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1.
J Gen Virol ; 104(2)2023 02.
Article in English | MEDLINE | ID: mdl-36809248

ABSTRACT

Hepatitis E virus (HEV) egresses from infected hepatocytes as quasienveloped particles containing open reading frame 3 (ORF3) protein. HEV ORF3 (small phosphoprotein) interacts with host proteins to establish a favourable environment for virus replication. It is a functional viroporin that plays an important role during virus release. Our study provides evidence that pORF3 plays a pivotal role in inducing Beclin1-mediated autophagy that helps HEV-1 replication as well as its exit from cells. The ORF3 interacts with host proteins involved in regulation of transcriptional activity, immune response, cellular and molecular processes, and modulation of autophagy, by interacting with proteins, DAPK1, ATG2B, ATG16L2 and also several histone deacetylases (HDACs). For autophagy induction, the ORF3 utilizes non-canonical NF-κB2 pathway and sequesters p52NF-κB and HDAC2 to upregulate DAPK1 expression, leading to enhanced Beclin1 phosphorylation. By sequestering several HDACs, HEV may prevent histone deacetylation to maintain overall cellular transcription intact to promote cell survival. Our findings highlight a novel crosstalk between cell survival pathways participating in ORF3-mediated autophagy.


Subject(s)
Hepatitis E virus , Hepatitis E , Humans , Autophagy , Autophagy-Related Proteins/metabolism , Beclin-1/genetics , Beclin-1/metabolism , Genotype , Hepatitis E virus/genetics , Hepatocytes , Vesicular Transport Proteins/genetics , Vesicular Transport Proteins/metabolism
2.
Indian J Med Res ; 144(3): 424-432, 2016 Sep.
Article in English | MEDLINE | ID: mdl-28139541

ABSTRACT

BACKGROUND & OBJECTIVES: Reduction of viraemia in patients with chronic hepatitis B virus (HBV) infection using nucleoside/nucleotide analogues reduces fatal liver disease-related events, but development of resistance in virus presents serious clinical challenge. Therefore, comparative evaluation of prolonged antiviral monotherapy and combination therapies was prospectively studied to assess their influence on viral suppression, rapidity of response, development of drug resistance and surfacing mutants in chronic liver disease (CLD) patients. METHODS: A total of 158 (62eAg-ve) chronic hepatitis B patients were prospectively studied for 24 months. Final analysis was performed on patients treated with lamivudine (LAM, n = 28), adefovirdipivoxil (ADV, n = 24), tenofovir disoproxil fumarate (TDF, n = 26), entecavir (ETV, n = 25), LAM + ADV (n = 28) and LAM + TDF (n = 27). Quantitative hepatitis B virus DNA was detected using real-time polymerase chain reaction. Multiple comparisons among drugs and genotypic mutations were analyzed. RESULTS: Progressive biochemical and virological response were noted with all the regimens at 24 months except LAM and ADV which were associated with viral breakthrough (VBT) in 46.4 and 25 per cent, respectively. Mutations: rtM204V (39.3%), M204V+L180M (10.7%) while rtA181V (8.1%) and rtN236T (8.3%) were observed with LAM and ADV regimen, respectively. LAM + ADV combination therapy revealed VBT in seven per cent of the cases without mutations whereas TDF, ETV and LAM + TDF therapies neither showed VBT nor mutations. INTERPRETATION & CONCLUSIONS: LAM was the least potent drug among all therapeutic options followed by ADV. TDF and ETV were genetically stable antivirals with a strong efficacy. Among newer combination therapies, LAM + TDF revealed more efficacy in virological remission and acted as a profound genetic barrier on long term. Hence, newer generation molecules (TDF, ETV) and effective combination therapy should be a certain choice.


Subject(s)
Drug Resistance, Viral/genetics , Guanine/analogs & derivatives , Hepatitis B virus/drug effects , Hepatitis B, Chronic/drug therapy , Tenofovir/administration & dosage , Adenine/administration & dosage , Adenine/analogs & derivatives , Adult , Drug Combinations , Drug Resistance, Viral/drug effects , Female , Guanine/administration & dosage , Hepatitis B virus/pathogenicity , Hepatitis B, Chronic/genetics , Hepatitis B, Chronic/virology , Humans , Lamivudine/administration & dosage , Male , Middle Aged , Mutation , Organophosphonates/administration & dosage , Pilot Projects
3.
Sci Total Environ ; 765: 142746, 2021 Apr 15.
Article in English | MEDLINE | ID: mdl-33092831

