Hepatitis C virus (HCV) is a major global pathogen estimated to infect over 170 million people worldwide. A recent study has shown that vaccination with adenoviral vectors, based on rare human and simian serotypes encoding the non-structural (NS) proteins of HCV, induces highly potent, multi-specific and durable T cell responses in healthy human volunteers. In this thesis I assess the safety and immunogenicity of these vaccines (ChAd3–NSmut and Ad6-NSmut), for the first time in HCV infected patients. This work also explores whether vaccine-induced T cell responses target in vivo circulating HCV antigens and common naturally occurring epitope variants. Patients with treatment naive chronic genotype 1 HCV infection were vaccinated (i.m.) with ChAd3-NSmut and Ad6-NSmut in a heterologous prime boost schedule, either with or without current IFN and ribavirin (IFN/RBV). Epitope-specific T cell responses were defined by fine mapping using HCV peptides. Circulating viral genomic sequence was determined in vaccinated patients at baseline and at any point of viral relapse. Cross-reactivity of vaccine-induced T cell responses was determined in T cell assays, using peptides corresponding to both circulating host virus and common population HCV epitope variants. An in vitro dendritic cell /T cell priming model was used to identify possible candidates for a cross-reactive vaccine immunogen at the most immunodominant epitope, NS3₁₄₀₆. 33 patients were vaccinated. Vaccination was well tolerated. At the highest vaccine dose (2.5 x 10¹⁰vp) vaccine-induced T cell responses were detectable in 11/20 patients receiving concurrent IFN/RBV and 2/4 patients receiving vaccination alone. In total 14 antigenic targets were identified, 2 of which have not previously been described. However, T cell responses were of lower magnitude and more narrowly focused than those observed in healthy volunteers vaccinated with the same regimen. Analysis of viral sequence showed that in many cases vaccine-induced T cells did not target the circulating virus. At the most immunodominant epitope (NS3₁₄₀₆), T cells induced by vaccination failed to target common circulating genotype 1 HCV variants. An in vitro model suggested that in order to target all genotype 1 sequences at this epitope, it would be necessary to insert both a genotype 1a and 1b version of this epitope into a vaccine immunogen. Vaccination with adenoviral vectors induces T cell responses in patients with chronic HCV infection, however immune responses are attenuated compared with healthy volunteers. Ultimately a successful therapeutic or prophylactic vaccine strategy will rely on inducing responses that target conserved or cross-reactive epitopes.

In der Promotion wird die Entwicklung, Optimierung und Validierung einer Reversed-phase-Chromatography Methode zur Messung des Ribavirinplasmaspiegels beschrieben. Diese wurde mit einer Solid Phase Extraction zur Probenvorbereitung kombiniert. Zudem finden sich zahlreiche Auswertungen von gemessenen Patienenchromatogrammen zu ausgewählten, klinisch relevanten Fragestellungen, wie beispielsweise die Darstellung des Ribavirinplasmaspiegels im Tagesverlauf, im Verlauf der ersten sechs Therapiewochen, im Vergleich von Männern und Frauen, sowie bei einem niereninsuffizienten Patienten. Zu den erhobenen Ergebnissen wird Stellung genommen, und daraus resultierende Schlussfolgerungen bezüglich einer zukünftigen Optimierung der Hepatitis-C-Therapie kommentiert. / The doctorate program will describe the development, optimization and validation of a reversed phase chromatography method for measuring ribavirinplasma levels. This has been combined with solid phase extraction for preparing samples. In addition, numerous analyses of patients’ chromatograms are included relative to clinically relevant questions such as the depiction of ribavirinplasma levels during the course of a day, during the course of the first six weeks of therapy, in comparison to other men and women as well as patients suffering from kidney insufficiencies. The collected data will be commented on, as well as the resulting implications relative to a future optimization of hepatitis-C therapy.

