Antiviral effect of peptoids on hepatitis B virus infection in cell culture.

Although antimicrobial peptides have been shown to inactivate viruses through disruption of their viral envelopes, clinical use of such peptides has been hampered by a number of factors, especially their enzymatically unstable structures. To overcome the shortcomings of antimicrobial peptides, peptoids (sequence-specific N-substituted glycine oligomers) mimicking antimicrobial peptides have been developed. We aimed to demonstrate the antiviral effects of antimicrobial peptoids against hepatitis B virus (HBV) in cell culture. The anti-HBV activity of antimicrobial peptoids was screened and evaluated in an infection system involving the HBV reporter virus and HepG2.2.15-derived HBV. By screening with the HBV reporter virus infection system, three (TM1, TM4, and TM19) of 12 peptoids were identified as reducing the infectivity of HBV, though they did not alter the production levels of HBs antigen in cell culture. These peptoids were not cytotoxic at the evaluated concentrations. Among these peptoids, TM19 was confirmed to reduce HBV infection most potently in a HepG2.2.15-derived HBV infection system that closely demonstrates authentic HBV infection. In cell culture, the most effective administration of TM19 was virus treatment at the infection step, but the reduction in HBV infectivity by pre-treatment or post-treatment of cells with TM19 was minimal. The disrupting effect of TM19 targeting infectious viral particles was clarified in iodixanol density gradient analysis. In conclusion, the peptoid TM19 was identified as a potent inhibitor of HBV. This peptoid prevents HBV infection by disrupting viral particles and is a candidate for a new class of anti-HBV reagents.

Oxidative stress sensor Keap1 recognizes HBx protein to activate the Nrf2/ARE signaling pathway, thereby inhibiting hepatitis B virus replication.

IMPORTANCE: The Kelch-like ECH-associated protein 1 (Keap1)/NF-E2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway is one of the most important defense mechanisms against oxidative stress. We previously reported that a cellular hydrogen peroxide scavenger protein, peroxiredoxin 1, a target gene of transcription factor Nrf2, acts as a novel HBV X protein (HBx)-interacting protein and negatively regulates hepatitis B virus (HBV) propagation through degradation of HBV RNA. This study further demonstrates that the Nrf2/ARE signaling pathway is activated during HBV infection, eventually leading to the suppression of HBV replication. We provide evidence suggesting that Keap1 interacts with HBx, leading to Nrf2 activation and inhibition of HBV replication via suppression of HBV core promoter activity. This study raises the possibility that activation of the Nrf2/ARE signaling pathway is a potential therapeutic strategy against HBV. Our findings may contribute to an improved understanding of the negative regulation of HBV replication by the antioxidant response.

Longitudinal Studies of Wearables in Patients with Diabetes: Key Issues and Solutions.

Glucose monitoring is key to the management of diabetes mellitus to maintain optimal glucose control whilst avoiding hypoglycemia. Non-invasive continuous glucose monitoring techniques have evolved considerably to replace finger prick testing, but still require sensor insertion. Physiological variables, such as heart rate and pulse pressure, change with blood glucose, especially during hypoglycemia, and could be used to predict hypoglycemia. To validate this approach, clinical studies that contemporaneously acquire physiological and continuous glucose variables are required. In this work, we provide insights from a clinical study undertaken to study the relationship between physiological variables obtained from a number of wearables and glucose levels. The clinical study included three screening tests to assess neuropathy and acquired data using wearable devices from 60 participants for four days. We highlight the challenges and provide recommendations to mitigate issues that may impact the validity of data capture to enable a valid interpretation of the outcomes.

Cardiovascular autonomic neuropathy is associated with increased glycemic variability driven by hyperglycemia rather than hypoglycemia in patients with diabetes.

