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Arora P, Sidarovich A, Graichen L, Hörnich B, Hahn A, Hoffmann M, Pöhlmann S. Functional analysis of polymorphisms at the S1/S2 site of SARS-CoV-2 spike protein. PLoS One 2022; 17:e0265453. [PMID: 35333910 PMCID: PMC8956166 DOI: 10.1371/journal.pone.0265453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 03/01/2022] [Indexed: 01/12/2023] Open
Abstract
Several SARS-CoV-2 variants emerged that harbor mutations in the surface unit of the viral spike (S) protein that enhance infectivity and transmissibility. Here, we analyzed whether ten naturally-occurring mutations found within the extended loop harboring the S1/S2 cleavage site of the S protein, a determinant of SARS-CoV-2 cell tropism and pathogenicity, impact S protein processing and function. None of the mutations increased but several decreased S protein cleavage at the S1/S2 site, including S686G and P681H, the latter of which is found in variants of concern B.1.1.7 (Alpha variant) and B.1.1.529 (Omicron variant). None of the mutations reduced ACE2 binding and cell-cell fusion although several modulated the efficiency of host cell entry. The effects of mutation S686G on viral entry were cell-type dependent and could be linked to the availability of cathepsin L for S protein activation. These results show that polymorphisms at the S1/S2 site can modulate S protein processing and host cell entry.
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Affiliation(s)
- Prerna Arora
- Infection Biology Unit, German Primate Center, Göttingen, Germany
- Faculty of Biology and Psychology, Georg-August-University Göttingen, Göttingen, Germany
| | - Anzhalika Sidarovich
- Infection Biology Unit, German Primate Center, Göttingen, Germany
- Faculty of Biology and Psychology, Georg-August-University Göttingen, Göttingen, Germany
| | - Luise Graichen
- Infection Biology Unit, German Primate Center, Göttingen, Germany
| | - Bojan Hörnich
- Junior Research Group Herpesviruses - Infection Biology Unit, German Primate Center, Göttingen, Germany
| | - Alexander Hahn
- Junior Research Group Herpesviruses - Infection Biology Unit, German Primate Center, Göttingen, Germany
| | - Markus Hoffmann
- Infection Biology Unit, German Primate Center, Göttingen, Germany
- Faculty of Biology and Psychology, Georg-August-University Göttingen, Göttingen, Germany
- * E-mail: (MH); (SP)
| | - Stefan Pöhlmann
- Infection Biology Unit, German Primate Center, Göttingen, Germany
- Faculty of Biology and Psychology, Georg-August-University Göttingen, Göttingen, Germany
- * E-mail: (MH); (SP)
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Jonaid GM, Dearnaley WJ, Casasanta MA, Kaylor L, Berry S, Dukes MJ, Spilman MS, Gray JL, Kelly DF. High-Resolution Imaging of Human Viruses in Liquid Droplets. Adv Mater 2021; 33:e2103221. [PMID: 34302401 PMCID: PMC8440499 DOI: 10.1002/adma.202103221] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/28/2021] [Indexed: 05/29/2023]
Abstract
Liquid-phase electron microscopy (LP-EM) is an exciting new area in the materials imaging field, providing unprecedented views of molecular processes. Time-resolved insights from LP-EM studies are a strong complement to the remarkable results achievable with other high-resolution techniques. Here, the opportunities to expand LP-EM technology beyond 2D temporal assessments and into the 3D regime are described. The results show new structures and dynamic insights of human viruses contained in minute volumes of liquid while acquired in a rapid timeframe. To develop this strategy, adeno-associated virus (AAV) is used as a model system. AAV is a well-known gene therapy vehicle with current applications involving drug delivery and vaccine development for COVID-19. Improving the understanding of the physical properties of biological entities in a liquid state, as maintained in the human body, has broad societal implications for human health and disease.
