scholarly journals Acute Liver Damage Associated with Innate Immune Activation in a Small Nonhuman Primate Model of Hepacivirus Infection

2016 ◽  
Vol 90 (20) ◽  
pp. 9153-9162 ◽  
Author(s):  
Cordelia Manickam ◽  
Premeela Rajakumar ◽  
Lynn Wachtman ◽  
Joshua A. Kramer ◽  
Amanda J. Martinot ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Hepatitis C ◽  
Immune Responses ◽  
Nk Cells ◽  
Nk Cell ◽  
Acute Infection ◽  
Innate Immune ◽  
Hcv Infection ◽  
Common Marmosets ◽  
Viral Loads

ABSTRACTDespite its importance in shaping adaptive immune responses, viral clearance, and immune-based inflammation, tissue-specific innate immunity remains poorly characterized for hepatitis C virus (HCV) infection due to the lack of access to acutely infected tissues. In this study, we evaluated the impact of natural killer (NK) cells and myeloid (mDCs) and plasmacytoid (pDCs) dendritic cells on control of virus replication and virus-induced pathology caused by another, more rapidly resolving hepacivirus, GB virus B (GBV-B), in infections of common marmosets. High plasma and liver viral loads and robust hepatitis characterized acute GBV-B infection, and while viremia was generally cleared by 2 to 3 months postinfection, hepatitis and liver fibrosis persisted after clearance. Coinciding with peak viral loads and liver pathology, the levels of NK cells, mDCs, and pDCs in the liver increased up to 3-fold. Although no obvious numerical changes in peripheral innate cells occurred, circulating NK cells exhibited increased perforin and Ki67 expression levels and increased surface expression of CXCR3. These data suggested that increased NK cell arming and proliferation as well as tissue trafficking may be associated with influx into the liver during acute infection. Indeed, NK cell frequencies in the liver positively correlated with plasma (R= 0.698;P= 0.015) and liver (R= 0.567;P= 0.057) viral loads. Finally, soluble factors associated with NK cells and DCs, including gamma interferon (IFN-γ) and RANTES, were increased in acute infection and also were associated with viral loads and hepatitis. Collectively, the findings showed that mobilization of local and circulating innate immune responses was linked to acute virus-induced hepatitis, and potentially to resolution of GBV-B infection, and our results may provide insight into similar mechanisms in HCV infection.IMPORTANCEHepatitis C virus (HCV) infection has created a global health crisis, and despite new effective antivirals, it is still a leading cause of liver disease and death worldwide. Recent evidence suggests that innate immunity may be a potential therapeutic target for HCV, but it may also be a correlate of increased disease. Due to a lack of access to human tissues with acute HCV infection, in this study we evaluated the role of innate immunity in resolving infection with a hepacivirus, GBV-B, in common marmosets. Collectively, our data suggest that NK cell and DC mobilization in acute hepacivirus infection can dampen virus replication but also regulate acute and chronic liver damage. How these two opposing effects on the host may be modulated in future therapeutic and vaccine approaches warrants further study.

scholarly journals Pathogen-Associated Molecular Pattern Recognition of Hepatitis C Virus Transmitted/Founder Variants by RIG-I Is Dependent on U-Core Length

2015 ◽  
Vol 89 (21) ◽  
pp. 11056-11068 ◽  
Author(s):  
Alison Kell ◽  
Mark Stoddard ◽  
Hui Li ◽  
Joe Marcotrigiano ◽  
George M. Shaw ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Acute Infection ◽  
Innate Immune ◽  
Hcv Infection ◽  
Immune Signaling ◽  
Molecular Pattern ◽  
Innate Immune Signaling ◽  
Acute Hcv

