrane fusion was observed predominantly from within Rab5-positive endosomes and often occurred within 40 s after delivery to endosomes. Furthermore, we confirmed that a valine at position 226 of the E1 protein enhances the cholesterol-dependent membrane fusion properties of CHIKV. To conclude, our work confirms that CHIKV enters cells via clathrin-mediated endocytosis and shows that fusion occurs from within acidic early endosomes. IMPORTANCE Since its reemergence in 2004, chikungunya virus (CHIKV) has spread rapidly around the world, leading to millions of infections. CHIKV often causes chikungunya fever, a self-limiting febrile illness with severe arthralgia. Currently, no vaccine or specific antiviral treatment against CHIKV is available. A potential antiviral strategy is to interfere with the cell entry process of the virus. However, conflicting results with regard to the cell entry pathway used by CHIKV have been published. Here we applied a novel technology to visualize the entry behavior of single CHIKV particles in living cells. Our results show that CHIKV cell entry is extremely rapid and occurs via clathrin-mediated endocytosis. Membrane fusion from within acidic early endosomes is observed. Furthermore, the membrane fusion capacity of CHIKV is strongly promoted by cholesterol in the target membrane. Taking these findings together, this study provides detailed insight into the cell entry process of CHIKV.
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18
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Zilbermintz L, Leonardi W, Jeong SY, Sjodt M, McComb R, Ho CLC, Retterer C, Gharaibeh D, Zamani R, Soloveva V, Bavari S, Levitin A, West J, Bradley KA, Clubb RT, Cohen SN, Gupta V, Martchenko M. Identification of agents effective against multiple toxins and viruses by host-oriented cell targeting. Sci Rep 2015; 5:13476. [PMID: 26310922 PMCID: PMC4550849 DOI: 10.1038/srep13476] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 07/28/2015] [Indexed: 01/25/2023] Open
Abstract
A longstanding and still-increasing threat to the effective treatment of infectious diseases is resistance to antimicrobial countermeasures. Potentially, the targeting of host proteins and pathways essential for the detrimental effects of pathogens offers an approach that may discover broad-spectrum anti-pathogen countermeasures and circumvent the effects of pathogen mutations leading to resistance. Here we report implementation of a strategy for discovering broad-spectrum host-oriented therapies against multiple pathogenic agents by multiplex screening of drugs for protection against the detrimental effects of multiple pathogens, identification of host cell pathways inhibited by the drug, and screening for effects of the agent on other pathogens exploiting the same pathway. We show that a clinically used antimalarial drug, Amodiaquine, discovered by this strategy, protects host cells against infection by multiple toxins and viruses by inhibiting host cathepsin B. Our results reveal the practicality of discovering broadly acting anti-pathogen countermeasures that target host proteins exploited by pathogens.
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Affiliation(s)
| | | | - Sun-Young Jeong
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305
| | - Megan Sjodt
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095
| | - Ryan McComb
- Keck Graduate Institute, Claremont, CA 91711
| | - Chi-Lee C Ho
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, 90095
| | - Cary Retterer
- US Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, MD, 21702
| | - Dima Gharaibeh
- US Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, MD, 21702
| | - Rouzbeh Zamani
- US Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, MD, 21702
| | - Veronica Soloveva
- US Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, MD, 21702
| | - Sina Bavari
- US Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, MD, 21702
| | | | - Joel West
- Keck Graduate Institute, Claremont, CA 91711
| | - Kenneth A Bradley
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, 90095
| | - Robert T Clubb
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095
| | - Stanley N Cohen
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305
| | - Vivek Gupta
- Keck Graduate Institute, Claremont, CA 91711
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19
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Abstract
Chikungunya virus (CHIKV) is a rapidly emerging mosquito-borne alphavirus causing millions of infections in the tropical and subtropical regions of the world. CHIKV infection often leads to an acute self-limited febrile illness with debilitating myalgia and arthralgia. A potential long-term complication of CHIKV infection is severe joint pain, which can last for months to years. There are no vaccines or specific therapeutics available to prevent or treat infection. This review describes the critical steps in CHIKV cell entry. We summarize the latest studies on the virus-cell tropism, virus-receptor binding, internalization, membrane fusion and review the molecules and compounds that have been described to interfere with virus cell entry. The aim of the review is to give the reader a state-of-the-art overview on CHIKV cell entry and to provide an outlook on potential new avenues in CHIKV research.