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Affiliation(s)
- GM Jonaid
- Bioinformatics and Genomics Graduate Program, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA 16802, USA
- Materials Research Institute, Pennsylvania State University, University Park, PA 16802, USA
- Center for Structural Oncology, Pennsylvania State University, University Park, PA 16802, USA
| | - William J. Dearnaley
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA 16802, USA
- Materials Research Institute, Pennsylvania State University, University Park, PA 16802, USA
- Center for Structural Oncology, Pennsylvania State University, University Park, PA 16802, USA
| | - Michael A. Casasanta
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA 16802, USA
- Materials Research Institute, Pennsylvania State University, University Park, PA 16802, USA
- Center for Structural Oncology, Pennsylvania State University, University Park, PA 16802, USA
| | - Liam Kaylor
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA 16802, USA
- Materials Research Institute, Pennsylvania State University, University Park, PA 16802, USA
- Center for Structural Oncology, Pennsylvania State University, University Park, PA 16802, USA
- Molecular, Cellular, and Integrative Biosciences Graduate Program, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - Samantha Berry
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA 16802, USA
- Materials Research Institute, Pennsylvania State University, University Park, PA 16802, USA
- Center for Structural Oncology, Pennsylvania State University, University Park, PA 16802, USA
| | | | | | - Jennifer L. Gray
- Materials Research Institute, Pennsylvania State University, University Park, PA 16802, USA
| | - Deborah F. Kelly
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA 16802, USA
- Materials Research Institute, Pennsylvania State University, University Park, PA 16802, USA
- Center for Structural Oncology, Pennsylvania State University, University Park, PA 16802, USA
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Alberione MP, Moeller R, Kirui J, Ginkel C, Doepke M, Ströh LJ, Machtens JP, Pietschmann T, Gerold G. Single-nucleotide variants in human CD81 influence hepatitis C virus infection of hepatoma cells. Med Microbiol Immunol 2020; 209:499-514. [PMID: 32322956 PMCID: PMC7176029 DOI: 10.1007/s00430-020-00675-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 04/06/2020] [Indexed: 02/07/2023]
Abstract
An estimated number of 71 million people are living with chronic hepatitis C virus (HCV) infection worldwide and 400,000 annual deaths are related to the infection. HCV entry into the hepatocytes is complex and involves several host factors. The tetraspanin human CD81 (hCD81) is one of the four essential entry factors and is composed of one large extracellular loop, one small extracellular loop, four transmembrane domains, one intracellular loop and two intracellular tails. The large extracellular loop interacts with the E2 glycoprotein of HCV. Regions outside the large extracellular loop (backbone) of hCD81 have a critical role in post-binding entry steps and determine susceptibility of hepatocytes to HCV. Here, we investigated the effect of five non-synonymous single-nucleotide variants in the backbone of hCD81 on HCV susceptibility. We generated cell lines that stably express the hCD81 variants and infected the cells using HCV pseudoparticles and cell culture-derived HCV. Our results show that all the tested hCD81 variants support HCV pseudoparticle entry with similar efficiency as wild-type hCD81. In contrast, variants A54V, V211M and M220I are less supportive to cell culture-derived HCV infection. This altered susceptibility is HCV genotype dependent and specifically affected the cell entry step. Our findings identify three hCD81 genetic variants that are impaired in their function as HCV host factors for specific viral genotypes. This study provides additional evidence that genetic host variation contributes to inter-individual differences in HCV infection and outcome.
