| 1. |
- Karoli, Tomislav, et al.
(author)
-
Synthesis, biological activity, and preliminary pharmacokinetic evaluation of analogues of a phosphosulfomannan angiogenesis inhibitor (PI-88).
- 2005
-
In: Journal of medicinal chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 48:26, s. 8229-36
-
Journal article (peer-reviewed)abstract
- The phosphosulfomannan 1 (PI-88) is a mixture of highly sulfated oligosaccharides that is currently undergoing clinical evaluation in cancer patients. As well as its anticancer properties, 1 displays a number of other interesting biological activities. A series of analogues of 1 were synthesized with a single carbon (pentasaccharide) backbone to facilitate structural characterization and interpretation of biological results. In a fashion similar to 1, all compounds were able to inhibit heparanase and to bind tightly to the proangiogenic growth factors FGF-1, FGF-2, and VEGF. The compounds also inhibited the infection of cells and cell-to-cell spread of herpes simplex virus (HSV-1). Preliminary pharmacokinetic data indicated that the compounds displayed different pharmacokinetic behavior compared with 1. Of particular note was the n-octyl derivative, which was cleared 3 times less rapidly than 1 and may provide increased systemic exposure.
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| 2. |
- Renner, Jens, et al.
(author)
-
The Synthesis and Biological Evaluation of Two Analogues of the C-Riboside Showdomycin
- 2005
-
In: Australian Journal of Chemistry. ; 58:2, s. 86-93
-
Journal article (peer-reviewed)abstract
- Two novel analogues, 2 and 3, of the C-riboside showdomycin (1) have been prepared by exploiting the N-TIPS-substituted pyrrole 7 as a synthetic equivalent for the maleimide C3 anion. The tetraacetate precursor, 12, of target 2 as well as target 3 itself were subjected to single-crystal X-ray analyses. Analogues 2 and 3 as well as showdomycin and its anomer (4) have each been evaluated in various assays for their cytotoxic, anti-bacterial, and anti-viral effects.
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| 3. |
- Abidine, Yara, et al.
(author)
-
Cellular Chondroitin Sulfate and the Mucin-like Domain of Viral Glycoprotein C Promote Diffusion of Herpes Simplex Virus 1 While Heparan Sulfate Restricts Mobility
- 2022
-
In: Viruses. - : MDPI AG. - 1999-4915. ; 14:8
-
Journal article (peer-reviewed)abstract
- The diffusion of viruses at the cell membrane is essential to reach a suitable entry site and initiate subsequent internalization. Although many viruses take advantage of glycosaminoglycans (GAG) to bind to the cell surface, little is known about the dynamics of the virus-GAG interactions. Here, single-particle tracking of the initial interaction of individual herpes simplex virus 1 (HSV-1) virions reveals a heterogeneous diffusive behavior, regulated by cell-surface GAGs with two main diffusion types: confined and normal free. This study reports that different GAGs can have competing influences in mediating diffusion on the cells used here: chondroitin sulfate (CS) enhances free diffusion but hinders virus attachment to cell surfaces, while heparan sulfate (HS) promotes virus confinement and increases entry efficiency. In addition, the role that the viral mucin-like domains (MLD) of the HSV-1 glycoprotein C plays in facilitating the diffusion of the virus and accelerating virus penetration into cells is demonstrated. Together, our results shed new light on the mechanisms of GAG-regulated virus diffusion at the cell surface for optimal internalization. These findings may be extendable to other GAG-binding viruses.
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| 4. |
- Adamiak, Beata, et al.
(author)
-
Herpes simplex virus type 2 glycoprotein g is targeted by the sulfated oligo- and polysaccharide inhibitors of virus attachment to cells
- 2007
-
In: Journal of Virology. - 0022-538X. ; 81:24, s. 13424-13434
-
Journal article (peer-reviewed)abstract
- Variants of herpes simplex virus type 2 (HSV-2) generated by virus passage in GMK-AH1 cells in the presence of the sulfated oligosaccharide PI-88 were analyzed. Many of these variants were substantially resistant to PI-88 in their initial infection of cells and/or their cell-to-cell spread. The major alteration detected in all variants resistant to PI-88 in the initial infection of cells was a frameshift mutation(s) in the glycoprotein G (gG) gene that resulted in the lack of protein expression. Molecular transfer of the altered gG gene into the wild-type background confirmed that the gG-deficient recombinants were resistant to PI-88. In addition to PI-88, all gG-deficient variants of HSV-2 were resistant to the sulfated polysaccharide heparin. The gG-deficient virions were capable of attaching to cells, and this activity was relatively resistant to PI-88. In addition to having a drug-resistant phenotype, the gG-deficient variants were inefficiently released from infected cells. Purified gG bound to heparin and showed the cell-binding activity which was inhibited by PI-88. Many PI-88 variants produced syncytia in cultured cells and contained alterations in gB, including the syncytium-inducing L792P amino acid substitution. Although this phenotype can enhance the lateral spread of HSV in cells, it conferred no virus resistance to PI-88. Some PI-88 variants also contained occasional alterations in gC, gD, gE, gK, and UL24. In conclusion, we found that glycoprotein gG, a mucin-like component of the HSV-2 envelope, was targeted by sulfated oligo- and polysaccharides. This is a novel finding that suggests the involvement of HSV-2 gG in interactions with sulfated polysaccharides, including cell surface glycosaminoglycans.
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| 5. |
- Adamiak, Beata, et al.
(author)
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Human antibodies to herpes simplex virus type 1 glycoprotein C are neutralizing and target the heparan sulfate-binding domain
- 2010
-
In: Virology. - : Elsevier BV. - 0042-6822. ; 400:2, s. 197-206
-
Journal article (peer-reviewed)abstract
- Human antibodies specific for glycoprotein C (gC1) of herpes simplex virus type 1 (HSV-1) neutralized the virus infectivity and efficiently inhibited attachment of HSV-1 to human HaCaT keratinocytes and to murine mutant L cells expressing either heparan sulfate or chondroitin sulfate at the cell surface. Similar activities were observed with anti-gC1 monoclonal antibody B1C1. In addition to HaCaT and L cells, B1C1 antibody neutralized HSV-1 infectivity in simian GMK AH1 cells mildly pre-treated with heparinase III. Human anti-gC1 antibodies efficiently competed with the binding of gC1 to B1C1 antibody whose epitope overlaps a part of the attachment domain of gC1. Human anti-gC1 and B1C1 antibodies extended survival time of mice experimentally infected with HSV-1. We conclude that in HaCaT cells and in cell systems showing restricted expression of glycosaminoglycans, human and some monoclonal anti-gC1 antibodies can target the cell-binding domain of this protein and neutralize viral infectivity.
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| 6. |
- Altgärde, Noomi, 1983, et al.
(author)
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Mucin-like region of herpes simplex virus type 1 attachment protein gC modulates the virus-glycosaminoglycan interaction.
- 2015
-
In: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 290:35, s. 21473-21485
-
Journal article (peer-reviewed)abstract
- Glycoprotein C (gC) mediates the attachment of herpes simplex virus type 1 (HSV-1) to susceptible host cells by interacting with glycosaminoglycans (GAGs) on the cell surface. gC contains a mucin-like region located near the GAG-binding site, which may affect the binding activity. Here, we address this issue by studying an HSV-1 mutant lacking the mucin- like domain in gC and the corresponding purified mutant protein (gCΔmuc), in cell culture and GAG-binding assays, respectively. The mutant virus exhibited two functional alterations as compared to native HSV-1, i.e. decreased sensitivity to GAG-based inhibitors of virus attachment to cells, and reduced release of viral particles from the surface of infected cells. Kinetic and equilibrium binding characteristics of purified gC were assessed using surface plasmon resonance-based sensing together with a surface platform consisting of end-on immobilized GAGs. Both native gC and gCΔmuc bound via the expected binding region to chondroitin sulfate and sulfated hyaluronan but not to the non-sulfated hyaluronan, confirming binding specificity. In contrast to native gC, gCΔmuc exhibited a decreased affinity for GAGs and a slower dissociation, indicating that once formed, the gCΔmuc-GAG complex is more stable. It was also found that a larger number of gCΔmuc bound to a single GAG chain, compared to native gC. Taken together, our data suggest that the mucin-like region of HSV-1 gC is involved in the modulation of the GAG-binding activity, a feature of importance both for unrestricted virus entry into the cells and release of newly produced viral particles from infected cells.