ABSTRACTDespite the introduction of direct-acting antiviral (DAA) drugs against hepatitis C virus (HCV), infection remains a major public health concern because DAA therapeutics do not prevent reinfection and patients can still progress to chronic liver disease. Chronic HCV infection is supported by a variety of viral immune evasion strategies, but, remarkably, 20% to 30% of acute infections spontaneously clear prior to development of adaptive immune responses, thus implicating innate immunity in resolving acute HCV infection. However, the virus-host interactions regulating acute infection are unknown. Transmission of HCV involves one or a few transmitted/founder (T/F) variants. In infected hepatocytes, the retinoic acid-inducible gene I (RIG-I) protein recognizes 5′ triphosphate (5′ppp) of the HCV RNA and a pathogen-associated molecular pattern (PAMP) motif located within the 3′ untranslated region consisting of poly-U/UC. PAMP binding activates RIG-I to induce innate immune signaling and type 1 interferon antiviral defenses. HCV poly-U/UC sequences can differ in length and complexity, suggesting that PAMP diversity in T/F genomes could regulate innate immune control of acute HCV infection. Using 14 unique poly-U/UC sequences from HCV T/F genomes recovered from acute-infection patients, we tested whether RIG-I recognition and innate immune activation correlate with PAMP sequence characteristics. We show that T/F variants are recognized by RIG-I in a manner dependent on length of the U-core motif of the poly-U/UC PAMP and are recognized by RIG-I to induce innate immune responses that restrict acute infection. PAMP recognition of T/F HCV variants by RIG-I may therefore impart innate immune signaling and HCV restriction to impact acute-phase-to-chronic-phase transition.IMPORTANCERecognition of nonself molecular patterns such as those seen with viral nucleic acids is an essential step in triggering the immune response to virus infection. Innate immunity is induced by hepatitis C virus infection through the recognition of viral RNA by the cellular RIG-I protein, where RIG-I recognizes a poly-uridine/cytosine motif in the viral genome. Variation within this motif may provide an immune evasion strategy for transmitted/founder viruses during acute infection. Using 14 unique poly-U/UC sequences from HCV T/F genomes recovered from acutely infected HCV patients, we demonstrate that RIG-I binding and activation of innate immunity depend primarily on the length of the uridine core within this motif. T/F variants found in acute infection contained longer U cores within the motif and could activate RIG-I and induce innate immune signaling sufficient to restrict viral infection. Thus, recognition of T/F variants by RIG-I could significantly impact the transition from acute to chronic infection.

scholarly journals Immunomodulation of the Natural Killer Cell Phenotype and Response during HCV Infection

2020 ◽  
Vol 9 (4) ◽  
pp. 1030 ◽  
Author(s):  
Gaitan Fabrice Njiomegnie ◽  
Scott A. Read ◽  
Nicole Fewings ◽  
Jacob George ◽  
Fiona McKay ◽  
...  
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Chronic Infection ◽  
Cell Function ◽  
Nk Cell ◽  
Acute Infection ◽  
Killer Cell ◽  
Innate Immune ◽  
Hcv Infection ◽  
Cell Phenotype

Hepatitis C virus (HCV) infection develops into chronic hepatitis in over two-thirds of acute infections. While current treatments with direct-acting antivirals (DAAs) achieve HCV eradication in >95% of cases, no vaccine is available and re-infection can readily occur. Natural killer (NK) cells represent a key cellular component of the innate immune system, participating in early defence against infectious diseases, viruses, and cancers. When acute infection becomes chronic, however, NK cell function is altered. This has been well studied in the context of HCV, where changes in frequency and distribution of NK cell populations have been reported. While activating receptors are downregulated on NK cells in both acute and chronic infection, NK cell inhibiting receptors are upregulated in chronic HCV infection, leading to altered NK cell responsiveness. Furthermore, chronic activation of NK cells following HCV infection contributes to liver inflammation and disease progression through enhanced cytotoxicity. Consequently, the NK immune response is a double-edged sword that is a significant component of the innate immune antiviral response, but persistent activation can drive tissue damage during chronic infection. This review will summarise the role of NK cells in HCV infection, and the changes that occur during HCV therapy.

scholarly journals Hepatitis C Virus Induces Toll-Like Receptor 4 Expression, Leading to Enhanced Production of Beta Interferon and Interleukin-6

2006 ◽  
Vol 80 (2) ◽  
pp. 866-874 ◽  
Author(s):  
Keigo Machida ◽  
Kevin T. H. Cheng ◽  
Vicky M.-H. Sung ◽  
Alexandra M. Levine ◽  
Steven Foung ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
B Cells ◽  
Immune Responses ◽  
Interleukin 6 ◽  
Innate Immune ◽  
Hcv Infection ◽  
Innate Immune Responses ◽  
Altered Expression ◽  
Beta Interferon

