scholarly journals Hepatitis C Virus Core Protein Leads to Immune Suppression and Liver Damage in a Transgenic Murine Model

2002 ◽  
Vol 76 (18) ◽  
pp. 9345-9354 ◽  
Author(s):  
Carolina Soguero ◽  
Myungsoo Joo ◽  
Kimberly A. Chianese-Bullock ◽  
Duong Tony Nguyen ◽  
Kenneth Tung ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
T Lymphocytes ◽  
T Lymphocyte ◽  
Liver Damage ◽  
Immune Cells ◽  
Core Protein ◽  
Hcv Infection

ABSTRACT Hepatitis C virus (HCV) is remarkably efficient in establishing persistent infection, possibly mediated by an impaired immune response to HCV infection. There is compelling evidence that HCV can infect immune cells, such as macrophages, B cells, and T cells. It has been previously reported that HCV core, the first protein expressed during the early phase of viral infection, contains the immunomodulatory function of suppressing host immune responses. This altered function of immune cells caused by HCV infection may explain the ineffective immune response to HCV. To further characterize the immunomodulatory role of HCV core in vivo, we generated transgenic (TG) mice by directing the expression of core protein to T lymphocytes by using the CD2 promoter. T-lymphocyte responses, including the production of gamma interferon and interleukin-2, were significantly diminished in these mice compared to their non-TG littermates. The inhibition of T-lymphocyte responsiveness may be due to the increased susceptibility of peripheral T lymphocytes to Fas-mediated apoptosis. Surprisingly, significant lymphocyte infiltration was observed in the portal tracts of livers isolated from core TG mice, associated with increasing serum alanine aminotransferase levels. Moreover, no intrahepatic lymphocytes or liver damage was found in non-TG littermates and core TG mice bred to Fas-deficient lpr mice. These results suggest that HCV core drives liver injury by increasing Fas-mediated apoptosis and liver infiltration of peripheral T cells.

scholarly journals Authentic Patient-Derived Hepatitis C Virus Infects and Productively Replicates in Primary CD4+and CD8+T LymphocytesIn Vitro

2017 ◽  
Vol 92 (3) ◽  
Author(s):  
Georgia Skardasi ◽  
Annie Y. Chen ◽  
Tomasz I. Michalak
Keyword(s):  
T Cells ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
T Lymphocytes ◽  
Immune Cells ◽  
Immune Cell ◽  
Cell Types ◽  
Hcv Rna ◽  
Biophysical Properties

ABSTRACTAccumulated evidence indicates that immune cells can support the replication of hepatitis C virus (HCV) in infected patients and in culture. However, there is a scarcity of data on the degree to which individual immune cell types support HCV propagation and on characteristics of virus assembly. We investigated the ability of authentic, patient-derived HCV to infectin vitrotwo closely related but functionally distinct immune cell types, CD4+and CD8+T lymphocytes, and assessed the properties of the virus produced by these cells. The HCV replication system in intermittently mitogen-stimulated T cells was adapted to infect primary human CD4+or CD8+T lymphocytes. HCV replicated in both cell types although at significantly higher levels in CD4+than in CD8+T cells. Thus, the HCV RNA replicative (negative) strand was detected in CD4+and CD8+cells at estimated mean levels ± standard errors of the means of 6.7 × 102± 3.8 × 102and 1.2 × 102± 0.8 × 102copies/μg RNA, respectively (P< 0.0001). Intracellular HCV NS5a and/or core proteins were identified in 0.9% of CD4+and in 1.2% of CD8+T cells. Double staining for NS5a and T cell type-specific markers confirmed that transcriptionally competent virus replicated in both cell types. Furthermore, an HCV-specific protease inhibitor, telaprevir, inhibited infection in both CD4+and CD8+cells. The emergence of unique HCV variants and the release of HCV RNA-reactive particles with biophysical properties different from those of virions in plasma inocula suggested that distinct viral particles were assembled, and therefore, they may contribute to the pool of circulating virus in infected patients.IMPORTANCEAlthough the liver is the main site of HCV replication, infection of the immune system is an intrinsic characteristic of this virus independent of whether infection is symptomatic or clinically silent. Many fundamental aspects of HCV lymphotropism remain uncertain, including the degree to which different immune cells support infection and contribute to virus diversity. We show that authentic, patient-derived HCV productively replicatesin vitroin two closely related but functionally distinct types of T lymphocytes, CD4+and CD8+cells. The display of viral proteins and unique variants, the production of virions with biophysical properties distinct from those in plasma serving as inocula, and inhibition of replication by an antiviral agent led us to ascertain that both T cell subtypes supported virus propagation. Infection of CD4+and CD8+T cells, which are central to adaptive antiviral immune responses, can directly affect HCV clearance, favor virus persistence, and decisively influence the development and progression of hepatitis C.

