| 1. |
- Skovbjerg, Susann, 1973, et al.
(författare)
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High cytokine levels in perforated acute otitis media exudates containing live bacteria
- 2010
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Ingår i: Clinical microbiology and infection. - : Elsevier BV. - 1469-0691 .- 1198-743X. ; 16:9, s. 1382-1388
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Tidskriftsartikel (refereegranskat)abstract
- Acute otitis media (AOM) is an inflammatory response to microbes in the middle ear, sometimes associated with rupture of the tympanic membrane. Human leukocytes produce different patterns of inflammatory mediators in vitro when stimulated with Gram-positive and Gram-negative bacteria, respectively. Here, we investigated the cytokine and prostaglandin E(2) (PGE(2)) responses in middle ear fluids (MEFs) from children with spontaneous perforated AOM and related the levels to the presence of pathogens detected by culture (live) or PCR (live or dead). Furthermore, in vivo cytokine pattern was compared with that induced in leukocytes stimulated by dead bacteria in vitro. MEFs with culturable pathogenic bacteria contained more IL-1beta (median 110 vs <7.5 ng/ml), TNF (6.3 vs <2.5 ng/ml), IL-8 (410 vs 38 ng/ml), and IL-10 (0.48 vs <0.30 ng/ml), than culture negative fluids, irrespective of PCR findings. IL-6 and PGE(2) were equally abundant (69-110 ng/ml) in effusions with live, dead or undetectable bacteria. Cytokine levels were unrelated to bacterial species and to the presence or absence of virus. Similar levels of TNF and IL-6 as found in the MEFs were obtained by in vitro stimulation of leukocytes, while 11x more IL-1beta and 3.5x more IL-8 was produced in vivo, and 22x more IL-10 was produced in vitro. A vigorous production of pro-inflammatory cytokines accompany AOM with membrane rupture regardless of causative agent, but the production seems to cease rapidly once the bacteria are killed and fragmented. IL-6 and PGE(2), however, remain after bacterial disintegration and may play a role in the resolution phase.
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| 2. |
- Skovbjerg, Susann, 1973, et al.
(författare)
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High Cytokine Levels in Tonsillitis Secretions Regardless of Presence of Beta-Hemolytic Streptococci
- 2015
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Ingår i: Journal of Interferon and Cytokine Research. - : Mary Ann Liebert Inc. - 1079-9907 .- 1557-7465. ; 35:9, s. 682-689
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Tidskriftsartikel (refereegranskat)abstract
- Acute pharyngotonsillitis denotes tonsillar inflammation caused by bacteria or viruses. Here, we investigated if beta-hemolytic streptococci (beta-HS) tonsillitis would differ in inflammatory mediator response from tonsillitis of other causes. Tonsillar secretions were obtained from 36 acute pharyngotonsillitis patients and 16 controls. Bacteria were cultured quantitatively and 18 different viruses were quantified by real-time polymerase chain reaction. Cytokine and prostaglandin E-2 (PGE(2)) levels were determined by enzyme-linked immunosorbent assays. Almost half of the patients' tonsillar secretions yielded high counts of beta-HS, and most samples contained viruses, irrespective of whether beta-HS were present or not. The Epstein-Barr virus (EBV) was the most common virus (patients 62% and controls 13%). Compared to controls, patients' secretions had higher levels of interleukin (IL)-1 beta, IL-6, IL-8, tumor necrosis factor (TNF), and PGE(2), while few samples contained IL-12, IL-10, or interferon-gamma (IFN-gamma). The presence of beta-HS in tonsillitis secretions could not be distinguished by any of the measured mediators, while the presence of EBV DNA tended to be associated with enhanced levels of IL-1 beta and IL-8. The results suggest a common inflammatory response in acute pharyngotonsillitis, regardless of causative agent. The suggested correlation between intense inflammation and the presence of EBV DNA in tonsillitis secretions may be due to reactivation of the virus and/or the EBV-containing B cells.
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| 3. |
- Abidine, Yara, et al.
(författare)
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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
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Ingår i: Viruses. - : MDPI AG. - 1999-4915. ; 14:8
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Tidskriftsartikel (refereegranskat)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.
(författare)
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Human antibodies to herpes simplex virus type 1 glycoprotein C are neutralizing and target the heparan sulfate-binding domain
- 2010
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Ingår i: Virology. - : Elsevier BV. - 0042-6822. ; 400:2, s. 197-206
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Tidskriftsartikel (refereegranskat)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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| 5. |
- Andersson, E. M., et al.
(författare)
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Comparison of the FilmArray assay and in-house real-time PCR for detection of respiratory infection
- 2014
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Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 46:12, s. 897-901
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Tidskriftsartikel (refereegranskat)abstract
- Recently, molecular methods capable of detecting almost all microbial agents that may cause acute respiratory infection have been introduced. The FilmArray Respiratory Panel assay, which integrates nucleic acid extraction, nested amplification and detection in a reaction pouch preloaded with all reagents required for detection of 17 viruses and 3 bacteria, was compared with an in-house real-time PCR that detects these agents in 8 parallel amplifications. When 128 clinical samples representing 18 of these agents were analysed by both assays the agreement was excellent, with kappa values ranging between 0.54 and 1.0. Discordances were mainly observed for adenovirus, but not when version 1.7 of FilmArray was used. The results show that these assays detect a wide range of pathogens with similar performance. FilmArray provides results after approximately 1 h, including approximate to 5 min hands-on time, and does not require advanced equipment or expertise in molecular diagnostics, making it a useful point-of-care-test for acute respiratory infections.
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| 6. |
- Bagdonaite, I., et al.
(författare)
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A Strategy for O-Glycoproteomics of Enveloped Viruses-the O-Glycoproteome of Herpes Simplex Virus Type 1
- 2015
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Ingår i: Plos Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 11:4
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Tidskriftsartikel (refereegranskat)abstract
- Glycosylation of viral envelope proteins is important for infectivity and interaction with host immunity, however, our current knowledge of the functions of glycosylation is largely limited to N-glycosylation because it is difficult to predict and identify site-specific O-glycosylation. Here, we present a novel proteome-wide discovery strategy for O-glycosylation sites on viral envelope proteins using herpes simplex virus type 1 (HSV-1) as a model. We identified 74 O-linked glycosylation sites on 8 out of the 12 HSV-1 envelope proteins. Two of the identified glycosites found in glycoprotein B were previously implicated in virus attachment to immune cells. We show that HSV-1 infection distorts the secretory pathway and that infected cells accumulate glycoproteins with truncated O-glycans, nonetheless retaining the ability to elongate most of the surface glycans. With the use of precise gene editing, we further demonstrate that elongated O-glycans are essential for HSV-1 in human HaCaT keratinocytes, where HSV-1 produced markedly lower viral titers in HaCaT with abrogated O-glycans compared to the isogenic counterpart with normal O-glycans. The roles of O-linked glycosylation for viral entry, formation, secretion, and immune recognition are poorly understood, and the O-glycoproteomics strategy presented here now opens for unbiased discovery on all enveloped viruses.
