T cell dysfunction has a crucial role in establishing and maintaining viral persistence. We have previously shown a decline in miR‐181a, which regulates CD4+ T cell responses via DUSP6 overexpression, in individuals with hepatitis C virus (HCV) infection. Here, we describe accelerated T cell senescence in HCV‐infected individuals compared with age‐ and sex‐matched healthy subjects. Mechanistic studies revealed that up‐regulation of transcription factor ΔNp63 led to the decline of miR‐181a expression, resulting in an overexpression of the antiaging protein Sirt1, in CD4+ T cells from HCV‐infected individuals. Either reconstituting miR‐181a or silencing ΔNp63 or Sirt1 expression in CD4+ T cells led to accelerated T cell senescence, as evidenced by an increased senescence‐associated β‐galactosidase (SA‐β‐gal) expression, shortened telomere length, and decreased EdU incorporation; this suggests that HCV‐induced T cell senescence is counterregulated by the ΔNp63–miR‐181a–Sirt1 pathway. An increase of IL‐2 production was observed in these senescent CD4+ T cells and was driven by a markedly reduced frequency of Foxp3+ regulatory T (Treg) cells and increased number of Foxp3− effector T (Teff) cells upon manipulating the ΔNp63–miR‐181a–Sirt1 pathway. In conclusion, these findings provide novel mechanistic insights into how HCV uses cellular senescent pathways to regulate T cell functions, revealing new targets for rejuvenating impaired T cell responses during chronic viral infection.

Hepatitis C viral infection is the major cause of acute hepatitis and chronic liver disease and remains the leading cause of liver transplants (NIH). An estimated 180 million people are infected globally (WHO). There is no vaccine available to prevent hepatitis C. The treatment with antiviral drugs is expensive, accompanied with various side effects and is limited only to those at risk of developing advanced liver disease. The treatment is also effective in only about 30% to 50% of treated patients and still a high percentage of patients are resistant to therapy. Therefore, there is an urgent need for the development of effective vaccine antigens and an efficacious HCV vaccine. The non-structural 3 protein of the hepatitis C virus is a multifunctional protein of the virus required for virus polyprotein processing and replication. Vaccine antigen production via chloroplast transformation system usually results in high expression levels and eliminates the possibility of contamination with vector sequences,human or animal pathogens. The HCV NS3 antigen was expressed in the chloroplast of Nicotiana tabacum var. Petit havana and LAMD-609. The 1.9kb NS3 gene was cloned into a chloroplast expression vector, pLD-Ct containing the 16S rRNA promoter, aadA gene coding for the spectinomycin selectable marker, psbA 5' untranslated region to enhance translation in the light and 3' untranslated region for transcript stability and trnI & trnA homologous flanking sequences for site specific integration into the chloroplast genome. Chloroplast integration of the NS3 gene was first confirmed by PCR. Southern blot analysis further confirmed site-specific gene integration and homoplasmy. The NS3 protein was detected in transgenic chloroplasts by immunoblot analysis. The NS3 protein was further quantified by ELISA. Maximum expression levels of NS3 up to 2% in the total soluble protein were observed even in old leaves, upon 3-day continuous illumination. These results demonstrate successful expression of the HCV non-structural 3 antigen in transgenic tobacco chloroplasts. Animal studies to test the immunogenecity of the chloroplast derived HCV NS3 will be performed using chloroplast derived NS3 antigen.

Porcine epidemic diarrhea Virus (PEDV) is a virus effecting swine. It is the cause of disease that manifests with symptoms ranging from depression, to severe dehydration and death. Young piglets are particularly susceptible to the virus, which can reach mortality rates of 100%. Presence of the virus on a swine farm can therefore cause severe economic losses. Treatments currently exist for PEDV, but are mostly generated from the virus itself. There has recently been renewed interest in a vaccine that is made from a different source, which might help eliminate some of the side effects of those that currently exist on the market. This project outlines three experiments performed in animals. During the first experiment, a structural protein from the Hepatitis B virus was genetically altered to include important structural portions of PEDV. This new protein is generated in E. coli and purified. After purification, the protein assembles into a virus-like particle (VLP). VLPs are structural proteins of existing viruses that are expressed and assembled to mimic the virus. By doing so, the immune system recognizes the protein as a potential threat, and launches a response in the form of antibodies. Manipulations of the VLPs as describe herein allow the new vaccine to generate antibodies toward other diseases such as PEDV. Although all five of the vaccines used in the first experiment were able to generate appropriate antibodies, only two of them were effective at preventing PEDV from entering susceptible cells (virus neutralization). A second experiment, with three newly designed vaccines was therefore performed. This experiment, like the first, was successful in producing antibodies to several of the included PEDV protein sections, but none were able to neutralize the virus. These results led to a third experiment, during which further design improvements were made to the basic vaccine structure in an attempt to increase the neutralization capabilities of the vaccines. The results from the third experiment indicated that several changes to the vaccine increased the immune response to the structural portions of PEDV, providing a better overall vaccine candidate. This also led to the conclusion that one specific sequence from PEDV has a better ability to neutralize the virus than the other sections. / PHD

Yes / Coronavirus is the most dangerous virus in the world wide and it can easy spread between people, animals and plants because it is existing on one strand of RNA (Ribonucleic Acid) and it can duplicate faster than any virus. The source of coronavirus is still unknown, but some sources said that it came from seafood market and other sources said that it came from bat and snakes. It starts in Wuhan; China and every day the fatality increases. The symptoms are like a SARS-CoV (acute respiratory syndrome coronavirus)) and MERS-CoV (Middle East Respiratory Syndrome Coronavirus). By using nucleotide sequence of coronavirus from NCBI (National Center for Biotechnology Information) and some programs that ran on Matlab, the results show that there are some differences and similarities between coronavirus and other viruses such as Ebola, Flu-b, Hepatitis B, HIV and Zika especially for DEBs (distinct excluded blocks) program that shows at 5bp (base pair) there is a common with slightly difference between coronavirus “cgggg” and Ebola virus “cgtgg”. The aim from this study is to find a way to help doctors and scientists to stop spreading the coronavirus or to destroy it.

