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Mohd Jaafar F, Belhouchet M, Monsion B, Bell-Sakyi L, Mertens PPC, Attoui H. Orbivirus NS4 Proteins Play Multiple Roles to Dampen Cellular Responses. Viruses 2023; 15:1908. [PMID: 37766314 PMCID: PMC10535134 DOI: 10.3390/v15091908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023] Open
Abstract
Non-structural protein 4 (NS4) of insect-borne and tick-borne orbiviruses is encoded by genome segment 9, from a secondary open reading frame. Though a protein dispensable for bluetongue virus (BTV) replication, it has been shown to counter the interferon response in cells infected with BTV or African horse sickness virus. We further explored the functional role(s) of NS4 proteins of BTV and the tick-borne Great Island virus (GIV). We show that NS4 of BTV or GIV helps an E3L deletion mutant of vaccinia virus to replicate efficiently in interferon-treated cells, further confirming the role of NS4 as an interferon antagonist. Our results indicate that ectopically expressed NS4 of BTV localised with caspase 3 within the nucleus and was found in a protein complex with active caspase 3 in a pull-down assay. Previous studies have shown that pro-apoptotic caspases (including caspase 3) suppress type I interferon response by cleaving mediators involved in interferon signalling. Our data suggest that orbivirus NS4 plays a role in modulating the apoptotic process and/or regulating the interferon response in mammalian cells, thus acting as a virulence factor in pathogenesis.
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Affiliation(s)
- Fauziah Mohd Jaafar
- UMR1161 VIROLOGIE, INRAE, Ecole Nationale Vétérinaire d’Alfort, ANSES, Université Paris-Est, 94700 Maisons-Alfort, France;
| | - Mourad Belhouchet
- Division of Structural Biology, Henry Wellcome Building for Genomic Medicine, Oxford OX3 7BN, UK;
| | - Baptiste Monsion
- UMR1161 VIROLOGIE, INRAE, Ecole Nationale Vétérinaire d’Alfort, ANSES, Université Paris-Est, 94700 Maisons-Alfort, France;
| | - Lesley Bell-Sakyi
- Department of Infection Biology and Microbiomes, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, 146 Brownlow Hill, Liverpool L3 5RF, UK;
| | - Peter P. C. Mertens
- One Virology, The Wolfson Centre for Global Virus Research, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire LE12 5RD, UK;
| | - Houssam Attoui
- UMR1161 VIROLOGIE, INRAE, Ecole Nationale Vétérinaire d’Alfort, ANSES, Université Paris-Est, 94700 Maisons-Alfort, France;
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Hung CH, Yen JB, Chang PJ, Chen LW, Huang TY, Tsai WJ, Tsai YC. Characterization of Human Norovirus Nonstructural Protein NS1.2 Involved in the Induction of the Filamentous Endoplasmic Reticulum, Enlarged Lipid Droplets, LC3 Recruitment, and Interaction with NTPase and NS4. Viruses 2023; 15:v15030812. [PMID: 36992520 PMCID: PMC10053803 DOI: 10.3390/v15030812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 03/09/2023] [Accepted: 03/20/2023] [Indexed: 03/31/2023] Open
Abstract
Human noroviruses (HuNVs) are the leading cause of gastroenteritis worldwide. NS1.2 is critical for HuNV pathogenesis, but the function is still unclear. The GII NS1.2 of HuNVs, unlike GI NS1.2, was localized to the endoplasmic reticulum (ER) and lipid droplets (LDs) and is accompanied by a distorted-filamentous ER morphology and aggregated-enlarged LDs. LC3 was recruited to the NS1.2-localized membrane through an autophagy-independent pathway. NS1.2, expressed from a cDNA clone of GII.4 norovirus, formed complexes with NTPase and NS4, which exhibited aggregated vesicle-like structures that were also colocalized with LC3 and LDs. NS1.2 is structurally divided into three domains from the N terminus: an inherently disordered region (IDR), a region that contains a putative hydrolase with the H-box/NC catalytic center (H-box/NC), and a C-terminal 251-330 a.a. region containing membrane-targeting domain. All three functional domains of NS1.2 were required for the induction of the filamentous ER. The IDR was essential for LC3 recruitment by NS1.2. Both the H-Box/NC and membrane-targeting domains are required for the induction of aggregated-enlarged LDs, NS1.2 self-assembly, and interaction with NTPase. The membrane-targeting domain was sufficient to interact with NS4. The study characterized the NS1.2 domain required for membrane targeting and protein-protein interactions, which are crucial for forming a viral replication complex.
