1
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Alfadhli A, Romanaggi C, Barklis RL, Barklis E. Analysis of HIV-1 envelope cytoplasmic tail effects on viral replication. Virology 2023; 579:54-66. [PMID: 36603533 PMCID: PMC10003682 DOI: 10.1016/j.virol.2022.12.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/27/2022] [Accepted: 12/28/2022] [Indexed: 01/03/2023]
Abstract
Trimers of the HIV-1 envelope (Env) protein perform receptor binding and virus-cell fusion functions during the virus life cycle. The cytoplasmic tail (CT) of Env forms an unusual baseplate structure, and is palmitoylated, rich in arginines, carries trafficking motifs, binds cholesterol, and interacts with host proteins. To dissect CT activities, we examined a panel of Env variants, including CT truncations, mutations, and an extension. We found that whereas all variants could replicate in permissive cells, viruses with CT truncations or baseplate mutations were defective in restrictive cells. We also identified a determinant in HIV-1 amphotericin sensitivity, and characterized variants that escape amphotericin inhibition via viral protease-mediated CT cleavage. Results additionally showed that full-length, his tagged Env can oligomerize and be co-assembled with CT truncations that delete portions of the baseplate, host protein binding sites, and trafficking signals. Our observations illuminate novel aspects of HIV-1 CT structure, interactions, and functions.
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Affiliation(s)
- Ayna Alfadhli
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, OR, USA
| | - CeAnn Romanaggi
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, OR, USA
| | - Robin Lid Barklis
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, OR, USA
| | - Eric Barklis
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, OR, USA.
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2
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On the Sensitivity of the Virion Envelope to Lipid Peroxidation. Microbiol Spectr 2022; 10:e0300922. [PMID: 36125312 PMCID: PMC9603946 DOI: 10.1128/spectrum.03009-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Emerging viruses are a public health threat best managed with broad spectrum antivirals. Common viral structures, like capsids or virion envelopes, have been proposed as targets for broadly active antiviral drugs. For example, a number of lipoperoxidators have been proposed to preferentially affect viral infectivity by targeting metabolically inactive enveloped virions while sparing metabolically active cells. However, this presumed preferential virion sensitivity to lipoperoxidation remains untested. To test whether virions are indeed more sensitive to lipoperoxidation than are cells, we analyzed the effects of two classic generic lipoperoxidators: lipophilic 2,2'-azobis(2,4-dimethylvaleronitrile) (AMVN) and hydrophilic 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AAPH) on Vero and human foreskin fibroblasts (HFF) cell viability, HSV-1 plaquing efficiency, and virion and cell lipoperoxidation. Cells or virions were incubated with the lipoperoxidators at 37°C for 2 h or incubated in atmospheric O2, and dose responses (half maximal cytotoxic and effective concentration [CC50 and EC50]) were evaluated by three or four parameter regression. The HSV-1 virions were slightly more sensitive to lipoperoxidators than were the cells (selectivity index [SI], 3.3 to 7.4). The effects of the lipophilic AMVN on both cell and virion viability directly correlated with the extent of membrane lipoperoxidation as evaluated by two different probes, C11-Bodipy and liperfluo. Moreover, the hydrophilic AAPH-induced virion inactivation at lower concentrations than did lipoperoxidation. Known lipoperoxidators inhibit infectivity via lipoperoxidation-independent mechanisms. Antioxidants protected against a loss of viral infectivity by less than 5-fold. Carrier bovine serum albumin (BSA) protected against both peroxidators to a similar extent when present together with the lipoperoxidating agents, suggesting that BSA quenches them as expected. Virions incubated in atmospheric oxidative conditions suffered losses of infectivity that were similar to those of chemically peroxidated virions, and they were protected by water soluble vitamin C and BSA with no evident lipoperoxidation, indicating predominant peroxidative damage to nonlipid virion components. Thus, lipoperoxidation is not a mechanism by which to specifically inhibit the infectivity of enveloped viruses, and the effects of known lipoperoxidators on virion infectivity are not solely mediated by lipoperoxidation. IMPORTANCE Small molecules that induce lipoperoxidation have been proposed repeatedly as potential antiviral drugs based on a presumed unique sensitivity of virions to this type of damage. Several small molecules that inactivate virions without affecting cells have been proposed to act primarily by inducing lipoperoxidation. However, the preferential sensitivity of virions to lipoperoxidators had not been experimentally evaluated. Using two of the best characterized small molecule lipoperoxidators, which are widely considered to be the prototypical water soluble and liposoluble lipoperoxidators, we show that lipoperoxidators have no preference for virions over cells. Moreover, they also inactivate virions by mechanisms other than the induction of lipoperoxidation. Therefore, the general induction of lipoperoxidation is not a path by which to develop antivirals. Moreover, molecules with specific antiviral activity which are not cytotoxic and have no preference to localize to virions over cells are unlikely to act primarily by inducing lipoperoxidation.
