| 1. |
- Adamiak, Beata, et al.
(author)
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Herpes simplex virus type 2 glycoprotein g is targeted by the sulfated oligo- and polysaccharide inhibitors of virus attachment to cells
- 2007
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In: Journal of Virology. - 0022-538X. ; 81:24, s. 13424-13434
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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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| 2. |
- Ekblad, Maria, 1978, et al.
(author)
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A highly lipophilic sulfated tetrasaccharide glycoside related to muparfostat (PI-88) exhibits virucidal activity against herpes simplex virus.
- 2010
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In: Antiviral research. - : Elsevier BV. - 1872-9096 .- 0166-3542. ; 86:2, s. 196-203
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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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| 3. |
- Ekblad, Maria, 1978
(author)
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Anti-herpes simplex virus activities of sulfomannan oligosaccharide PI-88 and disulfated cyclitols
- 2007
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Doctoral thesis (other academic/artistic)abstract
- Herpes simplex virus (HSV) initiates invasion of human cells by binding to the cell surface heparan sulfate (HS) glycosaminoglycan chains. This step is mediated by the viral envelope glycoproteins gC and/or gB. Sulfated polysaccharides are compounds that mimic the structure of HS chains, and therefore are capable of inhibiting HSV attachment to and subsequent infection of cells. However the high molecular weight and associated with it poor tissue-penetrating activity have limited potential antiviral application of sulfated polysaccharides in humans. Here we found that the HS mimetic PI-88, a sulfomannan oligosaccharide of low molecular weight, efficiently reduced, in contrast to conventional sulfated polysaccharides, the cell-to-cell spread of HSV. Analogues of PI-88 with chemical modifications based on the introduction of specific hydrophobic/aromatic group(s) at the reducing end of PI-88 oligosaccharide chain showed enhanced capability to inhibit infection of cells and the cell-to-cell transmission of HSV and respiratory syncytial virus (RSV). One of these analogues (denoted 536), prepared by modification of PI-88 with cholestanol group, exhibited in contrast to the parental compound an HSV-inactivating activity. Furthermore, several disulfated cyclitols, identified by screening for an anti-HSV activity of a large number of low molecular weight sulfated compounds, efficiently reduced the cell-to-cell spread of HSV and demonstrated the HSV-inactivating activity. The second aim of this thesis was to elucidate the molecular basis for viral resistance to PI-88. Variants of HSV type 1 (HSV-1) and type 2 (HSV-2), selected for by virus propagation in cultured cells in the presence of PI-88 were analysed. Many of these variants had a low infectious titer, indicative of a profound impairment in biological activities of the virus in response to continuous pressure from the drug. These variants were substantially resistant to PI-88 presence during their initial infection of cells and/or their cell-to-cell spread. Nucleotide sequence analysis revealed that PI-88 targeted predominantly the viral envelope glycoproteins that comprise mucin-like region(s), i.e., glycoprotein gC of HSV-1 and glycoprotein gG of HSV-2. The deletion of the mucin-like region of HSV-1 gC (amino acids 33-116) or the deletion of whole HSV-2 gG provided the virus with selective advantage to attach to and to infect cells in the presence of PI-88. In conclusion, we have identified several novel antiviral compounds. One of these compounds, the PI-88 analogue 536, seems to be an attractive candidate for the development of a topical virucide for prevention of genital HSV infections in humans. We have also identified a novel biological function of HSV-2 gG, i.e., its targeting by sulfated oligosaccharides, which suggests involvement of this protein in HSV-2 attachment to cells or in modulation of this step.
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| 4. |
- Ekblad, Maria, 1978, et al.
(author)
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Anti-herpes simplex virus activities of two novel disulphated cyclitols.
- 2006
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In: Antiviral chemistry & chemotherapy. - 0956-3202. ; 17:2, s. 97-106
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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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| 5. |
- Ekblad, Maria, 1978, et al.
(author)
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Molecular basis for resistance of herpes simplex virus type 1 mutants to the sulfated oligosaccharide inhibitor PI-88.
- 2007
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In: Virology. - : Elsevier BV. - 0042-6822. ; 367:2, s. 244-52
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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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| 6. |
- Görander, Staffan, 1952, et al.