AIM: Cardiac autonomic neuropathy (CAN) has been suggested to be associated with hypoglycemia and impaired hypoglycemia unawareness. We have assessed the relationship between CAN and extensive measures of glucose variability (GV) in patients with type 1 and type 2 diabetes. METHODS: Participants with diabetes underwent continuous glucose monitoring (CGM) to obtain measures of GV and the extent of hyperglycemia and hypoglycemia and cardiovascular autonomic reflex testing. RESULTS: Of the 40 participants (20 T1DM and 20 T2DM) (aged 40.70 ± 13.73 years, diabetes duration 14.43 ± 7.35 years, HbA1c 8.85 ± 1.70%), 23 (57.5%) had CAN. Despite a lower coefficient of variation (CV) (31.26 ± 11.87 vs. 40.33 ± 11.03, P = 0.018), they had a higher CONGA (8.42 ± 2.58 vs. 6.68 ± 1.88, P = 0.024) with a lower median LBGI (1.60 (range: 0.20-3.50) vs. 4.90 (range: 3.20-7.40), P = 0.010) and percentage median time spent in hypoglycemia (4 (range:4-13) vs. 1 (range:0-5), P = 0.008), compared to those without CAN. The percentage GRADEEuglycemia (3.30 ± 2.78 vs. 5.69 ± 3.09, P = 0.017) and GRADEHypoglycemia (0.3 (range: 0 - 3.80) vs. 1.8 (range: 0.9-6.5), P = 0.036) were significantly lower, while the percentage median GRADEHyperglycemia (95.45 (range:93-98) vs. 91.6 (82.8-95.1), P = 0.013) was significantly higher in participants with CAN compared to those without CAN. CONCLUSION: CAN was associated with increased glycemic variability with less time in euglycemia attributed to a greater time in hyperglycemia but not hypoglycemia.

Recent Advances in Protective Vaccines against Hepatitis Viruses: A Narrative Review.

Vaccination has been confirmed to be the safest and, sometimes, the only tool of defense against threats from infectious diseases. The successful history of vaccination is evident in the control of serious viral infections, such as smallpox and polio. Viruses that infect human livers are known as hepatitis viruses and are classified into five major types from A to E, alphabetically. Although infection with hepatitis A virus (HAV) is known to be self-resolving after rest and symptomatic treatment, there were 7134 deaths from HAV worldwide in 2016. In 2019, hepatitis B virus (HBV) and hepatitis C virus (HCV) resulted in an estimated 820,000 and 290,000 deaths, respectively. Hepatitis delta virus (HDV) is a satellite virus that depends on HBV for producing its infectious particles in order to spread. The combination of HDV and HBV infection is considered the most severe form of chronic viral hepatitis. Hepatitis E virus (HEV) is another orally transmitted virus, common in low- and middle-income countries. In 2015, it caused 44,000 deaths worldwide. Safe and effective vaccines are already available to prevent hepatitis A and B. Here, we review the recent advances in protective vaccines against the five major hepatitis viruses.

Continuous glucose monitoring reveals a novel association between duration and severity of hypoglycemia, and small nerve fiber injury in patients with diabetes.

Objective: Continuous glucose monitoring (CGM) has revealed that glycemic variability and low time in range are associated with albuminuria and retinopathy. We have investigated the relationship between glucose metrics derived from CGM and a highly sensitive measure of neuropathy using corneal confocal microscopy in participants with type 1 and type 2 diabetes. Methods: A total of 40 participants with diabetes and 28 healthy controls underwent quantification of corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), corneal nerve fiber length (CNFL) and inferior whorl length (IWL) and those with diabetes underwent CGM for four consecutive days. Results: CNBD was significantly lower in patients with high glycemic variability (GV) compared to low GV (median (range) (25.0 (19.0-37.5) vs 38.6 (29.2-46.9); P = 0.007); in patients who spent >4% compared to <4% time in level 1 hypoglycemia (54-69 mg/dL) (25.0 (22.9-37.5) vs 37.5 (29.2-46.9); P = 0.045) and in patients who spent >1% compared to <1% time in level 2 hypoglycemia (<54 mg/dL) (25.0 (19.8-41.7) vs 35.4 (28.1-44.8); P = 0.04). Duration in level 1 hypoglycemia correlated with CNBD (r = -0.342, P = 0.031). Duration in level 1 (181-250 mg/dL) and level 2 (>250 mg/dL) hyperglycemia did not correlate with CNFD (P > 0.05), CNBD (P > 0.05), CNFL (P > 0.05) or IWL (P > 0.05). Conclusions: Greater GV and duration in hypoglycemia, rather than hyperglycemia, are associated with nerve fiber loss in diabetes.