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20
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Nuckols JT, McAuley AJ, Huang YJS, Horne KM, Higgs S, Davey RA, Vanlandingham DL. pH-Dependent entry of chikungunya virus fusion into mosquito cells. Virol J 2014; 11:215. [PMID: 25476236 PMCID: PMC4266220 DOI: 10.1186/s12985-014-0215-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Accepted: 11/25/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Millions of human infections caused by arthropod-borne pathogens are initiated by the feeding of an infected mosquito on a vertebrate. However, interactions between the viruses and the mosquito vector, which facilitates successful infection and transmission of virus to a subsequent vertebrate host, are still not fully understood. FINDING Here we describe early chikungunya virus (CHIKV) infectious events in cells derived from one of the most important CHIKV vectors, Aedes albopictus. We demonstrated that CHIKV infection of mosquito cells depended on acidification of the endosome as indicated by significant inhibition following prophylactic treatment with the lysosomotropic drugs chloroquine, ammonium chloride, and monensin, which is consistent with observations in mammalian cells. While all three agents inhibited CHIKV infection in C6/36 cells, ammonium chloride was less toxic to cells than the other agents. CONCLUSION The observation of similar mechanisms for inhibition of CHIKV infection in mosquito and mammalian cell lines suggests that conserved entry pathways are utilized by CHIKV for vertebrate and invertebrate cell types.
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Affiliation(s)
- John T Nuckols
- Medical Countermeasure Systems, Joint Vaccine Acquisition Program, Fort Detrick, MD, 21702, USA.
| | - Alexander J McAuley
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, 77555, USA.
| | - Yan-Jang S Huang
- Biosecurity Research Institute, Kansas State University, Manhattan, Kansas, 66506, USA. .,Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, 66506, USA.
| | - Kate M Horne
- Biosecurity Research Institute, Kansas State University, Manhattan, Kansas, 66506, USA.
| | - Stephen Higgs
- Biosecurity Research Institute, Kansas State University, Manhattan, Kansas, 66506, USA. .,Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, 66506, USA.
| | - Robert A Davey
- Texas Biomedical Research Institute, San Antonio, TX, 78245, USA.
| | - Dana L Vanlandingham
- Biosecurity Research Institute, Kansas State University, Manhattan, Kansas, 66506, USA. .,Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, 66506, USA.
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21
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Hislop JN, Islam TA, Eleftheriadou I, Carpentier DCJ, Trabalza A, Parkinson M, Schiavo G, Mazarakis ND. Rabies virus envelope glycoprotein targets lentiviral vectors to the axonal retrograde pathway in motor neurons. J Biol Chem 2014; 289:16148-63. [PMID: 24753246 DOI: 10.1074/jbc.m114.549980] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Rabies pseudotyped lentiviral vectors have great potential in gene therapy, not least because of their ability to transduce neurons following their distal axonal application. However, very little is known about the molecular processes that underlie their retrograde transport and cell transduction. Using multiple labeling techniques and confocal microscopy, we demonstrated that pseudotyping with rabies virus envelope glycoprotein (RV-G) enabled the axonal retrograde transport of two distinct subtypes of lentiviral vector in motor neuron cultures. Analysis of this process revealed that these vectors trafficked through Rab5-positive endosomes and accumulated within a non-acidic Rab7 compartment. RV-G pseudotyped vectors were co-transported with both the tetanus neurotoxin-binding fragment and the membrane proteins thought to mediate rabies virus endocytosis (neural cell adhesion molecule, nicotinic acetylcholine receptor, and p75 neurotrophin receptor), thus demonstrating that pseudotyping with RV-G targets lentiviral vectors for transport along the same pathway exploited by several toxins and viruses. Using motor neurons cultured in compartmentalized chambers, we demonstrated that axonal retrograde transport of these vectors was rapid and efficient; however, it was not able to transduce the targeted neurons efficiently, suggesting that impairment in processes occurring after arrival of the viral vector in the soma is responsible for the low transduction efficiency seen in vivo, which suggests a novel area for improvement of gene therapy vectors.