scholarly journals Hepatitis C Virus Affects Tuberculosis-Specific T Cells in HIV-Negative Patients

Viruses ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 101 ◽  
Author(s):  
Mohamed Ahmed El-Mokhtar ◽  
Sherein G. Elgendy ◽  
Abeer Sharaf Eldin ◽  
Elham Ahmed Hassan ◽  
Ali Abdel Azeem Hasan ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
T Cell ◽  
Cd4 T Cells ◽  
Hcv Infection ◽  
Hla Dr ◽  
Ifn Γ ◽  
The Impact

The occurrence of tuberculosis (TB) and hepatitis C virus (HCV) infections in the same patient presents a unique clinical challenge. The impact of HCV infection on the immune response to TB remains poorly investigated in TB+/HCV+ patients. This study was conducted to evaluate the impact of HCV on the T-cell-mediated immune response to TB in coinfected patients. Sixty-four patients with active TB infections were screened for coinfection with HCV. The expression of immune activation markers IFN-γ, CD38, and HLA-DR on TB-specific CD4+ T cells was evaluated by flow cytometry in TB-monoinfected patients, TB/HCV-coinfected patients, and healthy controls. IL-2, IL-4, IFN-γ, TNF-α, and IL-10 levels were measured using ELISA. The end-of-treatment response to anti-TB therapy was recorded for both patient groups. Significantly lower levels of CD4+IFN-γ+CD38+ and CD4+IFN-γ+HLA-DR+ T cells were detected in TB/HCV-coinfected patients compared to TB monoinfected patients and controls. TB+/HCV+-coinfected patients showed higher serum levels of IL-10. The baseline frequencies of TB-specific activated T-cell subsets did not predict the response to antituberculous therapy in TB+/HCV+ patients. We concluded that different subsets of TB-specific CD4+ T cells in TB/HCV-infected individuals are partially impaired in early-stage HCV infection. This was combined with increased serum IL-10 level. Such immune modulations may represent a powerful risk factor for disease progression in patients with HCV/TB coinfection.

scholarly journals Diverse Functions of γδ T Cells in the Progression of Hepatitis B Virus and Hepatitis C Virus Infection

2021 ◽  
Vol 11 ◽  
Author(s):  
Wen Hou ◽  
Xiaoli Wu
Keyword(s):  
T Cells ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Hepatitis B Virus ◽  
Virus Infection ◽  
Immune Cells ◽  
Liver Diseases ◽  
Γδ T Cells ◽  
Hcv Infection ◽  
B Virus

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are primary risk factors for a wide spectrum of liver diseases that severely affect human health. The liver is an immunological organ that has an abundance of immune cells. Thus, various innate or adaptive immune cells are involved in the progression of HBV or HCV infection. Among those cells, a unique kind of immune cell, the γδ T cell, contributes to promoting or inhibiting the progression of liver diseases. To reveal the diverse roles of γδ T cells in HBV or HCV infection, the properties and functions of these cells in human and mouse models are analyzed. Here, we briefly describe the characteristics and functions of γδ T cells subsets in liver diseases. Then, we fully discuss the diverse roles of γδ T cells in the progression of HBV or HCV infection, including stages of acute infection, chronic infection, liver cirrhosis, and hepatocellular carcinoma. Finally, the functions and existing problems of γδ T cells in HBV or HCV infection are summarized. A better understanding of the function of γδ T cells during the progression of HBV and HCV infection will be helpful for the treatment of virus infection.

