scholarly journals PPP2R5D Promotes Hepatitis C Virus Infection Through Binding to NS5B Protein

Author(s):  
Muhammad Ikram Anwar ◽  
Ni Li ◽  
Qing Zhou ◽  
Mingxiao Chen ◽  
Chengguang Hu ◽  
...  

Abstract Background: Hepatitis C virus (HCV) is an important human pathogen causing chronic hepatitis C, end-stage liver diseases, and hepatocellular carcinoma. The development of infectious HCV cell culture systems primarily relied on the replication enhancement effect of adaptive mutations. Although the mode of action may vary, those adaptive mutations could direct the study of virus-host interactions required for efficient virus infection. We previously identified a substitution D559G in NS5B (RNA dependent RNA polymerase) critical for the replication of HCV genomes. In this study, we set out to study whether D559G-NS5B specifically interacted with some host factors crucial for HCV infection.Methods: Through mass spectrometry analysis of immunoprecipitation mixture of ectopically expressed wild-type and D559G-mutated NS5B, we identified candidate factors showing potential interactions with NS5B and D559G-NS5B. The requirement of selected host factor in HCV infection in vitro was demonstrated by gene knockout, overexpression, virus infection, and co-immunoprecipitation approaches.Results: From the results of immunoprecipitation and mass spectrometry analysis, we selected protein phosphatase 2 regulatory subunit B’delta (PPP2R5D) for further characterization. Co-immunoprecipitation confirmed that both wild-type and D559G NS5B proteins interacted with PPP2R5D, but the interaction between D559G-NS5B and PPP2R5D was more efficient. Silencing of PPP2R5D decreased HCV infection, and knockout of PPP2R5D nearly eliminated HCV infection in Huh7.5 cells. Transient and stably overexpression of PPP2R5D in PPP2R5D-knockout cells restored HCV infection to a level close to that seen for wild-type Huh7.5 cells. Conclusions: PPP2R5D is required for HCV infection in cultured hepatoma cells, and PPP2R5D may function through binding to HCV NS5B. The underlying mechanism of PPP2R5D in the complete HCV life cycle requires further investigation.

2013 ◽  
Vol 62 (8) ◽  
pp. 1235-1238 ◽  
Author(s):  
Inmaculada Castillo ◽  
Javier Bartolomé ◽  
Juan Antonio Quiroga ◽  
Vicente Carreño

Hepatitis C virus (HCV) infection in the absence of detectable antibodies against HCV and of viral RNA in serum is called occult HCV infection. Its prevalence and clinical significance in chronic hepatitis B virus (HBV) infection is unknown. HCV RNA was tested for in the liver samples of 52 patients with chronic HBV infection and 21 (40 %) of them were positive for viral RNA (occult HCV infection). Liver fibrosis was found more frequently and the fibrosis score was significantly higher in patients with occult HCV than in negative ones, suggesting that occult HCV infection may have an impact on the clinical course of HBV infection.


2016 ◽  
Vol 10 (2) ◽  
Author(s):  
Fatima Mehboob

Purpose of this study is to evaluate the different indications for screening for Anti HCV. This study was carried out in outdoor and indoor department of North Medical Ward of Mayo Hospital, Lahore. This is a non-interventional observational study. Two hundred patients ELISA proved HCV infection were evaluated to find out what were the different circumstances or symptomatology when tests for HCV infection were advised. So that a screening strategy can be formed. As hepatitis C virus infection has varied presentation and clinical features, the general practitioners, physicians, dermatologists and psychiatrists should be conscious about it an advise for Anti HCV detection whenever it is suspected. Screening of the early cases is beneficial both for the patients and its relatives.


Blood ◽  
1997 ◽  
Vol 90 (3) ◽  
pp. 1315-1320 ◽  
Author(s):  
Simone Cesaro ◽  
Maria Grazia Petris ◽  
Flavio Rossetti ◽  
Riccardo Cusinato ◽  
Corrado Pipan ◽  
...  

Abstract Sera of 658 patients who had completed treatment for pediatric malignancy were analyzed by a second-generation enzyme-linked immunosorbent assay and recombinant immunoblot assay test to assess the prevalence of hepatitis C virus (HCV)-seropositivity. All HCV-seropositive patients underwent detailed clinical, laboratory, virologic, and histologic study to analyze the course of HCV infection. One hundred seventeen of the 658 patients (17.8%) were positive for HCV infection markers. Among the 117 anti-HCV+ patients, 41 (35%) were also positive for markers of hepatitis B virus infection with or without delta virus infection markers, 91 (77.8%) had previously received blood product transfusions, and 25 (21.4%) showed a normal alanine aminotransferase (ALT) level during the last 5-year follow-up (11 of them never had abnormal ALT levels). The remaining 92 patients showed ALT levels higher than the upper limit of normal range. Eighty-one of 117 (70%) anti-HCV+ patients were HCV-RNA+, with genotype 1b being present in most patients (54%). In univariate analysis, no risk factor for chronic liver disease was statistically significant. In this study, the prevalence of HCV infection was high in patients who were treated for a childhood malignancy. In about 20% of anti-HCV+ patients, routes other than blood transfusions are to be considered in the epidemiology of HCV infection. After a 14-year median follow-up, chronic liver disease of anti-HCV+ positive patients did not show progression to liver failure.


