TY - JOUR
AU1 - Olivier, Reynard,
AU2 - Evelyne, Schaeffer,
AU3 - A, Volchkova, Valentina
AU4 - Andrea, Cimarelli,
AU5 - G, Mueller, Christopher
AU6 - E, Volchkov, Viktor
AB - Abstract The West African outbreak of Ebola virus (EBOV) infection during 2013–2016 highlighted the need for development of field-applicable therapeutic drugs for this infection. Here we report that mannoside glycolipid conjugates (MGCs) consisting of a trimannose head and a lipophilic chain assembled by a linker inhibit EBOV infection not only of human monocyte–derived dendritic cells and macrophages, but also of a number of susceptible cells. Analysis of the mode of action leads us to conclude that MGCs act directly on cells, notably by preventing virus endocytosis. Ebola virus, filovirus, mannoside glycolipid conjugates, macropinocytosis Ebola virus (EBOV) belongs to the Filoviridae family, a group of enveloped, negative-stranded RNA viruses causing a severe form of hemorrhagic fever in human and nonhuman primates [1]. The recent West African outbreak of EBOV has led to infection of >28000 people, approximately 11000 deaths, and a breakdown of the economy in affected countries. Currently, there are no approved vaccines or antiviral treatments available for human use, although several promising vaccine candidates are in clinical trials [2, 3]. Nucleoside analogues targeting the viral RNA polymerase have been shown to inhibit EBOV replication [4–6]. Some of them have been used during the outbreak in Western Africa, but their efficacy is difficult to fully appreciate because of the complexity of the outbreak management [7]. Efficient and preferably field-applicable prophylactic and therapeutic tools against EBOV are urgent public health demands. We have previously reported a new class of compounds possessing an antiviral activity based on mannoside glycolipid conjugates (MGCs) [8, 9]. These molecules were shown to bind DC-SIGN and other cellular C-type lectins, preventing human immunodeficiency virus (HIV) attachment to the cell surface and, notably, HIV trans-infection of T cells [8, 9]. Surface glycoprotein (GP) of EBOV and HIV possess certain structural and functional similarities; both are highly glycosylated, both are intracellularly processed into 2 subunits by furin cleavage [10, 11], and both bind to DC-SIGN and other cellular C-type lectins [12]. In this study, we demonstrate that MGCs efficiently block EBOV infection in a sustainable manner. MGCs neither prevent binding of the virus to the cells nor directly act on EBOV virions but instead prevent internalization of the EBOV virions, inhibiting infection of a variety of cells, including the virus major target cells, such as macrophages and dendritic cells. The data encourage us to classify these novel drugs as highly promising and to recommend their further investigation using animal models. MATERIALS AND METHODS Viruses, Cells, and Reagents Recombinant Zaire ebolavirus, strain Mayinga, expressing green fluorescent protein (EBOV-GFP) was generated as described earlier [13, 14] and used for infection of Vero E6 cells cultured at 37°C in Dulbecco’s modified Eagle’s medium (DMEM; Invitrogen) supplemented with 10% fetal calf serum (FCS). Experiments using live EBOV were performed in the Jean Merieux biosafety level 4 INSERM laboratory (Lyon, France). Generation of vesicular stomatitis virus (VSV) replicon pseudotypes have been described previously [15]. Human monocytes were purified from the blood of healthy donors by successive Ficoll and Percoll gradients. Cells were further purified and differentiated as previously described [16]. The synthesis and properties of MGCs were described elsewhere [17, 18]. Antiviral Activity Assays EBOV-GFP was used to inoculate Vero E6 cells at a multiplicity of infection (MOI) of 0.1 in the presence or absence of MGCs. After incubation for 1 hour at 37°C, virus was removed, and cells were washed twice with 1 mL of DMEM before the addition of DMEM plus 3% FCS. After 48 hours, cells were trypsinized, fixed for 20 minutes with 3% phosphate-buffered saline (PBS)–buffered