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| 7. |
- Bagdonaite, I., et al.
(författare)
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Global Mapping of O-Glycosylation of Varicella Zoster Virus, Human Cytomegalovirus, and Epstein-Barr Virus
- 2016
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Ingår i: Journal of Biological Chemistry. - 0021-9258. ; 291:23, s. 12014-12028
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Tidskriftsartikel (refereegranskat)abstract
- Herpesviruses are among the most complex and widespread viruses, infection and propagation of which depend on envelope proteins. These proteins serve as mediators of cell entry as well as modulators of the immune response and are attractive vaccine targets. Although envelope proteins are known to carry glycans, little is known about the distribution, nature, and functions of these modifications. This is particularly true for O-glycans; thus we have recently developed a "bottom up" mass spectrometry-based technique for mapping O-glycosylation sites on herpes simplex virus type 1. We found wide distribution of O-glycans on herpes simplex virus type 1 glycoproteins and demonstrated that elongated O-glycans were essential for the propagation of the virus. Here, we applied our proteome-wide discovery platform for mapping O-glycosites on representative and clinically significant members of the herpesvirus family: varicella zoster virus, human cytomegalovirus, and Epstein-Barr virus. We identified a large number of O-glycosites distributed on most envelope proteins in all viruses and further demonstrated conserved patterns of O-glycans on distinct homologous proteins. Because glycosylation is highly dependent on the host cell, we tested varicella zoster virus-infected cell lysates and clinically isolated virus and found evidence of consistent O-glycosites. These results present a comprehensive view of herpesvirus O-glycosylation and point to the widespread occurrence of O-glycans in regions of envelope proteins important for virus entry, formation, and recognition by the host immune system. This knowledge enables dissection of specific functional roles of individual glycosites and, moreover, provides a framework for design of glycoprotein vaccines with representative glycosylation.
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| 8. |
- Bagdonaite, Ieva, et al.
(författare)
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Glycoengineered keratinocyte library reveals essential functions of specific glycans for all stages of HSV-1 infection
- 2023
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Ingår i: Nature Communications. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Viral and host glycans represent an understudied aspect of host-pathogen interactions, despite potential implications for treatment of viral infections. This is due to lack of easily accessible tools for analyzing glycan function in a meaningful context. Here we generate a glycoengineered keratinocyte library delineating human glycosylation pathways to uncover roles of specific glycans at different stages of herpes simplex virus type 1 (HSV-1) infectious cycle. We show the importance of cellular glycosaminoglycans and glycosphingolipids for HSV-1 attachment, N-glycans for entry and spread, and O-glycans for propagation. While altered virion surface structures have minimal effects on the early interactions with wild type cells, mutation of specific O-glycosylation sites affects glycoprotein surface expression and function. In conclusion, the data demonstrates the importance of specific glycans in a clinically relevant human model of HSV-1 infection and highlights the utility of genetic engineering to elucidate the roles of specific viral and cellular carbohydrate structures.
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| 9. |
- Berg, L., et al.
(författare)
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LIR-1 expression on lymphocytes, and cytomegalovirus disease in lung-transplant recipients
- 2003
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Ingår i: Lancet. - 0140-6736. ; 361:9363, s. 1099-101
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Tidskriftsartikel (refereegranskat)abstract
- Human cytomegalovirus infection is a major cause of morbidity after lung transplantation. LIR-1 (leucocyte immunoglobulin-like receptor-1) is an inhibitory cell surface receptor that has high affinity for an MHC class I homologue (UL18) encoded by human cytomegalovirus. We aimed to investigate whether reactivation of human cytomegalovirus affects the expression of LIR-1. We measured LIR-1 expression on peripheral blood lymphocytes from 13 lung-transplant recipients and established human cytomegalovirus load using PCR. Eight patients developed cytomegalovirus disease. The percentage of cells expressing LIR-1 increased in the patients who developed cytomegalovirus disease several weeks before viral DNA was detectable by PCR. Measurement of LIR-1 expression might allow early identification of cytomegalovirus disease in lung-transplant patients.
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| 10. |
- Brittain-Long, Robin, 1969, et al.
(författare)
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Access to a polymerase chain reaction assay method targeting 13 respiratory viruses can reduce antibiotics: a randomised, controlled trial.
- 2011
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Ingår i: BMC medicine. - : Springer Science and Business Media LLC. - 1741-7015. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Viral respiratory infections are common worldwide and range from completely benign disease to life-threatening illness. Symptoms can be unspecific, and an etiologic diagnosis is rarely established because of a lack of suitable diagnostic tools. Improper use of antibiotics is common in this setting, which is detrimental in light of the development of bacterial resistance. It has been suggested that the use of diagnostic tests could reduce antibiotic prescription rates. The objective of this study was to evaluate whether access to a multiplex polymerase chain reaction (PCR) assay panel for etiologic diagnosis of acute respiratory tract infections (ARTIs) would have an impact on antibiotic prescription rate in primary care clinical settings. METHODS: Adult patients with symptoms of ARTI were prospectively included. Nasopharyngeal and throat swabs were analysed by using a multiplex real-time PCR method targeting thirteen viruses and two bacteria. Patients were recruited at 12 outpatient units from October 2006 through April 2009, and samples were collected on the day of inclusion (initial visit) and after 10 days (follow-up visit). Patients were randomised in an open-label treatment protocol to receive a rapid or delayed result (on the following day or after eight to twelve days). The primary outcome measure was the antibiotic prescription rate at the initial visit, and the secondary outcome was the total antibiotic prescription rate during the study period. RESULTS: A total sample of 447 patients was randomised. Forty-one were excluded, leaving 406 patients for analysis. In the group of patients randomised for a rapid result, 4.5% (9 of 202) of patients received antibiotics at the initial visit, compared to 12.3% (25 of 204) (P = 0.005) of patients in the delayed result group. At follow-up, there was no significant difference between the groups: 13.9% (28 of 202) in the rapid result group and 17.2% (35 of 204) in the delayed result group (P = 0.359), respectively. CONCLUSIONS: Access to a rapid method for etiologic diagnosis of ARTIs may reduce antibiotic prescription rates at the initial visit in an outpatient setting. To sustain this effect, however, it seems necessary to better define how to follow and manage the patient according to the result of the test, which warrants further investigation. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01133782.
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| 11. |
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| 12. |
- Brittain-Long, Robin, 1969, et al.
(författare)
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Seasonal variations of 15 respiratory agents illustrated by the application of a multiplex polymerase chain reaction assay.
- 2011
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Ingår i: Scandinavian journal of infectious diseases. - : Informa UK Limited. - 1651-1980 .- 0036-5548.