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Affiliation(s)
- James N Hislop
- From Gene Therapy, Centre for Neuroinflammation and Neurodegeneration, Division of Brain Sciences, Department of Medicine, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom
| | - Tarin A Islam
- From Gene Therapy, Centre for Neuroinflammation and Neurodegeneration, Division of Brain Sciences, Department of Medicine, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom
| | - Ioanna Eleftheriadou
- From Gene Therapy, Centre for Neuroinflammation and Neurodegeneration, Division of Brain Sciences, Department of Medicine, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom
| | - David C J Carpentier
- From Gene Therapy, Centre for Neuroinflammation and Neurodegeneration, Division of Brain Sciences, Department of Medicine, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom
| | - Antonio Trabalza
- From Gene Therapy, Centre for Neuroinflammation and Neurodegeneration, Division of Brain Sciences, Department of Medicine, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom
| | - Michael Parkinson
- Molecular NeuroPathoBiology Laboratory, Cancer Research UK London Research Institute, Lincoln's Inn Fields Laboratories, 44 Lincoln's Inn Fields, London WC2A 3LY, United Kingdom, and
| | - Giampietro Schiavo
- Molecular NeuroPathoBiology Laboratory, Cancer Research UK London Research Institute, Lincoln's Inn Fields Laboratories, 44 Lincoln's Inn Fields, London WC2A 3LY, United Kingdom, and Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, University College London, Queen Square, London WC1N 3BG, United Kingdom
| | - Nicholas D Mazarakis
- From Gene Therapy, Centre for Neuroinflammation and Neurodegeneration, Division of Brain Sciences, Department of Medicine, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom,
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Rider MA, Zou J, Vanlandingham D, Nuckols JT, Higgs S, Zhang Q, Lacey M, Kim J, Wang G, Hong YS. Quantitative proteomic analysis of the Anopheles gambiae (Diptera: Culicidae) midgut infected with o'nyong-nyong virus. JOURNAL OF MEDICAL ENTOMOLOGY 2013; 50:1077-1088. [PMID: 24180113 DOI: 10.1603/me12155] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Alphaviruses are arthropod-borne pathogens that infect a range of hosts. In humans and other mammals, alphavirus infection can cause severe disease. In mosquito hosts, however, there are generally few symptoms. Little is known about the cellular responses of mosquitoes that allow them to cope with infection. In this investigation, a six-plex tandem mass tagging proteomic approach was used to study protein accumulation changes in the midgut of Anopheles gambiae (Giles) (Diptera: Culicidae) mosquitoes infected with o'nyong-nyong virus (Togaviridae, Alphavirus). Five hundred thirty-six nonredundant proteins were identified. Twenty-two were found in significantly different quantities in infected midguts compared with controls. Of interest, analysis revealed molecular pathways possibly targeted by virus proteins, such as those involving TAF4 and DNA polymerase phi proteins. Also identified was an FK506-binding protein. FK506-binding protein orthologs have been described as conserved host resistance factors, which suppress dengue and West Nile virus infection in human HeLa cells. This investigation constitutes the first study of the midgut-specific proteome of An. gambiae in relation to alphavirus infection. Our findings offer insight into mosquito immunity, including factors that possibly contribute to the different pathological outcomes observed in vertebrate and insect hosts.