Student Number : 9903082V - MSc (Med) dissertation - Faculty of Health Sciences / Chronic infection with the hepatitis B virus (HBV) is endemic to sub-Saharan Africa and south-east Asia where it is a major risk factor for the development of cirrhosis and hepatocellular carcinoma (HCC). Currently available therapy is only effective in a small subset of chronic carriers. The development of novel treatment modalities for the management of HBV therefore remains an important global medical objective. Sequence plasticity of the HBV genome is limited by its small size and the overlapping nature of its open reading frames (ORFs). These features make HBV an ideal target for therapy based on nucleic acid hybridization. The use of ribozymes (RNA enzymes) and antisense molecules to inhibit gene expression is well documented. The recent discovery of RNA interference (RNAi) has added to the arsenal of therapy based on nucleic acid hybridization. RNAi is the process whereby short RNA duplexes (called short interfering RNA or siRNA) mediate the sequence-specific post-transcriptional silencing of genes homologous in sequence to the siRNA. siRNA function by guiding a protein complex (RNA Induced Silencing Complex or RISC) to target mRNA for degradation or translational repression. The protein X ORF (HBx ORF) is a conserved region of the HBV genome and is common to all viral transcripts. HBx is required for infection by the virus and plays an important role in the establishment of chronic infections in vivo as well as in the development of HCC. RNAi targeted against the HBx ORF may therefore prove useful as treatment of chronic HBV infection. Plasmid based expression cassettes capable of endogenously generating short hairpin RNA (shRNA) targeted to the HBx ORF were constructed. The shRNA function as substrates for the RNAi machinery and are processed into siRNA. The ability of the expression cassettes to knockdown markers of HBV gene expression was tested in a human hepatoma cell line. A panel of 10 U6 promoter-driven shRNA expression vectors was generated. The U6 promoter (an RNA polymerase III promoter) is normally involved in the transcription of small nuclear RNA and as such is ideal for the generation of shRNA of precisely defined length. Three cytomegalovirus (CMV) promoter-driven shRNA expression cassettes incorporating ribozymes that produce defined hairpin sequences were also generated. The CMV promoter (an RNA polymerase II) promoter is involved in the transcription of large messenger RNA. Two hammerhead ribozymes lying 5’ and 3’ of the shRNA encoding sequence were incorporated into the cassette. Cis-cleavage by the ribozymes releases a shRNA of defined length thereby overcoming the limitations imposed by extraneous sequences from CMV promoter-driven transcription. U6 promoter-driven shRNA expression vectors efficiently knocked down markers of HBV replication in liver cells. The CMV promoter-driven expression vectors were incapable of inhibiting HBV gene expression; however shRNA generated in vitro from these vectors mediated efficient knockdown of HBV replication. shRNA-mediated inhibition of gene expression therefore holds promise as a novel treatment strategy for the management of HBV and other mobile genetic elements.

Chronic hepatitis B virus (HBV) infection is endemic to sub-Saharan Africa, and despite the availability of anti-viral agents, there is currently no cure. This double stranded DNA virus is hepatotropic, and active viral replication results in two genomic equivalents, the relaxed circular DNA (rcDNA) and covalently closed circular DNA (cccDNA). The virion encapsulated rcDNA contains a partially synthesised positive DNA stand and a gap region within the negative strand. After infection of hepatocytes, the rcDNA is repaired in the nucleus to form cccDNA. An important objective of HBV therapy is the elimination of cccDNA, as its persistence within hepatocytes has been attributed to chronic HBV infection. Therefore a reliable assay for this replication intermediate is crucial. The objective of this study was to develop a method based on real-time PCR to detect and quantify HBV cccDNA. PCR primers which flank the rcDNA gap were designed to amplify cccDNA whilst primers flanking the pre-S1 region quantify total HBV DNA. Viral DNA was extracted from HepG2.2.15 cells, along