Secretion of Hepatitis C Virus Replication Intermediates Reduces Activation of Toll-Like Receptor 3 in Hepatocytes

Grünvogel, Oliver; Colasanti, Ombretta; Lee, Ji-Young; Klöss, Volker; Belouzard, Sandrine; Reustle, Anna; Esser-Nobis, Katharina; Hesebeck-Brinckmann, Jasper; Mutz, Pascal; Hoffmann, Katja; Mehrabi, Arianeb; Koschny, Ronald; Vondran, Florian W. R.; Gotthardt, Daniel; Schnitzler, Paul; Neumann‐Haefelin, Christoph; Thimme, Robert; Binder, Marco; Bartenschlager, Ralf; Dubuisson, Jean; Dalpke, Alexander H.; Lohmann, Volker

doi:10.1053/j.gastro.2018.03.020

Cited by 64 publications

(74 citation statements)

References 53 publications

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“…While goodness of fit based on cumulative AIC values for the three viruses (Table S4) demonstrates a marginal advantage in favour of our main model, measured CM formation dynamics [32,33] support our choice of the model. Moreover, independent experimental corroborations like recovery of steady state levels of replication intermediate [55,17,56] and steady state positive/negative RNA ratios [44,43], (Table S4) further supports our model. Due to the lack of molecular details for virus assembly, our model only qualitatively captures the virus assembly and release dynamics and we cannot discriminate between alternate sites (CMs vs cytoplasm) for virus assembly.…”

Section: Comparative Analysis Of Monopartite (+)Rna Virusessupporting

confidence: 76%

Life cycle process dependencies of positive-sense RNA viruses suggest strategies for inhibiting productive cellular infection

Chhajer¹,

Rizvi

Roy

2020

Preprint

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Positive strand (+)RNA viruses are the most common and clinically important human pathogens. Their life cycle processes are broadly conserved across many virus families but they employ different life cycle strategies for their growth in the cell. Upon RNA genome release into the cytoplasm post cellular entry, viral translation generates structural and non-structural proteins that induce intracellular remodelling, forming membrane compartments that foster viral replication leading to virus particle formation. We present a generalized dynamical model for intracellular (+)ssRNA virus growth that accounts for these critical steps. Our model can capture experimental growth dynamics for several RNA viruses as well as parse the effect of viral mutations and host cell permissivity. We show that Poliovirus (PV) employs rapid replication and virus assembly whereas Japanese Encephalitis virus leverages its higher rate of translation and efficient host membrane reorganization for enhanced viral dynamics compared to Hepatitis C virus. Since the slow membrane reorganization represents a crucial bottleneck for replication, stochastic simulations demonstrate that an infection event, even with multiple viral genomes, can go to extinction if all seeding viral RNA degrade before establishing robust viral replication. We estimate this probability of productive cellular infection, termed ‘Cellular Infectivity (Φ)’ using stochastic simulations. Φ varies for a virus-host pair with initial virus seeding and life cycle perturbations like increase in cytoplasmic RNA degradation and delay in compartment formation can reduce infectivity. Extent of synergy among these parameters while seemingly diverse for viruses is defined by Φ. Therefore, our model suggests new avenues for inhibition of viral infections by targeting early life cycle bottlenecks.

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Section: Comparative Analysis Of Monopartite (+)Rna Virusessupporting

confidence: 76%

Life cycle process dependencies of positive-sense RNA viruses suggest strategies for inhibiting productive cellular infection

Chhajer¹,

Rizvi

Roy

2020

Preprint

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“…Some parts of the RIs seem to be double stranded, since they can be detected by dsRNA-specific antibodies in infected cells, which recognize stretches of Ͼ40 bp (66). In addition, HCV replication activates pattern recognition receptors specific for dsRNA (RIG-I [37,62], MAVS [63], and TLR3 [67,68]). However, parts of the RI might remain single stranded, particularly in regions encompassing strong secondary structures, as in case of the UTRs, thereby facilitating recognition of initiation sites by NS5B, only fitting single-stranded templates in its closed initiation state (69)(70)(71).…”

Section: Discussionmentioning

confidence: 99%

Evidence for Internal Initiation of RNA Synthesis by the Hepatitis C Virus RNA-Dependent RNA Polymerase NS5B In Cellulo