(author)
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Anti-Glycoprotein G Antibodies of Herpes Simplex Virus 2 Contribute to Complete Protection after Vaccination in Mice and Induce Antibody-Dependent Cellular Cytotoxicity and Complement-Mediated Cytolysis
- 2014
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In: Viruses-Basel. - : MDPI AG. - 1999-4915. ; 6:11, s. 4358-4372
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Journal article (peer-reviewed)abstract
- We investigated the role of antibodies against the mature portion of glycoprotein G (mgG-2) of herpes simplex virus 2 (HSV-2) in protective immunity after vaccination. Mice were immunized intramuscularly with mgG-2 and oligodeoxynucleotides containing two CpG motifs plus alum as adjuvant. All C57BL/6 mice survived and presented no genital or systemic disease. High levels of immunoglobulin G subclass 1 (IgG1) and IgG2 antibodies were detected and re-stimulated splenic CD4(+) T cells proliferated and produced IFN-gamma. None of the sera from immunized mice exhibited neutralization, while all sera exerted antibody-dependent cellular cytotoxicity (ADCC) and complement-mediated cytolysis (ACMC) activity. Passive transfer of anti-mgG-2 monoclonal antibodies, or immune serum, to naive C57BL/6 mice did not limit disease progression. Immunized B-cell KO mice presented lower survival rate and higher vaginal viral titers, as compared with vaccinated B-cell KO mice after passive transfer of immune serum and vaccinated C57BL/6 mice. Sera from mice that were vaccinated subcutaneously and intranasally with mgG-2 presented significantly lower titers of IgG antibodies and lower ADCC and ACMC activity. We conclude that anti-mgG-2 antibodies were of importance to limit genital HSV-2 infection. ADCC and ACMC activity are potentially important mechanisms in protective immunity, and could tentatively be evaluated in future animal vaccine studies and in clinical trials.
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| 7. |
- Nyberg, Kicki, 2000, et al.
(author)
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The low molecular weight heparan sulfate-mimetic, PI-88, inhibits cell-to-cell spread of herpes simplex virus.
- 2004
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In: Antiviral research. - : Elsevier BV. - 0166-3542. ; 63:1, s. 15-24
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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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| 8. |
- Said, Joanna, et al.
(author)
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The Cholestanol-Conjugated Sulfated Oligosaccharide PG545 Disrupts the Lipid Envelope of Herpes Simplex Virus Particles
- 2016
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In: Antimicrobial agents and chemotherapy. - 1098-6596. ; 60:2, s. 1049-1057
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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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| 9. |
- Thomsson, Elisabeth, 1975, et al.
(author)
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Recombinant glycoprotein E produced in mammalian cells in large-scale as an antigen for varicella-zoster-virus serology.
- 2011
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In: Journal of virological methods. - : Elsevier BV. - 1879-0984 .- 0166-0934. ; 175:1, s. 53-9
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Journal article (peer-reviewed)abstract
- A recombinant glycoprotein E (gE) from varicella-zoster virus (VZV) was generated and produced in Chinese Hamster Ovary (CHO) cells, in the development of a specific antigen for analysis of IgG antibodies to VZV. Several stable gE-secreting clones were established and one clone was adapted to growth in serum-free suspension culture. When the cells were cultured in a perfusion bioreactor, gE was secreted into the medium, from where it could be easily purified. The recombinant gE was then evaluated as a serological antigen in ELISA. When compared to a conventional whole virus antigen, the VZV gE showed similar results in ELISA-based seroprevalence studies of 854 samples derived from blood donors, students, ischemic stroke patients and their controls, including samples with border-line results in previous analyses. Eight samples (0.9%) were discordant, all being IgG-negative by the VZV gE ELISA and positive by the whole virus ELISA. The sensitivity and specificity of the VZV gE ELISA were 99.9% and 100%, respectively, compared to 100% and 88.9% for the VZV whole virus ELISA. The elderly subjects showed similar reactivities to both antigens, while VZV gE gave lower signals in the younger cohorts, suggesting that antibodies to gE may increase with age. It was concluded that the recombinant VZV gE from CHO cells was suitable as a serological antigen for the detection of IgG antibodies specific for VZV.
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| 10. |
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