with serum and livers from HBV transgenic mice. According to this assay, cccDNA was readily detectable in transgenic mouse livers, but was present at low concentrations in serum samples. The intrahepatic HBV DNA profile of transgenic mice was found to be 40% cccDNA to 60% rcDNA. In HepG2.2.15 cells, only 2% of HBV DNA was cccDNA whilst the majority was in the form of rcDNA. These results were validated using non-radioactive Southern blothybridisation. Additionally, it was established that although RNAi-based effecters inhibit HBV replication, established cccDNA pools were not eliminated. Real-time PCR provides a convenient platform for HBV cccDNA detection as it allows for the rapid simultaneous amplification and quantification of a specific DNA target through either non-specific or specific DNA detection chemistries. In conclusion, this HBV qPCR assay should enable improved monitoring of patients’ responses to antiviral therapy

Hepatitis B virus (HBV) represents one of the hot topics of current basic and pharmaceutical research. Although an effective vaccine against HBV exists since 1982, the world prevalence of chronic infection is still alarming. The infection can lead to significant liver damage, often resulting in hepatocellular carcinoma. Chronic HBV infection cannot be cured due to the fact that the viral genome persists in the infected hepatocyte hidden from the host immune response as well as from the antiviral treatment. One of the novel approaches aiming for HBV cure suggests that this cccDNA pool could be destroyed using gene editing tools such as CRISPR/Cas9 system. In order to shift this gene editing system to possible medicinal application, CRISPR/Cas9 has to be specifically delivered into the target cell in order to minimize its putative off-target activity. This thesis focuses at first on the design and efficacy testing of new sgRNAs targeting HBV cccDNA and secondly, it describes modular lipid nanoparticles developed specially for delivery of the CRISPR/Cas9 system in the form of RNA. Keywords: hepatitis B virus, CRISPR/Cas9, gene editing, lipid nanoparticles, mRNA delivery, targeted delivery

O objetivo deste estudo foi avaliar a distribuição genotípica e mutações no genoma do vírus da hepatite B (VHB) em um grupo de pacientes co-infectados pelo VHB e vírus da imunodeficiência humana (HIV). Foram incluídos pacientes AgHBs +/HIV+ , atendidos em um ambulatório de referência para pacientes infectados pelo HIV, na cidade de São Paulo. Para a detecção dos marcadores sorológicos para infecção pelo VHB utilizou-se técnica de ELISA através de kits comerciais. A detecção do DNA-VHB foi realizada através de nested-PCR e sua quantificação foi realizada por COBAS AMPLICOR. De acordo com a literatura, a infecção pelo VHB no Brasil varia de 0,4 a 8,5%. Os genótipos de VHB, as mutações na região do core, BCP, pré-core e na região da polimerase foram determinados por seqüenciamento. Cinqüenta e nove pacientes foram incluídos neste estudo e cinqüenta e seis pacientes relatavam uso prévio de lamivudina ou tenofovir. A presença do DNA-VHB foi detectada em 22 pacientes AgHBs positivos. A identificação dos genótipos foi realizada em 16 pacientes e a distribuição dos genótipos do VHB foi: A (12-75%); G (2-13%), D (1-6%) e F (1-6%). Em 10 dos pacientes com viremia presente para DNA-VHB, foram observadas mutações na região da polimerase (rtL180M + rtM204V, rtV173L + rtL180M + rtM204V) e no gene do envelope (sI195M, sW196L, sI195M/sE164D). Mutações na região do BCP (A1762T, G1764A) e do pré-core (G1896A) foram identificados em quatro pacientes. Em conclusão, entre os pacientes analisados observou-se uma alta prevalência de mutações associadas a resistência à lamivudina e associadas a resistência a anti-HBs. O genótipo G, raramente descrito em nosso meio, foi também observado nesse grupo de pacientes. / The objective of this study was to evaluate the genotype distribution and genomic mutations of hepatitis B virus (HBV) among a group of HIVHBV co-infected patients from an AIDS outpatient clinic in São Paulo. HBV serological markers were detected by commercially available enzyme immunoassay kits. HBV DNA was detected by using an in-house nested PCR and quantified by COBAS AMPLICOR. HBV genotypes, basal core promoter (BCP) / pre-core / core region and surface / polymerase