ABSTRACT Hepatitis C virus (HCV) induces inflammatory signals, leading to hepatitis, hepatocellular carcinomas, and lymphomas. The mechanism of HCV involvement in the host's innate immune responses has not been well characterized. In this study, we analyzed expression and regulation of the entire panel of toll-like receptors (TLRs) in human B cells following HCV infection in vitro. Among all of the TLRs (TLRs 1 to 10) examined, only TLR4 showed an altered expression (a three- to sevenfold up-regulation) after HCV infection. Peripheral blood mononuclear cells from HCV-infected individuals also showed a higher expression level of TLR4 compared with those of healthy individuals. HCV infection significantly increased beta interferon (IFN-β) and interleukin-6 (IL-6) secretion from B cells, particularly after lipopolysaccharide stimulation. The increased IFN-β and IL-6 production was mediated by TLR4 induction, since the introduction of the small interfering RNA against TLR4 specifically inhibited the HCV-induced cytokine production. Among all of the viral proteins, only NS5A caused TLR4 induction in hepatocytes and B cells. NS5A specifically activated the promoter of the TLR4 gene in both hepatocytes and B cells. In conclusion, HCV infection directly induces TLR4 expression and thereby activates B cells, which may contribute to the host's innate immune responses.

scholarly journals In Vivo Study of the HC-TN Strain of Hepatitis C Virus Recovered from a Patient with Fulminant Hepatitis: RNA Transcripts of a Molecular Clone (pHC-TN) Are Infectious in Chimpanzees but Not in Huh7.5 Cells

2007 ◽  
Vol 81 (13) ◽  
pp. 7208-7219 ◽  
Author(s):  
Akito Sakai ◽  
Shingo Takikawa ◽  
Robert Thimme ◽  
Jean-Christophe Meunier ◽  
Hans Christian Spangenberg ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Immune Responses ◽  
Disease Severity ◽  
Neutralizing Antibodies ◽  
Viral Evolution ◽  
Acute Infection ◽  
Hcv Infection ◽  
Rna Transcripts

ABSTRACT Both viral and host factors are thought to influence the pathogenesis of hepatitis C virus (HCV) infection. We studied strain HC-TN (genotype 1a), which caused fulminant hepatic failure in a patient and, subsequently, severe hepatitis in a chimpanzee (CH1422), to analyze the relationship between disease severity, host immune response, viral evolution, and outcome. A second chimpanzee (CH1581) was infected from CH1422 plasma, and a third chimpanzee (CH1579) was infected from RNA transcripts of a consensus cDNA of HC-TN (pHC-TN). RNA transcripts of pHC-TN did not replicate in Huh7.5 cells, which were recently found to be susceptible to infection with another fulminant HCV strain (JFH1). The courses of viremia were similar in the three animals. However, CH1581 and CH1579 developed a less severe acute hepatitis than CH1422. CH1579 and CH1422 resolved the infection, whereas CH1581 became persistently infected. CH1579 and CH1581, despite their differing outcomes, both developed significant intrahepatic cellular immune responses, but not antibodies to the envelope glycoproteins or neutralizing antibodies, during the acute infection. We analyzed the polyprotein sequences of virus recovered at five and nine time points from CH1579 and CH1581, respectively, during the first year of follow-up. High mutation rates and high proportions of nonsynonymous mutations suggested immune pressure and positive selection in both animals. Changes were not selected until after the initial decrease in virus titers and after the development of immune responses and hepatitis. Subsequently, however, mutations emerged repeatedly in both animals. Overall, our results indicate that disease severity and outcome of acute HCV infection depend primarily on the host response.

Multidirectional interactions are bridging human NK cells with plasmacytoid and monocyte-derived dendritic cells during innate immune responses

Blood ◽  
2006 ◽  
Vol 108 (12) ◽  
pp. 3851-3858 ◽  
Author(s):  
Mariella Della Chiesa ◽  
Chiara Romagnani ◽  
Andreas Thiel ◽  
Lorenzo Moretta ◽  
Alessandro Moretta
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
Nk Cells ◽  
De Novo ◽  
Nk Cell ◽  
Innate Immune ◽  
Dependent Manner ◽  
B Cell Differentiation ◽  
Innate Immune Responses ◽  
Intrinsic Resistance