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Affiliation(s)
- María Pía Alberione
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, Feodor-Lynen-Straße 7, 30625, Hannover, Germany
| | - Rebecca Moeller
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, Feodor-Lynen-Straße 7, 30625, Hannover, Germany
| | - Jared Kirui
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, Feodor-Lynen-Straße 7, 30625, Hannover, Germany
| | - Corinne Ginkel
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, Feodor-Lynen-Straße 7, 30625, Hannover, Germany
| | - Mandy Doepke
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, Feodor-Lynen-Straße 7, 30625, Hannover, Germany
| | - Luisa J Ströh
- Institute of Virology, Hannover Medical School, Hannover, Germany
| | - Jan-Philipp Machtens
- Institute of Biological Information Processing (IBI-1), Molekular- und Zellphysiologie, and JARA-HPC, Forschungszentrum Jülich, Jülich, Germany
- Institute of Clinical Pharmacology, RWTH Aachen University, Aachen, Germany
| | - Thomas Pietschmann
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, Feodor-Lynen-Straße 7, 30625, Hannover, Germany
| | - Gisa Gerold
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, Feodor-Lynen-Straße 7, 30625, Hannover, Germany.
- Department of Clinical Microbiology, Virology and Wallenberg Centre for Molecular Medicine (WCMM), Umeå University, Umeå, Sweden.
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Tsukamoto T, Sakai E, Nishimae F, Sakurai F, Mizuguchi H. Efficient generation of adenovirus vectors carrying the Clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR associated proteins (Cas)12a system by suppressing Cas12a expression in packaging cells. J Biotechnol 2019; 304:1-9. [PMID: 31404563 DOI: 10.1016/j.jbiotec.2019.08.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 08/01/2019] [Accepted: 08/05/2019] [Indexed: 12/26/2022]
Abstract
Clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR associated proteins (Cas) 9 system is a powerful tool for genome editing and still being aggressively improved. Cas12a, a recently discovered Cas9 ortholog, is expected to become complementary to Cas9 due to its unique characteristics. Previously we attempted to establish an adenovirus (Ad) vector-mediated delivery of CRISPR-Cas12a system since Ad vector is widely used for gene transfer in basic researches and medical applications. However, we found difficulties preparing of Ad vectors at an adequate titer. In this study, we have developed Ad vectors that conditionally express Cas12a either by a tetracycline-controlled promoter or a hepatocyte specific promoter to avoid putative inhibitory effects of Cas12a. These vectors successfully proliferated in packaging cells, HEK293 cells, and were recovered at high titers. We have also developed packaging cells that express shRNA for Cas12a to suppress expression of Cas12a. Using the cells, the Ad vector directing constitutive expression of Cas12a proliferated efficiently and was successfully recovered at a high titer. Overall, we improved recovery of Ad vectors carrying CRISPR-Cas12a system, thus provided them as a tool in genome editing researches.
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Affiliation(s)
- Tomohito Tsukamoto
- Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Eiko Sakai
- Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Fumitaka Nishimae
- Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Fuminori Sakurai
- Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Hiroyuki Mizuguchi
- Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan; Laboratory of Hepatocyte Regulation, National Institute of Biomedical Innovation, Health and Nutrition, 7-6-8 Saito, Asagi, Ibaraki, Osaka 567-0085, Japan; Global Center for Advanced Medical Engineering and Informatics, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
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5
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Han B, Shi XL, Zhang Y, Gu ZZ, Yuan XW, Ren HZ, Qiu Y, Ding YT. No transmission of porcine endogenous retrovirus in an acute liver failure model treated by a novel hybrid bioartificial liver containing porcine hepatocytes. Hepatobiliary Pancreat Dis Int 2015; 14:492-501. [PMID: 26459725 DOI: 10.1016/s1499-3872(15)60401-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND A novel hybrid bioartificial liver (HBAL) was constructed using an anionic resin adsorption column and a multi-layer flat-plate bioreactor containing porcine hepatocytes co-cultured with bone marrow mesenchymal stem cells (MSCs). This study aimed to evaluate the microbiological safety of the HBAL by detecting the transmission of porcine endogenous retroviruses (PERVs) into canines with acute liver failure (ALF) undergoing HBAL. METHODS Eight dogs with ALF received a 6-hour HBAL treatment on the first day after the modeling by D-galactosamine administration. The plasma in the HBAL and the whole blood in the dogs were collected for PERV detection at regular intervals until one year later when the dogs were sacrificed to retrieve the tissues of several organs for immunohistochemistry and Western blotting for the investigation of PERV capsid protein gag p30 in the tissue. Furthermore, HEK293 cells were incubated to determine the in vitro infectivity. RESULTS PERV RNA and reverse transcriptase activity were observed in the plasma of circuit 3, suggesting that PERV particles released in circuit 3. No positive PERV RNA and reverse transcriptase activity were detected in other plasma. No HEK293 cells were infected by the plasma in vitro. In addition, all PERV-related analyses in peripheral blood mononuclear cells and tissues were negative. CONCLUSION No transmission of PERVs into ALF canines suggested a reliable microbiological safety of HBAL based on porcine hepatocytes.