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Affiliation(s)
- Mark A Rider
- Department of Tropical Medicine, Tulane University, 1430 Tulane Ave, SL-17, New Orleans, LA 70112, USA
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23
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Abstract
Intracellular membrane trafficking requires the complex interplay of several classes of trafficking proteins. Rab proteins, the largest subfamily of the Ras superfamily of small G-proteins, are central regulators of all aspects of intracellular trafficking processes including vesicle budding and uncoating, motility, tethering and fusion. In the present paper, we discuss the discovery, evolution and characterization of the Rab GTPase family. We examine their basic functional roles, their important structural features and the regulatory proteins which mediate Rab function. We speculate on outstanding issues in the field, such as the mechanisms of Rab membrane association and the co-ordinated interplay between distinct Rab proteins. Finally, we summarize the data implicating Rab proteins in an ever increasing number of diseases.
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24
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Lee RCH, Hapuarachchi HC, Chen KC, Hussain KM, Chen H, Low SL, Ng LC, Lin R, Ng MML, Chu JJH. Mosquito cellular factors and functions in mediating the infectious entry of chikungunya virus. PLoS Negl Trop Dis 2013; 7:e2050. [PMID: 23409203 PMCID: PMC3567007 DOI: 10.1371/journal.pntd.0002050] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 12/19/2012] [Indexed: 12/01/2022] Open
Abstract
Chikungunya virus (CHIKV) is an arthropod-borne virus responsible for recent epidemics in the Asia Pacific regions. A customized gene expression microarray of 18,760 transcripts known to target Aedes mosquito genome was used to identify host genes that are differentially regulated during the infectious entry process of CHIKV infection on C6/36 mosquito cells. Several genes such as epsin I (EPN1), epidermal growth factor receptor pathway substrate 15 (EPS15) and Huntingtin interacting protein I (HIP1) were identified to be differentially expressed during CHIKV infection and known to be involved in clathrin-mediated endocytosis (CME). Transmission electron microscopy analyses further revealed the presence of CHIKV particles within invaginations of the plasma membrane, resembling clathrin-coated pits. Characterization of vesicles involved in the endocytic trafficking processes of CHIKV revealed the translocation of the virus particles to the early endosomes and subsequently to the late endosomes and lysosomes. Treatment with receptor-mediated endocytosis inhibitor, monodansylcadaverine and clathrin-associated drug inhibitors, chlorpromazine and dynasore inhibited CHIKV entry, whereas no inhibition was observed with caveolin-related drug inhibitors. Inhibition of CHIKV entry upon treatment with low-endosomal pH inhibitors indicated that low pH is essential for viral entry processes. CHIKV entry by clathrin-mediated endocytosis was validated via overexpression of a dominant-negative mutant of Eps15, in which infectious entry was reduced, while siRNA-based knockdown of genes associated with CME, low endosomal pH and RAB trafficking proteins exhibited significant levels of CHIKV inhibition. This study revealed, for the first time, that the infectious entry of CHIKV into mosquito cells is mediated by the clathrin-dependent endocytic pathway. Deciphering the much neglected aspects of cellular factors in contributing to the infectious entry of CHIKV into mosquito cells may enhance our understanding of the conservation or diversity of these host factors amongst mammalian and arthropod for successful CHIKV replication. The study revealed that the infectious entry of chikungunya virus (CHIKV) into mosquito cells is mediated by the clathrin-dependent endocytic pathway. A customized gene expression microarray known to target the Aedes mosquito genome was used to identify host genes that are differentially regulated upon CHIKV infection. A combination of bio-imaging studies and pharmacological inhibitors confirmed the involvement of clathrin-mediated endocytosis as well as the importance of low endosomal pH during CHIKV infectious entry. Furthermore, the clathrin heavy chain, Eps15, RAB5, RAB7 and vacuolar ATPase B are shown to be essential for the infectious entry process of CHIKV. This study aims to underline the importance of cellular factors, particularly those associated with clathrin-dependent endocytosis, in mediating the infectious entry of CHIKV into mosquito cells.