Neutralization of hepatitis B virus with vaccine-escape mutations by hepatitis B vaccine with large-HBs antigen.

Although the current hepatitis B (HB) vaccine comprising small-HBs antigen (Ag) is potent and safe, attenuated prophylaxis against hepatitis B virus (HBV) with vaccine-escape mutations (VEMs) has been reported. We investigate an HB vaccine consisting of large-HBsAg that overcomes the shortcomings of the current HB vaccine. Yeast-derived large-HBsAg is immunized into rhesus macaques, and the neutralizing activities of the induced antibodies are compared with those of the current HB vaccine. Although the antibodies induced by the current HB vaccine cannot prevent HBV infection with VEMs, the large-HBsAg vaccine-induced antibodies neutralize those infections. The HBV genotypes that exhibited attenuated neutralization via these vaccines are different. Here, we show that the HB vaccine consisting of large-HBsAg is useful to compensate for the shortcomings of the current HB vaccine. The combined use of these HB vaccines may induce antibodies that can neutralize HBV strains with VEMs or multiple HBV genotypes.

Sense and Learn: Recent Advances in Wearable Sensing and Machine Learning for Blood Glucose Monitoring and Trend-Detection.

Diabetes mellitus is characterized by elevated blood glucose levels, however patients with diabetes may also develop hypoglycemia due to treatment. There is an increasing demand for non-invasive blood glucose monitoring and trends detection amongst people with diabetes and healthy individuals, especially athletes. Wearable devices and non-invasive sensors for blood glucose monitoring have witnessed considerable advances. This review is an update on recent contributions utilizing novel sensing technologies over the past five years which include electrocardiogram, electromagnetic, bioimpedance, photoplethysmography, and acceleration measures as well as bodily fluid glucose sensors to monitor glucose and trend detection. We also review methods that use machine learning algorithms to predict blood glucose trends, especially for high risk events such as hypoglycemia. Convolutional and recurrent neural networks, support vector machines, and decision trees are examples of such machine learning algorithms. Finally, we address the key limitations and challenges of these studies and provide recommendations for future work.

The kinesin KIF4 mediates HBV/HDV entry through the regulation of surface NTCP localization and can be targeted by RXR agonists in vitro.

Intracellular transport via microtubule-based dynein and kinesin family motors plays a key role in viral reproduction and transmission. We show here that Kinesin Family Member 4 (KIF4) plays an important role in HBV/HDV infection. We intended to explore host factors impacting the HBV life cycle that can be therapeutically addressed using siRNA library transfection and HBV/NLuc (HBV/NL) reporter virus infection in HepG2-hNTCP cells. KIF4 silencing resulted in a 3-fold reduction in luciferase activity following HBV/NL infection. KIF4 knockdown suppressed both HBV and HDV infection. Transient KIF4 depletion reduced surface and raised intracellular NTCP (HBV/HDV entry receptor) levels, according to both cellular fractionation and immunofluorescence analysis (IF). Overexpression of wild-type KIF4 but not ATPase-null KIF4 mutant regained the surface localization of NTCP and significantly restored HBV permissiveness in these cells. IF revealed KIF4 and NTCP colocalization across microtubule filaments, and a co-immunoprecipitation study revealed that KIF4 interacts with NTCP. KIF4 expression is regulated by FOXM1. Interestingly, we discovered that RXR agonists (Bexarotene, and Alitretinoin) down-regulated KIF4 expression via FOXM1-mediated suppression, resulting in a substantial decrease in HBV-Pre-S1 protein attachment to HepG2-hNTCP cell surface and subsequent HBV infection in both HepG2-hNTCP and primary human hepatocyte (PXB) (Bexarotene, IC50 1.89 ± 0.98 µM) cultures. Overall, our findings show that human KIF4 is a critical regulator of NTCP surface transport and localization, which is required for NTCP to function as a receptor for HBV/HDV entry. Furthermore, small molecules that suppress or alleviate KIF4 expression would be potential antiviral candidates targeting HBV and HDV entry.