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3
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Bellmann L, Klein R, Rarey M. Calculating and Optimizing Physicochemical Property Distributions of Large Combinatorial Fragment Spaces. J Chem Inf Model 2022; 62:2800-2810. [PMID: 35653228 DOI: 10.1021/acs.jcim.2c00334] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The distributions of physicochemical property values, like the octanol-water partition coefficient, are routinely calculated to describe and compare virtual chemical libraries. Traditionally, these distributions are derived by processing each member of a library individually and summarizing all values in a distribution. This process becomes impractical when operating on chemical spaces which surpass billions of compounds in size. In this work, we present a novel algorithmic method called SpaceProp for the property distribution calculation of large nonenumerable combinatorial fragment spaces. The novel method follows a combinatorial approach and is able to calculate physicochemical property distributions of prominent spaces like Enamine's REAL Space, WuXi's GalaXi Space, and OTAVA's CHEMriya Space for the first time. Furthermore, we present a first approach of optimizing property distributions directly in combinatorial fragment spaces.
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Affiliation(s)
- Louis Bellmann
- Universität Hamburg, ZBH - Center for Bioinformatics, Research Group for Computational Molecular Design, Bundesstraße 43, 20146 Hamburg, Germany
| | - Raphael Klein
- BioSolveIT GmbH, An der Ziegelei 79, 53757 Sankt Augustin, Germany
| | - Matthias Rarey
- Universität Hamburg, ZBH - Center for Bioinformatics, Research Group for Computational Molecular Design, Bundesstraße 43, 20146 Hamburg, Germany
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4
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Virucidal Activity of the Pyridobenzothiazolone Derivative HeE1-17Y against Enveloped RNA Viruses. Viruses 2022; 14:v14061157. [PMID: 35746629 PMCID: PMC9228864 DOI: 10.3390/v14061157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/19/2022] [Accepted: 05/24/2022] [Indexed: 02/01/2023] Open
Abstract
Pyridobenzothiazolone derivatives are a promising class of broad-spectrum antivirals. However, the mode of action of these compounds remains poorly understood. The HeE1-17Y derivative has already been shown to be a potent compound against a variety of flaviviruses of global relevance. In this work, the mode of action of HeE1-17Y has been studied for West Nile virus taking advantage of reporter replication particles (RRPs). Viral infectivity was drastically reduced by incubating the compound with the virus before infection, thus suggesting a direct interaction with the viral particles. Indeed, RRPs incubated with the inhibitor appeared to be severely compromised in electron microscopy analysis. HeE1-17Y is active against other enveloped viruses, including SARS-CoV-2, but not against two non-enveloped viruses, suggesting a virucidal mechanism that involves the alteration of the viral membrane.