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| 7. |
- Bergefall, Kicki, 1975, et al.
(author)
-
Chondroitin sulfate characterized by the E-disaccharide unit is a potent inhibitor of herpes simplex virus infectivity and provides the virus binding sites on gro2C cells.
- 2005
-
In: The Journal of biological chemistry. - 0021-9258. ; 280:37, s. 32193-9
-
Journal article (peer-reviewed)abstract
- Although cell surface chondroitin sulfate (CS) is regarded as an auxiliary receptor for binding of herpes simplex virus to cells, and purified CS chain types A, B, and C are known to interfere poorly or not at all with the virus infection of cells, we have found that CS type E (CS-E), derived from squid cartilage, exhibited potent antiviral activity. The IC(50) values ranged from 0.06 to 0.2 mug/ml and substantially exceeded the antiviral potency of heparin, the known inhibitor of virus binding to cells. Furthermore, in mutant gro2C cells that express CS but not heparan sulfate, CS-E showed unusually high anti-herpes virus activity with IC(50) values of <1 ng/ml. Enzymatic degradation of CS-E with chondroitinase ABC abolished its antiviral activity. CS-E inhibited the binding to cells of the purified virus attachment protein gC. A direct interaction of gC with immobilized CS-E and inhibition of this binding by CS-E oligosaccharide fragments greater than octasaccharide were demonstrated. Likewise, the gro2C-specific CS chains interfered with the binding of viral gC to these cells and were found to contain a considerable proportion (13%) of the E-disaccharide unit, suggesting that this unit is an essential component of the CS receptor for herpes simplex virus on gro2C cells and that the antiviral activity of CS-E was due to interference with the binding of viral gC to a CS-E-like receptor on the cell surface. Knowledge of the determinants of antiviral properties of CS-E will help in the development of inhibitors of herpes simplex virus infections in humans.
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| 8. |
- Bergström, Petra, et al.
(author)
-
Herpes Simplex Virus 1 and 2 Infections during Differentiation of Human Cortical Neurons
- 2021
-
In: Viruses-Basel. - : MDPI AG. - 1999-4915. ; 13:10
-
Journal article (peer-reviewed)abstract
- Herpes simplex virus 1 (HSV-1) and 2 (HSV-2) can infect the central nervous system (CNS) with dire consequences; in children and adults, HSV-1 may cause focal encephalitis, while HSV-2 causes meningitis. In neonates, both viruses can cause severe, disseminated CNS infections with high mortality rates. Here, we differentiated human induced pluripotent stem cells (iPSCs) towards cortical neurons for infection with clinical CNS strains of HSV-1 or HSV-2. Progenies from both viruses were produced at equal quantities in iPSCs, neuroprogenitors and cortical neurons. HSV-1 and HSV-2 decreased viability of neuroprogenitors by 36.0% and 57.6% (p < 0.0001), respectively, 48 h post-infection, while cortical neurons were resilient to infection by both viruses. However, in these functional neurons, both HSV-1 and HSV-2 decreased gene expression of two markers of synaptic activity, CAMK2B and ARC, and affected synaptic activity negatively in multielectrode array experiments. However, unaltered secretion levels of the neurodegeneration markers tau and NfL suggested intact axonal integrity. Viral replication of both viruses was found after six days, coinciding with 6-fold and 22-fold increase in gene expression of cellular RNA polymerase II by HSV-1 and HSV-2, respectively. Our results suggest a resilience of human cortical neurons relative to the replication of HSV-1 and HSV-2.
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| 9. |
- Delguste, Martin, et al.
(author)
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Regulatory Mechanisms of the Mucin-Like Region on Herpes Simplex Virus during Cellular Attachment
- 2019
-
In: ACS Chemical Biology. - : American Chemical Society (ACS). - 1554-8937 .- 1554-8929. ; 14:3, s. 534-542
-
Journal article (peer-reviewed)abstract
- Mucin-like regions, characterized by a local high density of O-linked glycosylation, are found on the viral envelope glycoproteins of many viruses. Herpes simplex virus type 1 (HSV-1), for example, exhibits a mucin-like region on its glycoprotein gC, a viral protein involved in initial recruitment of the virus to the cell surface via interaction with sulfated glycosaminoglycans. So far, this mucin-like region has been proposed to play a key role in modulating the interactions with cellular glycosaminoglycans, and in particular to promote release of HSV-1 virions from infected cells. However, the molecular mechanisms and the role as a pathogenicity factor remains unclear. Using single virus particle tracking, we show that the mobility of chondroitin sulfate-bound HSV-1 virions is decreased in absence of the mucin-like region. This decrease in mobility correlates with an increase in HSV-1-chondroitin sulfate binding forces as observed using atomic force microscopy-based force spectroscopy. Our data suggest that the mucin-like region modulates virus-glycosaminoglycan interactions by regulating the affinity, type, and number of glycoproteins involved in the virus-glycosaminoglycan interaction. This study therefore presents new evidence for a role of the mucin-like region in balancing the interaction of HSV-1 with glycosaminoglycans and provides further insights into the molecular mechanisms used by the virus to ensure both successful cell entry and release from the infected cell.
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| 10. |
- Ekblad, Maria, 1978, et al.
(author)
-
A highly lipophilic sulfated tetrasaccharide glycoside related to muparfostat (PI-88) exhibits virucidal activity against herpes simplex virus.
- 2010
-
In: Antiviral research. - : Elsevier BV. - 1872-9096 .- 0166-3542. ; 86:2, s. 196-203
-
Journal article (peer-reviewed)abstract
- Although sulfated polysaccharides potently inhibit the infectivity of herpes simplex virus (HSV) and human immunodeficiency virus in cultured cells, these compounds fail to show protective effects in humans, most likely due to their poor virucidal activity. Herein we report on sulfated oligosaccharide glycosides related to muparfostat (formerly known as PI-88) and their assessment for anti-HSV activity. Chemical modifications based on the introduction of specific hydrophobic groups at the reducing end of a sulfated oligosaccharide chain enhanced the compound's capability to inhibit the infection of cells by HSV-1 and HSV-2 and abrogated the cell-to-cell transmission of HSV-2. Furthermore, modification with a highly lipophilic cholestanyl group provided a compound with virucidal activity against HSV. This glycoside targeted the viral particle and, to a lesser degree, the cell, and exhibited an antiviral mode of action typical for sulfated polysaccharides and virucides, i.e., interference with the virus attachment to cells and irreversible inactivation of virus infectivity, respectively. The virucidal activity was decreased in the presence of human cervical secretions suggesting that higher doses of this glycoside might be needed for in vivo application. Altogether, the sulfated oligosaccharide-cholestanyl glycoside exhibits potent anti-HSV activity and is, therefore, a good candidate for development as a virucide.
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| 11. |
- Ekblad, Maria, 1978, et al.
(author)
-
Anti-herpes simplex virus activities of two novel disulphated cyclitols.