Uncovering serum placental-related non-coding RNAs as possible biomarkers of preeclampsia risk, onset and severity revealed MALAT-1, miR-363 and miR-17.

New predictors that could boost early detection of preeclampsia (PE) and prognosticate its severity are urgently needed. We examined serum miR-17, miR-363, MALAT-1 and HOTAIR as potential biomarkers of PE risk, onset and severity. This prospective study included 160 pregnant females; 82 PE cases and 78 healthy pregnancies. Serum samples were collected between 20 to 40 weeks of gestation. Early-onset PE was defined as developing clinical manifestations at ≤ 34 gestational weeks. Severe PE was defined as systolic blood pressure ≥ 160 mmHg and/or diastolic blood pressure ≥ 110 mmHg and proteinuria (≥ 2 g/24 h or ≥ 2+ dipstick). Selection of PE-related non-coding RNAs and functional target gene analysis were conducted using bioinformatics analysis. Expression profiles were assessed by RT-qPCR. Serum miR-363 and MALAT-1 were downregulated, meanwhile miR-17 was upregulated, and HOTAIR was not significantly altered in PE compared with healthy pregnancies. miR-17 was elevated while miR-363 and MALAT-1 were reduced in severe versus mild PE. miR-363 was lower in early-onset versus late-onset PE. MALAT-1, miR-17 and miR-363 showed diagnostic potential and discriminated severe PE, whereas miR-363 distinguished early-onset PE in the receiver-operating-characteristic analysis. miR-363 and MALAT-1 were significantly associated with early and severe PE, respectively in multivariate logistic analysis. In PE, miR-17 and MALAT-1 were significantly correlated with gestational age (r = - 0.328 and r = 0.322, respectively) and albuminuria (r = 0.312, and r = - 0.35, respectively). We constructed the MALAT-1, miR-363, and miR-17-related protein-protein interaction networks linked to PE. Serum miR-17, miR-363 and MALAT-1 could have utility as new biomarkers of PE diagnosis. miR-363 may be associated with early-onset PE and MALAT-1 downregulation correlates with PE severity.

IFN-γ‒Induced APOBEC3B Contributes to Merkel Cell Polyomavirus Genome Mutagenesis in Merkel Cell Carcinoma.

Merkel cell polyomavirus (MCPyV) is the causative agent of an aggressive skin tumor, Merkel cell carcinoma. The viral genome is integrated into the tumor genome and harbors nonsense mutations in the helicase domain of large T antigen. However, the molecular mechanisms by which the viral genome gains the tumor-specific mutations remain to be elucidated. Focusing on host cytosine deaminases APOBEC3s, we find that A3A, A3B, or A3G introduces A3-specific mutations into episomal MCPyV genomes in MCPyV-replicating 293-derivative cells. Sequence analysis of MCPyV genomes retrieved from the NCBI database revealed a decrease of TpC dinucleotide, a preferred target for A3A and A3B, in the 3'-region of the large T antigen‒coding sequence. The viral DNA isolated from tumors contained mutated cytosines, with a remarkable bias toward TpC dinucleotide. Analysis of publicly available microarray data showed that expression of IFN-γ and cytotoxic T lymphocyte markers was positively correlated with the A3A, A3B, and A3G levels in MCPyV-positive but not in MCPyV-negative tumors. Finally, IFN-γ treatment induced A3B and A3G expression in the MCPyV-positive Merkel cell carcinoma cell line MS-1. These results suggest that the IFN-γ-A3B axis plays pivotal roles in evolutionally shaping MCPyV genomic sequences and in generating tumor-specific large T antigen mutations during development of Merkel cell carcinoma.

Genetic Characterization of Rift Valley Fever Virus in Insectivorous Bats, Egypt.