formaldehyde, prior to flow cytometry on a Beckman Coulter Gallios flow cytometer (Beckman, Brea, CA). VSV–red fluorescent protein (RFP) replicons expressing filoviral surface GPs were incubated with MGCs for 30 minutes at 37°C and then were used to inoculate Vero E6 cells (MOI, 0.5). The percentage of RFP-positive cells was measured by flow cytometry on a BD LSRII instrument 8 hours after infection. Internalization Assay Vero E6 cells (3.106 cells/plate) in 48-well plates were pretreated or not with MGC 2 (10 µM), infected for 1 hour with VSV-RFP-EBOV GP, and either incubated at 37°C or kept on ice. Then cells were washed with DMEM without FCS and then treated with trypsin (0.25%; Thermo) for 30 minutes at 37°C to detach noninternalized viral particles. Cells were removed by centrifugation at 16 000 ×g for 1 minute. Viral RNA genomes (VSV or EBOV) present in the supernatant were extracted and the amounts were quantified by quantitative reverse transcription–polymerase chain reaction (qRT-PCR) analysis, using the EurobioGreen OneStep Lo-ROX qRT-PCR kit (Eurobio) in a Roche LC96 real-time PCR apparatus. For EBOV, the following primers were used: 5ʹ-CGGAGGCTTTAACCCAAATA and 5ʹ-TCATACATGGGAGTGTGGCT. For VSV-EBOV GP, the following primers were used: 5ʹ-AATTCCTGAATCCCGATGAG and 5ʹ-GGGAATCGGAAGAGAATTGA. Fluid-Phase Uptake Assay For the fluid-phase uptake assay, Vero E6 cells were incubated for 45 minutes with MGC 2 and/or PMA (200nM) and then 40 kDa of FITC-dextran (1 mg/mL) was added for the last 20 minutes at 37°C. Cells were then washed with ice-cold PBS, and surface-bound FITC-dextran was quenched by low-pH buffer (0.1 M sodium acetate and 0.05 M NaCl, pH 5.5) before flow cytometry (LSRII; Becton Dickinson). Statistical Analysis Statistical analysis was performed using a paired Mann-Whitney test. Data were considered significantly different when the P value was <.05. RESULTS AND DISCUSSION MGCs are composed of 3 building blocks: a trimannose head and a hydrophilic linker without (MGC 1) or with a lipid chain that is either saturated (MGC 2) or unsaturated (MGC 2U; Supplementary Figure 1) [8]. MGCs are water-soluble molecules, show little cell and animal toxicity [18, 19], and are stable during storage at room temperature, which can be easily transported and used in remote areas where EBOV frequently causes sporadic outbreaks. Previous studies have shown that MGCs interact with cell-surface lectin receptors that bind highly glycosylated molecules [9]. Recently, we have demonstrated that MGCs are capable of inhibiting infection of different cell types by dengue virus and thus are novel antiviral compounds with a potential broad antiviral activity [19]. MGCs Inhibit EBOV Infection To evaluate the effect of MGC on EBOV infection of Vero E6 cells, 3 different MGC compounds at concentrations 1, 10, and 100 µM were used. To facilitate the detection of virus replication, recombinant EBOV-GFP was used [14]. The percentage of GFP-positive cells observed either without the treatment or with MGC was assayed using flow cytometry (Figure 1A). Among the 3 MGCs, MGC 2 displayed the best antiviral activity; it significantly reduced EBOV infection at 100 µM and also reduced the percentage of infected cells by about 50% at a 10-µM concentration. Of note, the MGCs and the mock-treated cells revealed similar GFP mean fluorescence indexes (MFIs; Figure 1B). Since GFP is expressed under the control of virus-specific transcription signals, the data obtained suggest that MGC 2 treatment affects neither viral transcription nor RNA replication but exerts inhibitory action at early steps of viral invasion, most likely during virus entry. Figure 1. View largeDownload slide Mannoside glycolipid conjugates (MGCs) inhibit Ebola virus (EBOV) infection. Vero E6 cells were treated with MGCs for 30 minutes and infected with EBOV expressing green fluorescent protein (EBOV-GFP) in the presence of the drug (multiplicity of infection [MOI] = 0.1) and further cultured in medium containing MGCs. A, Infection was assessed by fluorescence-activated cell-sorting to detect GFP expression after 