mycophenolic-acid and Hepatitis-E

Exposure to hepatitis E virus (HEV) bears a high risk of developing chronic infection in immunocompromised patients, including organ transplant recipients and cancer patients. We aim to identify effective anti-HEV therapies through screening and repurposing safe-in-human broad-spectrum antiviral agents. In this study, a safe-in-human broad-spectrum antiviral drug library comprising of 94 agents was used. Upon screening, we identified gemcitabine, a widely used anti-cancer drug, as a potent inhibitor of HEV replication. The antiviral effect was confirmed in a range of cell culture models with genotype 1 and 3 HEV strains. As a cytidine analog, exogenous supplementation of pyrimidine nucleosides effectively reversed the antiviral activity of gemcitabine, but the level of pyrimidine nucleosides per se does not affect HEV replication. Surprisingly, similar to interferon-alpha (IFNα) treatment, gemcitabine activates STAT1 phosphorylation. This subsequently triggers activation of interferon-sensitive response element (ISRE) and transcription of interferon-stimulated genes (ISGs). Cytidine or uridine effectively inhibits gemcitabine-induced activation of ISRE and ISGs. As expected, JAK inhibitor 1 blocked IFNα, but not gemcitabine-induced STAT1 phosphorylation, ISRE/ISG activation, and anti-HEV activity. These effects of gemcitabine were completely lost in STAT1 knockout cells. In summary, gemcitabine potently inhibits HEV replication by triggering interferon-like response through STAT1 phosphorylation but independent of Janus kinases. This represents a non-canonical antiviral mechanism, which utilizes the innate defense machinery that is distinct from the classical interferon response. These results support repurposing gemcitabine for treating hepatitis E, especially for HEV-infected cancer patients, leading to dual anti-cancer and antiviral effects.

Topics: Antiviral Agents; Cell Line; Deoxycytidine; Drug Evaluation, Preclinical; Drug Repositioning; Drug Synergism; Gemcitabine; Gene Expression Regulation; Hepatitis E; Hepatitis E virus; Host Microbial Interactions; Humans; Interferon-alpha; Janus Kinases; Mycophenolic Acid; Phosphorylation; Pyrimidine Nucleosides; Response Elements; Ribavirin; Signal Transduction; STAT1 Transcription Factor; Virus Replication

Topics: Aged; Alanine Transaminase; Antiviral Agents; Graft Rejection; Hepatitis E; Hepatitis E virus; Hepatitis, Chronic; Humans; Immunocompromised Host; Immunoglobulin M; Immunosuppressive Agents; Kidney Transplantation; Male; Mycophenolic Acid; Polycystic Kidney Diseases; Polymerase Chain Reaction; Ribavirin; RNA, Viral; Tacrolimus; Viral Load

Topics: Aged; Drug Therapy, Combination; Enzyme Inhibitors; Female; Hepatitis E; Hepatitis E virus; Hepatitis, Chronic; Humans; Immunocompromised Host; Immunologic Factors; Mycophenolic Acid; Rituximab; Sjogren's Syndrome

Many recipients of organ transplants develop chronic hepatitis, due to infection with the hepatitis E virus (HEV). Although chronic HEV infection is generally associated with immunosuppressive therapies, little is known about how different immunosuppressants affect HEV infection.. A subgenomic HEV replication model, in which expression of a luciferase reporter gene is measured, and a full-length infection model were used. We studied the effects of different immunosuppressants, including steroids, calcineurin inhibitors (tacrolimus [FK506] and cyclosporin A), and mycophenolic acid (MPA, an inhibitor of inosine monophosphate dehydrogenase) on HEV replication in human hepatoma cell line Huh7. Expression of cyclophilins A and B (the targets of cyclosporin A) were knocked down using small hairpin RNAs.. Steroids had no significant effect on HEV replication. Cyclosporin A promoted replication of HEV in the subgenomic and infectious models. Knockdown of cyclophilin A and B increased levels of HEV genomic RNA by 4.0- ± 0.6-fold and 7.2- ± 1.9-fold, respectively (n = 6; P < .05). A high dose of FK506 promoted infection of liver cells with HEV. In contrast, MPA inhibited HEV replication. Incubation of cells with guanosine blocked the antiviral activity of MPA, indicating that the antiviral effects of this drug involve nucleotide depletion. The combination of MPA and ribavirin had a greater ability to inhibit HEV replication than MPA or ribavirin alone.. Cyclophilins A and B inhibit replication of HEV; this might explain the ability of cyclosporin A to promote HEV infection. On the other hand, the immunosuppressant MPA inhibits HEV replication. These findings should be considered when physicians select immunosuppressive therapies for recipients of organ transplants who are infected with HEV.

Topics: Antiviral Agents; Calcineurin; Calcineurin Inhibitors; Cell Line, Tumor; Cyclophilin A; Cyclophilins; Cyclosporine; Dose-Response Relationship, Drug; HEK293 Cells; Hepatitis E; Hepatitis E virus; Hepatitis, Chronic; Humans; Immunosuppressive Agents; Mycophenolic Acid; Ribavirin; RNA Interference; RNA, Viral; Time Factors; Transfection; Virus Replication