Dissertations / Theses on the topic 'CCCDCC'
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Mouzannar, Karim. "Identification du récepteur nucléaire des acides biliaires FXR alpha comme facteur proviral pour le virus de l’hépatite B." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1098/document.
Full textHepatitis B virus (HBV) infection is a major global health problem with more than 257 million chronic carriers worldwide that remain at significant risk for developing cirrhosis and/or hepatocellular carcinoma. The natural history of infection is very different depending on the age at which the infection is contracted. Whereas in adults most HBV infections spontaneously resolve, in infants and young children they usually result in chronic infection. cccDNA is the molecular form of viral persistence in infected hepatocytes and serves as a transcription template for all viral RNAs. The viral protein HBx plays a crucial role in the recruitment of epigenetic factors to the cccDNA and promotes its transcriptional activity. Currently, interferon and nucleot(s)ide analogues are the first-line agents in the treatment of chronic hepatitis B without allowing eradication of cccDNA and their interruption are almost always followed by a reactivation of the replication of the virus. New therapeutic molecules targeting cccDNA are therefore needed to hope for a functional cure in chronically infected patients. HBV infection and bile acid (BA) metabolism are tightly linked. Therefore, our team has previously shown that the bile acid nuclear receptor, the farnesoid X receptor alpha (FXRalpha) bind to two response elements present in the Enhancer II - Core promoter region of HBV genome and modulate its transcriptional activity. Moreover, HBV and BA compete for the same entry receptor of hepatocytes NTCP and modify BA cell concentration with consequences on the function and expression of FXRalpha. Finally, HBx interacts with FXRalpha and modify its activity. During my PhD. we have first identified a reciprocal regulation between HBV replication and FXRalpha. Second, we have showed in vitro, in HepaRG differentiated cells and in primary human hepatocytes, that FXRalpha is a proviral factor for HBV and that FXRalpha agonists inhibit the expression of all HBV markers in a dependent or independent manner of the viral protein HBx. Finally, in an in vivo model of C3H/HeN mice transduced with a recombinant AAV2/8-HBV vector, we obtained the inhibitory effect of FXRalpha agonists but only in adult and not in young mice. Considering the evolution of the gut flora with age and its importance in the metabolism of BA, these results suggest that the high rate of chronic progression in young children might be related to the immaturity of BA metabolism. The identification of a link between BA metabolism, gut microbiome composition and evolution of HBV infection will represent a big step toward the understanding of HBV natural history. Moreover, the identification of FXRalpha as a proviral factor for HBV and the capacity of FXRalpha ligands to modulate the transcriptional activity of cccDNA suggest that FXR ligands might represent a new class of molecules with the aim to obtain functional cure for HBV infected patients
竹内, 文彦. "レンチウイルスを用いたB型肝炎cccDNA阻害剤の探索." Kyoto University, 2019. http://hdl.handle.net/2433/242927.
Full textOfor, Okezie O. "Characterisation of novel protein partners of the CCCTC-binding factor in breast cancer cell lines." Thesis, Anglia Ruskin University, 2015. http://arro.anglia.ac.uk/701472/.
Full textOfor, Okezie O. "Characterisation of novel protein partners of the CCCTC-binding factor in breast cancer cell lines." Thesis, Anglia Ruskin University, 2015. https://arro.anglia.ac.uk/id/eprint/701472/1/Ofor_2015.pdf.
Full textBroja, Tim [Verfasser], and Jörg [Akademischer Betreuer] Petersen. "Untersuchungen der replikativen Aktivität der cccDNA in vivo in ruhenden und proliferierenden Hepatozyten mithilfe des uPA Mausmodelles / Tim Broja. Betreuer: Jörg Petersen." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2012. http://d-nb.info/1023947382/34.
Full textLENCI, ILARIA. "New strategies on management of hepatitis b virus after liver transplantation: complete and sustained weaning of hbv prophylaxis in a selected cohort of patients transplanted due to hbv-related cirrhosis." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2009. http://hdl.handle.net/2108/208923.
