scholarly journals Detection of Diverse Hepatitis C Virus (HCV)-Specific Cytotoxic T Lymphocytes in Peripheral Blood of Infected Persons by Screening for Responses to All Translated Proteins of HCV

2001 ◽  
Vol 75 (3) ◽  
pp. 1229-1235 ◽  
Author(s):  
David K. H. Wong ◽  
Darryll D. Dudley ◽  
Paul B. Dohrenwend ◽  
Georg M. Lauer ◽  
Raymond T. Chung ◽  
...  

ABSTRACT Broadly directed hepatitis C virus (HCV)-specific cytotoxic T lymphocytes (CTL) have been identified from liver-infiltrating lymphocytes but have been more difficult to assess in peripheral blood of infected persons. To enhance the detection of CTL from peripheral blood mononuclear cells (PBMC), we cocultured PBMC with autologous Epstein-Barr virus-transformed B-lymphoblastoid cell lines that had been infected with recombinant vaccinia virus constructs so that they expressed the entire translated polyprotein of HCV-H, a type 1a strain. These stimulated cells from HCV-infected as well as exposed seronegative persons were then cloned at limiting dilution and tested for HCV-specific CTL activity using a standard 51Cr release assay. HCV-specific CTL were detected in PBMC from seven of nine persons with chronic hepatitis, including five of seven in whom CTL had previously been detected from liver biopsy specimens but not PBMC. In a single person with chronic HCV infection, CTL directed against as many as five different epitopes were detected in peripheral blood and were similar in specificity to those detected in liver tissue. This technique was used to evaluate eight subjects identified to be at high risk for HCV exposure due to continued injection drug abuse; no evidence of CTL in PBMC was found. We conclude that CTL can be detected in PBMC from the majority of persons with chronic HCV infection but are present at lower levels or absent in exposed but persistently seronegative persons. The high degree of concordance of HCV epitopes identified from liver and PBMC suggests that this strategy is a reasonable alternative to liver biopsy for characterizing the CTL response to HCV in chronically infected persons.

2002 ◽  
Vol 76 (24) ◽  
pp. 12584-12595 ◽  
Author(s):  
Cheryl L. Day ◽  
Georg M. Lauer ◽  
Gregory K. Robbins ◽  
Barbara McGovern ◽  
Alysse G. Wurcel ◽  
...  

ABSTRACT Vigorous virus-specific CD4+ T-helper-cell responses are associated with successful control of hepatitis C virus (HCV) and other human viral infections, but the breadth and specificity of responses associated with viral containment have not been defined. To address this we evaluated the HCV-specific CD4+ T-helper-cell response in HCV antibody-positive persons who lack detectable plasma viremia, and compared this response to that in persons with chronic HCV infection. Peripheral blood mononuclear cells were stimulated with HCV proteins, followed by measurement of HCV-specific CD4+-T-cell responses to a comprehensive set of overlapping HCV peptides by intracellular gamma interferon production. In three persons with resolved HCV infection studied in detail, 13 to 14 epitopes were targeted, but none was recognized by all three. The 37 defined epitopes were predominantly distributed among the HCV proteins core, NS3, NS4, and NS5. In an expanded analysis of responses to these proteins in persons with resolved infection, an average of 10 epitopes was targeted, whereas in persons with chronic viremia never was more than one epitope targeted (P < 0.001). This comprehensive analysis of the breadth and specificity of HCV-specific T-helper-cell responses indicates that up to 14 viral epitopes can be simultaneously targeted by circulating virus-specific CD4+ T helper cells in a controlled human viral infection. Moreover, these data provide important parameters for evaluation of candidate HCV vaccines, and provide rationale for immunotherapy in chronic HCV infection.


2009 ◽  
Vol 23 (6) ◽  
pp. 425-430 ◽  
Author(s):  
Jennifer A Flemming ◽  
David J Hurlbut ◽  
Ben Mussari ◽  
Lawrence C Hookey