genes mutations were determined by sequencing. Among the 59 patients included in this study, 56 reported previous use of lamivudine or tenofovir. According to the literature HBV infection in Brazil varies from 0,4 to 8,5%. HBV DNA was detected in 16/22 patients and the genotypes distribution was A (n=12, 75%); G (n=2, 13%); D (n=1, 6%), and F (n=1, 6%). In 10 patients with viremia, lamivudine-resistance mutations in the polymerase gene (rtL180M + rtM204V, rtV173L + rtL180M + rtM204V) were found, accompanied by changes in the envelope gene (sI195M, sW196L, and sI195M/sE164D). Mutations in the BCP and pre-core regions were identified in 4 patients. In conclusion, genotype G, rarely seen in Brazil, was observed in this group of patients. A high prevalence of mutations associated with lamivudine-resistance accompanied by mutations associated with anti-HBs resistance was also found among these patients.

Die vorliegende Habilitationsschrift befasst sich schwerpunktmäßig vor allem mit der Klinik und Therapie der Hepatitis C. Evaluiert wurden: 1. verschiedene therapeutische Strategien, 2. die Ursachen der "Non-Response" auf eine anti-virale Therapie sowie 3. die klinische Relevanz der neu entdeckten Hepatitis-assoziierten Viren und 4. ihre Bedeutung bei Patienten mit akuter bzw. chronischer Lebererkrankung unklarer Ätiologie sowie bei Patienten vor und nach Lebertransplantation. Ad 1. Aus dem Vergleich verschiedener Therapie-Konzepte wie der Kurzzeit- Kombinationstherapie, Triple-Therapie, Hochdosis-Interferon?-Therapie und der Anwendung antiviraler Substanzen wie Ribavirin und Amantadin ergaben sich neue Erkenntnisse hinsichtlich relevanter prognostischer Parameter für die Therapieresponse. Ad 2. Analysiert wurden die möglichen molekularen Mechanismen der Therapieresponse bzw. Non-Response sowie der Stellenwert von Interaktionen bestimmter HCV-Proteine (NS5A, E2, sogenannte PKR-eIF2a Phosphorylisations-Homologie-Domäne [PePHD]) mit den Interferon? induzierten Effektorproteinen. Es konnte gezeigt werden, daß die Anzahl der Mutationen innerhalb des NS5A Proteins einen prognostischen Parameter darstellen hinsichtlich der Response auf eine Interferon?-Therapie. Dagegen spielen Mutationen innerhalb der PePHD-Region keine Rolle. Ad 3. Aus den Untersuchungen zur klinischen Relevanz der neu entdeckten Hepatitis-assoziierten Viren GB Virus-C/Hepatitis G Virus (GBV-C/HGV) und TT-Virus (TTV) ergaben sich keine Hinweise bzgl. eines Einflusses von GBV-C/HGV bzw. TTV-Infektionen auf den Verlauf der chronischen Hepatitis C. Die durchgeführten Verlaufsuntersuchungen bei koinfizierten Patienten sprechen dafür, daß es sich um Interferon-sensitive Viren handelt; jedenfalls beeinflussen sie nicht die IFN?-induzierte Response. Ad 4. Untersucht wurden ferner die Prävalenz, Transmission und Relevanz der GBV-C/HGV und TTV-Infektion im Hinblick auf ihre Hepatitis-induzierenden Eigenschaften. Die Ergebnisse belegen, dass beide Viren parenteral übertragen werden, und dass sie eine hohe Prävalenz bei Patienten mit parenteralen Risikofaktoren besitzen. Eine Hepatitis-induzierende Potenz dieser Viren konnten wir nicht beobachten; bei der Mehrzahl aller chronisch infizierter Personen ließen sich keine Zeichen einer chronischen Hepatitis finden. / The major goal of this thesis is the analysis of the clinical outcome of patients with Hepatitis C virus (HCV) infection and the response to therapy. Analysed were 1. different types of therapeutic strategies 2. causes responsible for ineffective antiviral therapy (non-response) 3. clinical relevance of the newly discovered hepatitis-associated viruses and 4. the role of these viruses in patients with acute or chronic hepatitis of unknown causes and in those receiving liver grafts. Ad 1. Compared were different therapeutic concepts such as short-term combination therapy, triple-therapy, high dose IFN?-therapy and the use of antiviral substances such as ribavirin and amantadine. It emerged that relevant prognostic parameters can be deduced with respect to the therapeutic response rate. Ad 2. Analysed were possible molecular mechanisms, which may interfere with response or non-response to antiviral therapy. In this respect, we focussed on the interaction of certain HCV-proteins as NS5A, E2, so-called PKR-eIF2a phosphorylisation-homology-domain (PePHD). with the interferon-?