- 2006
-
In: Antiviral chemistry & chemotherapy. - 0956-3202. ; 17:2, s. 97-106
-
Journal article (peer-reviewed)abstract
- By screening a library of sulphated compounds of low molecular weight, we have found that several cyclitol derivatives, each modified with two sulphate groups in addition to pyrrole and various aromatic moieties, inhibited infectivity of herpes simplex virus (HSV) at concentrations approximately 100 times lower than those toxic for cultured cells. These disulphated cyclitols interfered with HSV-1 attachment to cells, and efficiently reduced the cell-to-cell spread of the virus. This effect is most likely due to their low molecular weight and associated with the compounds' capability to access the narrow intercellular spaces. Furthermore, these disulphated cyclitols also inactivated infectivity of HSV. However, the virus-inactivating activities of these compounds were to some extent diminished in the presence of human cervical secretions or other protein-rich solutions suggesting that disulphated cyclitols may have some features of surfactant-type virucides. In conclusion, this new class of anti-HSV compounds offers potential for further development.
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| 12. |
- Ekblad, Maria, 1978, et al.
(author)
-
Molecular basis for resistance of herpes simplex virus type 1 mutants to the sulfated oligosaccharide inhibitor PI-88.
- 2007
-
In: Virology. - : Elsevier BV. - 0042-6822. ; 367:2, s. 244-52
-
Journal article (peer-reviewed)abstract
- Herpes simplex virus type 1 variants selected by virus propagation in cultured cells in the presence of the sulfated oligosaccharide PI-88 were analyzed. Many of these variants were substantially resistant to the presence of PI-88 during their initial infection of cells and/or their cell-to-cell spread. Nucleotide sequence analysis revealed that the deletion of amino acids 33-116 of gC but not lack of gC expression provided the virus with selective advantage to infect cells in the presence of PI-88. Purified gC (Delta33-116) was more resistant to PI-88 than unaltered protein in its binding to cells. Alterations that partly contributed to the virus resistance to PI-88 in its cell-to-cell spread activity were amino acid substitutions Q27R in gD and R770W in gB. These results suggest that PI-88 targets several distinct viral glycoproteins during the course of initial virus infection and cell-to-cell spread.
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| 13. |
- Guimond, S. E., et al.
(author)
-
Synthetic Heparan Sulfate Mimetic Pixatimod (PG545) Potently Inhibits SARS-CoV-2 by Disrupting the Spike-ACE2 Interaction
- 2022
-
In: ACS Central Science. - : American Chemical Society (ACS). - 2374-7943 .- 2374-7951. ; 8:5, s. 527-545
-
Journal article (peer-reviewed)abstract
- Heparan sulfate (HS) is a cell surface polysaccharide recently identified as a coreceptor with the ACE2 protein for the S1 spike protein on SARS-CoV-2 virus, providing a tractable new therapeutic target. Clinically used heparins demonstrate an inhibitory activity but have an anticoagulant activity and are supply-limited, necessitating alternative solutions. Here, we show that synthetic HS mimetic pixatimod (PG545), a cancer drug candidate, binds and destabilizes the SARS-CoV-2 spike protein receptor binding domain and directly inhibits its binding to ACE2, consistent with molecular modeling identification of multiple molecular contacts and overlapping pixatimod and ACE2 binding sites. Assays with multiple clinical isolates of SARS-CoV-2 virus show that pixatimod potently inhibits the infection of monkey Vero E6 cells and physiologically relevant human bronchial epithelial cells at safe therapeutic concentrations. Pixatimod also retained broad potency against variants of concern (VOC) including B.1.1.7 (Alpha), B.1.351 (Beta), B.1.617.2 (Delta), and B.1.1.529 (Omicron). Furthermore, in a K18-hACE2 mouse model, pixatimod significantly reduced SARS-CoV-2 viral titers in the upper respiratory tract and virus-induced weight loss. This demonstration of potent anti-SARS-CoV-2 activity tolerant to emerging mutations establishes proof-of-concept for targeting the HS-Spike protein-ACE2 axis with synthetic HS mimetics and provides a strong rationale for clinical investigation of pixatimod as a potential multimodal therapeutic for COVID-19.
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| 14. |
- Jennische, Eva, 1949, et al.
(author)
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The anterior commissure is a pathway for contralateral spread of herpes simplex virus type 1 after olfactory tract infection
- 2015
-
In: Journal of Neurovirology. - : Springer Science and Business Media LLC. - 1355-0284 .- 1538-2443. ; 21:2, s. 129-147
-
Journal article (peer-reviewed)abstract
- Herpes simplex encephalitis (HSE), targeting the limbic system, is the most common cause of viral encephalitis in the Western world. Two pathways for viral entry to the central nervous system (CNS) in HSE have been suggested: either via the trigeminal nerve or via the olfactory tract. This question remains unsettled, and studies of viral spread between the two brain hemispheres are scarce. Here, we investigated the olfactory infection as a model of infection and tropism of herpes simplex virus 1 (HSV-1), the causative agent of HSE, in the CNS of rats. Rats were instilled with HSV-1 in the right nostril and sacrificed 1-6 days post-infection, and tissues were analysed for viral spread using immunohistochemistry and quantitative PCR (qPCR). After nasal instillation, HSV-1 infected mitral cells of the olfactory bulb (OB) on the right side only, followed by limbic encephalitis. As a novel finding, the anterior commissure (AC) conveyed a rapid transmission of virus between the right and the left OB, acting as a shortcut also between the olfactory cortices. The neuronal cell population that conveyed the viral infection via the AC was positive for the water channel protein aquaporin 9 (AQP9) by immunohistochemistry. Quantification of AQP9 in cerebrospinal fluid samples of HSE patients showed increment as compared to controls. We conclude that the olfactory route and the AC are important for the spread of HSV-1 within the olfactory/limbic system of rats and furthermore, we suggest that AQP9 is involved in viral tropism and pathogenesis of HSE.
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| 15. |
- Kalenga, T. M., et al.
(author)
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Modified ent-Abietane Diterpenoids from the Leaves of Suregada zanzibariensis
- 2022
-
In: Journal of Natural Products. - : American Chemical Society (ACS). - 0163-3864 .- 1520-6025. ; 85:9, s. 2135-2141
-
Journal article (peer-reviewed)abstract
- The leaf extract of Suregada zanzibariensis gave two new modified ent-abietane diterpenoids, zanzibariolides A (1) and B (2), and two known triterpenoids, simiarenol (3) and fi-amyrin (4). The structures of the isolated compounds were elucidated based on NMR and MS data analysis. Single-crystal X-ray diffraction was used to establish the absolute configurations of compounds 1 and 2. The crude leaf extract inhibited the infectivity of herpes simplex virus 2 (HSV-2, IC50 11.5 mu g/mL) and showed toxicity on African green monkey kidney (GMK AH1) cells at CC50 52 mu g/ mL. The isolated compounds 1-3 showed no anti-HSV-2 activity and exhibited insignificant toxicity against GMK AH1 cells at >= 100 mu M.
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| 16. |
- Lundin, Anna, et al.
(author)
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Potent anti-respiratory syncytial virus activity of a cholestanol-sulfated tetrasaccharide conjugate.
- 2012
-
In: Antiviral research. - : Elsevier BV. - 1872-9096 .- 0166-3542. ; 93:1, s. 101-9
-
Journal article (peer-reviewed)abstract
- A number of different viruses including respiratory syncytial virus (RSV) initiate infection of cells by binding to cell surface glycosaminoglycans and sulfated oligo- and polysaccharide mimetics of these receptors exhibit potent antiviral activity in cultured cells. We investigated whether the introduction of different lipophilic groups to the reducing end of sulfated oligosaccharides would modulate their anti-RSV activity. Our results demonstrate that the cholestanol-conjugated tetrasaccharide (PG545) exhibited ∼5- to 16-fold enhanced anti-RSV activity in cultured cells compared with unmodified sulfated oligosaccharides. Furthermore, PG545 displayed virus-inactivating (virucidal) activity, a feature absent in sulfated oligosaccharides. To inhibit RSV infectivity PG545 had to be present during the initial steps of viral infection of cells. The anti-RSV activity of PG545 was due to both partial inhibition of the virus attachment to cells and a more profound interference with some post-attachment steps as PG545 efficiently neutralized infectivity of the cell-adsorbed virus. The anti-RSV activity of PG545 was reduced when tested in the presence of human nasal secretions. Serial passages of RSV in the presence of increasing concentrations of PG545 selected for weakly resistant viral variants that comprised the F168S and the P180S amino acid substitutions in the viral G protein. Altogether we identified a novel and potent inhibitor of RSV, which unlike sulfated oligo- and polysaccharide compounds, could irreversibly inactivate RSV infectivity.