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Affiliation(s)
- Chien-Hui Hung
- Graduate Institute of Clinical Medical Sciences, Chang Gung University, Taoyuan 33302, Taiwan
- Department of Internal Medicine, Division of Infectious Diseases, Chang Gung Memorial Hospital, Chiayi 61363, Taiwan
| | - Ju-Bei Yen
- Department of Pediatrics, Chang Gung Memorial Hospital, Chiayi 61363, Taiwan
| | - Pey-Jium Chang
- Graduate Institute of Clinical Medical Sciences, Chang Gung University, Taoyuan 33302, Taiwan
| | - Lee-Wen Chen
- Department of Respiratory Care, Chung Gung University of Science and Technology, Chiayi 61363, Taiwan
| | - Tsung-Yu Huang
- Department of Internal Medicine, Division of Infectious Diseases, Chang Gung Memorial Hospital, Chiayi 61363, Taiwan
| | - Wan-Ju Tsai
- Graduate Institute of Clinical Medical Sciences, Chang Gung University, Taoyuan 33302, Taiwan
| | - Yu-Chin Tsai
- Graduate Institute of Clinical Medical Sciences, Chang Gung University, Taoyuan 33302, Taiwan
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Jahun AS, Sorgeloos F, Chaudhry Y, Arthur SE, Hosmillo M, Georgana I, Izuagbe R, Goodfellow IG. Leaked genomic and mitochondrial DNA contribute to the host response to noroviruses in a STING-dependent manner. Cell Rep 2023; 42:112179. [PMID: 36943868 DOI: 10.1016/j.celrep.2023.112179] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 10/11/2022] [Accepted: 02/12/2023] [Indexed: 03/23/2023] Open
Abstract
The cGAS-STING pathway is central to the interferon response against DNA viruses. However, recent studies are increasingly demonstrating its role in the restriction of some RNA viruses. Here, we show that the cGAS-STING pathway also contributes to the interferon response against noroviruses, currently the commonest causes of infectious gastroenteritis worldwide. We show a significant reduction in interferon-β induction and a corresponding increase in viral replication in norovirus-infected cells after deletion of STING, cGAS, or IFI16. Further, we find that immunostimulatory host genome-derived DNA and mitochondrial DNA accumulate in the cytosol of norovirus-infected cells. Lastly, overexpression of the viral NS4 protein is sufficient to drive the accumulation of cytosolic DNA. Together, our data find a role for cGAS, IFI16, and STING in the restriction of noroviruses and show the utility of host genomic DNA as a damage-associated molecular pattern in cells infected with an RNA virus.
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Affiliation(s)
- Aminu S Jahun
- Division of Virology, Department of Pathology, University of Cambridge, Addenbrooke's Hospital Level 5, Hills Road, Cambridge CB2 0QQ, UK.
| | - Frederic Sorgeloos
- Division of Virology, Department of Pathology, University of Cambridge, Addenbrooke's Hospital Level 5, Hills Road, Cambridge CB2 0QQ, UK; Université catholique de Louvain, de Duve Institute, MIPA-VIRO 74-49, 74 Avenue Hippocrate, B-1200 Brussels, Belgium
| | - Yasmin Chaudhry
- Division of Virology, Department of Pathology, University of Cambridge, Addenbrooke's Hospital Level 5, Hills Road, Cambridge CB2 0QQ, UK
| | - Sabastine E Arthur
- Division of Virology, Department of Pathology, University of Cambridge, Addenbrooke's Hospital Level 5, Hills Road, Cambridge CB2 0QQ, UK
| | - Myra Hosmillo
- Division of Virology, Department of Pathology, University of Cambridge, Addenbrooke's Hospital Level 5, Hills Road, Cambridge CB2 0QQ, UK
| | - Iliana Georgana
- Division of Virology, Department of Pathology, University of Cambridge, Addenbrooke's Hospital Level 5, Hills Road, Cambridge CB2 0QQ, UK
| | - Rhys Izuagbe
- Division of Virology, Department of Pathology, University of Cambridge, Addenbrooke's Hospital Level 5, Hills Road, Cambridge CB2 0QQ, UK
| | - Ian G Goodfellow
- Division of Virology, Department of Pathology, University of Cambridge, Addenbrooke's Hospital Level 5, Hills Road, Cambridge CB2 0QQ, UK.