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Background: Nucleic acid amplification tests are increasingly being used to diagnose viral and bacterial respiratory tract infections. The high sensitivity of these tests affects our understanding of the epidemiology of respiratory tract infections. We have assessed the detection rate of a multiplex real-time polymerase chain reaction (PCR) test, with emphasis on epidemiology and seasonal distribution of the most common respiratory tract infections. Methods: Seven thousand eight hundred and fifty-three nasopharyngeal samples from 7220 patients (age range 0-98 y, median 22 y) obtained during 36 consecutive months (November 2006-October 2009), were analyzed with a multiplex PCR panel including influenza A (IfA) and B (IfB) virus, parainfluenza virus (PIV) 1-3, respiratory syncytial virus (RSV), human rhinovirus (HRV), human coronavirus (CoV) OC43, NL63, and 229E, human metapneumovirus (HMPV), adenovirus (AdV), enterovirus (EV), and 2 bacteria - Mycoplasma pneumoniae and Chlamydophila pneumoniae. Results: Of the total samples, 44.5% (n = 3496) were positive for at least 1 agent, with HRV being the most common (n = 1482, 38.0%), followed by RSV (n = 526, 13.5%) and IfA (n = 403, 10.3%). The diagnostic yield was significantly higher during the winter and early spring compared to the summer (n = 2439 of 4458 samples, 54.7% and n = 1057 of 3395 samples, 31.1%, respectively; p < 0.001). Conclusions: The diagnostic yield was highly dependent on the month of sampling and the age of the patient. However, the overall detection rate per month was above 30%, apart for August and September. Our findings support the use of similar tests in routine clinical care all year round. HRV was the most common finding in the respiratory tract, independent of season.
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| 13. |
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| 14. |
- Clo, E., et al.
(författare)
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Characterization of the Viral O-Glycopeptidome: a Novel Tool of Relevance for Vaccine Design and Serodiagnosis
- 2012
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Ingår i: Journal of Virology. - : American Society for Microbiology. - 0022-538X .- 1098-5514. ; 86:11, s. 6268-6278
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Tidskriftsartikel (refereegranskat)abstract
- Viral envelope proteins mediate interactions with host cells, leading to internalization and intracellular propagation. Envelope proteins are glycosylated and are known to serve important functions in masking host immunity to viral glycoproteins. However, the viral infectious cycle in cells may also lead to aberrant glycosylation that may elicit immunity. Our knowledge of immunity to aberrant viral glycans and glycoproteins is limited, potentially due to technical limitations in identifying immunogenic glycans and glycopeptide epitopes. This work describes three different complementary methods for high-throughput screening and identification of potential immunodominant O-glycopeptide epitopes on viral envelope glycoproteins: (i) on-chip enzymatic glycosylation of scan peptides, (ii) chemical glycopeptide microarray synthesis, and (iii) a one-bead-one-compound random glycopeptide library. We used herpes simplex virus type 2 (HSV-2) as a model system and identified a simple O-glycopeptide pan-epitope, (501)PPA(GalNAc)TAPG(507), on the mature gG-2 glycoprotein that was broadly recognized by IgG antibodies in HSV-2-infected individuals but not in HSV-1-infected or noninfected individuals. Serum reactivity to the extended sialyl-T glycoform was tolerated, suggesting that self glycans can participate in immune responses. The methods presented provide new insight into viral immunity and new targets for immunodiagnostic and therapeutic measures.
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| 15. |
- D'Arrigo, I., et al.
(författare)
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Diverse IgG serum response to novel glycopeptide epitopes detected within immunodominant stretches of Epstein-Barr virus glycoprotein 350/220: diagnostic potential of O-glycopeptide microarrays
- 2013
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Ingår i: Glycoconjugate Journal. - : Springer Science and Business Media LLC. - 0282-0080 .- 1573-4986. ; 30:7, s. 633-640
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Tidskriftsartikel (refereegranskat)abstract
- The Epstein-Barr virus (EBV) envelope glycoprotein 350/220 (gp350/220) is the most abundant molecule on the viral surface and it is responsible for the initial viral attachment to cell surface of the host. As many other viral envelope proteins, it is highly glycosylated, not least with O-linked glycans, most of which essential for EBV life cycle. EBV gp350/220 is also a primary target for neutralizing antibodies in the human hosts and a promising candidate for an EBV vaccine. Here we showed that recombinant GalNAc transferases can glycosylate scan peptides of the EBV gp350/220 envelope protein immobilized on microarray glass slides. We also identified serum IgG antibodies to a selection of peptides and O-glycopeptides, whereas sera from EBV-IgG negative individuals remained negative. We here describe novel glycopeptide epitopes present within immunodominant stretches of EBV gp350/220 and demonstrate a remarkable variability between individual samples with respect to their reactivity patterns to peptides and glycopeptides. The study provides additional insights into the complex B-cell response towards the EBV gp350/220 envelope protein, which may have implications for diagnostic and vaccine developments.
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| 16. |
- Delguste, Martin, et al.
(författare)
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Regulatory Mechanisms of the Mucin-Like Region on Herpes Simplex Virus during Cellular Attachment
- 2019
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Ingår i: ACS Chemical Biology. - : American Chemical Society (ACS). - 1554-8937 .- 1554-8929. ; 14:3, s. 534-542
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Tidskriftsartikel (refereegranskat)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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| 17. |
- Kullberg-Lindh, Carola, 1959, et al.
(författare)
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Comparison of serum and whole blood levels of cytomegalovirus and Epstein-Barr virus DNA.
- 2008
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Ingår i: Transplant infectious disease : an official journal of the Transplantation Society. - : Wiley. - 1399-3062. ; 10:5, s. 308-15
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Tidskriftsartikel (refereegranskat)abstract
- The monitoring of viral DNA levels after transplantation is crucial for prevention of complications from cytomegalovirus (CMV) or Epstein-Barr virus (EBV) infection but there is no consensus as to which matrix is the most adequate. To compare serum and whole blood (WB) as specimens for measuring viral DNA, clinical samples from a 3-year period were studied, with focus on cases where serum and WB were drawn on the same day. In 1896 paired serum and WB samples, CMV DNA was detected in both specimen types in 472 samples with 0.18 log higher levels (P<0.001) in WB than in serum (median level 2.73 vs. 2.56 log copies/mL), and in only either serum or WB in 127 and 108 samples, respectively, generally at levels below 1000 copies/mL. In 664 paired samples, EBV DNA was detected in both serum and WB in 160 samples, with 1.48 log higher levels (P<0.001) in WB (median 4.2 vs. 2.4 log copies/mL), in only WB in 227 cases with a median at 3.0 log copies/mL, and only in serum in 14 samples at low levels. The correlation between serum and WB DNA levels was weaker for EBV than for CMV (R(2) 0.31 vs. 0.74). We conclude that either serum or WB may be used for monitoring CMV and EBV DNA levels, that EBV DNA is detected post transplant in >50% of WB samples and at 30 times higher levels than in serum, and that post-transplantation lymphoproliferative disorder (PTLD) may develop without further increase of EBV DNA in WB. Identification of PTLD may require EBV DNA testing in both specimen types or complementary tests.