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Affiliation(s)
- Regina Ching Hua Lee
- Laboratory of Molecular RNA Virology and Antiviral Strategies, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore, Singapore
| | | | - Karen Caiyun Chen
- Laboratory of Molecular RNA Virology and Antiviral Strategies, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore, Singapore
| | - Khairunnisa' Mohamed Hussain
- Laboratory of Molecular RNA Virology and Antiviral Strategies, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore, Singapore
| | - Huixin Chen
- Laboratory of Molecular RNA Virology and Antiviral Strategies, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore, Singapore
| | - Swee Ling Low
- Enviromental Health Institute, National Environmental Agency, Singapore, Singapore
| | - Lee Ching Ng
- Enviromental Health Institute, National Environmental Agency, Singapore, Singapore
| | - Raymond Lin
- National Public Health Laboratory, Ministry of Health, Singapore, Singapore
| | - Mary Mah-Lee Ng
- Flavivirology Laboratory, Department of Microbiology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore, Singapore
| | - Justin Jang Hann Chu
- Laboratory of Molecular RNA Virology and Antiviral Strategies, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore, Singapore
- * E-mail:
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pH-dependent entry of chikungunya virus into Aedes albopictus cells. INFECTION GENETICS AND EVOLUTION 2012; 12:1275-81. [DOI: 10.1016/j.meegid.2012.02.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Revised: 02/07/2012] [Accepted: 02/08/2012] [Indexed: 02/04/2023]
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Mechanisms by which ambient humidity may affect viruses in aerosols. Appl Environ Microbiol 2012; 78:6781-8. [PMID: 22820337 DOI: 10.1128/aem.01658-12] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Many airborne viruses have been shown to be sensitive to ambient humidity, yet the mechanisms responsible for this phenomenon remain elusive. We review multiple hypotheses, including water activity, surface inactivation, and salt toxicity, that may account for the association between humidity and viability of viruses in aerosols. We assess the evidence and limitations for each hypothesis based on findings from virology, aerosol science, chemistry, and physics. In addition, we hypothesize that changes in pH within the aerosol that are induced by evaporation may trigger conformational changes of the surface glycoproteins of enveloped viruses and subsequently compromise their infectivity. This hypothesis may explain the differing responses of enveloped viruses to humidity. The precise mechanisms underlying the relationship remain largely unverified, and attaining a complete understanding of them will require an interdisciplinary approach.
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Campbell CL, Lehmann CJ, Gill SS, Dunn WA, James AA, Foy BD. A role for endosomal proteins in alphavirus dissemination in mosquitoes. INSECT MOLECULAR BIOLOGY 2011; 20:429-436. [PMID: 21496127 PMCID: PMC3138809 DOI: 10.1111/j.1365-2583.2011.01078.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Little is known about endosomal pathway proteins involved in arthropod-borne virus (arbovirus) assembly and cell-to-cell spread in vector mosquitoes. UNC93A and synaptic vesicle-2 (SV2) proteins are involved in intracellular transport in mammals. They show amino acid sequence conservation from mosquitoes to humans, and their transcripts are highly enriched in Aedes aegypti during arbovirus infection. Transient gene silencing of SV2 or UNC93A in mosquitoes infected with the recombinant alphavirus Sindbis MRE16-enhanced green fluorescent protein (SINV; family Togaviridae) resulted in the accumulation of viral positive- and negative-strand RNA, congregation of virus envelope antigen in intracellular networks, and reduced virus dissemination outside of the midgut. Further, UNC93A silencing, but not SV2 silencing, resulted in a 10-fold reduction in viral titres at 4 days post-infection. Together, these data support a role for UNC93A and SV2 in virus assembly or budding. Cis-regulatory elements (CREs) were identified at the 5'-ends of genes from the original data set in which SV2 and UNC93A were identified. Common CREs at the 5'-end genomic regions of a subset of enriched transcripts support the hypothesis that UNC93A transcription may be co-regulated with that of other ion transport and endosomal trafficking proteins.
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Affiliation(s)
- C L Campbell
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA.