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Wall GV, Wright IM, Barnardo C, Erasmus BJ, van Staden V, Potgieter AC. African horse sickness virus NS4 protein is an important virulence factor and interferes with JAK-STAT signaling during viral infection. Virus Res 2021; 298:198407. [PMID: 33812899 DOI: 10.1016/j.virusres.2021.198407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 03/25/2021] [Accepted: 03/29/2021] [Indexed: 12/24/2022]
Abstract
African horse sickness virus (AHSV) non-structural protein NS4 is a nucleocytoplasmic protein that is expressed in the heart, lung, and spleen of infected horses, binds dsDNA, and colocalizes with promyelocytic leukemia nuclear bodies (PML-NBs). The aim of this study was to investigate the role of AHSV NS4 in viral replication, virulence and the host immune response. Using a reverse genetics-derived virulent strain of AHSV-5 and NS4 deletion mutants, we showed that knockdown of NS4 expression has no impact in cell culture, but results in virus attenuation in infected horses. RNA sequencing (RNA-seq) was used to investigate the transcriptional response in these horses, to see how the lack of NS4 mediates the transition of the virus from virulent to attenuated. The presence of NS4 was shown to result in a 24 hour (h) delay in the transcriptional activation of several immune system processes compared to when the protein was absent. Included in these processes were the RIG-I-like, Toll-like receptor, and JAK-STAT signaling pathways, which are key pathways involved in innate immunity and the antiviral response. Thus, it was shown that AHSV NS4 suppresses the host innate immune transcriptional response in the early stages of the infection cycle. We investigated whether AHSV NS4 affects the innate immune response by impacting the JAK-STAT signaling pathway specifically. Using confocal laser scanning microscopy (CLSM) we showed that AHSV NS4 disrupts JAK-STAT signaling by interfering with the phosphorylation and/or translocation of STAT1 and pSTAT1 into the nucleus. Overall, these results showed that AHSV NS4 is a key virulence factor in horses and allows AHSV to overcome host antiviral responses in order to promote viral replication and spread.
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Affiliation(s)
- Gayle V Wall
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, 0002, South Africa
| | - Isabella M Wright
- Deltamune (Pty) Ltd, Moraine House - The Braes, 193 Bryanston Drive, Bryanston, Gauteng, 2191, South Africa
| | - Carin Barnardo
- Deltamune (Pty) Ltd, Moraine House - The Braes, 193 Bryanston Drive, Bryanston, Gauteng, 2191, South Africa
| | - Baltus J Erasmus
- Deltamune (Pty) Ltd, Moraine House - The Braes, 193 Bryanston Drive, Bryanston, Gauteng, 2191, South Africa
| | - Vida van Staden
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, 0002, South Africa
| | - A Christiaan Potgieter
- Deltamune (Pty) Ltd, Moraine House - The Braes, 193 Bryanston Drive, Bryanston, Gauteng, 2191, South Africa; Department of Biochemistry, Focus Area for Human Metabolomics, North-West University, Potchefstroom, South Africa.
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5
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Boughan S, Potgieter AC, van Staden V. African horse sickness virus NS4 is a nucleocytoplasmic protein that localizes to PML nuclear bodies. J Gen Virol 2020; 101:366-384. [PMID: 32125263 DOI: 10.1099/jgv.0.001396] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
African horse sickness virus (AHSV) is the causative agent of the often fatal disease African horse sickness in equids. The non-structural protein NS4 is the only AHSV protein that localizes to the nucleus. Here we report that all AHSV reference and representative field strains express one of the two forms of NS4, i.e. NS4-I or NS4-II. Both forms of NS4 are nucleocytoplasmic proteins, but NS4-I has a stronger nuclear presence whilst NS4-II has a proportionally higher cytoplasmic distribution. A subtype of NS4-II containing a nuclear localization signal (NLS), named NLS-NS4-II, displays distinct punctate foci in the nucleus. We showed that NS4 likely enters the nucleus via passive diffusion as a result of its small size. Colocalization analysis with nuclear compartments revealed that NS4 colocalizes with promyelocytic leukaemia nuclear bodies (PML-NBs), suggesting a role in the antiviral response or interferon signalling. Interestingly, we showed that two other AHSV proteins also interact with nuclear components. A small fraction of the NS1 tubules were present in the nucleus and associated with PML-NBs; this was more pronounced for a virus strain lacking NS4. A component of nuclear speckles, serine and arginine rich splicing factor 2 (SRSF2) was recruited to viral inclusion bodies (VIBs) in the cytoplasm of AHSV-infected cells and colocalized with NS2. Nuclear speckles are important sites for cellular mRNA transcript processing and maturation. Collectively, these results provide data on three AHSV non-structural proteins interacting with host cell nuclear components that could contribute to overcoming antiviral responses and creating conditions that will favour viral replication.