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Affiliation(s)
- Bing Han
- Department of Hepatobiliary Surgery, the Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, China.
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6
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Moor K, Ohtani K, Myrzakozha D, Zhanserkenova O, Andriana BB, Sato H. Noninvasive and label-free determination of virus infected cells by Raman spectroscopy. J Biomed Opt 2014; 19:067003. [PMID: 24898605 DOI: 10.1117/1.jbo.19.6.067003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 05/13/2014] [Indexed: 05/15/2023]
Abstract
The present study demonstrates that Raman spectroscopy is a powerful tool for the detection of virus-infected cells. Adenovirus infection of human embryonic kidney 293 cells was successfully detected at 12, 24, and 48 h after initiating the infection. The score plot of principal component analysis discriminated the spectra of the infected cells from those of the control cells. The viral infection was confirmed by the conventional immunostaining method performed 24 h after the infection. The newly developed method provides a fast and label-free means for the detection of virus-infected cells.
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Affiliation(s)
- Kamila Moor
- Kwansei Gakuin University, School of Science and Technology, Department of Bioscience, 2-1 Gakuen, Sanda, Hyogo 669-1337 Japan
| | - Kiyoshi Ohtani
- Kwansei Gakuin University, School of Science and Technology, Department of Bioscience, 2-1 Gakuen, Sanda, Hyogo 669-1337 Japan
| | - Diyas Myrzakozha
- Kazakh National Agrarian University, Kazakhstan-Japan Innovation Centre, 8, Abai Street, Almaty 050010, Kazakhstan
| | - Orik Zhanserkenova
- Kazakh National Agrarian University, Kazakhstan-Japan Innovation Centre, 8, Abai Street, Almaty 050010, Kazakhstan
| | - Bibin B Andriana
- Kwansei Gakuin University, School of Science and Technology, Department of Bioscience, 2-1 Gakuen, Sanda, Hyogo 669-1337 Japan
| | - Hidetoshi Sato
- Kwansei Gakuin University, School of Science and Technology, Department of Bioscience, 2-1 Gakuen, Sanda, Hyogo 669-1337 Japan
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Machnik G, Klimacka-Nawrot E, Sypniewski D, Matczyńska D, Gałka S, Bednarek I, Okopień B. Porcine endogenous retrovirus (PERV) infection of HEK-293 cell line alters expression of human endogenous retrovirus (HERV-W) sequences. Folia Biol (Praha) 2014; 60:35-46. [PMID: 24594055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The risk of infections of human recipients after xenotransplantations is now mainly represented by porcine endogenous retroviruses (PERVs) as these particles are part of the porcine genome. As in all vertebrates, human genome harbours its own numerous genetic sequences of retroviral origin; it is estimated that they comprise about 8 % of the human genome. Because some of them play an important role in human physiology, it is valuable to estimate whether the presence of PERVs in human cells influences homeostasis of the human endogenous retrovirus (HERV) expression pattern. The aim of the study was to evaluate whether the expression profile of HERV-W genes changes after infection of cells by porcine endogenous retroviruses. In the experimental settings, human embryonic kidney cell line (HEK-293) was infected by PERV particles and cultivated up to 22th passage after infection. HERV-W gag, pol and env, as well as env from locus 7q21.2 gene expression was monitored by means of realtime reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot techniques. We found that the expression level of HERV-W genes differs in PERV-infected HEK-293 cell cultures in comparison with that from non-infected cultures. Relative HERV-W gene expression also differed significantly between particular passages (P < 0.05). Moreover, we have noticed a high correlation between the HERV-W Env(7q21.2) mRNA and protein level (Spearman rank r = 0.65; P < 0.05) during the course of the experiment. As previously hypothesized, human genomic sequences of retroviral origin may be changed by the presence of porcine endogenous retroviruses.