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| 17. |
- Lundin, Anna, et al.
(author)
-
Screening and evaluation of anti-respiratory syncytial virus compounds in cultured cells.
- 2013
-
In: Antiviral Methods and Protocols. Ed. Edwin Yunhao Gong. (Methods in molecular biology, 1030). - Totowa, NJ : Humana Press. - 1940-6029. - 9781627034838 ; 1030, s. 345-63
-
Book chapter (peer-reviewed)abstract
- Respiratory syncytial virus (RSV) is a highly contagious pathogen that infects mainly ciliated cells of respiratory epithelium and type 1 pneumocytes in the alveoli frequently causing serious respiratory disease in infants, elderly, and immunocompromised patients. At present, prevention/treatment of RSV infection is limited to the use of specific anti-RSV antibody or an aerosol formulation of ribavirin, a drug of suboptimal efficacy and low safety profile. There is an urgent need for development of novel anti-RSV drugs and virucides. Here we describe the cell culture-based methods used in our laboratory in identification of novel inhibitors of RSV including the P13 fusion inhibitor, and the PG545 virucide. Protocols for antiviral screening, evaluation of anti-RSV potency, and elucidation of mode of antiviral activity of test compounds are described.
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| 18. |
- Lundin, Anna, et al.
(author)
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Targeting Membrane-Bound Viral RNA Synthesis Reveals Potent Inhibition of Diverse Coronaviruses Including the Middle East Respiratory Syndrome Virus
- 2014
-
In: Plos Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 10:5
-
Journal article (peer-reviewed)abstract
- Coronaviruses raise serious concerns as emerging zoonotic viruses without specific antiviral drugs available. Here we screened a collection of 16671 diverse compounds for anti-human coronavirus 229E activity and identified an inhibitor, designated K22, that specifically targets membrane-bound coronaviral RNA synthesis. K22 exerts most potent antiviral activity after virus entry during an early step of the viral life cycle. Specifically, the formation of double membrane vesicles (DMVs), a hallmark of coronavirus replication, was greatly impaired upon K22 treatment accompanied by near-complete inhibition of viral RNA synthesis. K22-resistant viruses contained substitutions in non-structural protein 6 (nsp6), a membrane-spanning integral component of the viral replication complex implicated in DMV formation, corroborating that K22 targets membrane bound viral RNA synthesis. Besides K22 resistance, the nsp6 mutants induced a reduced number of DMVs, displayed decreased specific infectivity, while RNA synthesis was not affected. Importantly, K22 inhibits a broad range of coronaviruses, including Middle East respiratory syndrome coronavirus (MERS-CoV), and efficient inhibition was achieved in primary human epithelia cultures representing the entry port of human coronavirus infection. Collectively, this study proposes an evolutionary conserved step in the life cycle of positive-stranded RNA viruses, the recruitment of cellular membranes for viral replication, as vulnerable and, most importantly, druggable target for antiviral intervention. We expect this mode of action to serve as a paradigm for the development of potent antiviral drugs to combat many animal and human virus infections.
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| 19. |
- Lundin, Anna, et al.
(author)
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Two novel fusion inhibitors of human respiratory syncytial virus
- 2010
-
In: Antiviral Research. - : Elsevier BV. - 0166-3542. ; 88:3, s. 317-324
-
Journal article (peer-reviewed)abstract
- To search for novel drugs against human respiratory syncytial virus (RSV), we have screened a diversity collection of 16,671 compounds for anti-RSV activity in cultures of HEp-2 cells. Two of the hit compounds, i.e., the N-(2-hydroxyethyl)-4-methoxy-N-methyl-3-(6-methyl[1,2,4]triazolo[3,4-a]phthalazin-3-yl)benzenesulfonamide (designated as P13) and the 1,4-bis(3-methyl-4-pyridinyl)-1,4-diazepane (designated as C15), reduced the virus infectivity with IC₅₀ values of 0.11 and 0.13μM respectively. The concentration of P13 and C15 that reduced the viability of HEp-2 cells by 50% was 310 and 75μM respectively. Both P13 and C15 exhibited no direct virucidal activity or inhibitory effects on the virus attachment to cells. However, to inhibit formation of RSV-induced syncytial plaques P13 and C15 had to be present during the virus entry into the cells and the cell-to-cell transmission of the virus. The RSV multiplication in HEp-2 cells in the presence of P13 or C15 resulted in rapid selection of viral variants that were ∼1000 times less sensitive to these drugs than original virus. Sequencing of resistant viruses revealed presence of amino acid substitutions in the F protein of RSV, i.e., the D489G for C15-selected, and the T400I and N197T (some clones) for the P13-selected virus variants. In conclusion, we have identified two novel fusion inhibitors of RSV, and the detailed understanding of their mode of antiviral activity including selection for the drug resistant viral variants may help to develop selective and efficient anti-RSV drugs.
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| 20. |
- Mahambo, Emanuel T, et al.
(author)
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Crotofolane Diterpenoids and Other Constituents Isolated from Croton kilwae.
- 2023
-
In: Journal of Natural Products. - : American Chemical Society (ACS). - 1520-6025 .- 0163-3864. ; 86:2, s. 380-389
-
Journal article (peer-reviewed)abstract
- Six new crotofolane diterpenoids (1-6) and 13 known compounds (7-19) were isolated from the MeOH-CH2Cl2 (1:1, v/v) extracts of the leaves and stem bark of Croton kilwae. The structures of the new compounds were elucidated by extensive analysis of spectroscopic and mass spectrometric data. The structure of crotokilwaepoxide A (1) was confirmed by single-crystal X-ray diffraction, allowing for the determination of its absolute configuration. The crude extracts and the isolated compounds were investigated for antiviral activity against respiratory syncytial virus (RSV) and human rhinovirus type-2 (HRV-2) in HEp-2 and HeLa cells, respectively, for antibacterial activity against the Gram-positive Bacillus subtilis and the Gram-negative Escherichia coli, and for antimalarial activity against the Plasmodium falciparum Dd2 strain. ent-3β,19-Dihydroxykaur-16-ene (7) and ayanin (16) displayed anti-RSV activities with IC50 values of 10.2 and 6.1 μM, respectively, while exhibiting only modest cytotoxic effects on HEp-2 cells that resulted in selectivity indices of 4.9 and 16.4. Compounds 2 and 5 exhibited modest anti-HRV-2 activity (IC50 of 44.6 μM for both compounds), while compound 16 inhibited HRV-2 with an IC50 value of 1.8 μM. Compounds 1-3 showed promising antiplasmodial activities (80-100% inhibition) at a 50 μM concentration.
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| 21. |
- Marchetti, Magda, et al.
(author)
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Inhibition of herpes simplex virus infection by lactoferrin is dependent on interference with the virus binding to glycosaminoglycans.