AbstractDuring innate immune responses, natural killer (NK) cells may interact with both plasmacytoid dendritic cells (pDCs) and monocyte-derived dendritic cells (MDDCs). We show that freshly isolated NK cells promote the release by pDCs of IFN-α, in a CpG-dependent manner, whereas they induce IL-6 production in a CpG-independent manner. In turn pDC-derived IFN-α up-regulates NK-mediated killing, whereas IL-6 could promote B-cell differentiation. We also show that exposure to exogenous IL-12 or coculture with maturing MDDCs up-regulates the NK-cell–dependent IFN-α production by pDCs. On the other hand, NK cells cocultured with pDCs acquire the ability to kill immature MDDCs, thus favoring their editing process. Finally, we show that activated NK cells are unable to lyse pDCs because these cells display an intrinsic resistance to lysis. The exposure of pDCs to IL-3 increased their susceptibility to NK-cell cytotoxicity resulting from a de novo expression of ligands for activating NK-cell receptors, such as the DNAM-1 ligand nectin-2. Thus, different cell-to-cell interactions and various cytokines appear to control a multidirectional network between NK cells, MDDCs, and pDCs that is likely to play an important role during the early phase of innate immune responses to viral infections and to tumors.

scholarly journals Neuralized E3 Ubiquitin Protein Ligase 3 Is an Inducible Antiviral Effector That Inhibits Hepatitis C Virus Assembly by Targeting Viral E1 Glycoprotein

2018 ◽  
Vol 92 (21) ◽  
Author(s):  
Yanan Zhao ◽  
Xuezhi Cao ◽  
Mingzhe Guo ◽  
Xuesong Wang ◽  
Tao Yu ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Hepatitis C ◽  
Envelope Glycoprotein ◽  
Biological Function ◽  
Rna Viruses ◽  
Innate Immune ◽  
Hcv Infection ◽  
Ubiquitin Protein Ligase ◽  
Host Innate Immunity ◽  
Insight Into

ABSTRACTHepatitis C virus (HCV) infection is a major cause of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. HCV can be sensed by host innate immunity to induce expression of interferons (IFNs) and a number of antiviral effectors. In this study, we found HCV infection induced the expression of neuralized E3 ubiquitin protein ligase 3 (NEURL3), a putative E3 ligase, in a manner that requires the involvement of innate immune sensing but is independent of the IFN action. Furthermore, we showed that NEURL3 inhibited HCV infection while it had little effect on other RNA viruses, including Zika virus (ZIKV), dengue virus (DENV), and vesicular stomatitis virus (VSV). Mechanistic studies demonstrated that NEURL3 inhibited HCV assembly by directly binding HCV envelope glycoprotein E1 to interfere with the E1/E2 heterodimerization, an important prerequisite for virion morphogenesis. Finally, we showed that knockout of NEURL3 significantly enhanced HCV infection. In summary, we identified NEURL3 as a novel inducible antiviral host factor that suppresses HCV assembly. Our results not only shed new insight into how host innate immunity acts against HCV but also revealed a new important biological function for NEURL3.IMPORTANCEThe exact biological function of NEURL3, a putative E3 ligase, remains largely unknown. In this study, we found that NEURL3 could be upregulated upon HCV infection in a manner dependent on pattern recognition receptor-mediated innate immune response. NEURL3 inhibits HCV assembly by directly binding viral E1 envelope glycoprotein to disrupt its interaction with E2, an action that requires its Neuralized homology repeat (NHR) domain but not the RING domain. Furthermore, we found that NEURL3 has a pangenotypic anti-HCV activity and interacts with E1 of genotypes 2a, 1b, 3a, and 6a but does not inhibit other closely related RNA viruses, such as ZIKV, DENV, and VSV. To our knowledge, our study is the first report to demonstrate that NEURL3 functions as an antiviral host factor. Our results not only shed new insight into how host innate immunity acts against HCV, but also revealed a new important biological function for NEURL3.

scholarly journals Hepatitis C Virus Sensing by Human Trophoblasts Induces Innate Immune Responses and Recruitment of Maternal NK Cells: Potential Implications for Limiting Vertical Transmission