Background: The endemic character of Rift Valley fever (RVF) disease points toward an interepidemic reservoir. Although not yet identified, bats and rodents may be implicated in RVF virus (RVFV) epidemiology. In this study, we investigated the putative role of Egyptian frugivorous and insectivorous bats in RVFV epidemiology in Egypt. Methods: From 2019 to 2021, 200 bats of two different species from six Egyptian governorates were tested for phleboviruses using real-time RT-PCR (rRT-PCR) and sequence analysis. Results: Screening through rRT-PCR showed evidence of the RVFV genome only in insectivorous bats. Partial sequence and phylogenetic analysis based on S and M genome segments showed that these viruses are genetically similar to those circulating (clade A) in livestock and humans during previously reported RVFV outbreaks in 1977/78 and 2003 in Egypt. Conclusions: Our molecular data suggest that the bat Pipistrellus deserti could play a role in RVFV ecology in Egypt.

Amino Acid Polymorphism in Hepatitis B Virus Associated With Functional Cure.

BACKGROUND & AIMS: To provide an adequate treatment strategy for chronic hepatitis B, it is essential to know which patients are expected to have a good prognosis and which patients do not require therapeutic intervention. Previously, we identified the substitution of isoleucine to leucine at amino acid 97 (I97L) in the hepatitis B core region as a key predictor among patients with stable hepatitis. In this study, we attempted to identify the point at which I97L affects the hepatitis B virus (HBV) life cycle and to elucidate the underlying mechanisms governing the stabilization of hepatitis. METHODS: To confirm the clinical features of I97L, we used a cohort of hepatitis B e antigen-negative patients with chronic hepatitis B infected with HBV-I97 wild-type (wt) or HBV-I97L. The effects of I97L on viral characteristics were evaluated by in vitro HBV production and infection systems with the HBV reporter virus and cell culture-generated HBV. RESULTS: The ratios of reduction in hepatitis B surface antigen and HBV DNA were higher in patients with HBV-I97L than in those with HBV-I97wt. HBV-I97L exhibited lower infectivity than HBV-I97wt in both infection systems with reporter HBV and cell culture-generated HBV. HBV-I97L virions exhibiting low infectivity primarily contained a single-stranded HBV genome. The lower efficiency of cccDNA synthesis was demonstrated after infection of HBV-I97L or transfection of the molecular clone of HBV-I97L. CONCLUSIONS: The I97L substitution reduces the level of cccDNA through the generation of immature virions with single-stranded genomes. This I97L-associated low efficiency of cccDNA synthesis may be involved in the stabilization of hepatitis.

Identification of natural compounds extracted from crude drugs as novel inhibitors of hepatitis C virus.

Natural product-derived crude drugs are expected to yield an abundance of new drugs to treat infectious diseases. Hepatitis C virus (HCV) is an oncogenic virus that significantly impacts public health. In this study, we sought to identify anti-HCV compounds in extracts of natural products. A total of 110 natural compounds extracted from several herbal medicine plants were examined for antiviral activity against HCV. Using a Huh7-mCherry-NLS-IPS reporter system for HCV infection, we first performed a rapid screening for anti-HCV compounds extracted from crude drugs. The compounds threo-2,3-bis(4-hydroxy-3-methoxyphenyl)-3-butoxypropan-1-ol (#106) and medioresinol (#110), which were extracted from Crataegus cuneate, exhibited anti-HCV activity and significantly inhibited HCV production in a dose-dependent manner. Analyses using HCV pseudoparticle and subgenomic replicon systems indicated that compounds #106 and #110 specifically inhibit HCV RNA replication but not viral entry or translation. Interestingly, compound #106 also inhibited the replication and production of hepatitis A virus. Our findings suggest that C. cuneate is a new source for novel anti-hepatitis virus drug development.

Predicting COVID-19 cases using bidirectional LSTM on multivariate time series.

To assist policymakers in making adequate decisions to stop the spread of the COVID-19 pandemic, accurate forecasting of the disease propagation is of paramount importance. This paper presents a deep learning approach to forecast the cumulative number of COVID-19 cases using bidirectional Long Short-Term Memory (Bi-LSTM) network applied to multivariate time series. Unlike other forecasting techniques, our proposed approach first groups the countries having similar demographic and socioeconomic aspects and health sector indicators using K-means clustering algorithm. The cumulative case data of the clustered countries enriched with data related to the lockdown measures are fed to the bidirectional LSTM to train the forecasting model. We validate the effectiveness of the proposed approach by studying the disease outbreak in Qatar and the proposed model prediction from December 1st until December 31st, 2020. The quantitative evaluation shows that the proposed technique outperforms state-of-art forecasting approaches.