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5
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Nieto-Garai JA, Contreras FX, Arboleya A, Lorizate M. Role of Protein-Lipid Interactions in Viral Entry. Adv Biol (Weinh) 2022; 6:e2101264. [PMID: 35119227 DOI: 10.1002/adbi.202101264] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/19/2021] [Indexed: 12/25/2022]
Abstract
The viral entry consists of several sequential events that ensure the attachment of the virus to the host cell and the introduction of its genetic material for the continuation of the replication cycle. Both cellular and viral lipids have gained a wider focus in recent years in the field of viral entry, as they are found to play key roles in different steps of the process. The specific role is summarized that lipids and lipid membrane nanostructures play in viral attachment, fusion, and immune evasion and how they can be targeted with antiviral therapies. Finally, some of the limitations of techniques commonly used for protein-lipid interactions studies are discussed, and new emerging tools are reviewed that can be applied to this field.
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Affiliation(s)
- Jon Ander Nieto-Garai
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country, Leioa, E-48940, Spain
| | - Francesc-Xabier Contreras
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country, Leioa, E-48940, Spain.,Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, Leioa, E-48940, Spain.,Ikerbasque, Basque Foundation for Science, Bilbao, 48013, Spain
| | - Aroa Arboleya
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country, Leioa, E-48940, Spain.,Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, Leioa, E-48940, Spain.,Fundación Biofísica Bizkaia/Biofisika Bizkaia Fundazioa (FBB), Barrio Sarriena s/n, Leioa, E-48940, Spain
| | - Maier Lorizate
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country, Leioa, E-48940, Spain.,Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, Leioa, E-48940, Spain
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6
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Sorice M, Misasi R, Riitano G, Manganelli V, Martellucci S, Longo A, Garofalo T, Mattei V. Targeting Lipid Rafts as a Strategy Against Coronavirus. Front Cell Dev Biol 2021; 8:618296. [PMID: 33614627 PMCID: PMC7890255 DOI: 10.3389/fcell.2020.618296] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/21/2020] [Indexed: 12/15/2022] Open
Abstract
Lipid rafts are functional membrane microdomains containing sphingolipids, including gangliosides, and cholesterol. These regions are characterized by highly ordered and tightly packed lipid molecules. Several studies revealed that lipid rafts are involved in life cycle of different viruses, including coronaviruses. Among these recently emerged the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The main receptor for SARS-CoV-2 is represented by the angiotensin-converting enzyme-2 (ACE-2), although it also binds to sialic acids linked to host cell surface gangliosides. A new type of ganglioside-binding domain within the N-terminal portion of the SARS-CoV-2 spike protein was identified. Lipid rafts provide a suitable platform able to concentrate ACE-2 receptor on host cell membranes where they may interact with the spike protein on viral envelope. This review is focused on selective targeting lipid rafts components as a strategy against coronavirus. Indeed, cholesterol-binding agents, including statins or methyl-β-cyclodextrin (MβCD), can affect cholesterol, causing disruption of lipid rafts, consequently impairing coronavirus adhesion and binding. Moreover, these compounds can block downstream key molecules in virus infectivity, reducing the levels of proinflammatory molecules [tumor necrosis factor alpha (TNF-α), interleukin (IL)-6], and/or affecting the autophagic process involved in both viral replication and clearance. Furthermore, cyclodextrins can assemble into complexes with various drugs to form host-guest inclusions and may be used as pharmaceutical excipients of antiviral compounds, such as lopinavir and remdesivir, by improving bioavailability and solubility. In conclusion, the role of lipid rafts-affecting drugs in the process of coronavirus entry into the host cells prompts to introduce a new potential task in the pharmacological approach against coronavirus.