ABSTRACT

The contagious SARS-CoV-2 virus, responsible for COVID-19 disease, has infected over 27 million people across the globe within a few months. While literature on SARS-CoV-2 indicates that its transmission may occur predominantly via aerosolization of virus-laden droplets, the possibility of alternate routes of transmission and/or reinfection via the environment requires considerable scientific attention. This review aims to collate information on possible transmission routes of this virus, to ascertain its fate in the environment. Concomitant with the presence of SARS-CoV-2 viral RNA in faeces and saliva of infected patients, studies also indicated its occurrence in raw wastewater, primary sludge and river water. Therefore sewerage system could be a possible route of virus outbreak, a possible tool to assess viral community spread and future surveillance technique. Hence, this review looked into detection, occurrence and fate of SARS-CoV-2 during primary, secondary, and tertiary wastewater and water treatment processes based on published literature on SARS-CoV and other enveloped viruses. The review also highlights the need for focused research on occurrence and fate of SARS-CoV-2 in various environmental matrices. Utilization of this information in environmental transmission models developed for other enveloped and enteric viruses can facilitate risk assessment studies. Preliminary research efforts with SARS-CoV-2 and established scientific reports on other coronaviruses indicate that the threat of virus transmission from the aquatic environment may be currently non-existent. However, the presence of viral RNA in wastewater provides an early warning that highlights the need for effective sewage treatment to prevent a future outbreak of SARS-CoV-2.


Subject(s)
COVID-19 , Water Purification , Attention , Humans , Pandemics , SARS-CoV-2 , Wastewater
4.
J Interferon Cytokine Res ; 34(7): 547-51, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24446686

ABSTRACT

Immune-mediated mechanisms have been found to play an important role in the progression of hepatitis B virus (HBV) infection. The outcomes of infection do not appear to be determined by viral strains. Instead, allelic variants in human genome are likely to affect the disease progression. Allelic variation of proinflammatory cytokines such as interferon gamma (IFN-γ) participates in the elimination of HBV, and interleukin-10 (IL-10) helps in inhibition of Th1 effector mechanisms for host defense. The aim of this study was to determine the influence of host genetic factors in chronic HBV infection and gene promoter polymorphism or single-nucleotide polymorphism analysis of IFN-γ+874 and IL-10 (-1082, -592, and -819) on disease progression and persistence. A total of 232 patients along with 76 healthy controls were included. Allele-specific primers for IFN-γ and restriction fragment length polymorphism for IL-10 were used. The study indicated that low IFN-γ expression probably impairs host immune response to HBV, rendering these subjects more prone to HBV infection. No significant differences were detected between the 2 groups in the distributions of IL-10 genotype at the -1082, -819, and -592 positions. Odds ratio indicated that heterozygosity of genotypes -819 CT and -592 AC was more strongly associated with liver chronicity. Significantly, AA homozygous genotype was dominant in chronic hepatitis B cases in IFN-γ+874 and IL-10 (-1082 and -592) and is associated with increased risk of persistent infection.


Subject(s)
Hepatitis B, Chronic/genetics , Interferon-gamma/genetics , Interferon-gamma/metabolism , Interleukin-10/genetics , Interleukin-10/metabolism , Polymorphism, Genetic , Adolescent , Adult , Female , Hepatitis B, Chronic/physiopathology , Humans , India , Male , Young Adult
5.
Antiviral Res ; 100(2): 300-5, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24012998

ABSTRACT

Decompensated cirrhosis has low survival rate compared to compensated state. Effective viral suppression due to antiviral therapy (tenofovir) has been shown to slow disease progression and may delay the burden of liver transplantation. We aimed to evaluate the usefulness of various prognostic indicators in predicting the 24-months survival in HBV related decompensated cirrhosis after tenofovir therapy and to evaluate the post-treatment outcome. Ninety-six HBV related decompensated patients on antiviral (tenofovir) therapy were prospectively studied for 24months survival and mortality. Cutoff levels for several prognostic indicators were generated by ROC. Prediction of overall probability of mortality was also calculated. The overall probability of survival observed at 12months was 0.947 whereas at 24months it was found to be 0.833. According to Cox proportional hazards model, the univariate analysis revealed cutoff of >7.4logcopies/ml for HBV DNA, >1.2mg/dl for serum creatinine, >3.7mg/dl for total bilirubin, ⩽0.75 for platelets count, >10 for CTP and >20 for MELD as predictors of poor survival. Multivariate analysis showed MELD score of >20 was the most robust predictor of mortality, with 58 times higher risk (HR: 58.73, p<0.001). Post-treatment response with tenofovir for 24months significantly improved the hepatic functions and reverses decompensation and showed incredible efficacy in improvement of hepatic functional status with reduced viremia in a great majority of decompensated cirrhosis subjects having high MELD and HBV DNA level.


Subject(s)
Adenine/analogs & derivatives , Hepatitis B, Chronic/drug therapy , Hepatitis B, Chronic/mortality , Liver Cirrhosis/drug therapy , Liver Cirrhosis/mortality , Organophosphonates/therapeutic use , Adenine/therapeutic use , Adult , Aged , Bilirubin/blood , Creatinine/blood , DNA, Viral/blood , Female , Hepatitis B, Chronic/complications , Humans , India , Longitudinal Studies , Male , Middle Aged , Platelet Count , Prospective Studies , Severity of Illness Index , Survival Analysis , Tenofovir , Treatment Outcome , Viral Load
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