BACKGROUND/OBJECTIVE: Liver biopsy has been the gold standard for grading and staging chronic hepatitis C virus (HCV)-mediated liver injury. Traditionally, this has been performed by trained practitioners using a nonimage-guided percutaneous technique at the bedside. Recent literature suggests an expanding role for radiologists in obtaining biopsies using an ultrasound (US)-guided technique. The present study was undertaken study to determine if the two techniques produced liver biopsy specimens of similar quality and hypothesized that at our institution, non-US-guided percutaneous liver biopsies for HCV would be of higher quality than US-guided specimens.METHODS: Liver biopsies from 100 patients with chronic HCV infection (50 consecutive US-guided and 50 consecutive non-US-guided), were retrospectively identified using a hospital histopathology database. All original biopsy slides were coded and prospectively reanalyzed by a single hepatopathologist who was blinded to the technique used in obtaining the biopsy. Additionally, all liver biopsies for chronic HCV infection completed at the centre from 1998 to 2007 were identified and the technique used was recorded. Biopsy quality was determined primarily by the number of complete portal tracts (CPTs) identifiable in the slides. The total length of specimen and the degree of fragmentation were secondary outcome measures.RESULTS: There was a slight difference observed between the US-guided and non-US-guided groups in mean age (46.3 years versus 42.5 years, repectively; P=0.018) but no differences in sex, presence of cirrhosis, bilirubin, creatinine, international normalized ratio, and grade or stage of disease. Biopsies obtained using the US-guided technique produced higher quality specimens than the non-US-guided technique based on our primary outcome of number of CPTs in the biopsy (11.8 versus 7.4; P<0.001). US-guided specimens also were longer (24.4 mm versus 19.7 mm; P=0.001), had less fragmentation (P=0.016), and a higher overall histopathological quality assessment (P=0.026) than the non-US-guided biopsies. However, there was no significant difference between the two groups in the ability to grade and stage the disease (96% US-guided versus 90% in non-US-guided (P=0.20). Over a 10-year period, 763 biopsies for chronic HCV infection were identified with an obvious trend toward the increased use of US-guided technique observed at 2% in 1998 to 85% in 2007.CONCLUSIONS: US-guided liver biopsies for chronic HCV are the most common method of obtaining specimens at the Kingston General Hospital, Kingston, Ontario, and are of higher quality than non-US-guided specimens. However, there is no significant difference in the two techniques in the ability to grade and stage chronic HCV.


1994 ◽  
Vol 39 (9) ◽  
pp. 2022-2031 ◽  
Author(s):  
Shinjiro Sato ◽  
Shigetoshi Fujiyama ◽  
Motohiko Tanaka ◽  
Masafumi Goto ◽  
Yuko Taura ◽  
...  

2001 ◽  
Vol 45 (2) ◽  
pp. 517-524 ◽  
Author(s):  
Jeffrey M. Jacobson ◽  
Lawrence Feinman ◽  
Leonard Liebes ◽  
Nancy Ostrow ◽  
Victoria Koslowski ◽  
...  

ABSTRACT Hypericin is a natural derivative of the common St. Johns wort plant, Hypericum perforatum. It has in vitro activity against several viruses, including bovine diarrhea virus, a pestivirus with structural similarities to hepatitis C virus (HCV). We conducted a phase I dose escalation study to determine the safety and antiviral activity of hypericin in patients with chronic HCV infection. The first 12 patients received an 8-week course of 0.05 mg of hypericin per kg of body weight orally once a day; 7 patients received an 8-week course of 0.10 mg/kg orally once a day. At the end of the 8-week period of treatment, no subject had a change of plasma HCV RNA level of more than 1.0 log10. Five of 12 subjects receiving the 0.05-mg/kg/day dosing schedule and 6 of 7 subjects receiving the 0.10-mg/kg/day dosing schedule developed phototoxic reactions. No other serious adverse events associated with hypericin use occurred. The pharmacokinetic data revealed a long elimination half-life (mean values of 36.1 and 33.8 h, respectively, for the doses of 0.05 and 0.1 mg/kg) and mean area under the curve determinations of 1.5 and 3.1 μg/ml × hr, respectively. In sum, hypericin given orally in doses of 0.05 and 0.10 mg/kg/d caused considerable phototoxicity and had no detectable anti-HCV activity in patients with chronic HCV infection.


2006 ◽  
Vol 80 (15) ◽  
pp. 7364-7374 ◽  
Author(s):  
Kyung-Soo Chang ◽  
Zhaohui Cai ◽  
Chen Zhang ◽  
Ganes C. Sen ◽  
Bryan R. G. Williams ◽  
...  