Full textBackground and Aim: HBV reactivation after liver transplantation is due to the persistence of covalently closed circular (ccc) DNA. We investigated the safety of HBV prophylaxis withdrawal in transplanted patients negative for intrahepatic total and ccc-DNA. Methods: thirty HBsAg-positive, HBeAg and HBV-DNA-negative patients at transplant, with undetectable intrahepatic total and ccc-DNA underwent HBIG withdrawal and were continued on lamivudine with monthly monitoring. After 6 months, a second liver biopsy was obtained: patients with confirmed total and ccc-DNA negativity also underwent lamivudine withdrawal and were monitored for additional 6 months, when a third biopsy was obtained. Patients negative for all virological assays were followed-up without prophylaxis for up to 2 years. Results: Twenty-five patients had undetectable total and ccc-DNA in all sequential biopsies and did not exhibit HBV reinfection after a median follow-up of 25.2 months following lamivudine withdrawal. Five patients became HBsAg-positive: one early, after HBIG withdrawal,the other 4 after lamivudine withdrawal. None of these had clinically relevant events. In the first patient HBIG were reinstituted with prompt HBsAg negativization. Of the other 4, only one remained HBsAg-positive with detectable HBV-DNA and mild ALT elevation, and was given tenofovir. In the remaining 3, HBsAg positivity was transient and followed by anti-HBs seroconversion. No antiviral treatment was given to these patients. Conclusions: Patients with undetectable HBV viremia at transplant and undetectable intrahepatic total and cccDNA may undergo cautious weaning of prophylaxis. A minority of them experience transient HBsAg positivization, without clinical or virological events, and some undergo spontaneous anti-HBs seroconversion.
Fournier, Maëlenn. "Implication du gène core dans l'accumulation de l'ADN circulaire clos de façon covalente du virus de l'hépatite B." Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10058/document.
Full textThe feature of hepatitis B virus is the synthesis of a covalently closed circular DNA (cccDNA) which is the persistence form of the virus in cell. cccDNA is maintained to 1 copy per human cell thanks to the recycling of capsids into the nucleus. Indeed, during the viral cycle, capsids are either transported into the nucleus to form cccDNA or enveloped and secreted to form new infectious virions. Because of its maintenance in the hepatocyte, cccDNA formation and regulation are still key elements of antiviral treatment. It has been shown that, in vitro, cccDNA accumulation was regulated by envelope proteins. Upon the study of cccDNA levels in liver biopsies of HIV-HBV co-infected patients, an individual with a cccDNA level 300 fold higher than the average of the cohort was identified. My thesis objective was to understand which is the mechanism leading to the cccDNA accumulation observed in vivo. This allowed us to highlight the role of core gene in cccDNA accumulation
Lee, Rory Amundson. "Addressing the situation an analysis of the CCCC Chairs' Addresses of the last 11 Years (1998-2008) /." Tallahassee, Florida : Florida State University, 2009. http://etd.lib.fsu.edu/theses/available/etd-07132009-125559/.
Full textAdvisor: Kathleen Yancey, Florida State University, College of Arts and Sciences, Dept. of Englsih. Title and description from dissertation home page (viewed on Oct. 28, 2009). Document formatted into pages; contains viii, 100 pages. Includes bibliographical references.
Ren, Shaotang. "Hepatitis B virion and cccDNA formation in primary tupaia hepatocytes and human hepatoma cell lines upon HBV genome transduction with replication defective adenovirus vectors and in vivo infection of tupaias." [S.l.] : [s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=961156007.
Full textLocatelli, Maëlle. "The histone chaperone HIRA is crucial for the early establishment of hepatitis B virus minichromosome." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1169/document.