- 2004
-
In: Virology. - : Elsevier BV. - 0042-6822. ; 318:1, s. 405-13
-
Journal article (peer-reviewed)abstract
- Previous reports have indicated that lactoferrin inhibits herpes simplex virus (HSV) infection during the very early phases of the viral replicative cycle. In the present work we investigated the mechanism of the antiviral activity of lactoferrin in mutant glycosaminoglycan (GAG)-deficient cells. Bovine lactoferrin (BLf) was a strong inhibitor of HSV-1 infection in cells expressing either heparan sulfate (HS) or chondroitin sulfate (CS) or both, but was ineffective or less efficient in GAG-deficient cells or in cells treated with GAG-degrading enzymes. In contrast to wild-type HSV-1, virus mutants devoid of glycoprotein C (gC) were significantly less inhibited by lactoferrin in GAG-expressing cells, indicating that lactoferrin interfered with the binding of viral gC to cell surface HS and/or CS. Finally, we demonstrated that lactoferrin bound directly to both HS and CS isolated from surfaces of the studied cells, as well as to commercial preparations of GAG chains. The results support the hypothesis that the inhibition of HSV-1 infectivity by lactoferrin is dependent on its interaction with cell surface GAG chains of HS and CS.
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| 22. |
- Miah, Masum, et al.
(author)
-
Identification of epidermal growth factor receptor-tyrosine kinase inhibitor targeting the VP1 pocket of human rhinovirus
- 2024
-
In: ANTIMICROBIAL AGENTS AND CHEMOTHERAPY. - 0066-4804 .- 1098-6596. ; 68:3
-
Journal article (peer-reviewed)abstract
- Screening a library of 1,200 preselected kinase inhibitors for anti-human rhinovirus 2 (HRV-2) activity in HeLa cells identified a class of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKI) as effective virus blockers. These were based on the 4-anilinoquinazoline-7-oxypiperidine scaffold, with the most potent representative AZ5385 inhibiting the virus with EC50 of 0.35 mu M. Several structurally related analogs confirmed activity in the low mu M range, while interestingly, other TKIs targeting EGFR lacked anti-HRV-2 activity. To further probe this lack of association between antiviral activity and EGFR inhibition, we stained infected cells with antibodies specific for activated EGFR (Y1068) and did not observe a dependency on EGFR-TK activity. Instead, consecutive passages of HRV-2 in HeLa cells in the presence of a compound and subsequent nucleotide sequence analysis of resistant viral variants identified the S181T and T210A alterations in the major capsid VP1 protein, with both residues located in the vicinity of a known hydrophobic pocket on the viral capsid. Further characterization of the antiviral effects of AZ5385 showed a modest virus-inactivating (virucidal) activity, while anti-HRV-2 activity was still evident when the inhibitor was added as late as 10 h post infection. The RNA copy/infectivity ratio of HRV-2 propagated in AZ5385 presence was substantially higher than that of control HRV indicating that the compound preferentially targeted HRV progeny virions during their maturation in infected cells. Besides HRV, the compound showed anti-respiratory syncytial virus activity, which warrants its further studies as a candidate compound against viral respiratory infections.
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| 23. |
- Mollel, Jackson T., et al.
(author)
-
Anti-respiratory syncytial virus and anti-herpes simplex virus activity of six Tanzanian medicinal plants with extended studies of Erythrina abyssinica stem bark
- 2022
-
In: Journal of Ethnopharmacology. - : Elsevier BV. - 0378-8741. ; 292
-
Journal article (peer-reviewed)abstract
- Ethnopharmacological relevance: Except for few highly pathogenic viruses, no antiviral drug has been approved for treatment of viral infections in humans. Plant extracts, selected based on their ethno-medical use, represent an important source of compounds for the development of novel candidate antiviral drugs. This especially concerns plants with ethnomedical records on their use in treatment of viral infections. Aim of the study: To identify and document medicinal plants used by traditional health practitioners (THPs) for treatment of respiratory infections and muco-cutaneous lesions in order to study their antiviral activity including identification of active components and elucidation of mode of antiviral activity. Materials and methods: The ethno-medical survey was performed in the Kagera region of Tanzania. The THPs were asked for plants used for treatment of signs and symptoms of respiratory infections and watery muco-cutaneous blisters in oral and genital regions. The plants identified were successively extracted with n-hexane, ethyl acetate and water, and the extracts assayed for anti-respiratory syncytial virus (RSV), anti-herpes simplex virus 2 (HSV-2), and anti-human parainfluenza virus 2 (HPIV-2) activity in cultured cells. Antiviral components were separated by ethanol precipitation and CL-6B chromatography, and the mode of antiviral activity elucidated by the time-of-addition assay and selection for the virus variants resistant to antiviral plant extract. Results: THPs identified fifteen plants used for treatment of respiratory infections and muco-cutaneous blisters. The water extract, but not n-hexane or ethyl acetate extracts, of six of these plants including Erythrina abyssinica stem bark, inhibited infectivity of two glycosaminoglycan-binding viruses i.e., RSV and HSV-2 but not the sialic acid binding HPIV-2. An activity-guided separation revealed that antiviral component(s) of water extract of E. abyssinica could be precipitated with ethanol. This sample potently and selectively inhibited RSV and HSV-2 infectivity in cultured cells with IC50 values of 2.1 μg/ml (selectivity index >476) and 0.14 μg/ml (selectivity index >7143) respectively. The sample exhibited inhibitory effect on the virus attachment to and entry into the cells by directly targeting the viral particles. Indeed, 10 consecutive virus passages in HEp-2 cells in the presence of this extract selected for a resistant RSV variant lacking the attachment, viral membrane-associated, G protein due to a stop codon at amino acid residue 33 (Leu33stop). Fractionation of the E. abyssinica extract on a CL-6B column revealed that anti-RSV and HSV-2 activity correlated with carbohydrate content. The most pronounced antiviral activity was associated with a carbohydrate containing ingredient of molecular mass of <5 kDa, which may polymerize to antiviral composites of up to 410 kDa. Conclusions: Altogether, the water extract of six medicinal plants showed anti-RSV and anti-HSV-2 activities. Extended studies of the stem bark of E. abyssinica identified antiviral components that potently and selectively inhibited infectivity of free RSV and HSV-2 particles, a feature of importance in topical treatment of these infections. This observation confirms ethno-medical information concerning the use of E. abyssinica extract for treatment of respiratory infections and herpetic lesions. © 2022 The Authors
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| 24. |
- Müller Kratz, Jadel, et al.
(author)
-
Anti-HSV-1 and anti-HIV-1 activity of gallic acid and pentyl gallate.
- 2008
-
In: Memórias do Instituto Oswaldo Cruz. - 1678-8060. ; 103:5, s. 437-42
-
Journal article (peer-reviewed)abstract
- The synthetic n-alkyl esters of gallic acid (GA), also known as gallates, especially propyl, octyl and dodecyl gallates, are widely employed as antioxidants by food and pharmaceutical industries. The inhibitory effects of GA and 15 gallates on Herpes Simplex Virus type 1 (HSV-1) and Human Immunodeficiency Virus (HIV-1) replication were investigated here. After a preliminary screening of these compounds, GA and pentyl gallate (PG) seemed to be the most active compounds against HSV-1 replication and their mode of action was characterized through a set of assays, which attempted to localize the step of the viral multiplication cycle where impairment occurred. The detected anti-HSV-1 activity was mediated by the inhibition of virus attachment to and penetration into cells, and by virucidal properties. Furthermore, an anti-HIV-1 activity was also found, to different degrees. In summary, our results suggest that both compounds could be regarded as promising candidates for the development of topical anti-HSV-1 agents, and further studies concerning the anti-HIV-1 activity of this group of molecules are merited.
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| 25. |
- Müller Kratz, Jadel, et al.
(author)
-
Evaluation of anti-HSV-2 activity of gallic acid and pentyl gallate.