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Affiliation(s)
- Shareen Boughan
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - A Christiaan Potgieter
- Department of Biochemistry, Focus Area for Human Metabolomics, North-West University, Potchefstroom, South Africa.,Deltamune (Pty) Ltd, Moraine house - The Braes, 193 Bryanston Drive, Bryanston, Gauteng, 2191, South Africa
| | - Vida van Staden
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
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Warkad SD, Song KS, Pal D, Nimse SB. Developments in the HCV Screening Technologies Based on the Detection of Antigens and Antibodies. Sensors (Basel) 2019; 19:E4257. [PMID: 31575036 DOI: 10.3390/s19194257] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 09/20/2019] [Accepted: 09/27/2019] [Indexed: 02/06/2023]
Abstract
Hepatitis C virus (HCV) accounts for 15%-20% of cases of acute infection, and chronic HCV infection is developed in about 50%-80% of HCV patients. Unfortunately, due to the lack of proper medical care, difficulty in screening for HCV infection, and lack of awareness resulted in chronic HCV infection in 71 million people on a global scale, and about 399,000 deaths in 2016. It is crucial to recognize that the effective use of antiviral medicines can cure more than 95% of HCV infected people. The Global Health Sector Strategy (GHSS) aim is to reduce the new HCV infections and the HCV associated mortality by 90% and 65%, respectively. Therefore, the methods that are simple, yet powerful enough to detect HCV infections with high sensitivity, specificity, and a shorter window period are crucial to restrain the global burden of HCV healthcare. This article focuses on the technologies used for the detection of HCV in clinical specimens.
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7
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Dighe SN, Ekwudu O, Dua K, Chellappan DK, Katavic PL, Collet TA. Recent update on anti-dengue drug discovery. Eur J Med Chem 2019; 176:431-455. [PMID: 31128447 DOI: 10.1016/j.ejmech.2019.05.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 04/12/2019] [Accepted: 05/06/2019] [Indexed: 01/27/2023]
Abstract
Dengue is the most important arthropod-borne viral disease of humans, with more than half of the global population living in at-risk areas. Despite the negative impact on public health, there are no antiviral therapies available, and the only licensed vaccine, Dengvaxia®, has been contraindicated in children below nine years of age. In an effort to combat dengue, several small molecules have entered into human clinical trials. Here, we review anti-DENV molecules and their drug targets that have been published within the past five years (2014-2018). Further, we discuss their probable mechanisms of action and describe a role for classes of clinically approved drugs and also an unclassified class of anti-DENV agents. This review aims to enhance our understanding of novel agents and their cognate targets in furthering innovations in the use of small molecules for dengue drug therapies.
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Affiliation(s)
- Satish N Dighe
- Innovative Medicines Group, Institute of Health & Biomedical Innovation, School of Clinical Sciences, Queensland University of Technology, Brisbane, Australia.
| | - O'mezie Ekwudu
- Innovative Medicines Group, Institute of Health & Biomedical Innovation, School of Clinical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Kamal Dua
- Discipline of Pharmacy, Graduate School of Health, University of Technology Sydney, Ultimo, Australia
| | - Dinesh Kumar Chellappan
- Department of Life Sciences, School of Pharmacy, International Medical University (IMU), Bukit Jalil, Kuala Lumpur, 57000, Malaysia
| | - Peter L Katavic
- Innovative Medicines Group, Institute of Health & Biomedical Innovation, School of Clinical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Trudi A Collet
- Innovative Medicines Group, Institute of Health & Biomedical Innovation, School of Clinical Sciences, Queensland University of Technology, Brisbane, Australia
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Abstract
Chronic hepatitis C virus (HCV) infection impacts approximately 71 million people and approximately 400,000 deaths are attributed to HCV-related liver disease annually worldwide. Mainstay of treatment for over 25 years has been pegylated interferon until the advent of protease inhibitors, which has led to all-oral HCV treatment regimens that have changed the outlook of hepatitis C treatment. Grazoprevir/elbasvir provides high rates of efficacy and tolerability and is an all-oral once daily treatment option for HCV infection. Efficacy of grazoprevir/elbasvir has been proven in patients with cirrhosis, patients who have previously failed treatment with peginterferon and ribavirin (RBV), patients with end-stage renal disease and patients with HIV co-infection. Data have shown a high barrier to resistance despite the presence of resistance-associated substitutions. Grazoprevir/elbasvir represents a very promising regimen for treatment of HCV infection. This review provides a summary of pharmacology, efficacy, and safety of grazoprevir/elbasvir for the treatment of HCV infection.