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| 18. |
- Kumlin, Urban, et al.
(författare)
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Sialic acid tissue distribution and influenza virus tropism
- 2008
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Ingår i: Influenza and Other Respiratory Viruses. - : Wiley. - 1750-2640 .- 1750-2659. ; 2:5, s. 147-154
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Forskningsöversikt (refereegranskat)abstract
- Avian influenza A viruses exhibit a strong preference for using alpha 2,3-linked sialic acid as a receptor. Until recently, the presumed lack of this receptor in human airways was believed to constitute an efficient barrier to avian influenza A virus infection of humans. Recent zoonotic outbreaks of avian influenza A virus have triggered researchers to analyse tissue distribution of sialic acid in further detail. Here, we review and extend the current knowledge about sialic acid distribution in human tissues, and discuss viruses with ocular tropism and their preference for a2,3-linked sialic acid.
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| 19. |
- Myhre, Susanna, 1974, et al.
(författare)
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Decreased immune reactivity towards a knobless, affibody-targeted adenovirus type 5 vector
- 2007
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Ingår i: Gene Therapy. - : Springer Science and Business Media LLC. - 0969-7128 .- 1476-5462. ; 14:4, s. 376-381
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a prototype Adenovirus type 5 (Ad5) vector deleted of the fiber knob domain and carrying an Affibody molecule as the targeting ligand showed decreased susceptibility to human pre-existing antibodies. This vector, Ad5/R7-Z(taq)Z(taq), has short fibers carrying seven shaft repeats, a non-native trimerization signal and an affibody molecule (Z(taq)) reactive to Taq polymerase. Ad5/R7-Z(taq)Z(taq) could be specifically targeted to 293 cells stably expressing membrane-bound anti-Z(taq) idiotypic affibody called Z(ztaq) (293Z(ztaq)). Sera from 50 blood donors were analyzed for neutralization activity (NA) against the parental Ad5/Fiwt vector and knobless Ad5/R7-Z(taq)Z(taq) on 293Z(ztaq) cells. Twenty-three sera had NA titers (>= 1:64) against Ad5/Fiwt (46%) and only two against Ad5/R7-Z(taq)Z(taq) (4%). Characterization of sera with NA titers showed that the knob domain is one of the targets of the antibodies. Neutralization assays using sera pre-adsorbed on knob and hexon proteins showed that the NA of the sera was carried mainly by anti-knob and anti-hexon antibodies, but in certain sera the anti-hexon antibodies represent the major population of the neutralizing antibodies (NAbs). Our results suggested that a combination of knob deletion and hexon switching could be an effective strategy for Ad vectors to better evade the anti-Ad NAbs.
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| 20. |
- Mårdberg, Kristina, 1970, et al.
(författare)
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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
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 14:7, s. 571-81
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Tidskriftsartikel (refereegranskat)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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| 21. |
- Namvar, Lilly, et al.
(författare)
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Detection and typing of Herpes Simplex virus (HSV) in mucocutaneous samples by TaqMan PCR targeting a gB segment homologous for HSV types 1 and 2.
- 2005
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Ingår i: Journal of clinical microbiology. - 0095-1137. ; 43:5, s. 2058-64
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Tidskriftsartikel (refereegranskat)abstract
- Herpes simplex virus types 1 (HSV-1) and 2 (HSV-2) are major causes of mucocutaneous lesions and severe infections of the central nervous system. Here a new semiautomated method for detecting and typing of HSV was used to analyze 479 mucocutaneous swab samples. After DNA extraction using a Magnapure LC robot, a 118-bp segment of the gB region was amplified by real-time PCR utilizing type-specific TaqMan probes to identify HSV-1 or HSV-2. HSV detection in a single well using probes labeled with carboxyfluorescein (FAM) for HSV-1 and JOE (6-carboxy-4',5'-dichloro-2',7'-dimethoxyfluorescein) for HSV-2 had a sensitivity similar to that seen in separate reactions. All but one of 217 samples (99.5%) that had been positive by virus culture were positive by TaqMan PCR, with a correct identification of type in all cases. Out of 262 samples negative by virus culture, 48 (18.3%) were positive by TaqMan PCR, with higher Ct values compared with culture positive samples (P < 0.0001). Overall, the Ct values for HSV-1 were lower than for HSV-2 (mean, 25.5 versus 27.9), but to some extent this could be due to weaker fluorescence by JOE. Lower C(t) values for HSV-1 were seen also in the 202 genital samples (79 HSV-1, 122 HSV-2, 1 HSV-1 and HSV-2), indicating that HSV-1 replicates as well as HSV-2 in the genital area. HSV-1 constituted 40% of genital infections and was associated with lower mean age (29.2 versus 36.4 years), probably reflecting the fact that recurrent genital HSV-1 infections are rare.
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| 22. |
- Nasir, Waqas, et al.
(författare)
-
Parvovirus B19 VLP recognizes globoside in supported lipid bilayers
- 2014
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Ingår i: Virology. - : Elsevier BV. - 0042-6822 .- 1096-0341. ; 456, s. 364-369
-
Tidskriftsartikel (refereegranskat)abstract
- Studies have suggested that the glycosphingolipid globoside (Gb4Cer) is a receptor for human parvovirus B19. Virus-like particles bind to Gb4Cer on thin-layer chromatograms, but a direct interaction between the virus and lipid membrane-associated Gb4Cer has been debated. Here, we characterized the binding of parvovirus B19 VP1/VP2 virus-like particles to glycosphingolipids (i) on thin-layer chromatograms (TLCs) and (ii) incorporated into supported lipid bilayers (SLBs) acting as cell-membrane mimics. The binding specificities of parvovirus B19 determined in the two systems were in good agreement; the VLP recognized both Gb4Cer and the Forssman glycosphingolipid on TLCs and in SLBs compatible with the role of Gb4Cer as a receptor for this virus.
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| 23. |
- Norberg, Peter, 1974, et al.
(författare)
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Glycoprotein I of herpes simplex virus type 1 contains a unique polymorphic tandem-repeated mucin region.
- 2007
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Ingår i: The Journal of general virology. - : Microbiology Society. - 0022-1317 .- 1465-2099. ; 88:Pt 6, s. 1683-8
-
Forskningsöversikt (refereegranskat)abstract
- Glycoprotein I (gI) of herpes simplex virus type 1 (HSV-1) contains a tandem repeat (TR) region including the amino acids serine and threonine, residues that can be utilized for O-glycosylation. The length of this TR region was determined for 82 clinical HSV-1 isolates and the results revealed a polymorphic distribution of two to six or eight repeated blocks with a majority harbouring between two and four repeats. Assessment of the O-glycosylation capacity of an acceptor peptide (STPSTTTSTPSTTT), representing two of the gI blocks, showed that the peptide was a universal substrate for O-glycosylation not only for the two most commonly expressed N-acetyl-d-galactosamine (GalNAc)-T1 and -T2 transferases, but also for the GalNAc-T3, -T4 and -T11 transferases. Immunoblotting of virus-infected cells showed that gI was exclusively O-glycosylated with GalNAc monosaccharides (Tn antigen). A polymorphic mucin region has not been described previously for HSV-1 and is a unique finding, as repeated blocks within gI homologues are lacking in other alphaherpesviruses.