- 2008
-
In: Biological & pharmaceutical bulletin. - 0918-6158. ; 31:5, s. 903-7
-
Journal article (peer-reviewed)abstract
- The synthetic n-alkyl esters of gallic acid, also known as gallates, are widely employed as antioxidants by food and pharmaceutical industries. Besides the antioxidant activity, other biological activities have been described for this group of molecules, mainly anticancer, antibacterial and antifungal properties. In the present study, the anti-herpes simplex virus (HSV)-2 activity of gallic acid and pentyl gallate was evaluated followed by the determination of the site of antiviral activity of these compounds. Our results demonstrated that both compounds reduced HSV-2 replication in a concentration-dependent manner when either incubated with the virus prior to the addition of the mixture to cells, or added to and incubated with cells after their infection. In summary, the anti-HSV-2 activity of gallic acid and pentyl gallate was ascribed to their virucidal effect on virus particles, a change that was likely accompanied by partial inhibition of the virus attachment to cells and its subsequent cell-to-cell spread activity. This suggests that these compounds can be regarded as promising candidates for development as topical anti-HSV-2 agents.
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| 26. |
- Mårdberg, Kristina, 1970, et al.
(author)
-
Basic amino acids as modulators of an O-linked glycosylation signal of the herpes simplex virus type 1 glycoprotein gC: functional roles in viral infectivity.
- 2004
-
In: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 14:7, s. 571-81
-
Journal article (peer-reviewed)abstract
- The herpes simplex virus type 1 (HSV-1) glycoprotein gC-1 is engaged both in viral attachment and viral immune evasion mechanisms in the infected host. Besides several N-linked glycans, gC-1 contains numerous O-linked glycans, mainly localized in two pronase-resistant clusters in the N-terminal domain of gC-1. In the present study we construct and characterize one gC-1 mutant virus, in which two basic amino acids (114K and 117R) in a putative O-glycosylation sequon were changed to alanine. We found that this modification did not modify the N-linked glycosylation but increased the content of O-linked glycans considerably. Analysis of the O-glycosylation capacity of wild-type and mutant gC-1 was performed by in vitro glycosylation assays with synthetic peptides derived from the mutant region predicted to present new O-glycosylation sites. Thus the mutant peptide region served as a better substrate for polypeptide GalNAc-transferase 2 than the wild-type peptide, resulting in increased rate and number of O-glycan attachment sites. The predicted increase in O-linked glycosylation resulted in two modifications of the biological properties of mutant virus-that is, an impaired binding to cells expressing chondroitin sulfate but not heparan sulfate on the cell surface and a significantly reduced plaque size in cultured cells. The results suggested that basic amino acids present within O-glycosylation signals may down-regulate the amount of O-linked glycans attached to a protein and that substitution of such amino acid residues may have functional consequences for a viral glycoprotein involving virus attachment to permissive cells as well as viral cell-to-cell spread.
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| 27. |
- Nordén, Rickard, 1977, et al.
(author)
-
Involvement of viral glycoprotein gC-1 in expression of the selectin ligand sialyl-Lewis X induced after infection with herpes simplex virus type 1.
- 2013
-
In: APMIS : acta pathologica, microbiologica, et immunologica Scandinavica. - : Wiley. - 1600-0463. ; 121:4, s. 280-289
-
Journal article (peer-reviewed)abstract
- Several herpesviruses induce expression of the selectin receptor sialyl-Lewis X (sLe(x) ) by activating transcription of one or more of silent host FUT genes, each one encoding a fucosyltransferase that catalyses the rate-limiting step of sLe(x) synthesis. The aim here was to identify the identity of the glycoconjugate associated with sLe(x) glycoepitope in herpes simplex virus type 1 (HSV-1) infected human diploid fibroblasts, using immunofluorescence confocal microscopy. Cells infected with all tested HSV-1 strains analysed demonstrated bright sLe(x) fluorescence, except for two mutant viruses that were unable to induce proper expression of viral glycoprotein gC-1: One gC-1 null mutant and another mutant expressing gC-1 devoid of its major O-glycan-containing region (aa 33-116). The sLe(x) reactivity of HSV-1 infected cells was abolished by mild alkali treatment. Altogether the results indicated that the detectable sLe(x) was associated with O-linked glycans, situated in the mucin region of gC-1. No evidence for sLe(x) (i) in other HSV-1 glycoproteins with mucin domains such as gI-1 or (ii) in host cell glycoproteins/glycolipids was found. Thus, the mucin domain of HSV-1 gC-1 may support expression of selectin ligands such as sLe(x) and other larger O-linked glycans in cell types lacking endogenous mucin domain-containing glycoproteins, optimized for O-glycan expression, provided that the adequate host glycosyltransferase genes are activated.
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| 28. |
- Nyberg, Kicki, 2000, et al.
(author)
-
The low molecular weight heparan sulfate-mimetic, PI-88, inhibits cell-to-cell spread of herpes simplex virus.
- 2004
-
In: Antiviral research. - : Elsevier BV. - 0166-3542. ; 63:1, s. 15-24
-
Journal article (peer-reviewed)abstract
- Although a number of sulfated polysaccharides have been shown to inhibit infection of cells by herpes simplex virus (HSV), little is known about their effects on the cell-to-cell spread of the virus. These compounds act by inhibiting the virus binding to cells, and their antiviral potencies usually increase with increasing molecular weight and sulfation density. We report that the low molecular weight HS-mimetic, PI-88, which is a mixture of highly sulfated mannose-containing di- to hexa-saccharides, inhibited HSV infection of cells and cell-to-cell spread of HSV-1 and HSV-2. Compared to a relatively large heparin polysaccharide, PI-88 demonstrated weaker inhibition of HSV infectivity but more efficient reduction of cell-to-cell spread of HSV. A tetrasaccharide fraction of PI-88 was the minimum fragment necessary to inhibit HSV-1 infectivity, while a trisaccharide was sufficient to reduce cell-to-cell spread. A reduction in HSV lateral spread was also observed in cells incubated with another low molecular weight compound, pentosan polysulfate but not with much larger polysaccharide chondroitin sulfate E. Some differences as regards the effects of PI-88, heparin, protamine, poly-L-lysine and sodium chlorate on intercellular spread of HSV-1 and HSV-2 were found. We conclude that structurally different sulfated oligosaccharides are preferred for inhibition of HSV infectivity and the cell-to-cell spread. The latter was efficiently inhibited by a relatively small but densely sulfated PI-88 oligosaccharide, very likely due to the capability of the compound to access the narrow intercellular space.
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| 29. |
- Olofsson, Sigvard, 1948, et al.
(author)
-
Structure and Role of O-Linked Glycans in Viral Envelope Proteins
- 2023
-
In: Annual Review of Virology. - : Annual Reviews. - 2327-056X. ; 10:1, s. 283-304
-
Journal article (peer-reviewed)abstract
- N- and O-glycans are both important constituents of viral envelope glycoproteins. O-linked glycosylation can be initiated by any of 20 different human polypeptide O-acetylgalactosaminyl transferases, resulting in an important functional O-glycan heterogeneity. O-glycans are organized as solitary glycans or in clusters of multiple glycans forming mucin-like domains. They are functional both in the viral life cycle and in viral colonization of their host. Negatively charged O-glycans are crucial for the interactions between glycosaminoglycan-binding viruses and their host. A novel mechanism, based on controlled electrostatic repulsion, explains how such viruses solve the conflict between optimized viral attachment to target cells and efficient egress of progeny virus. Conserved solitary O-glycans appear important for viral uptake in target cells by contributing to viral envelope fusion. Dual roles of viral O-glycans in the host B cell immune response, either epitope blocking or epitope promoting, may be exploitable for vaccine development. Finally, specific virus-induced O-glycans may be involved in viremic spread.
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| 30. |
- Peerboom, Nadia, 1990, et al.