MafF Is an Antiviral Host Factor That Suppresses Transcription from Hepatitis B Virus Core Promoter.

Hepatitis B virus (HBV) is a stealth virus that exhibits only minimal induction of the interferon system, which is required for both innate and adaptive immune responses. However, 90% of acutely infected adults can clear the virus, suggesting the presence of additional mechanisms that facilitate viral clearance. Here, we report that Maf bZIP transcription factor F (MafF) promotes host defense against infection with HBV. Using a small interfering RNA (siRNA) library and an HBV/NanoLuc (NL) reporter virus, we screened to identify anti-HBV host factors. Our data showed that silencing of MafF led to a 6-fold increase in luciferase activity after HBV/NL infection. Overexpression of MafF reduced HBV core promoter transcriptional activity, which was relieved upon mutation of the putative MafF binding region. Loss of MafF expression through CRISPR/Cas9 editing (in HepG2-hNTCP-C4 cells) or siRNA silencing (in primary hepatocytes [PXB cells]) induced HBV core RNA and HBV pregenomic RNA (pgRNA) levels, respectively, after HBV infection. MafF physically binds to the HBV core promoter and competitively inhibits HNF-4α binding to an overlapping sequence in the HBV enhancer II sequence (EnhII), as seen by chromatin immunoprecipitation (ChIP) analysis. MafF expression was induced by interleukin-1ß (IL-1ß) or tumor necrosis factor alpha (TNF-α) treatment in both HepG2 and PXB cells, in an NF-κB-dependent manner. Consistently, MafF expression levels were significantly enhanced and positively correlated with the levels of these cytokines in patients with chronic HBV infection, especially in the immune clearance phase. IMPORTANCE HBV is a leading cause of chronic liver diseases, infecting about 250 million people worldwide. HBV has developed strategies to escape interferon-dependent innate immune responses. Therefore, the identification of other anti-HBV mechanisms is important for understanding HBV pathogenesis and developing anti-HBV strategies. MafF was shown to suppress transcription from the HBV core promoter, leading to significant suppression of the HBV life cycle. Furthermore, MafF expression was induced in chronic HBV patients and in primary human hepatocytes (PXB cells). This induction correlated with the levels of inflammatory cytokines (IL-1ß and TNF-α). These data suggest that the induction of MafF contributes to the host's antiviral defense by suppressing transcription from selected viral promoters. Our data shed light on a novel role for MafF as an anti-HBV host restriction factor.

Current situation of viral hepatitis in Egypt.

An estimated 8-10 million people suffer from viral hepatitis in Egypt. Hepatitis A virus (HAV) and hepatitis E virus (HEV) are the major causes of viral hepatitis in Egypt as 50% or more of the Egyptian population are already exposed to HAV infection by the age of 15. In addition, over 60% of the Egyptian population test seropositive for anti-HEV in the first decade of life. HEV mainly causes self-limiting hepatitis; however, cases of fulminant hepatitis and liver failure were reported in Egypt. Hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis D virus (HDV) are the main causes of chronic hepatitis, liver cirrhosis, and liver cancer (hepatocellular carcinoma [HCC]) in Egypt. Globally, Egypt had the highest age-standardized death rate due to cirrhosis from 1990 to 2017. The prevalence rate of HBV (1.3%-1.5%) has declined after national infantile immunization. Coinfection of HBV patients with HDV is common in Egypt because HDV antibodies (IgG) vary in range from 8.3% to 43% among total HBV patients. After the conduction of multiple national programs to control HCV infection, a lower rate of HCV prevalence (4.6%) was recently reported. Data about the incidence of HCV after treatment with direct antiviral agents (DAAs) are lacking. An HCC incidence of 29/1000/year in cirrhotic patients after DAA treatment is reported. A higher rate of infiltrative pattern among HCC patients after DAA treatment is also recognized. Viral hepatitis is one of the major public health concerns in Egypt that needs more attention and funding from health policymakers.