-induced effector proteins. There is evidence, that number of mutations within the NS5A proteins are of prognostic relevance with respect to the response to interferon?-therapy. In contrast, mutations within the PePHD-region do not play any role in this respect. Ad 3. We also studied the clinical relevance of the newly discovered viruses GBV-C/HGV and TTV, and found, that they have no impact concerning the course of chronic hepatitis C. These viruses are interferon-sensitive and do not influence the IFNa-response as it could be documented by following the course of co-infected patients. Ad 4. Our studies also focused on the prevalence, transmission and relevance of GBV-C/HGV and TTV infections with respect to their role as hepatitis-inducing agents. We can show that both virus types are parenterally transmitted. There is a high prevalence for both types in patients confronted with risk factors for parenteral factors. From analysis of many patients being chronically infected with these viruses it became quite clear that they lack any important potency to provoke chronic liver disease.

Yu Chi Hung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 124-139). / Abstracts in English and Chinese. / Acknowledgement --- p.i / Table of Contents --- p.ii / Abbreviations --- p.iv / Abstract --- p.v / 論文摘要 --- p.vi / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- General introduction / Chapter 1.2 --- HBV and its potential oncogenic properties / Chapter 1.3 --- Aim of the present study / Chapter 1.4 --- Expressed sequence tag (EST) analysis: an approach to reveal gene expression pattern in a specific tissue / Chapter 1.5 --- cDNA subtraction / Chapter Chapter 2 --- Materials and Methods --- p.17 / Chapter 2.1 --- Plating out the adult human normal liver cDNA library / Chapter 2.2 --- PCR amplification of cloned human normal liver cDNA inserts / Chapter 2.3 --- Cycle sequencing of cloned human normal liver cDNA inserts / Chapter 2.4 --- mRNA preparation from the HCC tissue and its surrounding normal counterpart / Chapter 2.5 --- PCR-Select cDNA subtraction / Chapter 2.6 --- Construction of HCC subtracted cDNA library by T/A cloning method / Chapter 2.7 --- PCR amplification of cloned subtracted cDNA / Chapter 2.8 --- Cycle sequencing of cloned subtracted cDNA / Chapter 2.9 --- Sequence analysis / Chapter 2.10 --- Differential hybridization of HCC subtracted clones / Chapter Chapter 3 --- Results --- p.46 / Chapter 3.1 --- The sequencing results of adult human normal liver cDNA clones / Chapter 3.2 --- Categorization of ESTs sequenced from the adult normal liver / Chapter 3.3 --- Adaptor ligation efficiency analysis / Chapter 3.4 --- Primary and secondary PCR Amplification / Chapter 3.5 --- PCR analysis of subtraction efficiency / Chapter 3.6 --- The sequencing results of subtracted HCC cDNA clones / Chapter 3.7 --- Categorization of ESTs sequenced from the subtracted HCC cDNA library / Chapter 3.8 --- Differential hybridization of subtracted cDNA clones / Chapter Chapter 4 --- Discussions --- p.90 / Chapter 4.1 --- Characterization of the ESTs generated from human normal liver cDNA library / Chapter 4.2 --- EST analysis on subtracted HCC cDNA clones / Chapter 4.3 --- Candidate genes differentially expressed in HCC / Appendix A The coordinates of dot blots (in numerical order according to clone numbers) / Appendix B The coordinates of dot blots (in alphabetical order according to putative identity) / References --- p.124

by Cheung Yuk Yin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves xx-xxviii). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / 摘要 --- p.iii / Table of Content --- p.iv / Abbreviations / for Amino Acids --- p.viii / for Standard Genetic Code --- p.ix / for Units --- p.x / for Prefixes --- p.xi / for Terms commonly used in the report --- p.xii / List of Figures --- p.xiii / List of Tables --- p.xiv / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Epidemiology of Hepatitis B Virus (HBV) --- p.1 / Chapter 1.2 --- Relationship between Hepatitis B Virus and Hepatocellular Carcinoma --- p.2 / Chapter 1.3 --- Brief Description of HBV Genome --- p.2 / Chapter 1.4 --- Possible Roles of HBx in Hepatocellular Carcinoma --- p.4 / Chapter 1.5 --- Novel Interacting Partner of HBx - HBx-lnteracting Protein (XIP) --- p.6 / Chapter 1.6 --- Objective --- p.6 / Chapter Chapter 2 --- Methodology / Chapter 2.1 --- Information of the HBx and XIP Clones --- p.7 / Chapter 2.2 --- "Information of the Expression Vectors (pRSETA, 6xHis-pRSETA and pET8C)" --- p.7 / Chapter 2.3 --- Sub-Cloning of HBx and XIP into Different Vectors --- p.9 / Chapter 2.3.1 --- Design of Primers for Cloning of HBx and XIP into Different Vectors --- p.9 / Chapter 2.3.2 --- Polymerase Chain Reaction (PCR) Protocol --- p.12 / Chapter 2.3.3 --- Enzyme Digestion Reaction Protocol --- p.14 / Chapter 2.3.4 --- Ligation Protocol --- p.16 / Chapter 2.3.5 --- Preparation of Competent Cells --- p.17 / Chapter 2.3.6 --- Transformation --- p.18 / Chapter 2.3.7 --- Gel Extraction Protocol --- p.19 / Chapter 2.3.7.1 --- Life Technologies CONCERT´ёØ Rapid Gel Extraction System --- p.19 / Chapter 2.3.7.2 --- QIAGEN Gel Extraction Kit --- p.20 / Chapter 2.3.8 --- Plasmid Preparation Protocol --- p.22 / Chapter 2.3.8.1 --- Life Technologies CONCERT´ёØ Rapid Plasmid Minipreps --- p.22 / Chapter 2.3.8.2 --- QIAGEN Plasmid Maxi Kit --- p.23 / Chapter 2.4 --- Expression of HBx and XIP in E. coli Strain C41 (DE3) --- p.25 / Chapter 2.4.1 --- Transformation --- p.25 / Chapter 2.4.2 --- Expression of HBx and 6xHis-HBx in E. coli Strain C41 (DE3) --- p.26 / Chapter 2.4.3 --- Expression of XIP in E. coli Strain C41 (DE3) --- p.27 / Chapter 2.5 --- Preparation of Buffers for Chromatography and Circular Dichroism Spectrum Measurement --- p.28 / Chapter 2.6 --- Purification and Refolding of HBx and His-Tagged HBx --- p.28 / Chapter 2.6.1 --- Washing of HBx and His-Tagged HBx Inclusion Bodies --- p.28 / Chapter 2.6.2 --- His-Tagged HBx Purification by Affinity Chromatography --- p.29 / Chapter 2.6.3 --- HBx Purification by Size Exclusion Chromatography --- p.30 / Chapter 2.6.4 --- Refolding of HBx and His-Tagged HBx by Oxidative Dialysis --- p.30 / Chapter 2.7 --- Purification of XIP --- p.33 / Chapter 2.7.1 --- Screening of Chromatographic Conditions for the Purification of XIP --- p.33 / Chapter 2.7.2 --- XIP 1st Step of Purification by Hydrophobic Interaction Chromatography --- p.34 / Chapter 2.7.3 --- XIP 2nd step of Purification by Size Exclusion Chromatography --- p.34 / Chapter 2.8 --- Chemical Denaturation Experiment of HBx and XIP --- p.36 / Chapter 2.8.1 --- Preparation of Urea Buffers for the Chemical Denaturation of HBx --- p.37 / Chapter 2.8.2 --- Preparation of Different GdnHCI Buffer for the Chemical Denaturation of XIP --- p.38 / Chapter 2.8.3 --- Calculation for Chemical Denaturation Experiment --- p.39 / Chapter 2.8.3.1 --- Protein Concentration Calculation --- p.39 / Chapter 2.8.3.2 --- Residual Molar Elipticity Calculation --- p.39 / Chapter 2.8.3.3 --- Free Energy Change (ΔGu) Calculation --- p.40 / Chapter 2.9 --- Two-dimensional Heteronuclear Nuclear Magnetic Resonance (NMR) Experiment --- p.41 / Chapter 2.10 --- Interaction Confirmation between HBx and XIP --- p.42 / Chapter 2.10.1 --- "Transfection of pEGFP, pEGFP-HBx and pEGFP-XIP into HepG2" --- p.42 / Chapter 2.10.2 --- Yeast Two Hybrid System for Confirmation of HBx and XIP Interaction --- p.44 / Chapter 2.10.2.1 --- Preparation of Y187 Competent Cells --- p.44 / Chapter 2.10.2.2 --- Transformation of pGBKT7-HBx and pACT2-XIP into Y187 --- p.45 / Chapter 2.10.2.3 --- β-galactosidase Colony Lift Assay --- p.46 / Chapter Chapter 3 --- "Expression, Purification and Characterization of Hepatitis B Virus X Protein (HBx)" / Chapter 3.1 --- Introduction --- p.47 / Chapter 3.2 --- Construction of Recombinant HBx-pRSETA and 6xHis-HBx-pRSETA Plasmids --- p.48 / Chapter 3.3 --- Expression of 6xHis-HBx in E. coli C41 (DE3) using M9ZB Medium --- p.52 / Chapter 3.4 --- Expression of HBx in E. coli C41 (DE3) using M9ZB Medium --- p.54 / Chapter 3.5 --- Purification and Refolding of 6xHis-HBx Fusion Proteins --- p.56 / Chapter 3.6 --- Purification and Refolding of HBx Proteins --- p.60 / Chapter 3.7 --- Structural Characterization of Refolded HBx --- p.65 / Chapter 3.7.1 --- Introduction --- p.55 / Chapter 3.7.2 --- Experimental Analysis of HBx Secondary Structure --- p.66 / Chapter 3.7.3 --- Chemical Unfolding Experiment of HBx --- p.68 / Chapter 3.8 --- Discussion --- p.70 / Chapter 3.8.1 --- "HBx was Expressed, Purified and Characterized instead of 6xHis-HBx" --- p.71 / Chapter 3.8.2 --- High Concentration of DTT was