48 hours relative to that obtained in the mock-treated condition. *P < .05, by the Mann–Whitney U test, for comparison to the untreated condition. B, Mean fluorescence intensities (MFIs) of GFP expressed in infected cells exposed to EBOV-GFP in the absence or presence of MGCs, using cells assayed in Figure 1A. Horizontal bars represent means, and errors bars are standard deviations. C, Dose-response analysis of MGC 2, assessed as in panel A. Horizontal bars represent means, and errors bars are standard deviations. D, Long-term inhibitory effect of MGC 2 on infections due to EBOV-GFP or Nipah virus expressing GFP (NiV-GFP). Cells were left untreated (mock) or pretreated for 30 minutes with MGC 2 before exposure to the indicated viruses (MOI, 0.01). Cells were further cultured in medium containing MGC 2. Productive infection after 2, 3, and 6 days was visualized by fluorescence microscopy of GFP expression. Figure 1. View largeDownload slide Mannoside glycolipid conjugates (MGCs) inhibit Ebola virus (EBOV) infection. Vero E6 cells were treated with MGCs for 30 minutes and infected with EBOV expressing green fluorescent protein (EBOV-GFP) in the presence of the drug (multiplicity of infection [MOI] = 0.1) and further cultured in medium containing MGCs. A, Infection was assessed by fluorescence-activated cell-sorting to detect GFP expression after 48 hours relative to that obtained in the mock-treated condition. *P < .05, by the Mann–Whitney U test, for comparison to the untreated condition. B, Mean fluorescence intensities (MFIs) of GFP expressed in infected cells exposed to EBOV-GFP in the absence or presence of MGCs, using cells assayed in Figure 1A. Horizontal bars represent means, and errors bars are standard deviations. C, Dose-response analysis of MGC 2, assessed as in panel A. Horizontal bars represent means, and errors bars are standard deviations. D, Long-term inhibitory effect of MGC 2 on infections due to EBOV-GFP or Nipah virus expressing GFP (NiV-GFP). Cells were left untreated (mock) or pretreated for 30 minutes with MGC 2 before exposure to the indicated viruses (MOI, 0.01). Cells were further cultured in medium containing MGC 2. Productive infection after 2, 3, and 6 days was visualized by fluorescence microscopy of GFP expression. To determine the half maximal inhibitory concentration (IC50; ie, the concentration of MGC 2 that inhibits 50% of EBOV infection), dose-response experiments were performed (Figure 1C). The data showed that the mean IC50 (±SD) for MGC 2 is about 6 ± 0.6 µM. Of note, the compound completely prevents infection at concentrations >10 µM. Next we evaluated the duration of the MGC-induced inhibitory effect. Vero E6 cells were pretreated for 30 minutes with MGC 2 and then infected with EBOV-GFP at a MOI of 0.1. Virus replication and spread were visualized by GFP expression, using fluorescence microscopy (Figure 1D). The results demonstrate that, at a concentration of 50–100 µM, the compound effectively prevented virus replication and spread for at least 6 days after infection. At a 10-µM concentration, MGC 2 prevented virus replication for 3 days, as the same cells showed GFP expression 6 days after infection. For comparison, the effect of MGC 2 was also evaluated for Nipah virus, an enveloped virus belonging to the order of the Mononegavirales and highly pathogenic to humans (Figure 1D) [20]. Treatment of cells with MGC 2 did not reveal any significant inhibitory effect even at 100 µM concentration. The lack of inhibitory activity in the case of Nipah virus, as well as for canine distemper virus, another paramyxovirus, which displays an entry mechanism similar to that of Nipah virus (data not shown), may best be explained by the fact that both viruses enter the cells via direct cell-surface membrane fusion and do not require internalization [21]. To better understand the mode of MGC action on EBOV infection, we used an infectious clone system based on VSV. In this system, the gene encoding the surface GP G of VSV has been replaced by a transcription cassette carrying the sequence of the RFP under the control