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Sulejmani N, Jafri SM, Gordon SC. Pharmacodynamics and pharmacokinetics of elbasvir and grazoprevir in the treatment of hepatitis C. Expert Opin Drug Metab Toxicol 2016; 12:353-61. [PMID: 26849059 DOI: 10.1517/17425255.2016.1148685] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
INTRODUCTION Approximately 130 - 150 million people have chronic hepatitis C virus (HCV) infection and upwards of 500,000 deaths annually are attributed to HCV related liver disease worldwide. Pegylated interferon and ribavirin have been the mainstay of treatment for greater than 25 years until recent advent of protease inhibitors which has led to all oral HCV treatment regimens that have changed the outlook of hepatitis C treatment. AREAS COVERED This review provides summary of pharmacokinetics, pharmacodynamics, efficacy and safety of grazoprevir/elbasvir therapy for treatment of HCV infection. EXPERT OPINION Grazoprevir/elbasvir provides an all-oral once daily treatment option for HCV infection with high rates of efficacy and tolerability in a pangenotypic fashion. It highly efficacious in treating patients with cirrhosis, patients who have previously failed treatment with pegylated interferon and ribavirin, and patients with HIV co-infection. Grazoprevir/elbasvir has demonstrated higher barrier to resistance even in the presence of variants associated with resistance such as Q41R, F43S, R155K, V36M, T54S, and D168. It is one of only few HCV treatment regimens evaluated for use in patients with advanced chronic kidney disease and dialysis. It is a very promising regimen for treatment of HCV infection.
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Affiliation(s)
- Nimisha Sulejmani
- a Department of Pharmacy , Henry Ford Hospital , Detroit , MI , USA.,b Division of Gastroenterology , Henry Ford Hospital , Detroit , MI , USA
| | | | - Stuart C Gordon
- b Division of Gastroenterology , Henry Ford Hospital , Detroit , MI , USA
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Attallah AM, Abdallah SO, El-Far M, Omran MM, Tabll AA, Ghaly MF, Ezzat SM, Elhamshary MO, El-Gohary ZM, Mohamedin AH, El-Morsi AA, Askora AA, Abdelrazek MA, El-Kafrawy HM, Keneber MH, Khalil MR, Aggag MM, Elbendary MS, El-Deeb MM, Abuzaid MS, Mansour AT, Attallah AA. Perinatal transmission of hepatitis C antigens: envelope 1, envelope 2 and non-structural 4. Infect Dis (Lond) 2015; 47:568-74. [PMID: 25922972 DOI: 10.3109/23744235.2015.1042035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Perinatal exposure to hepatitis C virus (HCV) antigens during pregnancy may affect the developing immune system in the fetus. We aimed to study the perinatal transmission of HCV structural and non-structural antigens. METHODS Sera from 402 pregnant mothers were tested for anti-HCV antibody and HCV RNA. HCV antigens were determined in sera from 101 HCV-infected mothers and their cord blood. RESULTS In both serum and cord blood samples, HCV NS4 (non-structural 4) at 27 kDa, E1 (envelope 1) at 38 kDa and E2 (envelope 2) at 40 kDa were identified, purified and quantified using western blotting, electroelution and ELISA. Maternal sera and neonate cord blood samples had similar detection rates for NS4 (94.1%), E1 (90.1%) and E2 (90.1%). The mean maternal serum levels (optical density, OD) of HCV NS4 (0.87 ± 0.01), E1 (0.86 ± 0.01) and E2 (0.85 ± 0.01) did not differ significantly (p > 0.05) from those of neonatal cord blood (0.83 ± 0.01, 0.87 ± 0.01 and 0.85 ± 0.01, respectively). Also, strong correlations (p < 0.0001) were shown between sera and cord blood sample levels of HCV NS4, r = 0.77; E1, r = 0.76 and E2, r = 0.80. The vertical transmission of these antigens in vaginal delivery did not differ significantly (p > 0.05) from those in caesarean section. CONCLUSIONS These findings indicate that vertical transmission of HCV NS4, E1 and E2 antigens was very high. Thus, exposure to these antigens may influence the developing immune responses to natural infection or future vaccination.