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Replication of alphaviruses: a review on the entry process of alphaviruses into cells. Adv Virol 2011; 2011:249640. [PMID: 22312336 PMCID: PMC3265296 DOI: 10.1155/2011/249640] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 05/03/2011] [Indexed: 02/04/2023] Open
Abstract
Alphaviruses are small, enveloped viruses, ~70 nm in diameter, containing a single-stranded, positive-sense, RNA genome. Viruses belonging to this genus are predominantly arthropod-borne viruses, known to cause disease in humans. Their potential threat to human health was most recently exemplified by the 2005 Chikungunya virus outbreak in La Reunion, highlighting the necessity to understand events in the life-cycle of these medically important human pathogens. The replication and propagation of viruses is dependent on entry into permissive cells. Viral entry is initiated by attachment of virions to cells, leading to internalization, and uncoating to release genetic material for replication and propagation. Studies on alphaviruses have revealed entry via a receptor-mediated, endocytic pathway. In this paper, the different stages of alphavirus entry are examined, with examples from Semliki Forest virus, Sindbis virus, Chikungunya virus, and Venezuelan equine encephalitis virus described.
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29
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Abstract
The study of enveloped animal viruses has greatly advanced our understanding of the general properties of membrane fusion and of the specific pathways that viruses use to infect the host cell. The membrane fusion proteins of the alphaviruses and flaviviruses have many similarities in structure and function. As reviewed here, alphaviruses use receptor-mediated endocytic uptake and low pH-triggered membrane fusion to deliver their RNA genomes into the cytoplasm. Recent advances in understanding the biochemistry and structure of the alphavirus membrane fusion protein provide a clearer picture of this fusion reaction, including the protein’s conformational changes during fusion and the identification of key domains. These insights into the alphavirus fusion mechanism suggest new areas for experimental investigation and potential inhibitor strategies for anti-viral therapy.
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Affiliation(s)
- Margaret Kielian
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-718-430-3638; Fax: +1-718-430-8574
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Solignat M, Gay B, Higgs S, Briant L, Devaux C. Replication cycle of chikungunya: a re-emerging arbovirus. Virology 2009; 393:183-97. [PMID: 19732931 PMCID: PMC2915564 DOI: 10.1016/j.virol.2009.07.024] [Citation(s) in RCA: 229] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2009] [Revised: 07/07/2009] [Accepted: 07/22/2009] [Indexed: 12/13/2022]
Abstract
Arboviruses (or arthropod-borne viruses), represent a threat for the new century. The 2005-2006 year unprecedented epidemics of chikungunya virus (CHIKV) in the French Reunion Island in the Indian Ocean, followed by several outbreaks in other parts of the world such as India, have attracted the attention of clinicians, scientists, and state authorities about the risks linked to this re-emerging mosquito-borne virus. CHIKV, which belongs to the Alphaviruses genus, was not previously regarded as a highly pathogenic arbovirus. However, this opinion was challenged by the death of several CHIKV-infected persons in Reunion Island. The epidemic episode began in December 2005 and four months later the seroprevalence survey report indicated that 236,000 persons, more than 30% of Reunion Island population, had been infected with CHIKV, among which 0.4-0.5% of cases were fatal. Since the epidemic peak, the infection case number has continued to increase to almost 40% of the population, with a total of more than 250 fatalities. Although information available on CHIKV is growing quite rapidly, we are still far from understanding the strategies required for the ecologic success of this virus, virus replication, its interactions with its vertebrate hosts and arthropod vectors, and its genetic evolution. In this paper, we summarize the current knowledge of CHIKV genomic organization, cell tropism, and the virus replication cycle, and evaluate the possibility to predict its future evolution. Such understanding may be applied in order to anticipate future epidemics and reduce the incidence by development and application of, for example, vaccination and antiviral therapy.