ABSTRACT Hepatitis C virus (HCV) infection causes chronic hepatitis and is currently treated with alpha interferon (IFN-α)-based therapies. The underlying mechanisms of chronic HCV infection and IFN-based therapies, however, have not been defined. Protein kinase R (PKR) was implicated in the control of HCV replication and mediation of IFN-induced antiviral response. In this report, we demonstrate that a subgenomic RNA replicon of genotype 2a HCV replicated efficiently in mouse embryonic fibroblasts (MEFs), as determined by cell colony formation efficiency and the detection of HCV proteins and both positive- and negative-strand RNAs. Additionally, the subgenomic HCV RNA was found to replicate more efficiently in the PKR knockout (PKR−/−) MEF than in the wild-type (PKR+/+) MEF. The knockdown expression of PKR by specific small interfering RNAs significantly enhanced the level of HCV RNA replication, suggesting that PKR is involved in the control of HCV RNA replication. The level of ISG56 (p56) was induced by HCV RNA replication, indicating the activation of PKR-independent antiviral pathways. Furthermore, IFN-α/β inhibited HCV RNA replication in PKR−/− MEFs as efficiently as in PKR+/+ MEFs. These findings demonstrate that PKR-independent antiviral pathways play important roles in controlling HCV replication and mediating IFN-induced antiviral effect. Our findings also provide a foundation for the development of transgenic mouse models of HCV replication and set a stage to further define the roles of cellular genes in the establishment of chronic HCV infection and the mediation of intracellular innate antiviral response by using MEFs derived from diverse gene knockout animals.


1996 ◽  
Vol 60 (2) ◽  
pp. 179-182 ◽  
Author(s):  
Francesco Negro ◽  
Hugo Troonen ◽  
Gerd Michel ◽  
Emiliano Giostra ◽  
Monika Albrecht ◽  
...  

2008 ◽  
Vol 13 (21) ◽  
Author(s):  
W L Irving ◽  
D Salmon ◽  
C Boucher ◽  
I M Hoepelman

Around 25% of people infected with hepatitis C virus (HCV) are able to clear the infection spontaneously, while the majority become chronically infected, with a subsequent risk for the individual patient of progressive inflammatory liver disease, cirrhosis, hepatocellular carcinoma and liver-related death (Figure 1). Much is known about the epidemiology, pathogenesis, diagnosis and management of chronic HCV infection. In comparison, knowledge about acute HCV infection is patchy. In this article, we will highlight concerns relating to acute HCV infection and suggest that public health bodies responsible for managing the HCV epidemic should redirect at least some of their resources to dealing with these issues.


2006 ◽  
Vol 59 (5-6) ◽  
pp. 230-234 ◽  
Author(s):  
Dragan Delic ◽  
Zorica Nesic ◽  
Jasmina Simonovic ◽  
Neda Svirtlih ◽  
Ljubisa Dokic ◽  
...  

Introduction. Hepatitis C virus (HCV) RNA status and HCV genotypes have become extremely important for exact diagnosis, prognosis, duration of treatment and monitoring of antiviral therapy of chronic HCV infection. Material and methods. For the purpose of precise and objective assessment of virologic analyses, such as the determination of the number of virus copies and virus genotypes, 110 patients with chronic HCV infection were tested. Genotyping of HCV isolates and HCV RNA quantification were performed by using the PCR method. Genotype lb infection was verified in 49.1% of patients, genotype 3a infection was found in 28.2%, genotype 4 in 9.1%, genotype 2 in 4.5%, while mixed genotype infections were diagnosed in 9.1% of cases. Results. Patients infected by genotype lb had significantly higher serum HCV RNA level in relation to patients infected by other genotypes (p<0.05). Over 70% of patients infected by genotype lb had more than 2xl06 virus copies in 1 ml of blood, while in genotypes 2, 3a and 4, the percentage was 40%, 38.5% and 30%, respectively. Male patients had approximately 7.7x10.6 virus copies in 1 ml of blood, which was significantly higher in comparison with female patients (2.3xl06 copies/ml; p<0.05). Conclusion. Our results are in concordance with the results of other authors reporting that genotype lb is predominant in Europe, as well as significantly higher incidence of viremia in patients with genotype lb infection in relation to other HCV genotypes. Based on these results, we can conclude that our patients, most commonly, present with severe clinical course of chronic HCV infection and require longer treatment (48 weeks), which causes economic problems. .


Sign in / Sign up

Export Citation Format

Share Document