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11
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Attallah AM, Abdallah SO, El-Far M, Omran MM, Tabll AA, Ghaly MF, Ezzat SM, Elhamshary MO, El-Gohary ZM, Mohamedin AH, El-Morsi AA, Askora AA, Abdelrazek MA, El-Kafrawy HM, Keneber MH, Khalil MR, Aggag MM, Elbendary MS, El-Deeb MM, Abuzaid MS, Mansour AT, Attallah AA. Perinatal transmission of hepatitis C antigens: envelope 1, envelope 2 and non-structural 4. Infect Dis (Lond) 2015. [PMID: 25922972 DOI: 10.3109/23744235.2015.1042035.] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Perinatal exposure to hepatitis C virus (HCV) antigens during pregnancy may affect the developing immune system in the fetus. We aimed to study the perinatal transmission of HCV structural and non-structural antigens. METHODS Sera from 402 pregnant mothers were tested for anti-HCV antibody and HCV RNA. HCV antigens were determined in sera from 101 HCV-infected mothers and their cord blood. RESULTS In both serum and cord blood samples, HCV NS4 (non-structural 4) at 27 kDa, E1 (envelope 1) at 38 kDa and E2 (envelope 2) at 40 kDa were identified, purified and quantified using western blotting, electroelution and ELISA. Maternal sera and neonate cord blood samples had similar detection rates for NS4 (94.1%), E1 (90.1%) and E2 (90.1%). The mean maternal serum levels (optical density, OD) of HCV NS4 (0.87 ± 0.01), E1 (0.86 ± 0.01) and E2 (0.85 ± 0.01) did not differ significantly (p > 0.05) from those of neonatal cord blood (0.83 ± 0.01, 0.87 ± 0.01 and 0.85 ± 0.01, respectively). Also, strong correlations (p < 0.0001) were shown between sera and cord blood sample levels of HCV NS4, r = 0.77; E1, r = 0.76 and E2, r = 0.80. The vertical transmission of these antigens in vaginal delivery did not differ significantly (p > 0.05) from those in caesarean section. CONCLUSIONS These findings indicate that vertical transmission of HCV NS4, E1 and E2 antigens was very high. Thus, exposure to these antigens may influence the developing immune responses to natural infection or future vaccination.
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Singh S, Vedi S, Li W, Samrat SK, Kumar R, Agrawal B. Recombinant adenoviral vector expressing HCV NS4 induces protective immune responses in a mouse model of Vaccinia-HCV virus infection: a dose and route conundrum. Vaccine 2014; 32:2712-21. [PMID: 24631092 DOI: 10.1016/j.vaccine.2014.02.080] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 02/19/2014] [Accepted: 02/26/2014] [Indexed: 12/18/2022]
Abstract
Hepatitis C virus (HCV) leads to chronic infection in the majority of infected patients presumably due to failure or inefficiency of the immune responses generated. Both antibody and cellular immune responses have been suggested to be important in viral clearance. Non-replicative adenoviral vectors expressing antigens of interest are considered as attractive vaccine vectors for a number of pathogens. In this study, we sought to evaluate cellular and humoral immune responses against HCV NS4 protein using recombinant adenovirus as a vaccine vector expressing NS4 antigen. We have also measured the effect of antigen doses and routes of immunization on the quality and extent of the immune responses, especially their role in viral load reduction, in a recombinant Vaccinia-HCV (Vac-HCV) infection mouse model. Our results show that an optimum dose of adenovirus vector (2×10(7)pfu/mouse) administered intramuscularly (i.m.) induces high T cell proliferation, granzyme B-expressing CD8(+) T cells, pro-inflammatory cytokines such as IFN-γ, TNF-α, IL-2 and IL-6, and antibody responses that can significantly reduce the Vac-HCV viral load in the ovaries of female C57BL/6 mice. Our results demonstrate that recombinant adenovirus vector can induce both humoral and cellular protective immunity against HCV-NS4 antigen, and that immunity is intricately controlled by route and dose of immunizing vector.
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Affiliation(s)
- Shakti Singh
- Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Satish Vedi
- Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada; Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Wen Li
- Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Subodh Kumar Samrat
- Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Rakesh Kumar
- Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Babita Agrawal
- Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.
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