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Affiliation(s)
- Maurizio Sorice
- Department of Experimental Medicine, “Sapienza” University, Rome, Italy
| | - Roberta Misasi
- Department of Experimental Medicine, “Sapienza” University, Rome, Italy
| | - Gloria Riitano
- Department of Experimental Medicine, “Sapienza” University, Rome, Italy
| | | | - Stefano Martellucci
- Biomedicine and Advanced Technologies Rieti Center, “Sabina Universitas”, Rieti, Italy
| | - Agostina Longo
- Department of Experimental Medicine, “Sapienza” University, Rome, Italy
| | - Tina Garofalo
- Department of Experimental Medicine, “Sapienza” University, Rome, Italy
| | - Vincenzo Mattei
- Biomedicine and Advanced Technologies Rieti Center, “Sabina Universitas”, Rieti, Italy
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7
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Nieto‐Garai JA, Arboleya A, Otaegi S, Chojnacki J, Casas J, Fabriàs G, Contreras F, Kräusslich H, Lorizate M. Cholesterol in the Viral Membrane is a Molecular Switch Governing HIV-1 Env Clustering. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2003468. [PMID: 33552873 PMCID: PMC7856888 DOI: 10.1002/advs.202003468] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/13/2020] [Indexed: 05/07/2023]
Abstract
HIV-1 entry requires the redistribution of envelope glycoproteins (Env) into a cluster and the presence of cholesterol (chol) in the viral membrane. However, the molecular mechanisms underlying the specific role of chol in infectivity and the driving force behind Env clustering remain unknown. Here, gp41 is demonstrated to directly interact with chol in the viral membrane via residues 751-854 in the cytoplasmic tail (CT751-854). Super-resolution stimulated emission depletion (STED) nanoscopy analysis of Env distribution further demonstrates that both truncation of gp41 CT751-854 and depletion of chol leads to dispersion of Env clusters in the viral membrane and inhibition of virus entry. This work reveals a direct interaction of gp41 CT with chol and indicates that this interaction is an important orchestrator of Env clustering.
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Affiliation(s)
- Jon Ander Nieto‐Garai
- Instituto Biofisika (UPV/EHU, CSIC)University of the Basque CountryLeioaE‐48940Spain
- Fundación Biofísica Bizkaia/Biofisika Bizkaia Fundazioa (FBB)Barrio Sarriena s/nLeioaE‐48940Spain
| | - Aroa Arboleya
- Instituto Biofisika (UPV/EHU, CSIC)University of the Basque CountryLeioaE‐48940Spain
- Fundación Biofísica Bizkaia/Biofisika Bizkaia Fundazioa (FBB)Barrio Sarriena s/nLeioaE‐48940Spain
| | - Sara Otaegi
- Instituto Biofisika (UPV/EHU, CSIC)University of the Basque CountryLeioaE‐48940Spain
- Department of Biochemistry and Molecular BiologyFaculty of Science and TechnologyUniversity of the Basque CountryLeioaE‐48940Spain
| | | | - Josefina Casas
- Research Unit on BioActive Molecules. Department of Biological ChemistryInstitute for Advanced Chemistry of Catalonia (IQAC‐CSIC)BarcelonaCatalonia08034Spain
- Liver and Digestive Diseases Networking Biomedical Research Center (CIBEREHD) ISCIIMadrid28029Spain
| | - Gemma Fabriàs
- Research Unit on BioActive Molecules. Department of Biological ChemistryInstitute for Advanced Chemistry of Catalonia (IQAC‐CSIC)BarcelonaCatalonia08034Spain
- Liver and Digestive Diseases Networking Biomedical Research Center (CIBEREHD) ISCIIMadrid28029Spain
| | - F‐Xabier Contreras
- Instituto Biofisika (UPV/EHU, CSIC)University of the Basque CountryLeioaE‐48940Spain
- Department of Biochemistry and Molecular BiologyFaculty of Science and TechnologyUniversity of the Basque CountryLeioaE‐48940Spain
- IkerbasqueBasque Foundation for ScienceBilbao48013Spain
| | - Hans‐Georg Kräusslich
- Department of Infectious DiseasesVirologyUniversitätsklinikum HeidelbergHeidelberg69120Germany
| | - Maier Lorizate
- Instituto Biofisika (UPV/EHU, CSIC)University of the Basque CountryLeioaE‐48940Spain