of VSV transcription signals [15]. Transient expression of EBOV GP in cells infected with such VSV replicons allowed pseudotyping of VSV particles that will then bear surface GP of EBOV. Infection of cells with VSV-RFP-EBOV GP allows for a single-cycle infection that can be used for tracking RFP expression following viral entry. The results presented in Figure 2A demonstrate that infection with VSV-RFP-EBOV GP can be inhibited by MGC 2 in a manner similar to that for EBOV infection. Figure 2. View largeDownload slide Mannoside glycolipid conjugate (MGC) range of action. MGCs inhibit infection of Vero cells (A and B), human monocyte-derived macrophages (C), and dendritic cells (D) by vesicular stomatitis virus expressing red fluorescent protein and glycoprotein (VSV-RFP/GP) pseudovirions. Cells were treated with MGCs at the indicated concentrations in micromoles per liter or left untreated (mock) and then immediately exposed to VSV-RFP (MOI, 0.5) bearing the Ebola virus envelope (A, C, D) or the indicated envelope GPs (MGC 2 was used at a concentration of 100 µM; B). Cells were analyzed 8 hours after infection for RFP expression. Infection is shown relative to that obtained in the absence of MGC. Results correspond to 2 different blood donors. Horizontal bars represent means, and errors bars are standard deviations. *P < .05, by the Mann–Whitney U test, for comparison to the untreated condition. Figure 2. View largeDownload slide Mannoside glycolipid conjugate (MGC) range of action. MGCs inhibit infection of Vero cells (A and B), human monocyte-derived macrophages (C), and dendritic cells (D) by vesicular stomatitis virus expressing red fluorescent protein and glycoprotein (VSV-RFP/GP) pseudovirions. Cells were treated with MGCs at the indicated concentrations in micromoles per liter or left untreated (mock) and then immediately exposed to VSV-RFP (MOI, 0.5) bearing the Ebola virus envelope (A, C, D) or the indicated envelope GPs (MGC 2 was used at a concentration of 100 µM; B). Cells were analyzed 8 hours after infection for RFP expression. Infection is shown relative to that obtained in the absence of MGC. Results correspond to 2 different blood donors. Horizontal bars represent means, and errors bars are standard deviations. *P < .05, by the Mann–Whitney U test, for comparison to the untreated condition. EBOV is believed to enter cells primarily through macropinocytosis, although other routes of uptake have also been reported [22]. While the mechanism triggering EBOV uptake remains unclear, VSV pseudovirions bearing the surface GP of EBOV are most likely internalized in a similar manner, owing to the particular properties of this viral protein. On one hand, EBOV entry is determined by low-affinity internalization mechanisms associated with interaction between GP and cell-surface-attachment partners such C-type lectins, including LSECTin, DC-SIGN, L-SIGN, mannose-binding lectin, and hMGL [23, 24]. On the other hand, EBOV entry is thought to rely on interaction between viral envelope phosphatidylserine (PtdSer) molecules and cellular PtdSer receptors. Noteworthy is that the expression of EBOV GP has recently been shown to induce PtdSer relocalization and exposure on the surface of the viral particles [25]. To evaluate the efficacy of MGCs on a broad spectrum of known filoviruses, we also generated a set of VSV replicon–based pseudotypes bearing GPs of other members of the Filoviridae family, including 5 representatives of Ebolavirus genus and 1 each from the Marburgvirus and Cuevavirus genera [15]. The results presented in Figure 2B demonstrate that all tested VSV pseudotypes were effectively inhibited upon MGC 2 treatment. Using the VSV-RFP-EBOV GP replicon, we also studied whether MGCs can inhibit infection of human monocyte–derived dendritic cells and macrophages, which are considered to be major target cells during EBOV infection [2, 26, 27]. The data obtained indicated that, of the 2 tested inhibitors, MGC 2 was more efficient and blocks the infection in a dose-dependent manner (Figure 2C and 2D). MGC 1 showed lower activity but was