(author)
-
Binding Kinetics and Lateral Mobility of HSV-1 on End-Grafted Sulfated Glycosaminoglycans
- 2017
-
In: Biophysical Journal. - : Elsevier BV. - 0006-3495 .- 1542-0086. ; 113:6, s. 1223-1234
-
Journal article (peer-reviewed)abstract
- Many viruses, including herpes simplex (HSV), are recruited to their host cells via interaction between their envelope glycoproteins and cell-surface glycosaminoglycans (GAGs). This initial attachment is of a multivalent nature, i.e., it requires the establishment of multiple bonds between amino acids of viral glycoproteins and sulfated saccharides on the GAG chain. To gain understanding of how this binding process is modulated, we performed binding kinetics and mobility studies using end-grafted GAG chains that mimic the end attachment of these chains to proteoglycans. Total internal reflection fluorescence microscopy was used to probe binding and release, as well as the diffusion of single HSV-1 particles. To verify the hypothesis that the degree of sulfation, but also the arrangement of sulfate groups along the GAG chain, plays a key role in HSV binding, we tested two native GAGs (chondroitin sulfate and heparan sulfate) and compared our results to chemically sulfated hyaluronan. HSV-1 recognized all sulfated GAGs, but not the nonsulfated hyaluronan, indicating that binding is specific to the presence of sulfate groups. Furthermore we observed that a notable fraction of GAG-bound virions exhibit lateral mobility, although the multivalent binding to the immobilized GAG brushes ensures firm virus attachment to the interface. Diffusion was faster on the two native GAGs, one of which, chondroitin sulfate, was also characterized by the highest association rate per GAG chain. This highlights the complexity of multivalent virus-GAG interactions and suggests that the spatial arrangement of sulfates along native GAG chains may play a role in modulating the characteristics of the HSV-GAG interaction. Altogether, these results, obtained with a minimal and well-controlled model of the cell membrane, provide, to our knowledge, new insights into the dynamics of the HSV-GAG interaction.
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| 31. |
- Peerboom, Nadia, 1990, et al.
(author)
-
Cell Membrane Derived Platform To Study Virus Binding Kinetics and Diffusion with Single Particle Sensitivity
- 2018
-
In: Acs Infectious Diseases. - : American Chemical Society (ACS). - 2373-8227. ; 4:6, s. 944-953
-
Journal article (peer-reviewed)abstract
- Discovery and development of new antiviral therapies essentially rely on two key factors: an in-depth understanding of the mechanisms involved in viral infection and the development of fast and versatile drug screening platforms. To meet those demands, we present a biosensing platform to probe virus-cell membrane interactions on a single particle level. Our method is based on the formation of supported lipid bilayers from cell membrane material. Using total internal reflection fluorescence microscopy, we report the contribution of viral and cellular components to the interaction kinetics of herpes simplex virus type 1 with the cell membrane. Deletion of glycoprotein C (gC), the main viral attachment glycoprotein, or deletion of heparan sulfate, an attachment factor on the cell membrane, leads to an overall decrease in association of virions to the membrane and faster dissociation from the membrane. In addition to this, we perform binding inhibition studies using the antiviral compound heparin to estimate its IC50 value. Finally, single particle tracking is used to characterize the diffusive behavior of the virus particles on the supported lipid bilayers. Altogether, our results promote this platform as a complement to existing bioanalytical assays, being at the interface between simplified artificial membrane models and live cell experiments.
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| 32. |
- Saguti, Fredy, et al.
(author)
-
Surveillance of wastewater revealed peaks of SARS-CoV-2 preceding those of hospitalized patients with COVID-19
- 2021
-
In: Water Research. - : Elsevier BV. - 0043-1354 .- 1879-2448. ; 189
-
Journal article (peer-reviewed)abstract
- SARS-CoV-2 was discovered among humans in Wuhan, China in late 2019, and then spread rapidly, causing a global pandemic. The virus was found to be transmitted mainly by respiratory droplets from infected persons or by direct contact. It was also shown to be excreted in feces, why we investigated whether the virus could be detected in wastewater and if so, to which extent its levels reflects its spread in society. Samples of wastewater from the city of Gothenburg, and surrounding municipalities in Sweden were collected daily from mid-February until June 2020 at the Rya wastewater treatment plant. Flow proportional samples of wastewater were collected to ensure that comparable amounts were obtained for analysis. Daily samples were pooled into weekly samples. Virus was concentrated on a filter and analyzed by RT-qPCR. The amount of SARS-CoV-2 varied with peaks approximately every four week, preceding variations in number of newly hospitalized patients by 19-21 days. At that time virus testing for COVID-19 was limited to patients with severe symptoms. Local differences in viral spread was shown by analyzing weekly composite samples of wastewater from five sampling sites for four weeks. The highest amount of virus was found from the central, eastern, and northern parts of the city. SARS-CoV-2 was also found in the treated effluent wastewater from the WWTP discharged into the recipient, the Göta River, although with a reduction of 4-log10. The viral peaks with regular temporal intervals indicated that SARS-CoV-2 may have a cluster spread, probably reflecting that the majority of infected persons only spread the disease during a few days. Our results are important for both the planning of hospital care and to rapidly identify and intervene against local spread of the virus.
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| 33. |
- Said, Joanna, et al.
(author)
-
HIV-1 variants with reduced sensitivity to sulfated oligosaccharide muparfostat contain mutations in the envelope glycoproteins gp120 and gp41
- 2013
-
In: Journal of Antivirals and Antiretrovirals. - : OMICS Publishing Group. - 1948-5964. ; 5:3, s. 50-56
-
Journal article (peer-reviewed)abstract
- Attachment of human immunodefciency virus type 1 (HIV-1) to host cells is primarily mediated by cell surface molecules CD4 and either of the chemokine co-receptors CCR5 or CXCR4, and is facilitated by cellular heparansulfate chains of syndecans. Although mimetics of heparansulfate exhibit potent anti-HIV-1 activity in cultured cells, these compounds failed to prevent infection in humans when used in clinical trials as microbicides. We have previously shown that the low molecular weight and extensively sulfated oligosaccharide muparfostat coupled to cholestanol exhibited virucidal activity while the non-conjugated muparfostat (formerly known as PI-88) inhibited HIV-1 infection of cultured cells in a reversible manner only. To initiate clarifcation of distinct anti-HIV-1 potencies of muparfostat and muparfostat-cholestanol conjugate, in this work we sought to select for viral resistance using the less potent muparfostat. The laboratory strain HIV-1IIIB was successively propagated in H9 cells in the presence of the compound. The virus selected for after 21-24 passages appeared to be approximately 3-4 times less sensitive to muparfostat than the original HIV-1IIIB strain or control virus passaged in parallel in the absence of muparfostat. Comparative analysis of nucleotide sequences of these viruses revealed presence of the I152V substitution in V2, the K276R change in V3, the deletion of fve amino acid repeat 366FNSTW370 in V4 of gp120, and the L33S and A101T alterations in transmembrane gp41 component of the muparfostat passaged virus. Selection for viral variants with mutations in gp41 was an unexpected observation as this protein of HIV-1 is seldom targeted by sulfated polysaccharides. © 2013 Said J, et al.
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| 34. |
- Said, Joanna, et al.
(author)
-
Lipophile-conjugated sulfated oligosaccharides as novel microbicides against HIV-1.
- 2010
-
In: Antiviral research. - : Elsevier BV. - 1872-9096 .- 0166-3542. ; 86:3, s. 286-295
-
Journal article (peer-reviewed)abstract
- With the aim of providing compounds suitable for further development as microbicides active against human immunodeficiency virus 1 (HIV-1) a library containing 37 lipophile-conjugated sulfated oligosaccharides was screened for antiviral and virucidal activity against this virus. Four highly active compounds had low drug inhibition concentrations (IC(50)) for HIV-1 and inactivated viral particles, suggestive of virucidal properties. Two of these compounds comprising a sulfated tetrasaccharide linked to a cholestanol group by a glycosidic bond, showed low toxicity and high selectivity indices. The two compounds were active both against CCR5 and dual-tropic CCR5/CXCR4 clinical HIV-1 isolates. Since herpes simplex virus type 2 (HSV-2) may be a cofactor for HIV-1 infection, the virucidal effect of the compounds was demonstrated against both viruses when mixed and incubated together on permissive cells. Incubation of compounds with serum, and to a lesser degree, cervical secretions, reduced the HIV-1 inactivating capacity, which suggests the need for molecular modification to reduce host protein binding. Considering the virucidal effect and low toxicity, these sulfated oligosaccharides with lipophilic tails may offer new possibilities of microbicide development.