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| 24. |
- Norberg, Peter, 1974, et al.
(författare)
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Published sequences do not support transfer of oseltamivir resistance mutations from avian to human influenza A virus strains
- 2015
-
Ingår i: Bmc Infectious Diseases. - : Springer Science and Business Media LLC. - 1471-2334. ; 15
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Tamiflu (oseltamivir phosphate ester, OE) is a widely used antiviral active against influenza A virus. Its active metabolite, oseltamivir carboxylate (OC), is chemically stable and secreted into wastewater treatment plants. OC contamination of natural habitats of waterfowl might induce OC resistance in influenza viruses persistently infecting waterfowl, and lead to transfer of OC-resistance from avian to human influenza. The aim of this study was to evaluate whether such has occurred. Methods: A genomics approach including phylogenetic analysis and probability calculations for homologous recombination was applied on altogether 19,755 neuraminidase (N1 and N2) genes from virus sampled in humans and birds, with and without resistance mutations. Results: No evidence for transfer of OE resistance mutations from avian to human N genes was obtained, and events suggesting recombination between human and avian influenza virus variants could not be traced in the sequence material studied. Conclusions: The results indicate that resistance in influenza viruses infecting humans is due to the selection pressure posed by the global OE administration in humans rather than transfer from avian influenza A virus strains carrying mutations induced by environmental exposure to OC.
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| 25. |
- Nordén, Rickard, 1977, et al.
(författare)
-
Activation of host antiviral RNA-sensing factors necessary for herpes simplex virus type 1-activated transcription of host cell fucosyltransferase genes FUT3, FUT5, and FUT6 and subsequent expression of sLex in virus-infected cells.
- 2009
-
Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 19:7, s. 776-88
-
Tidskriftsartikel (refereegranskat)abstract
- Herpes simplex virus type 1 (HSV-1) induces expression of a selectin receptor, the carbohydrate epitope sialyl Lewis X (sLe(x)), at the surface of infected cells. The molecular background to this phenomenon is that a viral immediate early RNA interacts with as yet unidentified host factors, eventually resulting in transcription of three dormant host fucosyltransferase genes (FUT3, FUT5, and FUT6), whose gene products are rate-limiting for synthesis of sLe(x). The aim of the present study was to define the immediate targets for the viral RNA in this process. We found that the Protein Kinase R (PKR) inhibitors 2-aminopurine (2-AP) and C16 inhibited FUT3, FUT5, and FUT6 expression as well as HSV-1-induced expression of sLe(x), indicating a primary role of PKR as a viral RNA target. The PKR-dependent activation of the FUT genes seemed neither to involve PKR effects on translation nor to involve NF-kappaB- or JNK-dependent activation. IMD-0354, known as an inhibitor of the NF-kappaB-activating factor IKK-2, induced FUT transcription via a novel IKK-2-independent mechanism, irrespective of whether the cells were virus-infected or not. Altogether, the results suggested that PKR is the primary target for HSV-1 early RNA during induction of FUT3, FUT5, and FUT6, and that the subsequent steps in the transcriptional activation of these host genes involve a hitherto unknown IMD-0354, yet IKK-2-independent, pathway.
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| 26. |
- Nordén, Rickard, 1977, et al.
(författare)
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Inhibition of protein deacetylation augments herpes simplex virus type 1-activated transcription of host fucosyltransferase genes associated with virus-induced sLex expression.
- 2010
-
Ingår i: Archives of virology. - : Springer Science and Business Media LLC. - 1432-8798 .- 0304-8608. ; 155:3, s. 305-13
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Tidskriftsartikel (refereegranskat)abstract
- Herpes simplex virus type 1 induces expression of the selectin ligand sialyl Lewis X in infected cells by activating transcription of three normally silent host glycosyltransferase genes, FUT3, FUT5, and FUT6, a process that is initiated by binding of viral RNA to cellular protein kinase R. We investigated the involvement of protein deacetylation and promoter methylation in viral activation of host FUT genes by analysing the effects of appropriate inhibitors on the transcription rates of the FUT genes in virus-infected cells. The histone deacetylase inhibitor trichostatin A augmented the viral activation of FUT transcription, whereas inhibition of DNA methylation did not affect transcription of these genes. The trichostatin A enhancement did not involve interference with expression of viral late genes or viral DNA replication. Thus, the virus-activated FUT genes are at least partially suppressed by deacetylation of histones or other regulatory proteins in uninfected HEL cells, whereas promoter methylation is a less important factor.
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| 27. |
- Nordén, Rickard, 1977, et al.
(författare)
-
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
-
Ingår i: APMIS : acta pathologica, microbiologica, et immunologica Scandinavica. - : Wiley. - 1600-0463. ; 121:4, s. 280-289
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Tidskriftsartikel (refereegranskat)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. |
- Nordén, Rickard, 1977, et al.
(författare)
-
O-linked glycosylation of the mucin domain of the herpes simplex virus type 1 specific glycoprotein gC-1 is temporally regulated in a seed-and-spread manner.
- 2015
-
Ingår i: The Journal of biological chemistry. - 1083-351X. ; 290:8, s. 5078-5091
-
Tidskriftsartikel (refereegranskat)abstract
- The herpes simplex virus type 1 (HSV-1) glycoprotein gC-1, participating in viral receptor interactions and immunity interference, harbors a mucin-like domain with multiple clustered O-linked glycans. Using HSV-1 infected diploid human fibroblasts, an authentic target for HSV-1 infection, and a protein immunoaffinity procedure, we enriched fully glycosylated gC-1 and a series of its biosynthetic intermediates. This fraction was subjected to trypsin digestion and a LC-MS/MS glycoproteomics approach. In parallel, we characterized the expression patterns of the 20 isoforms of human GalNAc transferases responsible for initiation of O-linked glycosylation. The gC-1 O-glycosylation was regulated in an orderly manner initiated by synchronous addition of one GalNAc unit each to T87 and T91, and one GalNAc unit to either T99 or T101, forming a core glycopeptide for subsequent additions of in all 11 GalNAc residues to selected Ser and Thr residues of the T76-L107 stretch of the mucin domain. The expression patterns of GalNAc transferases in the infected cells suggested that initial additions of GalNAc were carried out by initiating GalNAc transferases, in particular GalNAc-T2, whereas subsequent GalNAc additions were carried out by follow up transferases, in particular GalNAc-T10. Essentially all of the susceptible Ser or Thr residues had to acquire their GalNAc units before any elongation to longer O-linked glycans of the gC-1-associated GalNAc units was permitted. Since the GalNAc occupancy pattern is of relevance for receptor binding of gC-1, the data provides a model to delineate biosynthetic steps of O-linked glycosylation of the gC-1 mucin domain in HSV-1 infected target cells.