scholarly journals Analysis of Successful Immune Responses in Persons Infected with Hepatitis C Virus

2000 ◽  
Vol 191 (9) ◽  
pp. 1499-1512 ◽  
Author(s):  
Franziska Lechner ◽  
David K.H. Wong ◽  
P. Rod Dunbar ◽  
Roger Chapman ◽  
Raymond T. Chung ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
T Lymphocyte ◽  
Cytotoxic T Lymphocyte ◽  
Acute Infection ◽  
Hcv Infection ◽  
Ctl Response ◽  
Acute Hcv ◽  
Ifn Γ ◽  
Acute Hcv Infection

Although hepatitis C virus (HCV) infection is very common, identification of patients during acute infection is rare. Consequently, little is known about the immune response during this critical stage of the disease. We analyzed the T lymphocyte response during and after acute resolving HCV infection in three persons, using interferon (IFN)-γ enzyme-linked immunospot (ELISPOT) and human histocompatibility leukocyte antigen (HLA) peptide tetramer assays. Acute infection was associated with a broadly directed T helper and cytotoxic T lymphocyte (CTL) response, which persisted after resolution of clinical hepatitis and clearance of viremia. At the earliest time point studied, highly activated CTL populations were observed that temporarily failed to secrete IFN-γ, a “stunned” phenotype, from which they recovered as viremia declined. In long-term HCV-seropositive persons, CTL responses were more common in persons who had cleared viremia compared with those with persistent viremia, although the frequencies of HCV-specific CTLs were lower than those found in persons during and after resolution of acute HCV infection. These studies demonstrate a strong and persistent CTL response in resolving acute HCV infection, and provide rationale to explore immune augmentation as a therapeutic intervention in chronic HCV infection.

scholarly journals High Level of PD-1 Expression on Hepatitis C Virus (HCV)-Specific CD8+ and CD4+ T Cells during Acute HCV Infection, Irrespective of Clinical Outcome

2011 ◽  
Vol 85 (9) ◽  
pp. 4633-4633
Author(s):  
V. Kasprowicz ◽  
J. S. zur Wiesch ◽  
T. Kuntzen ◽  
B. E. Nolan ◽  
S. Longworth ◽  
...  
Keyword(s):  
T Cells ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Clinical Outcome ◽  
Cd4 T Cells ◽  
Hcv Infection ◽  
Acute Hcv ◽  
High Level ◽  
Acute Hcv Infection

scholarly journals Adaptive Immune Response against Hepatitis C Virus

2020 ◽  
Vol 21 (16) ◽  
pp. 5644
Author(s):  
Janine Kemming ◽  
Robert Thimme ◽  
Christoph Neumann-Haefelin
Keyword(s):  
Immune Response ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Persistent Infection ◽  
Adaptive Immune Response ◽  
Hcv Infection ◽  
Viral Escape ◽  
Continuous Exposure ◽  
Adaptive Immune ◽  
Adaptive Immune Cells

A functional adaptive immune response is the major determinant for clearance of hepatitis C virus (HCV) infection. However, in the majority of patients, this response fails and persistent infection evolves. Here, we dissect the HCV-specific key players of adaptive immunity, namely B cells and T cells, and describe factors that affect infection outcome. Once chronic infection is established, continuous exposure to HCV antigens affects functionality, phenotype, transcriptional program, metabolism, and the epigenetics of the adaptive immune cells. In addition, viral escape mutations contribute to the failure of adaptive antiviral immunity. Direct-acting antivirals (DAA) can mediate HCV clearance in almost all patients with chronic HCV infection, however, defects in adaptive immune cell populations remain, only limited functional memory is obtained and reinfection of cured individuals is possible. Thus, to avoid potential reinfection and achieve global elimination of HCV infections, a prophylactic vaccine is needed. Recent vaccine trials could induce HCV-specific immunity but failed to protect from persistent infection. Thus, lessons from natural protection from persistent infection, DAA-mediated cure, and non-protective vaccination trials might lead the way to successful vaccination strategies in the future.