Full textHepatitis B virus (HBV) chronically infects 240 million people worldwide and is the major cause of hepatocellular carcinoma (HCC). Currently standard-of-care treatments can achieve longterm viral suppression, but are not able to completely eliminate the virus, due to the persistence of the covalently closed circular DNA (cccDNA). cccDNA, the viral minichromosome, resides in the nucleus of infected hepatocytes by virtue of its chromatin structure. Indeed, upon entry into hepatocytes, the partially double stranded viral DNA (relaxed circular (rc)DNA) is released into the nucleus, where it is repaired and wrapped by histones to form an episomal chromatinized structure. The mechanisms leading to cccDNA formation and chromatinization are still largely unknown and their elucidation would be a first step toward the identification of new therapeutic targets to impair cccDNA persistence. To this aim, we investigated the role of host factors belonging to DNA repair and nucleosome assembly pathways in cccDNA formation at early time points (i.e. between 30 minutes and 72 hours) post-infection in both HepG2-NTCP cell line and Primary Human Hepatocytes (PHH). We particularly focused on the histone chaperone Hira, which is known to deposit histone variant 3.3 (H3.3) onto cellular DNA in a replication-independent manner and in association to nucleosome reshuffling during transcription and DNA repair. We were able to detect cccDNA in the nuclear fraction of hepatocytes as early as 30 minutes and 24h post-infection, by qPCR and Southern Blotting (SB), respectively. Knock-down of Hira by RNA interference before virus inoculation led to a strong decrease in cccDNA accumulation (both in qPCR and SB) which was independent from HBx protein expression (using an HBx defective virus). rcDNA levels remained stable, indicating either a possible incomplete or delayed rcDNA to cccDNA transition. Chromatin Immunoprecipitation analysis showed that Hira was bound to cccDNA already at 2 hours post-infection and that its recruitment was concomitant with the deposition of histone H3.3 and the binding of HBV capsid protein (HBc). After 24 hours of infection, an increase of H3.3 and Pol2 binding on cccDNA was observed, correlating with the initiation of the transcription of the 3.5 kb RNA. By Co-Immunoprecipitation and Proximity Ligation Assay experiments, we showed that Hira was able to interact with HBc in infected hepatocytes and in a HepaRG cell line expressing HBc in an inducible manner. Altogether, our results suggest that chromatinization of incoming viral DNA is a very early event, requiring the histone chaperone Hira. While HBx is not required for this process, HBc could play a major role, suggesting that the interaction between Hira and HBc could represent a new therapeutic target to be investigated
Surridge, Karen Suzanne. "Do individuals in mental health neurological outpatient and non-clinical populations have distinct profiles on the common cognitive complaints checklist (CCCC)?" Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4143/.
Full textWreyford, Natalie Louise. "The gendered contexts of screenwriting work : socialized recruitment and judgments of taste and talent in the UK film industry." Thesis, King's College London (University of London), 2016. https://kclpure.kcl.ac.uk/portal/en/theses/the-gendered-contexts-of-screenwriting-work(41c1b788-cccd-4a41-bf31-0a6d0fd05b4d).html.
Full textQuioc-Salomon, Barbara. "Rôle de la protéine HBC du virus de l'hépatite B sur la biologie des ARN viraux." Thesis, Université de Paris (2019-....), 2019. https://theses.md.univ-paris-diderot.fr/QUIOC_SALOMON_Barbara_va.pdf.
Full textChronic HBV carriers (CHB) are at high risk of developing hepatocellular carcinoma. Because covalently closed circular DNA (cccDNA) persists in infected cells through RNA expression, deciphering the mechanisms involved in RNA transcription and stability is a crucial step to identify new antiviral targets. In addition to its role in capsid formation, HBV core protein (HBc) has been shown to be associated with the cccDNA and to modulate its structure, yet the impact of this modification on HBV transcription is not fully understood. To better understand the role of HBc in this context we constructed several mutants deficient for HBc expression. The first mutant has two stop codons after codon 27 in HBc followed by a substitution of the HBc sequence by a sequence encoding different epitopes. During infection, this virus shows a strong decrease in expression of viral RNA, which cannot be rescued by re-expression of HBc. The quantification of nascent RNAs shows that the defect appears to be post-transcriptional and is present as early as 2h after transcription. These results suggest that the observed defect is independent of HBc and that the deleted sequence in the HBV genome of this mutant could be involved in a post-transcriptional regulatory mechanism. With this mutant, we have been able to demonstrate that the HBc protein provided by the capsid during infection is able to re-associate onto the cccDNA in the nucleus. We then studied HBc mutants generated in the context of the the wild-type virus sequence, without the substitution. When expressed from a plasmid expressing both the genome and the HBc protein under the control of SV40 promoter, we observe a decrease of the pgRNA expression for mutants having the stop codons after the 27th or 38th codon of HBc, but not when the stop codon is located after the 67th codon. These results suggest that displacement of the HBc stop codon induces a decrease in pgRNA expression, independently of HBc protein, and that the natural stop codon of HBc could be protected from viral RNA surveillance pathways such as nonsense-mediated decay (NMD) that recognizes RNAs with a premature stop codon. During infections with these viruses, and therefore in the absence of HBc, we observed an increased in the defect for viruses having stop codons at position 27 and 38 and a defect appears for a virus having the stop codon at position 67. In this context, in the absence of HBc, we have seen that RNAs encoding surface proteins are also impacted and that RNA expression can be partially restored by HBc expression. By chromosome conformation capture techniques we were able to observe that the HBc-27* HBV virus is no longer excluded from repressed regions associated with lamins, indicating that the HBc protein could be involved in the localization of the cccDNA at active chromatin regions favorable for transcription.In order to understand the mechanisms involved in HBc regulation, we have isolated the nuclear partners of HBc and highlighted many factors involved in the RNA and DNA regulation, in the DNA damage repair and RNA processing.Overall, our results shed light on the regulatory mechanisms of HBV RNA biology
Marquezini, Diego Dias. "Interação entre conversores chaveados com baixa ondulação e células de combustível." Universidade Federal de Santa Maria, 2007. http://repositorio.ufsm.br/handle/1/8530.