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Affiliation(s)
- G Machnik
- Department of Pharmacology, Medical University of Silesia, Katowice, Poland
| | - E Klimacka-Nawrot
- Department of Basic Biomedical Sciences, Medical University of Silesia, Katowice, Poland
| | - D Sypniewski
- Department of Biotechnology and Genetic Engineering, Medical University of Silesia, Katowice, Poland
| | - D Matczyńska
- Department of Biotechnology and Genetic Engineering, Medical University of Silesia, Katowice, Poland
| | - S Gałka
- Department of Biotechnology and Genetic Engineering, Medical University of Silesia, Katowice, Poland
| | - I Bednarek
- Department of Biotechnology and Genetic Engineering, Medical University of Silesia, Katowice, Poland
| | - B Okopień
- Department of Pharmacology, Medical University of Silesia, Katowice, Poland
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Lucas TM, Janaka SK, Stephens EB, Johnson MC. Vpu downmodulates two distinct targets, tetherin and gibbon ape leukemia virus envelope, through shared features in the Vpu cytoplasmic tail. PLoS One 2012; 7:e51741. [PMID: 23284757 PMCID: PMC3526647 DOI: 10.1371/journal.pone.0051741] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Accepted: 11/09/2012] [Indexed: 11/21/2022] Open
Abstract
During human immunodeficiency virus-1 (HIV-1) assembly, the host proteins CD4 (the HIV-1 receptor) and tetherin (an interferon stimulated anti-viral protein) both reduce viral fitness. The HIV-1 accessory gene Vpu counteracts both of these proteins, but it is thought to do so through two distinct mechanisms. Modulation of CD4 likely occurs through proteasomal degradation from the endoplasmic reticulum. The exact mechanism of tetherin modulation is less clear, with possible roles for degradation and alteration of protein transport to the plasma membrane. Most investigations of Vpu function have used different assays for CD4 and tetherin. In addition, many of these investigations used exogenously expressed Vpu, which could result in variable expression levels. Thus, few studies have investigated these two Vpu functions in parallel assays, making direct comparisons difficult. Here, we present results from a rapid assay used to simultaneously investigate Vpu-targeting of both tetherin and a viral glycoprotein, gibbon ape leukemia virus envelope (GaLV Env). We previously reported that Vpu modulates GaLV Env and prevents its incorporation into HIV-1 particles through a recognition motif similar to that found in CD4. Using this assay, we performed a comprehensive mutagenic scan of Vpu in its native proviral context to identify features required for both types of activity. We observed considerable overlap in the Vpu sequences required to modulate tetherin and GaLV Env. We found that features in the cytoplasmic tail of Vpu, specifically within the cytoplasmic tail hinge region, were required for modulation of both tetherin and GaLV Env. Interestingly, these same regions features have been determined to be critical for CD4 downmodulation. We also observed a role for the transmembrane domain in the restriction of tetherin, as previously reported, but not of GaLV Env. We propose that Vpu may target both proteins in a mechanistically similar manner, albeit in different cellular locations.