Unequal but essential: How subsistence consumer-entrepreneurs negotiate unprecedented shock with extraordinary resilience during COVID-19.

We use qualitative interviews to study subsistence consumers confronting the global, pervasive and extended challenges of COVID-19, encompassing literally all realms of daily life. For subsistence consumers whose circumstances are filled with day-to-day uncertainty and a small margin of error to begin with, the pandemic has led to manifold uncertainties and a disappearing margin of error, with potentially lethal consequences. Their constraints to thinking and lack of self-confidence arising from both low income and low literacy are magnified in the face of the complex, invisible pandemic and the fear and panic it has caused. Characteristic relational strengths are weakened with social distancing and fear of infection. Yet, subsistence consumers display humanity in catastrophe, and confront the uncontrollable by reiterating a higher power. Consumption is reduced to the very bare essentials and income generation involves staying the course versus finding any viable alternative. We derive implications for consumer affairs.

N-Terminal PreS1 Sequence Regulates Efficient Infection of Cell-Culture-Generated Hepatitis B Virus.

BACKGROUND AND AIMS: An efficient cell-culture system for hepatitis B virus (HBV) is indispensable for research on viral characteristics and antiviral reagents. Currently, for the HBV infection assay in cell culture, viruses derived from HBV genome-integrated cell lines of HepG2.2.15 or HepAD-38 are commonly used. However, these viruses are not suitable for the evaluation of polymorphism-dependent viral characteristics or resistant mutations against antiviral reagents. HBV obtained by the transient transfection of the ordinary HBV molecular clone has limited infection efficiencies in cell culture. APPROACH AND RESULTS: We found that an 11-amino-acid deletion (d11) in the preS1 region enhances the infectivity of cell-culture-generated HBV (HBVcc) to sodium taurocholate cotransporting polypeptide-transduced HepG2 (HepG2/NTCP) cells. Infection of HBVcc derived from a d11-introduced genotype C strain (GTC-d11) was ~10-fold more efficient than infection of wild-type GTC (GTC-wt), and the number of infected cells was comparable between GTC-d11- and HepG2.2.15-derived viruses when inoculated with the same genome equivalents. A time-dependent increase in pregenomic RNA and efficient synthesis of covalently closed circular DNA were detected after infection with the GTC-d11 virus. The involvement of d11 in the HBV large surface protein in the enhanced infectivity was confirmed by an HBV reporter virus and hepatitis D virus infection system. The binding step of the GTC-d11 virus onto the cell surface was responsible for this efficient infection. CONCLUSIONS: This system provides a powerful tool for studying the infection and propagation of HBV in cell culture and also for developing the antiviral strategy against HBV infection.

MCPIP1 reduces HBV-RNA by targeting its epsilon structure.

Hepatitis B virus (HBV) is the major causative factor of chronic viral hepatitis, liver cirrhosis, and hepatocellular carcinoma. We previously demonstrated that a proinflammatory cytokine IL-1ß reduced the level of HBV RNA. However, the mechanism underlying IL-1ß-mediated viral RNA reduction remains incompletely understood. In this study, we report that immune regulator Monocyte chemotactic protein-1-induced protein 1 (MCPIP1) can reduce HBV RNA in hepatocytes. MCPIP1 expression level was higher in the liver tissue of HBV-infected patients and mice. Overexpression of MCPIP1 decreased HBV RNA, whereas ablating MCPIP1 in vitro enhanced HBV production. The domains responsible for RNase activity or oligomerization, were required for MCPIP1-mediated viral RNA reduction. The epsilon structure of HBV RNA was important for its antiviral activity and cleaved by MCPIP1 in the cell-free system. Lastly, knocking out MCPIP1 attenuated the anti-HBV effect of IL-1ß, suggesting that MCPIP1 is required for IL-1ß-mediated HBV RNA reduction. Overall, these results suggest that MCPIP1 may be involved in the antiviral effect downstream of IL-1ß.