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Affiliation(s)
- Maxime Solignat
- Université Montpellier 1, Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé (CPBS), Montpellier, France
- CNRS, UMR5236, CPBS, F-34965 Montpellier, France
- Université Montpellier 2, CPBS, F-34095 Montpellier, France
| | - Bernard Gay
- Université Montpellier 1, Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé (CPBS), Montpellier, France
- CNRS, UMR5236, CPBS, F-34965 Montpellier, France
- Université Montpellier 2, CPBS, F-34095 Montpellier, France
| | - Stephen Higgs
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Laurence Briant
- Université Montpellier 1, Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé (CPBS), Montpellier, France
- CNRS, UMR5236, CPBS, F-34965 Montpellier, France
- Université Montpellier 2, CPBS, F-34095 Montpellier, France
| | - Christian Devaux
- Université Montpellier 1, Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé (CPBS), Montpellier, France
- CNRS, UMR5236, CPBS, F-34965 Montpellier, France
- Université Montpellier 2, CPBS, F-34095 Montpellier, France
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Abstract
The endocytosis pathway controls multiple cellular and physiological events. The lysosome is the destination of newly synthesized lysosomal hydrolytic enzymes. Internalized molecules or particles are delivered to the lysosome for degradation through sequential transport along the endocytic pathway. The endocytic pathway is also emerging as a signalling platform, in addition to the well-known role of the plasma membrane for signalling. Rab7 is a late endosome-/lysosome-associated small GTPase, perhaps the only lysosomal Rab protein identified to date. Rab7 plays critical roles in the endocytic processes. Through interaction with its partners (including upstream regulators and downstream effectors), Rab7 participates in multiple regulation mechanisms in endosomal sorting, biogenesis of lysosome [or LRO (lysosome-related organelle)] and phagocytosis. These processes are closely related to substrates degradation, antigen presentation, cell signalling, cell survival and microbial pathogen infection. Consistently, mutations or dysfunctions of Rab7 result in traffic disorders, which cause various diseases, such as neuropathy, cancer and lipid metabolism disease. Rab7 also plays important roles in microbial pathogen infection and survival, as well as in participating in the life cycle of viruses. Here, we give a brief review on the central role of Rab7 in endosomal traffic and summarize the studies focusing on the participation of Rab7 in disease pathogenesis. The underlying mechanism governed by Rab7 and its partners will also be discussed.
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A dominant-negative mutant of rab5 inhibits infection of cells by foot-and-mouth disease virus: implications for virus entry. J Virol 2009; 83:6247-56. [PMID: 19357169 DOI: 10.1128/jvi.02460-08] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Foot-and-mouth disease virus (FMDV) can use a number of different integrins (alphavbeta1, alphavbeta3, alphavbeta6, and alphavbeta8) as receptors to initiate infection. Infection mediated by alphavbeta6 is known to occur by clathrin-mediated endocytosis and is dependent on the acidic pH within endosomes. On internalization, virus is detected rapidly in early endosomes (EE) and subsequently in perinuclear recycling endosomes (PNRE), but not in late endosomal compartments. Due to the extreme sensitivity of FMDV to acidic pH, it is thought that EE can provide a pH low enough for infection to occur; however, definitive proof that infection takes place from within these compartments is still lacking. Here we have investigated the intracellular transport steps required for FMDV infection of IBRS-2 cells, which express alphavbeta8 as their FMDV receptor. These experiments confirmed that FMDV infection mediated by alphavbeta8 is also dependent on clathrin-mediate endocytosis and an acidic pH within endosomes. Also, the effect on FMDV infection of dominant-negative (DN) mutants of cellular rab proteins that regulate endosomal traffic was examined. Expression of DN rab5 reduced the number of FMDV-infected cells by 80%, while expression of DN rab4 or DN rab7 had virtually no effect on infection. Expression of DN rab11 inhibited infection by FMDV, albeit to a small extent ( approximately 35%). These results demonstrate that FMDV infection takes place predominantly from within EE and does not require virus trafficking to the late endosomal compartments. However, our results suggest that infection may not be exclusive to EE and that a small amount of infection could occur from within PNRE.
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Vela EM, Colpitts TM, Zhang L, Davey RA, Aronson JF. Pichindé virus is trafficked through a dynamin 2 endocytic pathway that is dependent on cellular Rab5- and Rab7-mediated endosomes. Arch Virol 2008; 153:1391-6. [DOI: 10.1007/s00705-008-0129-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Accepted: 04/30/2008] [Indexed: 11/29/2022]
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