2015 ◽  
Vol 195 (8) ◽  
pp. 3737-3747 ◽  
Author(s):  
Silvia Giugliano ◽  
Margaret G. Petroff ◽  
Bryce D. Warren ◽  
Susmita Jasti ◽  
Caitlin Linscheid ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Immune Responses ◽  
Nk Cells ◽  
Vertical Transmission ◽  
Innate Immune ◽  
Innate Immune Responses

scholarly journals Persistent Replication of HIV, Hepatitis C Virus (HCV), and HBV Results in Distinct Gene Expression Profiles by Human NK Cells

2018 ◽  
Vol 93 (9) ◽  
Author(s):  
Lauke L. Boeijen ◽  
Jun Hou ◽  
Rik A. de Groen ◽  
Annelies Verbon ◽  
André Boonstra
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Nk Cells ◽  
Nk Cell ◽  
Cytotoxic Action ◽  
Activation Markers ◽  
Gene Signatures ◽  
Viral Loads ◽  
Cell Gene

ABSTRACT Natural killer (NK) cells during chronic viral infection have been well studied in the past. We performed an unbiased next-generation RNA-sequencing approach to identify commonalities or differences of the effect of HIV, HCV, and HBV viremia on NK cell transcriptomes. Using cell sorting, we obtained CD3− CD56+ NK cells from blood of 6 HIV-, 8 HCV-, and 32 HBV-infected patients without treatment. After library preparation and sequencing, we used an in-house analytic pipeline to compare expression levels with matched healthy controls. In NK cells from HIV-, HCV-, and HBV-infected patients, transcriptome analysis identified 272, 53, and 56 differentially expressed genes, respectively (fold change, >1.5; q-value, 0.2). Interferon-stimulated genes were induced in NK cells from HIV/HCV patients, but not during HBV infection. HIV viremia downregulated ribosome assembly genes in NK cells. In HBV-infected patients, viral load and alanine aminotransferase (ALT) variation had little effect on genes related to NK effector function. In conclusion, we compare, for the first time, NK cell transcripts of viremic HIV, HCV, and HBV patients. We clearly demonstrate distinctive NK cell gene signatures in three different populations, suggestive for a different degree of functional alterations of the NK cell compartment compared to healthy individuals. IMPORTANCE Three viruses exist that can result in persistently high viral loads in immunocompetent humans: human immunodeficiency virus (HIV), hepatitis C virus, and hepatitis B virus. In the last decades, by using flow cytometry and in vitro assays on NK cells from patients with these types of infections, several impairments have been established, particularly during and possibly contributing to HIV viremia. However, the background of NK cell impairments in viremic patients is not well understood. In this study, we describe the NK cell transcriptomes of patients with high viral loads of different etiologies. We clearly demonstrate distinctive NK cell gene signatures with regard to interferon-stimulated gene induction and the expression of genes coding for activation markers or proteins involved in cytotoxic action, as well immunological genes. This study provides important details necessary to uncover the origin of functional and phenotypical differences between viremic patients and healthy subjects and provides many leads that can be confirmed using future in vitro manipulation experiments.

scholarly journals Rapid dose-dependent Natural Killer (NK) cell modulation and cytokine responses following human rVSV-ZEBOV Ebolavirus vaccination

npj Vaccines ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
David Pejoski ◽  
◽  
Casimir de Rham ◽  
Paola Martinez-Murillo ◽  
Francesco Santoro ◽  
...  
Keyword(s):  
Immune Responses ◽  
Nk Cells ◽  
Nk Cell ◽  
Protective Efficacy ◽  
Innate Immune ◽  
Receptor Expression ◽  
Innate Immune Responses ◽  
Plasma Cytokines ◽  
Surface Receptor ◽  
Dose Dependent

Abstract The rVSV-ZEBOV Ebolavirus vaccine confers protection within days after immunization, suggesting the contribution of innate immune responses. We report modulation of rVSV-ZEBOV vaccinee blood CD56+ NK cell numbers, NKG2D or NKp30 surface receptor expression, Killer Immunoglobulin-like Receptor (KIR)+ cell percentages and NK-cell-related genes on day 1 post immunization. Inverse correlations existed between the concentration of several plasma cytokines and inhibitory KIR+ CD56dim or cytokine-responsive CD56bright NK cells. Thus, NK cells may contribute to the early protective efficacy of rVSV-ZEBOV in humans.

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