- Department of Biochemistry and Molecular BiologyFaculty of Science and TechnologyUniversity of the Basque CountryLeioaE‐48940Spain
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8
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Barklis E, Alfadhli A, Kyle JE, Bramer LM, Bloodsworth KJ, Barklis RL, Leier HC, Petty RM, Zelnik ID, Metz TO, Futerman AH, Tafesse FG. Ceramide synthase 2 deletion decreases the infectivity of HIV-1. J Biol Chem 2021; 296:100340. [PMID: 33515546 PMCID: PMC7949126 DOI: 10.1016/j.jbc.2021.100340] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 01/19/2021] [Accepted: 01/22/2021] [Indexed: 01/01/2023] Open
Abstract
The lipid composition of HIV-1 virions is enriched in sphingomyelin (SM), but the roles that SM or other sphingolipids (SLs) might play in the HIV-1 replication pathway have not been elucidated. In human cells, SL levels are regulated by ceramide synthase (CerS) enzymes that produce ceramides, which can be converted to SMs, hexosylceramides, and other SLs. In many cell types, CerS2, which catalyzes the synthesis of very long chain ceramides, is the major CerS. We have examined how CerS2 deficiency affects the assembly and infectivity of HIV-1. As expected, we observed that very long chain ceramide, hexosylceramide, and SM were reduced in CerS2 knockout cells. CerS2 deficiency did not affect HIV-1 assembly or the incorporation of the HIV-1 envelope (Env) protein into virus particles, but it reduced the infectivites of viruses produced in the CerS2-deficient cells. The reduced viral infection levels were dependent on HIV-1 Env, since HIV-1 particles that were pseudotyped with the vesicular stomatitis virus glycoprotein did not exhibit reductions in infectivity. Moreover, cell-cell fusion assays demonstrated that the functional defect of HIV-1 Env in CerS2-deficient cells was independent of other viral proteins. Overall, our results indicate that the altered lipid composition of CerS2-deficient cells specifically inhibit the HIV-1 Env receptor binding and/or fusion processes.
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Affiliation(s)
- Eric Barklis
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon, USA.
| | - Ayna Alfadhli
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon, USA
| | - Jennifer E Kyle
- Biological Sciences Division, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory (PNNL), Richland, Washington, USA
| | - Lisa M Bramer
- Computing and Analytics Division, National Security Directorate PNNL, Richland, Washington, USA
| | - Kent J Bloodsworth
- Biological Sciences Division, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory (PNNL), Richland, Washington, USA
| | - Robin Lid Barklis
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon, USA
| | - Hans C Leier
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon, USA
| | - R Max Petty
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon, USA
| | - Iris D Zelnik
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Thomas O Metz
- Biological Sciences Division, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory (PNNL), Richland, Washington, USA
| | - Anthony H Futerman
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Fikadu G Tafesse
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon, USA.
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9
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Abstract
Viruses manipulate cellular lipids and membranes at each stage of their life cycle. This includes lipid-receptor interactions, the fusion of viral envelopes with cellular membranes during endocytosis, the reorganization of cellular membranes to form replication compartments, and the envelopment and egress of virions. In addition to the physical interactions with cellular membranes, viruses have evolved to manipulate lipid signaling and metabolism to benefit their replication. This review summarizes the strategies that viruses use to manipulate lipids and membranes at each stage in the viral life cycle.