Schult

Nattermann

Lauber

et al. 2019

J Virol

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Initiation of RNA synthesis by the hepatitis C virus (HCV) RNA-dependent RNA polymerase (RdRp) NS5B has been extensively studied in vitro and in cellulo. Intracellular replication is thought to rely exclusively on terminal de novo initiation, as it conserves all genetic information of the genome. In vitro, however, additional modes of initiation have been observed. In this study, we aimed to clarify whether the intracellular environment allows for internal initiation of RNA replication by the HCV replicase. We used a dual luciferase replicon harboring a terminal and an internal copy of the viral genomic 5= untranslated region, which was anticipated to support noncanonical initiation. Indeed, a shorter RNA species was detected by Northern blotting with low frequency, depending on the length and sequence composition upstream of the internal initiation site. By introducing mutations at either site, we furthermore established that internal and terminal initiation shared identical sequence requirements. Importantly, lethal point mutations at the terminal site resulted exclusively in truncated replicons. In contrast, the same mutations at the internal site abrogated internal initiation, suggesting a competitive selection of initiation sites, rather than recombination or templateswitching events. In conclusion, our data indicate that the HCV replicase is capable of internal initiation in its natural environment, although functional replication likely requires only terminal initiation. Since many other positive-strand RNA viruses generate subgenomic messenger RNAs during their replication cycle, we surmise that their capability for internal initiation is a common and conserved feature of viral RdRps. IMPORTANCE Many aspects of viral RNA replication of hepatitis C virus (HCV) are still poorly understood. The process of RNA synthesis is driven by the RNAdependent RNA polymerase (RdRp) NS5B. Most mechanistic studies on NS5B so far were performed with in vitro systems using isolated recombinant polymerase. In this study, we present a replicon model, which allows the intracellular assessment of noncanonical modes of initiation by the full HCV replicase. Our results add to the understanding of the biochemical processes underlying initiation of RNA synthesis by NS5B by the discovery of internal initiation in cellulo. Moreover, they validate observations made in vitro, showing that the viral polymerase acts very similarly in isolation and in complex with other viral and host proteins. Finally, these observations provide clues about the evolution of RdRps of positive-strand RNA viruses, which might contain the intrinsic ability to initiate internally.

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“…Finally, it has also been shown that EVs are released from monocytic cells and induce polarization towards the anti-inflammatory M2 phenotype of neighboring naive monocytes by delivering cargo miR-27a, thus contributing to resolution of inflammation [41]. Other examples of modulation of immune response have been shown in studies of hepatitis B and C [42,43], which can participate in exacerbating liver injury when both viral infection and other injuring agents (i.e., alcohol) are at play.…”

Section: Evs and Liver Inflammationmentioning

confidence: 99%

Extracellular Vesicles in NAFLD/ALD: From Pathobiology to Therapy

Hernández

Arab

Reyes

et al. 2020

Cells

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In recent years, knowledge on the biology and pathobiology of extracellular vesicles (EVs) has exploded. EVs are submicron membrane-bound structures secreted from different cell types containing a wide variety of bioactive molecules (e.g., proteins, lipids, and nucleic acids (coding and non-coding RNA) and mitochondrial DNA). EVs have important functions in cell-to-cell communication and are found in a wide variety of tissues and body fluids. Better delineation of EV structures and advances in the isolation and characterization of their cargo have allowed the diagnostic and therapeutic implications of these particles to be explored. In the field of liver diseases, EVs are emerging as key players in the pathogenesis of both nonalcoholic liver disease (NAFLD) and alcoholic liver disease (ALD), the most prevalent liver diseases worldwide, and their complications, including development of hepatocellular carcinoma. In these diseases, stressed/damaged hepatocytes release large quantities of EVs that contribute to the occurrence of inflammation, fibrogenesis, and angiogenesis, which are key pathobiological processes in liver disease progression. Moreover, the specific molecular signatures of released EVs in biofluids have allowed EVs to be considered as promising candidates to serve as disease biomarkers. Additionally, different experimental studies have shown that EVs may have potential for therapeutic use as a liver-specific delivery method of different agents, taking advantage of their hepatocellular uptake through interactions with specific receptors. In this review, we focused on the most recent findings concerning the role of EVs as new structures mediating autocrine and paracrine intercellular communication in both ALD and NAFLD, as well as their potential use as biomarkers of disease severity and progression. Emerging therapeutic applications of EVs in these liver diseases were also examined, along with the potential for successful transition from bench to clinic.

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Secretion of Hepatitis C Virus Replication Intermediates Reduces Activation of Toll-Like Receptor 3 in Hepatocytes

Cited by 64 publications

References 53 publications

Life cycle process dependencies of positive-sense RNA viruses suggest strategies for inhibiting productive cellular infection

Life cycle process dependencies of positive-sense RNA viruses suggest strategies for inhibiting productive cellular infection

Evidence for Internal Initiation of RNA Synthesis by the Hepatitis C Virus RNA-Dependent RNA Polymerase NS5B In Cellulo

Extracellular Vesicles in NAFLD/ALD: From Pathobiology to Therapy

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