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| 35. |
- Said, Joanna, et al.
(author)
-
The Cholestanol-Conjugated Sulfated Oligosaccharide PG545 Disrupts the Lipid Envelope of Herpes Simplex Virus Particles
- 2016
-
In: Antimicrobial agents and chemotherapy. - 1098-6596. ; 60:2, s. 1049-1057
-
Journal article (peer-reviewed)abstract
- Herpes simplex virus (HSV) and many other viruses including HIV initiate infection of host cells by binding to glycosaminoglycan (GAG) chains of cell surface proteoglycans. Although GAG mimetics such as sulfated oligo- and polysaccharides exhibit potent antiviral activity in cultured cells, the prophylactic application of these inhibitors as vaginal microbicides failed to protect women on their exposure to HIV infection. A possible explanation for this failure is that sulfated oligo- and polysaccharides exhibit no typical virucidal activity as their interaction with viral particles is largely electrostatic and reversible, and thereby vulnerable to competition with GAG-binding proteins of genital tract. Here we report that the cholestanol-conjugated sulfated oligosaccharide PG545, but not several other sulfated oligosaccharides lacking this modification, exhibited virucidal activity manifested as disruption of the lipid envelope of HSV-2 particles. Significance of the virus particle-disrupting activity of PG545 was also documented in experimental animals, as this compound in contrast to unmodified sulfated oligosaccharide protected mice against genital infection with HSV-2. Thus, PG545 offers a novel prophylaxis option against infections caused by GAG-binding viruses.
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| 36. |
- Trybala, Edward, 1955, et al.
(author)
-
Herpes Simplex Virus Type 2 Mucin-Like Glycoprotein mgG Promotes Virus Release from the Surface of Infected Cells
- 2021
-
In: Viruses. - : MDPI AG. - 1999-4915. ; 13:5
-
Journal article (peer-reviewed)abstract
- The contribution of virus components to liberation of herpes simplex virus type 2 (HSV-2) progeny virions from the surface of infected cells is poorly understood. We report that the HSV-2 mutant deficient in the expression of a mucin-like membrane-associated glycoprotein G (mgG) exhibited defect in the release of progeny virions from infected cells manifested by similar to 2 orders of magnitude decreased amount of infectious virus in a culture medium as compared to native HSV-2. Electron microscopy revealed that the mgG deficient virions were produced in infected cells and present at the cell surface. These virions could be forcibly liberated to a nearly native HSV-2 level by the treatment of cells with glycosaminoglycan (GAG)-mimicking oligosaccharides. Comparative assessment of the interaction of mutant and native virions with surface-immobilized chondroitin sulfate GAG chains revealed that while the mutant virions associated with GAGs similar to fourfold more extensively, the lateral mobility of bound virions was much poorer than that of native virions. These data indicate that the mgG of HSV-2 balances the virus interaction with GAG chains, a feature critical to prevent trapping of the progeny virions at the surface of infected cells.
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| 37. |
- Trybala, Edward, 1955, et al.
(author)
-
Structural and functional features of the polycationic peptide required for inhibition of herpes simplex virus invasion of cells.
- 2004
-
In: Antiviral research. - : Elsevier BV. - 0166-3542. ; 62:3, s. 125-34
-
Journal article (peer-reviewed)abstract
- Glycoprotein C (gC) of herpes simplex virus type 1 (HSV-1) mediates initial virus contact with cells by binding to heparan sulfate (HS) chains. The synthetic peptide 137GSRVQIRCRFRNSTR151 overlapping a major part of the HS-binding site of gC inhibited HSV-1 infection and, to some extent, HSV-2 infection of cells. Experiments on mutant, glycosaminoglycan-deficient cells as well as the binding assays involving peptide and purified cell surface components identified HS, and, to a lesser degree, chondroitin sulfate as sites of peptide activity. Anti-HSV-1 activity of the peptide was due to (i) partial inhibition of virus binding to cells and (ii) arresting the virions, which managed to attach to the cells in the presence of peptide, at a step of initial relatively weak binding. Analysis of the ionic-strength dependence of the peptide-HS and the virus-HS interactions revealed that the more efficient inhibition by the peptide of HSV-1 than HSV-2 infectivity was due to a relatively high affinity of HSV-2 for HS, a feature of importance in overcoming the peptide block. Mutational analysis of viral gC and peptide variants identified, apart from basic amino acids, two hydrophobic residues Ile(142) and Phe(146) as important in maintaining the specific affinity of peptide for HS and, hence, its anti-HSV activity. These results could contribute to the development of anti-HSV compounds that target initial events in the virus-cell interaction.
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| 38. |
- Umereweneza, Daniel, et al.
(author)
-
Antiviral iridoid glycosides from Clerodendrum myricoides
- 2021
-
In: Fitoterapia. - : Elsevier BV. - 0367-326X .- 1873-6971. ; 155
-
Journal article (peer-reviewed)abstract
- The methanol root extract of Clerodendrum myricoides (Hochst.) Vatke afforded two new (1, 2) and two known (3, 4) iridoid glycosides. The structures of the isolated compounds were established based on NMR, IR, UV and MS data analyses. The crude extract and the isolated constituents were assayed for antiviral activity against the human respiratory syncytial virus (RSV) in human laryngeal epidermoid carcinoma (HEp-2) cells. The crude extract inhibited RSV infectivity at EC50 = 0.21 mu g/ml, while it showed cytotoxicity against HEp-2 cells with CC50 = 9 mu g/ml. Compound 2 showed 43.2% virus inhibition at 100 mu M, while compounds 1 as well as 3 and 4 had only weak antiviral and cytotoxic activities.
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| 39. |
- Uyama, Toru, et al.
(author)
-
Chondroitin 4-O-sulfotransferase-1 regulates E disaccharide expression of chondroitin sulfate required for herpes simplex virus infectivity.
- 2006
-
In: The Journal of biological chemistry. - 0021-9258. ; 281:50, s. 38668-74
-
Journal article (peer-reviewed)abstract
- We have demonstrated a defect in expression of chondroitin 4-O-sulfotransferase-1 (C4ST-1) in murine sog9 cells, which are poorly sensitive to infection by herpes simplex virus type 1 (HSV-1). Sog9 cells were previously isolated as CS-deficient cells from gro2C cells, which were partially resistant to HSV-1 infection and defective in the expression of heparan sulfate (HS) because of a splice site mutation in the EXT1 gene encoding the HS-synthesizing enzyme. Here we detected a small amount of CS chains in sog9 cells with a drastic decrease in 4-O-sulfation compared with the parental gro2C cells. RT-PCR revealed that sog9 cells had a defect in the expression of C4ST-1 in addition to EXT1. Gel filtration analysis showed that the decrease in the amount of CS in sog9 cells was the result of a reduction in the length of CS chains. Transfer of C4ST-1 cDNA into sog9 cells (sog9-C4ST-1) restored 4-O-sulfation and amount of CS, verifying that sog9 cells had a specific defect in C4ST-1. Furthermore, the expression of C4ST-1 rendered sog9 cells significantly more susceptible to HSV-1 infection, suggesting that CS modified by C4ST-1 is sufficient for the binding and infectivity of HSV-1. Analysis of CS chains of gro2C and sog9-C4ST-1 cells revealed a considerable proportion of the E disaccharide unit, consistent with our recent finding that this unit is an essential component of the HSV receptor. These results suggest that C4ST-1 regulates the expression of the E disaccharide unit and the length of CS chains, the features that facilitate infection of cells by HSV-1.
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