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| 29. |
- Nordén, Rickard, 1977, et al.
(författare)
-
Recombinant Glycoprotein E of Varicella Zoster Virus Contains Glycan-Peptide Motifs That Modulate B Cell Epitopes into Discrete Immunological Signatures
- 2019
-
Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1422-0067. ; 20:4
-
Tidskriftsartikel (refereegranskat)abstract
- A recombinant subunit vaccine (Shingrix((R))) was recently licensed for use against herpes zoster. This vaccine is based on glycoprotein E (gE) of varicella zoster virus (VZV), the most abundantly expressed protein of VZV, harboring sites for N- and O-linked glycosylation. The subunit vaccine elicits stronger virus-specific CD4+ T cell response as well as antibody B cell response to gE, compared to the currently used live attenuated vaccine (Zostavax((R))). This situation is at variance with the current notion since a live vaccine, causing an active virus infection, should be far more efficient than a subunit vaccine based on only one single viral glycoprotein. We previously found gE to be heavily glycosylated, not least by numerous clustered O-linked glycans, when it was produced in human fibroblasts. However, in contrast to Zostavax((R)), which is produced in fibroblasts, the recombinant gE of Shingrix((R)) is expressed in Chinese hamster ovary (CHO) cells. Hence, the glycan occupancy and glycan structures of gE may differ considerably between the two vaccine types. Here, we aimed at (i) defining the glycan structures and positions of recombinant gE and (ii) identifying possible features of the recombinant gE O-glycosylation pattern contributing to the vaccine efficacy of Shingrix((R)). Firstly, recombinant gE produced in CHO cells (Shingrix situation) is more scarcely decorated by O-linked glycans than gE from human fibroblasts (Zostavax situation), with respect to glycan site occupancy. Secondly, screening of immunodominant B cell epitopes of gE, using a synthetic peptide library against serum samples from VZV-seropositive individuals, revealed that the O-linked glycan signature promoted binding of IgG antibodies via a decreased number of interfering O-linked glycans, but also via specific O-linked glycans enhancing antibody binding. These findings may, in part, explain the higher protective efficacy of Shingrix((R)), and can also be of relevance for development of subunit vaccines to other enveloped viruses.
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| 30. |
- Nordén, Rickard, 1977, et al.
(författare)
-
Virus-induced appearance of the selectin ligand sLeX in herpes simplex virus type 1-infected T cells: Involvement of host and viral factors.
- 2013
-
Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 23:3, s. 310-321
-
Tidskriftsartikel (refereegranskat)abstract
- Circulating leukocytes that express selectin ligands such as the carbohydrate epitope sialyl Lewis X (sLeX) may interact with endothelial selectins, resulting in transmigration of the leukocyte across the endothelial wall to adjacent tissue. Due to the potential of selectin-ligand interactions as targets in viral pathogenesis, we aimed at determining whether herpes simplex virus type 1 (HSV1) is able to induce appearance of sLeX at the surface of infected leukocytes. We found that HSV1 infection of a T cell line resulted in transcriptional activation of human fucosyltransferase genes FUT3, FUT6 and FUT7, the two latter genes encoding fucosyltransferases rate limiting for sLeX synthesis. Flow cytometry and confocal microscopy demonstrated that HSV1 infection resulted in a two-fold rise in the proportion of sLeX-positive cells. Increased levels of FUT3, FUT6 and FUT7 RNA were detected already at 3 h post infection, and treatment with cycloheximide, a translation inhibitor, blocked HSV1-induced increase in expression of FUT3, FUT6 and FUT7 RNA, suggesting involvement of viral or cellular proteins. Studies with infectious viral mutants indicated that the viral immediate early (α) protein ICP0 is essential for initiation of FUT7 though not for FUT3 or FUT6 transcription. In CD3+ cells, derived from peripheral blood mononuclear cells, HSV1 infection induced expression of FUT3, FUT5 and FUT6, whereas FUT7 was not altered. The mean sLeX fluorescence intensity of CD3+ cells was significantly higher in HSV1-infected CD3+ cells. This suggests that infected leukocytes during HSV1 viremia may express selectin ligands with possible but as yet unproven roles in viral pathogenesis.
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| 31. |
- Nyström, Kristina, 1977, et al.
(författare)
-
Induction of sialyl-Lex expression by herpes simplex virus type 1 is dependent on viral immediate early RNA-activated transcription of host fucosyltransferase genes. : Induction of sialyl-Lewis x expression by HSV-1
- 2009
-
Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 19:8, s. 847-59
-
Tidskriftsartikel (refereegranskat)abstract
- We have previously shown that varicella-zoster virus (VZV) and cytomegalovirus (CMV) infection of diploid human fibroblasts (HEL) results in neo-expression of Lewis antigens sialyl Lewis x (sLe(x)) and Lewis y (Le(y)), respectively, after transcriptional activation of different combinations of dormant human fucosyltransferase genes (FUT1, FUT3, FUT5, and FUT6), whose gene products are responsible for the synthesis of Le antigens. Here, we show that herpes simplex virus type 1 (HSV-1) also induces sLe(x) expression dependent on induction of FUT3, FUT5, and FUT6 transcription in infected cells. HSV-1 induction of FUT5 was subsequently used as a model system for analyzing the mechanism of viral activation of dormant fucosyltransferase genes. We show that this is a rapid process, which gives rise to elevated FUT5 RNA levels already at 90 min postinfection. Augmented FUT5 transcription was found to be dependent on transcription of viral genes, but not dependent on the immediate early proteins ICP0 and ICP4, as demonstrated by experiments with HSV-1 mutants defective in expression of these genes. Augmented FUT5 transcription takes place in cycloheximide-treated HSV-1-infected cells, suggesting a more direct role for IE viral RNA during activation of cellular FUT5.
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| 32. |
- Nyström, Kristina, 1977, et al.
(författare)
-
Real time PCR for monitoring regulation of host gene expression in herpes simplex virus type 1-infected human diploid cells
- 2004
-
Ingår i: J Virol Methods. ; 118:2, s. 83-94
-
Tidskriftsartikel (refereegranskat)abstract
- Herpes simplex virus type 1 (HSV-1) induces prominent shifts in the rates of transcription of host cellular genes of relevance for the outcome of the viral infection. The quantitative analysis of transcription may be obscured by virus-induced alterations in the levels of RNA encoded by cellular housekeeping genes that are used commonly for normalisation of real time reverse transcription PCR (RT-qPCR). In the present study, we analysed beta-actin, GAPDH and 18S rRNA for their usefulness in normalisation of RT-qPCR analysis of the transcription of the HSV-1 gamma gB-1 gene and FUT5, a cellular gene induced by viral infection. The transcription of these genes was monitored in a TaqMan-based real time RT-PCR system over a 24h interval of virus infection of human embryonic lung fibroblasts. The levels of gB-1 and FUT5 RNA were normalised via difference in the threshold cycle (deltaC(t)) values relative to each and one of the housekeeping genes or calculated in relation to the number of infected cells without any further normalisation. The levels of RNA encoded by beta-actin or GAPDH were found to vary by several orders of magnitude during HSV-1 infection, introducing large errors in the estimation of the gB-1 and FUT5 RNA levels. In contrast, the variation of C(t) values for 18S rRNA was less than one cycle during 24h period of HSV-1 infection. The FUT5 and gB-1 RNA figures obtained by DeltaC(t) normalisation relative 18S rRNA were identical to those calculated in relation to the number of infected cells. These data recommend 18S rRNA for normalisation in HSV-1-infected human cells but discourage the use of beta-actin and GAPDH RNA for this purpose. By applying these procedures, it was shown that the transcription of FUT5 was increased by 50-fold 5-24h after HSV-1 infection and 200-fold by the inhibition of viral DNA replication in HSV-infected cells.