2020 ◽  
Vol 34 ◽  
pp. 205873842096120
Author(s):  
Abeya A Lotfi ◽  
Asmaa E Mohamed ◽  
Nahela A Shalaby ◽  
Deena S Eissa ◽  
Ehab El-Dabaa ◽  
...  

Despite the link between HCV and malignant lymphoproliferative disorders has been established, the association between occult hepatitis C virus infection and malignant lymphoproliferative disorders remains obscure. The present study intended to identify the possible association between occult HCV infection and malignant lymphoproliferative disorders. Newly diagnosed patients with LPDs were screened for the presence of HCV-RNA in both plasma and PBMCs. PBMCs of the subjects were also, examined by transmission and immuno-electron microscopy. LPD patients showed a high percentage of HCV infection (71.9%): OCI-HCV (37.5%) and HCV (34.38%). Meanwhile, 28.13% of LPD patients did not show any evidence of HCV infection. Ultrastructural examination of PBMCs revealed the presence of intracytoplasmic vacuoles enclosing viral like particles, which were less prominent in occult HCV patients. The possibility of occult HCV should be considered in patients with LPDs which can be helpful in the management of the treatment protocol in order to set up a balance between the control of the tumor progression and minimizing post chemotherapy complications related to HCV infection.


1994 ◽  
Vol 14 (3) ◽  
pp. 253-258 ◽  
Author(s):  
Kazunari Yamaguchi ◽  
Hiroyuki Kiyowa ◽  
Jiroh Machida ◽  
Akira Obayashi ◽  
Noriyuki Nojiri ◽  
...  

2006 ◽  
Vol 80 (10) ◽  
pp. 5097-5099 ◽  
Author(s):  
Paolo Muratori ◽  
Susan E. Sutherland ◽  
Luigi Muratori ◽  
Alessandro Granito ◽  
Marcello Guidi ◽  
...  

ABSTRACT GM and KM allotypes—genetic markers of immunoglobulin (Ig) γ and κ chains, respectively—are associated with humoral immunity to several infection- and autoimmunity-related epitopes. We hypothesized that GM and KM allotypes contribute to the generation of autoantibodies to liver/kidney microsomal antigen 1 (LKM1) in hepatitis C virus (HCV)-infected persons. To test this hypothesis, we characterized 129 persons with persistent HCV infection for several GM and KM markers and for anti-LKM1 antibodies. The heterozygous GM 1,3,17 23 5,13,21 phenotype was significantly associated with the prevalence of anti-LKM1 antibodies (odds ratio, 5.13; P = 0.002), suggesting its involvement in this autoimmune phenomenon in HCV infection.


2002 ◽  
Vol 76 (6) ◽  
pp. 2997-3006 ◽  
Author(s):  
Masanori Ikeda ◽  
MinKyung Yi ◽  
Kui Li ◽  
Stanley M. Lemon

ABSTRACT Dicistronic, selectable subgenomic replicons derived from the Con1 strain of hepatitis C virus (HCV) are capable of autonomous replication in cultured Huh7 cells (Lohmann et al., Science 285:110-113, 1999). However, adaptive mutations in the NS3, NS5A, and/or NS5B proteins are required for efficient replication of these RNAs and increase by orders of magnitude the numbers of G418-resistant colonies selected following transfection of Huh7 cells. Here, we demonstrate that a subgenomic replicon (NNeo/3-5B) derived from an infectious molecular clone of a second genotype 1b virus, HCV-N (Beard et al., Hepatology 30:316-324, 1999) is also capable of efficient replication in Huh7 cells. G418-resistant cells selected following transfection with NNeo/3-5B RNA contained abundant NS5A antigen and HCV RNA detectable by Northern analysis. Replicon RNA in one of three clonally isolated cell lines contained no mutations in the NS3-NS5B polyprotein, confirming that adaptive mutations are not required for efficient replication in these cells. However, the deletion of a unique 4-amino-acid insertion that is present within the interferon sensitivity-determining region (ISDR) of the NS5A protein in wild-type HCV-N drastically decreased the number of G418-resistant colonies obtained following transfection of Huh7 cells. This effect could be reversed by inclusion of a previously described Con1 cell culture-adaptive mutation (S2005→I), confirming that this natural insertion has a controlling role in determining the replication capacity of wild-type HCV-N RNA in Huh7 cells. Additional selectable, dicistronic RNAs encoding NS2-NS5B, E1-NS5B, or the full-length HCV polyprotein were also capable of replication and gave rise to G418-resistant cell clones following transfection of Huh7 cells. We conclude that RNA derived from this documented infectious molecular clone has a unique capacity for replication in Huh7 cells in the absence of additional cell culture-adaptive mutations.