still able to block the infection at a concentration of 100 µM, similar to the inhibition of EBOV infection of Vero E6 cells. MGC 2 Prevents Virus Internalization Overall, the data presented suggest that MGC 2 affects early steps of interaction between virus and cells. To better understand the mode of action, we performed time-of-addition assays (Figure 3A). Three different treatment conditions were used. Vero E6 cells were (1) left untreated (No), (2) pretreated with the compound (Pre; 30 minutes before infection), (3) treated with MGC 2 during infection (Simult), or (4) treated only after infection (Post). In all cases, the cells were washed free of the compounds and/or virus after the incubations (Figure 3A). The cells were cultured for 8 hours after infection, before virus-infected cells were quantified by measuring RFP expression using flow cytometry (Figure 3A). The results showed that the cells were resistant to infection when pretreated with MGC 2 and when infected in the presence of the compound. However, treatment of cells after virus inoculation showed only a limited inhibitory effect. These observations corroborate with our hypothesis that MGC blocks early virus replication steps. Figure 3. View largeDownload slide Mannoside glycolipid conjugate (MGC) mechanism of action. A–C, Time-of-addition assays. A, Vero E6 cells were exposed to MGC 2 (100 µM) and vesicular stomatitis virus expressing red fluorescent protein and Ebola virus glycoprotein (VSV-RFP-EBOV GP), according to the scheme on the left panel. No, no treatment; Post, MGC 2 added 1 h after infection; Pre, pretreatment with MGC 2; Simult, simultaneous addition of MGC 2 and virus. Values were normalized to the mean of the No condition. B, Vero E6 cells were preincubated with 100 µM MGC 2 for 1, 2, or 3 hours before being washed and infected during 1 hour. C, Vero E6 cells were incubated for 30 minutes with 100 µM MGC 2 and then immediately infected or incubated 1, 2, or 3 hours in culture medium before infection. For panels A–C, infection was monitored after 8 hours by flow cytometry. D, In one adhesion assay, cells were incubated with virus, with or without MGC 2 at 100 µM, on ice (left). After trypsin detachment, cell-surface-bound virion genome was quantified by quantitative reverse transcription–polymerase chain reaction (qRT-PCR) analysis. In another adhesion assay, cells were incubated for 1 hour at 37°C with virus, with or without MGC 2 at 100 µM (right). After trypsin detachment, cell-surface-bound virion genome was quantified by qRT-PCR. For panels A–C, horizontal bars represent means, and error bars represent standard deviations. E, In a fluid-phase uptake assay, cells were stimulated with 200 nM PMA and/or treated with 100 µM MGC 2 for 45 minutes, incubated with FITC-dextran for 20 minutes, and underwent fluorescence analysis by flow cytometry. *P < .05, by the Mann–Whitney U test, for comparison to the untreated condition. Figure 3. View largeDownload slide Mannoside glycolipid conjugate (MGC) mechanism of action. A–C, Time-of-addition assays. A, Vero E6 cells were exposed to MGC 2 (100 µM) and vesicular stomatitis virus expressing red fluorescent protein and Ebola virus glycoprotein (VSV-RFP-EBOV GP), according to the scheme on the left panel. No, no treatment; Post, MGC 2 added 1 h after infection; Pre, pretreatment with MGC 2; Simult, simultaneous addition of MGC 2 and virus. Values were normalized to the mean of the No condition. B, Vero E6 cells were preincubated with 100 µM MGC 2 for 1, 2, or 3 hours before being washed and infected during 1 hour. C, Vero E6 cells were incubated for 30 minutes with 100 µM MGC 2 and then immediately infected or incubated 1, 2, or 3 hours in culture medium before infection. For panels A–C, infection was monitored after 8 hours by flow cytometry. D, In one adhesion assay, cells were incubated with virus, with or without MGC 2 at 100 µM, on ice (left). After trypsin detachment, cell-surface-bound virion genome was quantified by quantitative reverse transcription–polymerase chain reaction (qRT-PCR) analysis. In another adhesion