used to Minimize Formation of HBx Aggregates --- p.72 / Chapter 3.8.3 --- Oxidative Refolding to Ensure Proper Disulfide Bond Formation --- p.73 / Chapter 3.8.4 --- Computational Prediction and Experimental Prediction of Secondary Structure of HBx --- p.75 / Chapter 3.9 --- Concluding Remarks --- p.77 / Chapter Chapter 4 --- "Expression, Purification and Characterization of HBx-lnteracting Protein (XIP)" / Chapter 4.1 --- Introduction --- p.78 / Chapter 4.2 --- Construction of Recombinant XIP-pET8C --- p.78 / Chapter 4.3 --- Expression of XIP in E. coli C41 (DE3) using M9ZB and M9 Mediums --- p.82 / Chapter 4.4 --- Screening of Chromatographic Conditions for the Purification of XIP --- p.83 / Chapter 4.4.1 --- Introduction --- p.83 / Chapter 4.4.2 --- Purification Details --- p.83 / Chapter 4.5 --- Purification of XIP by HiTrap Phenyl HP 5-ml Column --- p.87 / Chapter 4.6 --- Purification of XIP by HiLoad 26/60 Superdex 75 Prep Grade --- p.89 / Chapter 4.7 --- Structural Characterization of XIP --- p.92 / Chapter 4.7.1 --- CD Spectrum --- p.92 / Chapter 4.7.2 --- Chemical Denaturation Experiment of XIP --- p.93 / Chapter 4.7.3 --- Two-Dimensional Heteronuclear Nuclear Magnetic Resonance (NMR) Spectrum of 15N Labeled XIP --- p.95 / Chapter 4.8 --- Discussion --- p.97 / Chapter 4.8.1 --- Purification Method Development --- p.97 / Chapter 4.8.2 --- "Do Different Protein Cosolutes, Protein Stabilizers and Detergents Help XIP to Adopt a Stable Conformation?" --- p.99 / Chapter 4.9 --- Concluding Remarks --- p.101 / Chapter Chapter 5 --- In vivo Studies of HBx and XIP Interactions / Chapter 5.1 --- Investigation of Sub-Cellular Localization of HBx and XIP in Liver Cells --- p.102 / Chapter 5.1.1 --- Introduction --- p.102 / Chapter 5.1.2 --- "Construction of Recombinant HBx-pECFP-C1, HBx-pEGFP-C1, HBx-pEYFP-C1 and XIP-pECFP-C1, XIP-pEGFP-C1, XIP-pEYFP-C1" --- p.103 / Chapter 5.1.3 --- Transfection of pEGFP-C1 HBx and pEGFP-C1 XIP into HepG2 to Find Out HBx and XIP Sub-Cellular Localization --- p.106 / Chapter 5.1.3.1 --- Introduction --- p.107 / Chapter 5.1.3.2 --- Investigation of EGFP Proteins Expression using the Confocal Microscope and the Leica TCS Software --- p.108 / Chapter 5.1.4 --- Discussion and Future Prospects --- p.111 / Chapter 5.2 --- Interaction of HBx and XIP Studied by Yeast Two-Hybrid System --- p.113 / Chapter 5.2.1 --- Introduction --- p.113 / Chapter 5.2.2 --- Construction of Recombinant HBx-pGBKT7 and XIP-pACT2 Plasmids --- p.114 / Chapter 5.2.3 --- Confirmation of HBx and XIP Interaction by Yeast Two-Hybrid System --- p.117 / Chapter 5.2.4 --- Discussion --- p.121 / Chapter Chapter 6 --- Conclusion --- p.123 / Appendix I Sequence of HBx and XIP --- p.I / Chapter II --- Vector Sequences --- p.II / Chapter III --- Vector Maps --- p.VI / Chapter IV --- Electrophoresis Markers --- p.XI / Chapter V --- Agarose Gel Electrophoresis --- p.XII / Chapter VI --- SDS-PAGE Eectrophoresis --- p.XIII / Chapter VII --- Medium for Bacterial Culture --- p.XV / Chapter VIII --- Medium for Cell Culture --- p.XVII / Chapter IX --- Medium for Yeast Culture --- p.XVIII / Chapter X --- Buffers for Yeast Transformation --- p.XIX / Reference --- p.XX

by Ray, Kit Ng. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 112-121). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgments --- p.iv / Abbreviations --- p.x / List of Figures --- p.xii / List of Tables --- p.xiv / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Hepatitis B Virus (HBV) --- p.1 / Chapter 1.2 --- Hepatitis B Virus X Protein (HBx) --- p.5 / Chapter 1.2.1 --- The Genomic Structure of HBx --- p.5 / Chapter 1.2.2 --- The HBx Protein Structure --- p.6 / Chapter 1.2.3 --- Subcellular Localization of HBx --- p.7 / Chapter 1.2.4 --- Possible Functions of HBx --- p.8 / Chapter 1.3 --- Etiology of Hepatocellular Carcinoma (HCC) --- p.12 / Chapter 1.4 --- Relationship between HCC and HBx --- p.13 / Chapter 1.5 --- Aims of Study --- p.14 / Chapter 1.6 --- The Basis of Tet-On System --- p.15 / Chapter 1.7 --- The Basis of DNA Microarray --- p.18 / Chapter 1.8 --- The Basis of Two-Dimensional Electrophoresis --- p.20 / Chapter Chapter 2 --- Materials and Methods / Chapter 2.1 --- Construction of a Tet-On HBx Expressing Cell Model --- p.22 / Chapter 2.1.1 --- Cloning of HBx Gene into pTRE2 Vector --- p.22 / Chapter 