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Affiliation(s)
- Ellen Ketter
- Department of Microbiology, The University of Chicago, Chicago, Illinois 60637, USA;
| | - Glenn Randall
- Department of Microbiology, The University of Chicago, Chicago, Illinois 60637, USA;
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10
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Labyrinthopeptins Exert Broad-Spectrum Antiviral Activity through Lipid-Binding-Mediated Virolysis. J Virol 2020; 94:JVI.01471-19. [PMID: 31666384 DOI: 10.1128/jvi.01471-19] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 10/23/2019] [Indexed: 12/31/2022] Open
Abstract
To counteract the serious health threat posed by known and novel viral pathogens, drugs that target a variety of viruses through a common mechanism have attracted recent attention due to their potential in treating (re)emerging infections, for which direct-acting antivirals are not available. We found that labyrinthopeptins A1 and A2, the prototype congeners of carbacyclic lanthipeptides, inhibit the proliferation of diverse enveloped viruses, including dengue virus, Zika virus, West Nile virus, hepatitis C virus, chikungunya virus, Kaposi's sarcoma-associated herpesvirus, cytomegalovirus, and herpes simplex virus, in the low micromolar to nanomolar range. Mechanistic studies on viral particles revealed that labyrinthopeptins induce a virolytic effect through binding to the viral membrane lipid phosphatidylethanolamine (PE). These effects are enhanced by a combined equimolar application of both labyrinthopeptins, and a clear synergism was observed across a concentration range corresponding to 10% to 90% inhibitory concentrations of the compounds. Time-resolved experiments with large unilamellar vesicles (LUVs) reveal that membrane lipid raft compositions (phosphatidylcholine [PC]/PE/cholesterol/sphingomyelin at 17:10:33:40) are particularly sensitive to labyrinthopeptins in comparison to PC/PE (90:10) LUVs, even though the overall PE amount remains constant. Labyrinthopeptins exhibited low cytotoxicity and had favorable pharmacokinetic properties in mice (half-life [t 1/2] = 10.0 h), which designates them promising antiviral compounds acting by an unusual viral lipid targeting mechanism.IMPORTANCE For many viral infections, current treatment options are insufficient. Because the development of each antiviral drug is time-consuming and expensive, the prospect of finding broad-spectrum antivirals that can fight multiple, diverse viruses-well-known viruses as well as (re)emerging species-has gained attention, especially for the treatment of viral coinfections. While most known broad-spectrum agents address processes in the host cell, we found that targeting lipids of the free virus outside the host cell with the natural products labyrinthopeptin A1 and A2 is a viable strategy to inhibit the proliferation of a broad range of viruses from different families, including chikungunya virus, dengue virus, Zika virus, Kaposi's sarcoma-associated herpesvirus, and cytomegalovirus. Labyrinthopeptins bind to viral phosphatidylethanolamine and induce virolysis without exerting cytotoxicity on host cells. This represents a novel and unusual mechanism to tackle medically relevant viral infections.
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11
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O'Donnell VB, Thomas D, Stanton R, Maillard JY, Murphy RC, Jones SA, Humphreys I, Wakelam MJO, Fegan C, Wise MP, Bosch A, Sattar SA. Potential Role of Oral Rinses Targeting the Viral Lipid Envelope in SARS-CoV-2 Infection. FUNCTION 2020; 1:zqaa002. [PMID: 33215159 PMCID: PMC7239187 DOI: 10.1093/function/zqaa002] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 05/04/2020] [Accepted: 05/08/2020] [Indexed: 01/06/2023] Open
Abstract
Emerging studies increasingly demonstrate the importance of the throat and salivary glands as sites of virus replication and transmission in early COVID-19 disease. SARS-CoV-2 is an enveloped virus, characterized by an outer lipid membrane derived from the host cell from which it buds. While it is highly sensitive to agents that disrupt lipid biomembranes, there has been no discussion about the potential role of oral rinsing in preventing transmission. Here, we review known mechanisms of viral lipid membrane disruption by widely available dental mouthwash components that include ethanol, chlorhexidine, cetylpyridinium chloride, hydrogen peroxide, and povidone-iodine. We also assess existing formulations for their potential ability to disrupt the SARS-CoV-2 lipid envelope, based on their concentrations of these agents, and conclude that several deserve clinical evaluation. We highlight that already published research on other enveloped viruses, including coronaviruses, directly supports the idea that oral rinsing should be considered as a potential way to reduce transmission of SARS-CoV-2. Research to test this could include evaluating existing or specifically tailored new formulations in well-designed viral inactivation assays, then in clinical trials. Population-based interventions could be undertaken with available mouthwashes, with active monitoring of outcome to determine efficacy. This is an under-researched area of major clinical need.