scholarly journals Differential Effects of Hepatitis C Virus JFH1 on Human Myeloid and Plasmacytoid Dendritic Cells

2009 ◽  
Vol 83 (11) ◽  
pp. 5693-5707 ◽  
Author(s):  
Hua Liang ◽  
Rodney S. Russell ◽  
Nicole L. Yonkers ◽  
David McDonald ◽  
Benigno Rodriguez ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Cd4 T Cells ◽  
Ex Vivo ◽  
Hcv Infection ◽  
Poly I:C ◽  
Dc Function ◽  
Cd40 Expression

ABSTRACT Dendritic cells (DCs) are reported to be functionally deficient during chronic hepatitis C virus (HCV) infection. Differing results have been reported on direct effects of intact replicative-form HCV on DC function. To better understand the effect of HCV on DC function, we treated freshly purified human myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) with HCV JFH1. We found that HCV upregulated mDC maturation marker (CD83, CD86, and CD40) expression and did not inhibit Toll-like receptor 3 (TLR3) ligand [poly(I:C)]-induced mDC maturation, a finding consistent with the phenotype of DCs from HCV-infected subjects. At the same time, HCV JFH1 inhibited the ability of poly(I:C)-treated mDCs to activate naive CD4 T cells. In contrast, although there was no direct effect of virus on pDC maturation, HCV JFH1 inhibited TLR7 ligand (R848)-induced pDC CD40 expression, and this was associated with impaired ability to activate naive CD4 T cells. Parallel experiments with recombinant HCV proteins indicated HCV core protein may be responsible for a portion of the activity. Furthermore, HCV-mediated mDC maturation was dependent upon CD81-E2 interaction and, in part, TLR2. Using UV-treated HCV, we show that HCV-mediated mDC and pDC maturation is virus replication independent and, using strand specific PCR, we found no evidence for HCV replication within DCs. Because these effects of HCV on DC subset maturation and function in part recapitulate direct ex vivo analysis of DCs in chronic HCV infection, the mechanisms described here likely account for a portion of the DC subset defects observed in vivo.

scholarly journals Hepatitis C virus enhances Rubicon expression, leading to autophagy inhibition and intracellular innate immune activation

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yuto Shiode ◽  
Hayato Hikita ◽  
Satoshi Tanaka ◽  
Kumiko Shirai ◽  
Akira Doi ◽  
...  
Keyword(s):  
Immune Response ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Late Stage ◽  
Early Stage ◽  
Hcv Infection ◽  
Infected Cells ◽  
The Impact ◽  
Chronic Hepatitis C Patients

Abstract Autophagy, a degradation system, works to maintain cellular homeostasis. However, as the impact of Hepatitis C virus (HCV) infection on hepatocyte autophagy and its effect on HCV replication remain unclear, we examined them. HCV infection suppressed late-stage autophagy and increased Rubicon. siRNA-mediated knockdown of Rubicon promoted autophagy in HCV-infected cells. In Huh-7 cells harbouring the HCV replicon, Rubicon knockdown downregulated the expression of type 1 interferon (IFN)-related genes and upregulated HCV replication. Rubicon overexpression or administration of bafilomycin A1 or chloroquine, an inhibitor of late-stage autophagy, suppressed autophagy and activated the type 1 IFN pathway. On the other hand, Atg7 knockout suppressed early-stage autophagy and did not activate the type 1 IFN pathway. In livers of humanized liver chimeric mice, HCV infection increased Rubicon and enhanced type 1 IFN signalling. Elimination of HCV in the mice reduced the increase in Rubicon due to HCV infection. The expression levels of Rubicon and IFN-stimulated genes in chronic hepatitis C patients were higher than those in non-B, non-C hepatitis patients. HCV infection increased Rubicon and suppressed hepatocyte autophagy, leading to activation of the intracellular immune response. Rubicon induction is involved in HCV replication via activation of the intracellular immune response.

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