In 2014, an analysis was conducted to evaluate the hepatitis C virus (HCV) epidemiology and disease burden in Germany. Since then, there have been considerable developments in HCV management such as the implementation of direct acting antivirals. The aim of this analysis was to assess the recent data available for Germany, establish an updated 2020 HCV prevalence and cascade of care and evaluate the impact of what-if scenarios on the future burden of disease using modelling analysis. A dynamic Markov model was used to forecast the HCV disease burden in Germany. Model inputs were retrieved through literature review, unpublished sources and expert input. Next, three “what-if” scenarios were developed to evaluate the status quo, COVID-19 pandemic, and steps needed to achieve the WHO targets for elimination. At the beginning of 2020, there were 189,000 (95% UI: 76,700–295,000) viremic infections in Germany, a decline of more than 85,000 viremic infections since 2012. Annual treatment starts went down since 2015. Compared with 2019, the COVID-19 pandemic resulted in a further 11% decline in 2020. If this continues for two years, it could result in 110 excess HCC cases and 200 excess liver related deaths by 2030. To achieve the WHO targets, 81,200 people need to be diagnosed, with 118,600 initiated on treatment by 2030. This could also avert 1,020 deaths and 720 HCC cases between 2021 and 2030. Germany has made strides towards HCV elimination, but more efforts are needed to achieve the WHO targets by 2030.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第24841号 / 医博第5009号 / 新制||医||1068(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 朝長, 啓造, 教授 波多野, 悦朗, 教授 竹内, 理 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

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As obligatory intracellular parasites, viruses are in a constant battle with their host to establish infection. They can facilitate their propagation by modulating host immune or metabolic pathways. This modulation involves targeting various molecular factors such as microRNAs (miRNA), enzymes, or small molecules. Understanding how viruses alter the chemical makeup of a cell is crucial to identifying what pathways are being targeted, furthering our understanding of the virus life cycle, and may aid in identifying biomarkers of disease. Here, we examine host-virus interactions in the context of two viruses, hepatitis c virus (HCV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). First, the modulation of serine hydrolases by a pro-viral microRNA, miRNA-122, is investigated using activity-based protein profiling (ABPP). This study identifies a downstream target of miRNA-122 that is differentially activated during HCV infection which can be targeted pharmacologically to reduce HCV infectivity. Second, we apply similar techniques to identify serine hydrolase changes associated with SARS-CoV-2 infection. Results point towards enrichment of endocannabinoid metabolism which may offer an alternative therapeutic avenue for combating SARS-CoV-2 infection. Together, the work presented in this thesis provides avenues for further investigation into miRNA-122 interactions during HCV infection and endocannabinoid metabolism in SARS-CoV-2 infection.

Hepatitis B virus (HBV) is a major etiologic agent of chronic liver disease (CLD) and hepatocellular carcinoma (HCC). The virally encoded X antigen, HBx, contributes importantly to the development of HCC through its trans-activating role in various signal transduction pathways. Pathways implicated in stem cell self-renewal also contribute to carcinogenesis. Thus, experiments were designed to test if HBx triggers malignant transformation by promoting properties that are characteristic of cancer stem cells (CSCs). To test this hypothesis, HBx expressing (HepG2X) and control (HepG2CAT) human cell lines were assayed for phenotypic and molecular characteristics of "stemness." Western blotting of protein extracts from HepG2X and HepG2CAT cells as well as immunohistochemical staining of HCC and adjacent liver tissue sections from HBV infected patients showed up-regulation of "stemness"-associated (EpCAM and beta-catenin) and "stemness" (Oct-4, Nanog, Klf-4) markers by HBx. Moreover, HBx stimulated cell migration and spheroid formation. HBx expression was also associated with depressed levels of E-cadherin and subsequent activation of beta-catenin and EpCAM. Results from ChIP-chip data performed previously in this lab suggest an associative link between HBx and the expression of epigenetic co-repressor, mSin3A, which is known to repress E-cadherin when complexed with histone deacetylases. Thus, experiments were also designed to test if HBx represses the E-cadherin gene (CDH1) through histone deacetylation by the mSin3A/HDAC complex. In HepG2X cells, decreased levels of E-cadherin and elevated levels of mSin3A were detected. Reciprocal immunoprecipitation with anti-HBx and anti-mSin3A demonstrated mutual binding. Further, HBx-mSin3A co-localization was showed by immunofluorescent staining. Chromatin immunoprecipitation revealed that HBx mediated the recruitment of the mSin3A/HDAC complex to the CDH1 promoter. HDAC inhibition by Trichostatin A treatment restored E-cadherin expression. Thus, HBx-associated epigenetic repression of E-cadherin and up-regulated expression of multiple "stemness" markers support the hypothesis that HBx contributes to hepatocarcinogenesis, at least in part, by promoting changes in gene expression that are characteristic of CSCs. This work is the first to propose that HBV promotes "stemness" in the pathogenesis of HCC. / Biology