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Affiliation(s)
- Tiffany M. Lucas
- Department of Molecular Microbiology and Immunology, Christopher S. Bond Life Science Center, University of Missouri-School of Medicine, Columbia, Missouri, United States of America
| | - Sanath K. Janaka
- Department of Molecular Microbiology and Immunology, Christopher S. Bond Life Science Center, University of Missouri-School of Medicine, Columbia, Missouri, United States of America
| | - Edward B. Stephens
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Marc C. Johnson
- Department of Molecular Microbiology and Immunology, Christopher S. Bond Life Science Center, University of Missouri-School of Medicine, Columbia, Missouri, United States of America
- * E-mail:
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9
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Berard AR, Cortens JP, Krokhin O, Wilkins JA, Severini A, Coombs KM. Quantification of the host response proteome after mammalian reovirus T1L infection. PLoS One 2012; 7:e51939. [PMID: 23240068 PMCID: PMC3519901 DOI: 10.1371/journal.pone.0051939] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Accepted: 11/13/2012] [Indexed: 12/24/2022] Open
Abstract
All viruses are dependent upon host cells for replication. Infection can induce profound changes within cells, including apoptosis, morphological changes, and activation of signaling pathways. Many of these alterations have been analyzed by gene arrays to measure the cellular "transcriptome." We used SILAC (stable isotope labeling by amino acids in cell culture), combined with high-throughput 2-D HPLC/mass spectrometry, to determine relative quantitative differences in host proteins at 6 and 24 hours after infecting HEK293 cells with reovirus serotype 1 Lang (T1L). 3,076 host proteins were detected at 6 hpi, of which 132 and 68 proteins were significantly up or down regulated, respectively. 2,992 cellular proteins, of which 104 and 49 were up or down regulated, respectively, were identified at 24 hpi. IPA and DAVID analyses indicated proteins involved in cell death, cell growth factors, oxygen transport, cell structure organization and inflammatory defense response to virus were up-regulated, whereas proteins involved in apoptosis, isomerase activity, and metabolism were down-regulated. These proteins and pathways may be suitable targets for intervention to either attenuate virus infection or enhance oncolytic potential.
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Affiliation(s)
- Alicia R. Berard
- Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
- Manitoba Center for Proteomics and Systems Biology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - John P. Cortens
- Manitoba Center for Proteomics and Systems Biology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Oleg Krokhin
- Manitoba Center for Proteomics and Systems Biology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - John A. Wilkins
- Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
- Manitoba Center for Proteomics and Systems Biology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Alberto Severini
- Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
- National Microbiology Laboratory, Winnipeg, Manitoba, Canada
| | - Kevin M. Coombs
- Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
- Manitoba Center for Proteomics and Systems Biology, University of Manitoba, Winnipeg, Manitoba, Canada
- Manitoba Institute of Child Health, University of Manitoba, Winnipeg, Manitoba, Canada
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10
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Jiang X, Kinch L, Brautigam CA, Chen X, Du F, Grishin N, Chen ZJ. Ubiquitin-induced oligomerization of the RNA sensors RIG-I and MDA5 activates antiviral innate immune response. Immunity 2012; 36:959-73. [PMID: 22705106 PMCID: PMC3412146 DOI: 10.1016/j.immuni.2012.03.022] [Citation(s) in RCA: 306] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 02/17/2012] [Accepted: 03/16/2012] [Indexed: 12/21/2022]
Abstract
RIG-I and MDA5 detect viral RNA in the cytoplasm and activate signaling cascades leading to the production of type-I interferons. RIG-I is activated through sequential binding of viral RNA and unanchored lysine-63 (K63) polyubiquitin chains, but how polyubiquitin activates RIG-I and whether MDA5 is activated through a similar mechanism remain unresolved. Here, we showed that the CARD domains of MDA5 bound to K63 polyubiquitin and that this binding was essential for MDA5 to activate the transcription factor IRF3. Mutations of conserved residues in MDA5 and RIG-I that disrupt their ubiquitin binding also abrogated their ability to activate IRF3. Polyubiquitin binding induced the formation of a large complex consisting of four RIG-I and four ubiquitin chains. This hetero-tetrameric complex was highly potent in activating the antiviral signaling cascades. These results suggest a unified mechanism of RIG-I and MDA5 activation and reveal a unique mechanism by which ubiquitin regulates cell signaling and immune response.