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Affiliation(s)
| | - David Thomas
- Systems Immunity Research Institute.,School of Dentistry
| | | | - Jean-Yves Maillard
- Systems Immunity Research Institute.,School of Pharmacy and Pharmaceutical Sciences, Cardiff University, CF14 4XN, UK
| | - Robert C Murphy
- Department of Pharmacology, University of Colorado Denver, Aurora, CO 80045, USA
| | - Simon A Jones
- Systems Immunity Research Institute.,School of Medicine
| | - Ian Humphreys
- Systems Immunity Research Institute.,School of Medicine
| | | | | | - Matt P Wise
- University Hospital of Wales, Cardiff, CF14 4XW, UK
| | - Albert Bosch
- Enteric Virus Laboratory, University of Barcelona, 08028 Barcelona, Spain
| | - Syed A Sattar
- Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5 Canada
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12
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Quantification of phosphoinositides reveals strong enrichment of PIP 2 in HIV-1 compared to producer cell membranes. Sci Rep 2019; 9:17661. [PMID: 31776383 PMCID: PMC6881329 DOI: 10.1038/s41598-019-53939-z] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Accepted: 10/09/2019] [Indexed: 02/06/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) acquires its lipid envelope during budding from the plasma membrane of the host cell. Various studies indicated that HIV-1 membranes differ from producer cell plasma membranes, suggesting budding from specialized membrane microdomains. The phosphoinositide PI(4,5)P2 has been of particular interest since PI(4,5)P2 is needed to recruit the viral structural polyprotein Gag to the plasma membrane and thus facilitates viral morphogenesis. While there is evidence for an enrichment of PIP2 in HIV-1, fully quantitative analysis of all phosphoinositides remains technically challenging and therefore has not been reported, yet. Here, we present a comprehensive analysis of the lipid content of HIV-1 and of plasma membranes from infected and non-infected producer cells, resulting in a total of 478 quantified lipid compounds, including molecular species distribution of 25 different lipid classes. Quantitative analyses of phosphoinositides revealed strong enrichment of PIP2, but also of PIP3, in the viral compared to the producer cell plasma membrane. We calculated an average of ca. 8,000 PIP2 molecules per HIV-1 particle, three times more than Gag. We speculate that the high density of PIP2 at the HIV-1 assembly site is mediated by transient interactions with viral Gag polyproteins, facilitating PIP2 concentration in this microdomain. These results are consistent with our previous observation that PIP2 is not only required for recruiting, but also for stably maintaining Gag at the plasma membrane. We believe that this quantitative analysis of the molecular anatomy of the HIV-1 lipid envelope may serve as standard reference for future investigations.