assay, cells were incubated for 1 hour at 37°C with virus, with or without MGC 2 at 100 µM (right). After trypsin detachment, cell-surface-bound virion genome was quantified by qRT-PCR. For panels A–C, horizontal bars represent means, and error bars represent standard deviations. E, In a fluid-phase uptake assay, cells were stimulated with 200 nM PMA and/or treated with 100 µM MGC 2 for 45 minutes, incubated with FITC-dextran for 20 minutes, and underwent fluorescence analysis by flow cytometry. *P < .05, by the Mann–Whitney U test, for comparison to the untreated condition. Next, we tested whether the efficacy of MGC 2 is dependent on the duration of pretreatment and whether it declined after compound removal. First, we pretreated the cells for 1, 2, or 3 hours before virus inoculation (Figure 3B). All conditions resulted in full inhibition. In the following experiment, the cells were pretreated with MGC 2 for 30 minutes, washed free of the compound, and then infected at different intervals after treatment. Strikingly, pretreatment had an extended inhibition effect on the cells, with only a slightly diminished viral inhibition 3 hours after compound removal (Figure 3C). These results are in agreement with the compound affecting cellular viral-entry mechanisms, rather than the virus, and show extended prophylactic effects. We next determined how MGC 2 confers infection resistance to the cells. First, we studied whether the compound affects attachment of the virus to the cells. Vero E6 cells were pretreated with MGC 2 or left untreated in a manner similar to that described above and then were placed on ice and inoculated with the VSV-RFP-EBOV GP replicon (Figure 3D). Attached, noninternalized virions were detached from the cell surface upon treatment with trypsin and then were quantified by qRT-PCR. Comparable numbers of genomic RNA copies of VSV replicons were detected in samples obtained from both MGC 2–treated and MGC 2–untreated cells (Figure 3D). Next, experiments were performed in which the cells were incubated with VSV pseudovirions at 37°C. Again, noninternalized particles were detached from the cell surface with trypsin, followed by quantification of the viral genome by qRT-PCR. Total RNA was extracted from trypsin-treated cells and used for quantification of the viral genome by qRT-PCR. When compared with experiments performed at 4°C, approximately 3 times more copies of viral genome were found in trypsin-washed samples at 37°C. Again, comparable genome copy numbers were found in trypsin-treated cell washes for both MGC 2–treated and MGC 2–untreated cells (Figure 3D). However, significantly fewer genome copies were found within MGC 2–treated cells as compared to mock-treated cells. Overall, the results revealed that MGC 2 does not affect virus binding to the cells but prevents internalization of the surface-bound particles. Finally, to further assess the impact of MGC 2 on the cells’ ability to internalize surface-bound particles, a fluid-phase uptake assay was performed using FITC-labeled dextran [22]. Vero E6 cells were left untreated (mock) or were stimulated with PMA (inducing fluid-phase uptake) and/or treated with MGC 2. Shortly after treatment, FITC-dextran was loaded onto the cells. Prior to measuring dextran uptake, the cells were washed free of surface-bound FITC-dextran with ice-cold PBS, and remaining label was quenched using a low pH buffer. Data showed that the uptake of dextran particles was very low when the cells were not stimulated with PMA (Figure 3E). Uptake was increased almost 10-fold upon PMA stimulation. Treatment of PMA-stimulated cells with MGC 2 completely abrogated dextran uptake. In conclusion, the results obtained with EBOV and VSV-RFP-EBOV GP pseudovirions demonstrated that MGCs inhibit virus cell entry by acting on an early step of the viral replication cycle. To exert its inhibitory function, the compound does not need to be in direct contact with the viral particles; neither does it affect virus attachment to the cells. The results further indicated that MGCs likely alter the dynamics of the