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Affiliation(s)
- Xiaomo Jiang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148
| | - Lisa Kinch
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148
| | - Chad A. Brautigam
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148
| | - Xiang Chen
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148
| | - Fenghe Du
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148
| | - Nick Grishin
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148
| | - Zhijian J. Chen
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148
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Kueck T, Neil SJD. A cytoplasmic tail determinant in HIV-1 Vpu mediates targeting of tetherin for endosomal degradation and counteracts interferon-induced restriction. PLoS Pathog 2012; 8:e1002609. [PMID: 22479182 PMCID: PMC3315493 DOI: 10.1371/journal.ppat.1002609] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Accepted: 02/11/2012] [Indexed: 01/12/2023] Open
Abstract
The HIV-1 accessory protein Vpu counteracts tetherin (BST-2/CD317) by preventing its incorporation into virions, reducing its surface expression, and ultimately promoting its degradation. Here we characterize a putative trafficking motif, EXXXLV, in the second alpha helix of the subtype-B Vpu cytoplasmic tail as being required for efficient tetherin antagonism. Mutation of this motif prevents ESCRT-dependent degradation of tetherin/Vpu complexes, tetherin cell surface downregulation, but not its physical interaction with Vpu. Importantly, this motif is required for efficient cell-free virion release from CD4+ T cells, particularly after their exposure to type-1 interferon, indicating that the ability to reduce surface tetherin levels and promote its degradation is important to counteract restriction under conditions that the virus likely encounters in vivo. Vpu EXXXLV mutants accumulate with tetherin at the cell surface and in endosomal compartments, but retain the ability to bind both β-TrCP2 and HRS, indicating that this motif is required for a post-binding trafficking event that commits tetherin for ESCRT-dependent degradation and prevents its transit to the plasma membrane and viral budding zones. We further found that while Vpu function is dependent on clathrin, and the entire second alpha helix of the Vpu tail can be functionally complemented by a clathrin adaptor binding peptide derived from HIV-1 Nef, none of the canonical clathrin adaptors nor retromer are required for this process. Finally we show that residual activity of Vpu EXXXLV mutants requires an intact endocytic motif in tetherin, suggesting that physical association of Vpu with tetherin during its recycling may be sufficient to compromise tetherin activity to some degree. Tetherin inhibits the release of several diverse enveloped viruses from infected cells and is counteracted by the HIV-1 accessory gene Vpu. Vpu prevents tetherin's incorporation into nascent viral particles, promotes its downregulation from the cell surface and targets tetherin for degradation. Here we identify a determinant that resembles an acidic-dileucine-based sorting sequence in the Vpu cytoplasmic tail that is required for efficient counteraction of tetherin activity, particularly in CD4+ T cells treated with type-1 interferon. Mutation of this motif prevents cell-surface downregulation and degradation of Vpu/tetherin complexes but does not affect their interaction. Rather, in its absence, Vpu accumulates in early endosomes and at the cell surface where it becomes incorporated into assembling virions with tetherin, indicating that this motif modulates sub-cellular trafficking of tetherin. Furthermore Vpu activity is clathrin-dependent and can be reconstituted by replacing a portion of the cytoplasmic tail encompassing this motif with one derived from HIV-1 Nef that is known to bind several clathrin adaptors. Finally, we demonstrate that residual function of the mutant Vpu requires a trafficking motif in tetherin, suggesting that physical interaction of tetherin with Vpu during its recycling to the cell-surface can interfere with its function to a variable extent.
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Affiliation(s)
| | - Stuart J. D. Neil
- Department of Infectious Disease, King's College London School of Medicine, Guy's Hospital, London, United Kingdom
- * E-mail:
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