2.1.1.1 --- PCR of HBx Gene --- p.22 / Chapter 2.1.1.2 --- Purification of the PCR Product --- p.23 / Chapter 2.1.1.3 --- Restriction Enzyme Digestion --- p.23 / Chapter 2.1.1.4 --- Ligation of HBx into pTRE Vector --- p.24 / Chapter 2.1.1.5 --- Transformation of the Ligation Product into Competent Cells --- p.24 / Chapter 2.1.2 --- Preparation of the Plasmid DNA --- p.24 / Chapter 2.1.2.1 --- DNA Sequencing of the Cloned Plasmid DNA --- p.25 / Chapter 2.1.3 --- Cell Culture of AML12 Cell Line --- p.26 / Chapter 2.1.4 --- Transfection of pTet-On Vector into AML12 Cells --- p.26 / Chapter 2.1.5 --- Selection of the Transfected AML12 Cells by G418 --- p.27 / Chapter 2.1.6 --- Single Clone Isolation --- p.27 / Chapter 2.1.6.1 --- Luciferase Assay for Selection of Highly Inducible Clones --- p.28 / Chapter 2.1.7 --- Second Transfection of pTRE-HBx Plasmid --- p.28 / Chapter 2.1.8 --- Selection of the Transfected Cells by Hygromycin --- p.29 / Chapter 2.1.9 --- Second Single Clone Isolation --- p.29 / Chapter 2.1.10 --- Total RNA Isolation --- p.29 / Chapter 2.1.11 --- DNase I Digestion --- p.30 / Chapter 2.1.12 --- First-Strand cDNA Synthesis --- p.31 / Chapter 2.1.13 --- RT-PCR of HBx Gene --- p.31 / Chapter 2.1.14 --- Northern Blotting --- p.32 / Chapter 2.1.15 --- Preparation of the Probe --- p.33 / Chapter 2.1.16 --- Northern Blot Hybridization --- p.33 / Chapter 2.1.17 --- 3H-Thymidine Incorporation Assay --- p.34 / Chapter 2.1.18 --- Analysis of Cell Cycle by Flow Cytometry --- p.35 / Chapter 2.2 --- Microarray Analysis of Differential Gene Expression upon HBx Induction --- p.35 / Chapter 2.2.1 --- Sample Preparation for Microarray Analysis --- p.35 / Chapter 2.2.2 --- Probe Labelling --- p.36 / Chapter 2.2.3 --- Microarray Hybridization --- p.37 / Chapter 2.2.4 --- RT-PCR of the Candidate Genes --- p.38 / Chapter 2.2.5 --- Northern Blot Analysis of the Candidate Genes --- p.39 / Chapter 2.3 --- Two-Dimensional (2D) Gel Electrophoretic Analysis --- p.40 / Chapter 2.3.1 --- Protein Sample Preparation for 2D Gel Electrophoresis --- p.40 / Chapter 2.3.2 --- First-Dimension Isoelectric Focusing (IEF) --- p.40 / Chapter 2.3.3 --- Second-Dimension SDS-PAGE --- p.41 / Chapter 2.3.4 --- Silver Stain of 2D Gel --- p.42 / Chapter 2.3.5 --- Mass Spectroscopic Analysis --- p.43 / Chapter 2.4 --- Subcellular Localization of HBx --- p.44 / Chapter 2.4.1 --- Cloning of HBx into Green Fluorescent Protein (GFP) Expression Vector --- p.44 / Chapter 2.4.2 --- Transfection of GFP-HBx --- p.44 / Chapter 2.4.3 --- Propidium Iodide (PI) Staining --- p.45 / Chapter 2.4.4 --- Mitochondria Staining --- p.45 / Chapter 2.4.5 --- Subcellular Localization Study using Epi-Fluorescent Microscopy --- p.45 / Chapter 2.5 --- Analysis of Mitochondrial Transmembrane Potential --- p.46 / Chapter Chapter 3 --- Results / Chapter 3.1 --- Construction of Tet-On AML12 Cell Line of HBx Gene --- p.47 / Chapter 3.2 --- Characterization of the HBx-Expressing Cell Model --- p.53 / Chapter 3.2.1 --- 3H-Thymidine Proliferation Assay --- p.53 / Chapter 3.2.2 --- Cell Cycle Analysis --- p.55 / Chapter 3.3 --- Microarray Analysis of Differential Gene Expression Pattern upon HBx Induction --- p.57 / Chapter 3.4 --- Northern Blot Analysis and RT-PCR of the Candidate Genes --- p.65 / Chapter 3.5 --- Differential Protein Expression Pattern under HBx Induction --- p.70 / Chapter 3.6 --- Subcellular Localization of HBx --- p.77 / Chapter 3.7 --- Analysis of Mitochondrial Transmembrane Potential --- p.83 / Chapter Chapter 4 --- Discussion / Chapter 4.1 --- Conditional HBx-Expressing Cell Model --- p.84 / Chapter 4.2 --- The Effects of HBx in Clone X18 --- p.86 / Chapter 4.2.1 --- Proliferative Effect of HBx --- p.86 / Chapter 4.2.2 --- Deregulation of G2/M Checkpoint by HBx --- p.86 / Chapter 4.3 --- Early Differential Gene Expression due to HBx Induction --- p.88 / Chapter 4.4 --- The Relationship of the Potential Candidate Genes and Cancer Development --- p.90 / Chapter 4.5 --- The Protein Expression Pattern due to HBx Induction --- p.93 / Chapter 4.6 --- The Subcellular Localization of HBx --- p.96 / Chapter 4.7 --- The Possible Involvement of HBx in Mitochondrial Transmembrane Potential --- p.98 / Chapter 4.8 --- Conclusions --- p.101 / Chapter 4.9 --- Future Prospects --- p.104 / Appendix --- p.107 / References --- p.112