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13
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Salimi H, Johnson J, Flores MG, Zhang MS, O'Malley Y, Houtman JC, Schlievert PM, Haim H. The lipid membrane of HIV-1 stabilizes the viral envelope glycoproteins and modulates their sensitivity to antibody neutralization. J Biol Chem 2019; 295:348-362. [PMID: 31757809 DOI: 10.1074/jbc.ra119.009481] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 11/19/2019] [Indexed: 11/06/2022] Open
Abstract
The envelope glycoproteins (Envs) of HIV-1 are embedded in the cholesterol-rich lipid membrane of the virus. Chemical depletion of cholesterol from HIV-1 particles inactivates their infectivity. We observed that diverse HIV-1 strains exhibit a range of sensitivities to such treatment. Differences in sensitivity to cholesterol depletion could not be explained by variation in Env components known to interact with cholesterol, including the cholesterol-recognition motif and cytoplasmic tail of gp41. Using antibody-binding assays, measurements of virus infectivity, and analyses of lipid membrane order, we found that depletion of cholesterol from HIV-1 particles decreases the conformational stability of Env. It enhances exposure of partially cryptic epitopes on the trimer and increases sensitivity to structure-perturbing treatments such as antibodies and cold denaturation. Substitutions in the cholesterol-interacting motif of gp41 induced similar effects as depletion of cholesterol. Surface-acting agents, which are incorporated into the virus lipid membrane, caused similar effects as disruption of the Env-cholesterol interaction. Furthermore, substitutions in gp120 that increased structural stability of Env (i.e. induced a "closed" conformation of the trimer) increased virus resistance to cholesterol depletion and to the surface-acting agents. Collectively, these results indicate a critical contribution of the viral membrane to the stability of the Env trimer and to neutralization resistance against antibodies. Our findings suggest that the potency of poorly neutralizing antibodies, which are commonly elicited in vaccinated individuals, may be markedly enhanced by altering the lipid composition of the viral membrane.
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Affiliation(s)
- Hamid Salimi
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Jacklyn Johnson
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Manuel G Flores
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Michael S Zhang
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Yunxia O'Malley
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Jon C Houtman
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Patrick M Schlievert
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Hillel Haim
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242.
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14
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Design and Characterization of Cholesterylated Peptide HIV-1/2 Fusion Inhibitors with Extremely Potent and Long-Lasting Antiviral Activity. J Virol 2019; 93:JVI.02312-18. [PMID: 30867304 DOI: 10.1128/jvi.02312-18] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Accepted: 03/06/2019] [Indexed: 12/11/2022] Open
Abstract
HIV infection requires lifelong treatment with multiple antiretroviral drugs in a combination, which ultimately causes cumulative toxicities and drug resistance, thus necessitating the development of novel antiviral agents. We recently found that enfuvirtide (T-20)-based lipopeptides conjugated with fatty acids have dramatically increased in vitro and in vivo anti-HIV activities. Herein, a group of cholesterol-modified fusion inhibitors were characterized with significant findings. First, novel cholesterylated inhibitors, such as LP-83 and LP-86, showed the most potent activity in inhibiting divergent human immunodeficiency virus type 1 (HIV-1), HIV-2, and simian immunodeficiency virus (SIV). Second, the cholesterylated inhibitors were highly active to inhibit T-20-resistant mutants that still conferred high resistance to the fatty acid derivatives. Third, the cholesterylated inhibitors had extremely potent activity to block HIV envelope (Env)-mediated cell-cell fusion, especially a truncated minimum lipopeptide (LP-95), showing a greatly increased potency relative to its inhibition on virus infection. Fourth, the cholesterylated inhibitors efficiently bound to both the cellular and viral membranes to exert their antiviral activities. Fifth, the cholesterylated inhibitors displayed low cytotoxicity and binding capacity with human serum albumin. Sixth, we further demonstrated that LP-83 exhibited extremely potent and long-lasting anti-HIV activity in rhesus monkeys. Taken together, the present results help our understanding on the mechanism of action of lipopeptide-based viral fusion inhibitors and facilitate the development of novel anti-HIV drugs.IMPORTANCE The peptide drug enfuvirtide (T-20) remains the only membrane fusion inhibitor available for treatment of viral infection, which is used in combination therapy of HIV-1 infection; however, it exhibits relatively low antiviral activity and a genetic barrier to inducing resistance, calling for the continuous development for novel anti-HIV agents. In this study, we report cholesterylated fusion inhibitors showing the most potent and broad anti-HIV activities to date. The new inhibitors have been comprehensively characterized for their modes of action and druggability, including small size, low cytotoxicity, binding ability to human serum albumin (HSA), and, especially, extremely potent and long-lasting antiviral activity in rhesus monkeys. Therefore, the present studies have provided new drug candidates for clinical development, which can also be used as tools to probe the mechanisms of viral entry and inhibition.
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