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| 33. |
- Nyström, Kristina, 1977, et al.
(författare)
-
Virus-induced transcriptional activation of host FUT genes associated with neo-expression of Ley in cytomegalovirus-infected and sialyl-Lex in varicella-zoster virus-infected diploid human cells
- 2007
-
Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 17:4, s. 355-66
-
Tidskriftsartikel (refereegranskat)abstract
- Cell surface carbohydrate structures including sialyl-Lewis X (sLe(x)) and Lewis Y (Le(y)) are important ligands in normal and malignant tissues. The aim here was to determine the possible influence on the expression of such antigens by two viruses varicella-zoster virus (VZV) and cytomegalovirus (CMV) involved in persistent infections of humans. We found that infection of human diploid fibroblasts with both viruses resulted in transcriptional activation of several fucosyltransferase (FUT) genes that were either dormant or expressed at low levels in uninfected cells. Both viruses induced FUT3, FUT5, and FUT6, encoding alpha1,3- and/or alpha1,4-specific fucosyltransferases. CMV, but not VZV, induced transcription of FUT1 (encoding an alpha1,2-specific fucosyltransferase), FUT7, and FUT9. The changes in transcription of FUT genes were expectedly associated with expression of Le(y) in CMV-infected cells and sLe(x) in the VZV-infected fibroblasts although no expression of these antigens was observed in uninfected cells. One major explanation for this difference between CMV- and VZV-infected cells was that CMV, but not VZV, induced expression of FUT1, necessary for Le(y) expression. The induced carbohydrate antigens in CMV- and VZV-infected cells could be of significance for virus spread and possible escape from immune responses.
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| 34. |
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| 35. |
- Olofsson, Sigvard, 1948, et al.
(författare)
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Glycoconjugate glycans as viral receptors.
- 2005
-
Ingår i: Annals of medicine. - : Informa UK Limited. - 0785-3890 .- 1365-2060. ; 37:3, s. 154-72
-
Tidskriftsartikel (refereegranskat)abstract
- The carbohydrate parts of cell surface glycoproteins, glycolipids, and proteoglycans constitute receptors for many enveloped as well as non-enveloped human viruses. The majority of viral receptors of carbohydrate nature are negatively charged, including sulfated glycosaminoglycans (GAGs) or glycans containing sialic acid. Not uncommonly, virus-carbohydrate interactions are responsible for specific tissue tropism, where the affinity of influenza virus for glycans in the respiratory tract containing (a2-6)-linked sialic acid is an important example. Similarly, the number and spacing of sulfates may guide viruses to optimal GAG molecules, although this remains unproven on tissue level. A further understanding of structure and tissue distribution of carbohydrate virus receptors and their viral ligands is essential for elucidating the pathogenesis of such viruses. Also neutral glycans such as histo-blood group substances may function as virus receptors. Here, natural resistance to a given viral disease may occur in a human subpopulation due to lack of such receptors caused by deletion-mutants in critical human genes. As regards antiviral applications, the receptor-destroying enzymes, in contrast to receptor binding proteins, at the surface of, for example, influenza virus have proven to be an excellent target for intervention, which is why sialic acid analogues are now in clinical use both for prophylaxis and treatment.
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| 36. |
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| 37. |
- Olofsson, Sigvard, 1948, et al.
(författare)
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PCR for detection of respiratory viruses: seasonal variations of virus infections
- 2011
-
Ingår i: EXPERT REVIEW OF ANTI-INFECTIVE THERAPY. - 1478-7210. ; 9:8, s. 615-626
-
Forskningsöversikt (refereegranskat)abstract
- Real-time PCR and related methods have revolutionized the laboratory diagnosis of viral respiratory infections because of their high detection sensitivity, rapidness and potential for simultaneous detection of 15 or more respiratory agents. Results from studies with this diagnostic modality have significantly expanded our knowledge about the seasonality of viral respiratory diseases, pinpointed the difficulties to make a reliable etiologic diagnosis without the aid of an unbiased multiplex molecular assay for respiratory viruses, and revealed previously unknown details as to possible infections with multiple agents as aggravating factors. The scope of this article is to review and discuss this new knowledge and its implications for diagnostic strategies and other measures essential for the clinical management of respiratory viral infections and for epidemiological surveillance of seasonal respiratory infections.
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| 38. |
- Olofsson, Sigvard, 1948, et al.
(författare)
-
Structure and Role of O-Linked Glycans in Viral Envelope Proteins
- 2023
-
Ingår i: Annual Review of Virology. - : Annual Reviews. - 2327-056X. ; 10:1, s. 283-304
-
Tidskriftsartikel (refereegranskat)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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| 39. |
- Olofsson, Sigvard, 1948, et al.
(författare)
-
Viral O-GalNAc peptide epitopes: a novel potential target in viral envelope glycoproteins.
- 2016
-
Ingår i: Reviews in medical virology. - : Wiley. - 1099-1654 .- 1052-9276. ; 26:1, s. 34-48
-
Tidskriftsartikel (refereegranskat)abstract
- Viral envelope glycoproteins are major targets for antibodies that bind to and inactivate viral particles. The capacity of a viral vaccine to induce virus-neutralizing antibodies is often used as a marker for vaccine efficacy. Yet the number of known neutralization target epitopes is restricted owing to various viral escape mechanisms. We expand the range of possible viral glycoprotein targets, by presenting a previously unknown type of viral glycoprotein epitope based on a short peptide stretch modified with small O-linked glycans. Besides being immunologically active, these epitopes have a high potential for antigenic variation. Thus, sera from patients infected with EBV develop individual IgG responses addressing the different possible glycopeptide glycoforms of one short peptide backbone that reflect individual variations in the course of virus infection. In contrast, in HSV type 2 meningitis patients, CSF antibodies are focussed to only one single glycoform peptide of a major viral glycoprotein. Thus, dependent on the viral disease, the serological response may be variable or constant with respect to the number of targeted peptide glycoforms. Mapping of these epitopes relies on a novel three-step procedure that identifies any reactive viral O-glycosyl peptide epitope with respect to (i) relevant peptide sequence, (ii) the reactive glycoform out of several possible glycopeptide isomers of that peptide sequence, and (iii) possibly tolerated carbohydrate or peptide structural variations at glycosylation sites. In conclusion, the viral O-glycosyl peptide epitopes may be of relevance for development of subunit vaccines and for improved serodiagnosis of viral diseases.