membrane, preventing the cells from internalizing cell-surface particles. Interestingly, we have recently demonstrated that MGCs were also capable of inhibiting dengue virus infection [19]. For this virus, inhibition was also attributed to an action on cellular membranes but with a likely negative impact on the fusion of viral and cellular endosomal membranes. While further work is required to determine the molecular details of how precisely MGC 2 exerts its activity against EBOV, this study clearly demonstrates high therapeutic potential of MGCs for treatment or prevention of EBOV infection during outbreaks, particularly for medical personnel engaged in work at Ebola treatment centers. Supplementary Data Supplementary materials are available at The Journal of Infectious Diseases online. Consisting of data provided by the authors to benefit the reader, the posted materials are not copyedited and are the sole responsibility of the authors, so questions or comments should be addressed to the corresponding author. Notes Acknowledgments.  We thank the biosafety level 4 facility team members and the SFR Bioscience cytometry platform staff, for their help. Disclaimer.  This work was supported by the Institut National de la Santé Et de la Recherche Médicale, the Agence Nationale de la Recherche (ANR-14-EBOL-0002-01), European Union FP7 project ANTIGONE (278976), the Centre National de la Recherche Scientifique, and the Agence Nationale de la Recherche (program Investissements d’Avenir ANR-11-EQPX-022 and ANR-10-LABX-0034). Potential conflicts of interest. All authors: No reported conflicts of interest. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed. References 1. Messaoudi I , Amarasinghe GK , Basler CF . Filovirus pathogenesis and immune evasion: insights from Ebola virus and Marburg virus . Nat Rev Microbiol 2015 ; 13 : 663 – 76 . Google Scholar Crossref Search ADS PubMed 2. Rivera A , Messaoudi I . Pathophysiology of Ebola virus infection: current challenges and future hopes . ACS Infect Dis 2015 ; 1 : 186 – 97 . Google Scholar Crossref Search ADS PubMed 3. Burd EM . Ebola virus: a clear and present danger . J Clin Microbiol 2015 ; 53 : 4 – 8 . Google Scholar Crossref Search ADS PubMed 4. Bai CQ , Mu JS , Kargbo D , et al. Clinical and virological characteristics of Ebola virus disease patients treated with favipiravir (T-705)-Sierra Leone, 2014 . Clin Infect Dis 2016 ; 63 : 1288 – 94 . Google Scholar Crossref Search ADS PubMed 5. Bixler SL , Bocan TM , Wells J , et al. Efficacy of favipiravir (T-705) in nonhuman primates infected with Ebola virus or Marburg virus . Antiviral Res 2018 ; 151 : 97 – 104 . Google Scholar Crossref Search ADS PubMed 6. Reynard O , Nguyen XN , Alazard-Dany N , Barateau V , Cimarelli A , Volchkov VE . Identification of a new ribonucleoside inhibitor of ebola virus replication . Viruses 2015 ; 7 : 6233 – 40 . Google Scholar Crossref Search ADS PubMed 7. Cardile AP , Warren TK , Martins KA , Reisler RB , Bavari S . Will there be a cure for Ebola ? Annu Rev Pharmacol Toxicol 2017 ; 57 : 329 – 48 . Google Scholar Crossref Search ADS PubMed 8. Dehuyser L , Schaeffer E , Chaloin O , Mueller CG , Baati R , Wagner A . Synthesis of novel mannoside glycolipid conjugates for inhibition of HIV-1 trans-infection . Bioconjug Chem 2012 ; 23 : 1731 – 9 . Google Scholar Crossref Search ADS PubMed 9. Schaeffer E , Dehuyser L , Sigwalt D , et al. Dynamic micelles of mannoside glycolipids are more efficient than polymers for inhibiting HIV-1 trans-infection . Bioconjug Chem 2013 ; 24 : 1813 – 23 . Google Scholar Crossref Search ADS PubMed 10. Volchkov VE , Feldmann H , Volchkova VA , Klenk HD . Processing of the Ebola virus glycoprotein by the proprotein convertase furin . Proc Natl Acad Sci U S A 1998 ; 95 : 5762 – 7 . Google Scholar Crossref Search ADS PubMed 11. Hallenberger S , Bosch V , Angliker H , Shaw E , Klenk HD , Garten W . Inhibition of furin-mediated cleavage activation of HIV-1 glycoprotein gp160 . Nature 1992 ; 360 : 358 – 61 . Google Scholar Crossref Search ADS PubMed 12. Baribaud F , Doms RW , Pöhlmann S . The