2005 ◽  
Vol 33 (6) ◽  
pp. 641-646 ◽  
Author(s):  
AI Olut ◽  
F Ozsakarya ◽  
M Dilek

The seroprevalence of hepatitis C virus (HCV) infection was investigated among haemodialysis (HD) patients. Mean serum aminotransferase levels were also compared over 3 months in HCV-seropositive patients with and without viraemia, as well as in HCV-seronegative HD patients and HCV-seropositive, non-uraemic, viraemic patients. Seroprevalence of HCV infection was 19% among the 437 HD patients tested. Of the 61 HD HCV-seropositive, hepatotoxic medication- and alcohol-free patients, 38 (62%) were found to be viraemic, using quantitative HCV-RNA, on at least one occasion. Mean serum aminotransferase levels were significantly higher in viraemic HD patients (compared with non-viraemic patients), suggesting that HCV-RNA positivity is an important predictor of increased enzyme activity in these patients. As expected, aminotransferase levels in HCV-seropositive HD patients tended to be lower than levels in HCV-seropositive non-uraemic patients.


mSphere ◽  
2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Sharon E. Hopcraft ◽  
Kristopher D. Azarm ◽  
Benjamin Israelow ◽  
Nicolas Lévêque ◽  
Megan C. Schwarz ◽  
...  

ABSTRACT Hepatitis C virus (HCV) is the leading cause of liver cancer in the Western Hemisphere. HCV infection requires miR-122, which is expressed only in liver cells, and thus is one reason that replication of this virus occurs efficiently only in cells of hepatic origin. To understand how HCV genetics impact miR-122 usage, we knocked out miR-122 using clustered regularly interspaced short palindromic repeat (CRISPR) technology and adapted virus to replicate in the presence of noncognate miR-122 RNAs. In doing so, we identified viral mutations that allow replication in the complete absence of miR-122. This work provides new insights into how HCV genetics influence miR-122 requirements and proves that replication can occur without this miRNA, which has broad implications for how HCV tropism is maintained. Hepatitis C virus (HCV) replication requires binding of the liver-specific microRNA (miRNA) miR-122 to two sites in the HCV 5′ untranslated region (UTR). Although we and others have shown that viral genetics impact the amount of active miR-122 required for replication, it is unclear if HCV can replicate in the complete absence of this miRNA. To probe the absolute requirements for miR-122 and the genetic basis for those requirements, we used clustered regularly interspaced short palindromic repeat (CRISPR) technology to knock out miR-122 in Huh-7.5 cells and reconstituted these knockout (KO) cells with either wild-type miR-122 or a mutated version of this miRNA. We then characterized the replication of the wild-type virus, as well as a mutated HCV bearing 5′ UTR substitutions to restore binding to the mutated miR-122, in miR-122 KO Huh-7.5 cells expressing no, wild-type, or mutated miR-122. We found that while replication was most efficient when wild-type or mutated HCV was provided with the matched miR-122, inefficient replication could be observed in cells expressing the mismatched miR-122 or no miR-122. We then selected viruses capable of replicating in cells expressing noncognate miR-122 RNAs. Unexpectedly, these viruses contained multiple mutations throughout their first 42 nucleotides that would not be predicted to enhance binding of the provided miR-122. These mutations increased HCV RNA replication in cells expressing either the mismatched miR-122 or no miR-122. These data provide new evidence that HCV replication can occur independently of miR-122 and provide unexpected insights into how HCV genetics influence miR-122 requirements. IMPORTANCE Hepatitis C virus (HCV) is the leading cause of liver cancer in the Western Hemisphere. HCV infection requires miR-122, which is expressed only in liver cells, and thus is one reason that replication of this virus occurs efficiently only in cells of hepatic origin. To understand how HCV genetics impact miR-122 usage, we knocked out miR-122 using clustered regularly interspaced short palindromic repeat (CRISPR) technology and adapted virus to replicate in the presence of noncognate miR-122 RNAs. In doing so, we identified viral mutations that allow replication in the complete absence of miR-122. This work provides new insights into how HCV genetics influence miR-122 requirements and proves that replication can occur without this miRNA, which has broad implications for how HCV tropism is maintained.


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