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| 40. |
- Riise, Gerdt C., 1956, et al.
(författare)
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Quantification of cytomegalovirus DNA in BAL fluid: a longitudinal study in lung transplant recipients
- 2000
-
Ingår i: Chest. - 0012-3692. ; 118:6, s. 1653-60
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Tidskriftsartikel (refereegranskat)abstract
- STUDY OBJECTIVES: Cytomegalovirus (CMV) infection is common in patients receiving solid organ transplants, and it is associated with increased morbidity as well as risk for development of chronic rejection. A rapid and sensitive diagnostic method would improve the therapeutic management of CMV infection, including the monitoring of treatment effects. We investigated whether longitudinal determinations of CMV DNA quantities in BAL fluid could be useful for this purpose. DESIGN: CMV DNA levels in 340 BAL samples from 35 consecutive lung transplant recipients were studied during a median of 18 months. Seventeen (49%) of the patients developed CMV disease with pneumonitis. Twenty-seven CMV disease episodes were diagnosed. RESULTS: Patients with CMV disease had a significantly higher mean level of CMV copies per milliliter BAL fluid (1,120 +/- 4,379) compared with those without (180 +/- 1,177, p < 0.01). Viral load as well as acute rejection requiring treatment (>/= A2) were independent risk factors associated with CMV disease. Differences between the groups concerning HLA-DR matching, basic immunosuppressive therapy, and CMV serologic status D/R -/+ vs D/R +/+ were not significant. A diagnostic definition of normality based on the mean level of all episodes without CMV disease +2 SD would discriminate only 9 of the 27 CMV episodes. CONCLUSIONS: Although the viral load is increased during episodes of clinical CMV disease in lung transplant recipients, the quantitative PCR assessment of CMV DNA in BAL fluid is not discriminative enough to be useful as a diagnostic tool for CMV disease.
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| 41. |
- Risinger, C., et al.
(författare)
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Linear Multiepitope (Glyco)peptides for Type-Specific Serology of Herpes Simplex Virus (HSV) Infections
- 2017
-
Ingår i: Acs Infectious Diseases. - : American Chemical Society (ACS). - 2373-8227. ; 3:5, s. 360-367
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Tidskriftsartikel (refereegranskat)abstract
- Detection of type-specific antibodies is an important and essential part of accurate diagnosis, even in silent carriers of herpes simplex virus (HSV)-1 (oral) and HSV-2 (genital) infections. Serologic assays that identify HSV-1 and HSV-2 type-specific antibodies have been commercially available for more than a decade but often face problems related to cross-reactivity and similar issues. Attempts to identify type-specific peptide epitopes for use in serology for both HSV-1 and HSV-2 have been limited. We recently demonstrated epitope mapping of envelope glycoprotein G2 and identified a type-specific glycopeptide epitope that broadly recognized HSV-2 infected individuals. In the present work we have performed a comprehensive glycopeptide synthesis and rnicroarray epitope mapping of 14 envelope proteins from HSV-1 and HSV-2, namely, gB, gC, gD, gE, gG, gH, and gI, using sera from HSV-1-and HSV-2-infected individuals and control sera. Several unique type-specific peptide epitopes with high sensitivity were identified and synthesized as one large linear multiepitope sequence using microwave-assisted solid-phase (glyco)peptide synthesis. Microarray validation with clinically defined HSV and Varicella Zoster (VZV) sera confirmed excellent cumulative specificities and sensitivities.
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| 42. |
- Rowcliffe, Eric, 1976, et al.
(författare)
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Demonstration of neutralizing mucosal IgA response to intranasal HIV-1 env DNA vaccines with or without the V3 glycosylation site
- 2004
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Ingår i: Scand J Inf Dis. ; 36, s. 360-364
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Tidskriftsartikel (refereegranskat)abstract
- HIV-1 env based DNA vaccines are generally found to be poor B-cell immunogens. We examined the role of an N-glycan located in the V3 loop of HIV-1 (N306) that is known to modulate the immunogenicity of gp120. Here we describe intranasal immunizations with env (HIV-1 BRU) based genetic immunogens in combination with subcutaneous boosts of recombinant gp160 (rgp160) in mice. Immunization with DNA alone resulted in detectable IgA responses to rgp160 in both faeces and bronchoalveolar lavage (BAL) fluid, but the additional boosting increased the faecal IgA titres only. Protein boosting was required for induction of faecal IgA antibodies capable of neutralizing a homologous laboratory strain and a subtype B primary isolate. The B-cell response towards V3 loop peptides was not only directed against the homologous subtype B but also against the subtype F. In contrast to our previous observations on IgG, there were no differences in anti-gp160 IgA titres elicited by the N-glycan mutant and the wild-type immunogen. These results indicate that intranasal administration of plasmids containing env in combination with a subcutaneous boost proved to be an effective way of eliciting neutralizing mucosal IgA against HIV-1.
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| 43. |
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| 44. |
- Trybala, Edward, 1955, et al.
(författare)
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Structural and functional features of the polycationic peptide required for inhibition of herpes simplex virus invasion of cells.
- 2004
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Ingår i: Antiviral research. - : Elsevier BV. - 0166-3542. ; 62:3, s. 125-34
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Tidskriftsartikel (refereegranskat)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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| 45. |
- Westin, Johan, 1965, et al.
(författare)
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Multiplex real-time PCR for detection of respiratory tract infections
- 2008
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Ingår i: Journal of Clinical Virology. - : Elsevier BV. - 1386-6532. ; 41:1, s. 53-56
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Tidskriftsartikel (refereegranskat)abstract
- Background Broad diagnostics of respiratoryinfection by molecular assays has not yet won acceptance due to technical difficulties and high costs. Objectives To evaluate clinical applicability of multiplexreal-timePCR. Study design An assay targeting influenza virus A (IfA) and B (IfB), parainfluenza 1-3 (PIV), human metapneumovirus (MPV), respiratory syncytial virus (RSV), rhinovirus (RV), enterovirus (EV), adenovirus (AdV), human coronaviruses (229E, OC43, NL63), M. pneumoniae and Ch. pneumoniae was developed and run daily on consecutive clinical nasopharyngeal swab samples. Results An etiology was identified in 48% of the 954 samples, with IfA in 25%, RV in 20%, MPV in 10% and M. pneumoniae in 10% of the positive. By a rational procedure costs could be reduced and the customer price set relatively low (€33 per sample). Conclusion Streamlined testing and cost limitation is achievable and probably critical for implementation of a broad molecular diagnostics of respiratoryinfections.
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| 46. |
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