role of DC-SIGN and DC-SIGNR in HIV and Ebola virus infection: can potential therapeutics block virus transmission and dissemination ? Expert Opin Ther Targets 2002 ; 6 : 423 – 31 . Google Scholar Crossref Search ADS PubMed 13. Volchkov VE , Volchkova VA , Muhlberger E , et al. Recovery of infectious Ebola virus from complementary DNA: RNA editing of the GP gene and viral cytotoxicity . Science 2001 ; 291 : 1965 – 9 . Google Scholar Crossref Search ADS PubMed 14. Martínez MJ , Biedenkopf N , Volchkova V , et al. Role of Ebola virus VP30 in transcription reinitiation . J Virol 2008 ; 82 : 12569 – 73 . Google Scholar Crossref Search ADS PubMed 15. Reynard O , Volchkov VE . Characterization of a novel neutralizing monoclonal antibody against Ebola virus GP . J Infect Dis 2015 ; 212 ( Suppl 2 ): S372 – 8 . Google Scholar Crossref Search ADS PubMed 16. Tartour K , Appourchaux R , Gaillard J , et al. IFITM proteins are incorporated onto HIV-1 virion particles and negatively imprint their infectivity . Retrovirology 2014 ; 11 : 103 . Google Scholar Crossref Search ADS PubMed 17. Schaeffer E , Dehuyser L , Sigwalt D , et al. Dynamic micelles of mannoside glycolipids are more efficient than polymers for inhibiting HIV-1 trans-infection . Bioconjug Chem 2013 ; 24 : 1813 – 23 . Google Scholar Crossref Search ADS PubMed 18. Flacher V , Neuberg P , Point F , et al. Mannoside glycolipid conjugates display anti-inflammatory activity by inhibition of toll-like receptor-4 mediated cell activation . ACS Chem Biol 2015 ; 10 : 2697 – 705 . Google Scholar Crossref Search ADS PubMed 19. Schaeffer E , Flacher V , Neuberg P , et al. Inhibition of dengue virus infection by mannoside glycolipid conjugates . Antiviral Res 2018 ; 154 : 116 – 23 . Google Scholar Crossref Search ADS PubMed 20. Lee KE , Umapathi T , Tan CB , et al. The neurological manifestations of Nipah virus encephalitis, a novel paramyxovirus . Ann Neurol 1999 ; 46 : 428 – 32 . Google Scholar Crossref Search ADS PubMed 21. Aguilar HC , Henderson BA , Zamora JL , Johnston GP . Paramyxovirus glycoproteins and the membrane fusion process . Curr Clin Microbiol Rep 2016 ; 3 : 142 – 54 . Google Scholar Crossref Search ADS PubMed 22. Aleksandrowicz P , Marzi A , Biedenkopf N , et al. Ebola virus enters host cells by macropinocytosis and clathrin-mediated endocytosis . J Infect Dis 2011 ; 204 ( Suppl 3 ): S957 – 67 . Google Scholar Crossref Search ADS PubMed 23. Alvarez CP , Lasala F , Carrillo J , Muñiz O , Corbí AL , Delgado R . C-type lectins DC-SIGN and L-SIGN mediate cellular entry by Ebola virus in cis and in trans . J Virol 2002 ; 76 : 6841 – 4 . Google Scholar Crossref Search ADS PubMed 24. Colmenares M , Puig-Kröger A , Pello OM , Corbí AL , Rivas L . Dendritic cell (DC)-specific intercellular adhesion molecule 3 (ICAM-3)-grabbing nonintegrin (DC-SIGN, CD209), a C-type surface lectin in human DCs, is a receptor for Leishmania amastigotes . J Biol Chem 2002 ; 277 : 36766 – 9 . Google Scholar Crossref Search ADS PubMed 25. Nanbo A , Maruyama J , Imai M , et al. Ebola virus requires a host scramblase for externalization of phosphatidylserine on the surface of viral particles . PLoS Pathog 2018 ; 14 : e1006848 . Google Scholar Crossref Search ADS PubMed 26. Martinez O , Leung LW , Basler CF . The role of antigen-presenting cells in filoviral hemorrhagic fever: gaps in current knowledge . Antiviral Res 2012 ; 93 : 416 – 28 . Google Scholar Crossref Search ADS PubMed 27. Bray M , Geisbert TW . Ebola virus: the role of macrophages and dendritic cells in the pathogenesis of Ebola hemorrhagic fever . Int J Biochem Cell Biol 2005 ; 37 : 1560 – 6 . Google Scholar Crossref Search ADS PubMed © The Author(s) 2018. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)
TI - Mannoside Glycolipid Conjugates Display Antiviral Activity Against Ebola Virus
JF - The Journal of Infectious Diseases
DO - 10.1093/infdis/jiy464
DA - 2018-11-22
UR - https://www.deepdyve.com/lp/oxford-university-press/mannoside-glycolipid-conjugates-display-antiviral-activity-against-TikU6GNGe2
SP - S666
VL - 218
IS - suppl_5
DP - DeepDyve
ER -