Full textEsta dissertação discute a interação entre as células de combustível e o conversor de potência conectado aos seus terminais. Para isto é apresentado um algoritmo modificado para a modelagem dinâmica de conversores chaveados tanto quanto um estudo sobre os efeitos das ondulações de corrente sobre as células. Células do tipo PEM (Proton Exchange Membrane) são estudadas, obtendo-se um modelo razoável para análise das características eletroquímicas e elétricas dos fenômenos envolvidos na geração de energia elétrica com células de combustível. Como interface utiliza-se um conversor CC-CC associado a um filtro do tipo T . Este conversor tem a função de evitar a grande ondulação de corrente absorvida pela célula bem como, manter constante o fluxo de potência entre a FC e o barramento CC evitando-se assim, possíveis transitórios nos terminais da célula. O projeto do conversor de potência prevê a conexão à rede da concessionária através de um conversor CC-CA trifásico para injetar ou absorver corrente da rede com reduzida distorção harmônica e estabilização da tensão do barramento CC. Foram projetados controladores para a corrente CC, a tensão CC e a corrente CA. Como formas de validação foram realizadas simulações para avaliar o comportamento dos sistemas de controle para a pilha e para a injeção e/ou absorção de energia. Também foram comparados os resultados teóricos com os dados práticos de uma pilha submetida à variação de carga em seus terminais.
Khawaja, Ghada. "Évaluation d’une nouvelle approche vaccinale basée sur l’électroporation in vivo d’ADN pour le traitement des hépatites B chroniques." Thesis, Lyon 1, 2012. http://www.theses.fr/2012LYO10045.
Full textDespite the existence of an effective prophylactic vaccine, chronic hepatitis B virus (HBV) infection remains a major public health problem. Since persistence of HBV infection is mostly associated with insufficient immune responses, therefore DNA vaccination capable of activating both humoral and cellular immune responses appears as a pertinent strategy for chronic hepatitis B therapy. However, the efficacy of such therapeutic approach remains limited in humans. Improvement of DNA vaccine efficacy is therefore needed for future therapeutic applications in clinic. The main objective of this thesis was to investigate in the duck hepatitis B virus (DHBV) model, whether the protective and therapeutic efficacy of DNA vaccine can be enhanced using EP-based delivery system. Firstly, we showed in naïve ducks that EP-based delivery was able to improve the dose efficiency of DNA vaccine and to maintain a highly neutralizing, multi-specific B-cell response even with relatively low DNA doses, suggesting that it may be an effective approach for chronic hepatitis B therapy at clinically feasible DNA dose. Secondly, we showed in chronic DHBV-carriers that in vivo EP is able to dramatically enhance the therapeutic potency of DNA vaccine targeting hepadnaviral proteins. Indeed, this approach was able to consistently restore humoral immune response and to sustainably decrease and even clear viral infection. Thus, these data strongly support the use of this approach for chronic hepatitis B therapy in humans
Chapus, Fleur. "Role of the DEAD-box Helicases DDX5 and DDX17 in Hepatitis B Virus RNA processing." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSE1098.
Full textRole of the DEAD-box helicases DDX5 and DDX17 in HBV transcriptional regulation and RNA processingChronicity of hepatitis B virus (HBV) infection hinges on the persistence of covalently-closed-circular DNA (cccDNA) in the nucleus of infected hepatocytes. The viral genome associates with histones and non-histone proteins to build a chromatin structure that is subjected to epigenetic regulation translating into different levels of biological activity. A better understanding of the host factors orchestrating HBV minichromosome transcriptional regulation and RNA processing is fundamental for deciphering the mechanisms at the basis of HBV persistence and reactivation. In order to identify the cellular factors regulating cccDNA biology, an ambitious project of cccDNA proteomics (ChroP) has been initiated by Dr. Barbara Testoni. Among the identified cccDNA-associated proteins, the DEAD-box RNA helicases DDX5 and DDX17 particularly interested us for their driving role in mammalian transcriptional regulation and RNA metabolism. Thus, we investigated their role in cccDNA transcriptional activity regulation and HBV RNA processing. Precise characterization of HBV transcripts was performed with a 5' RACE approach set up and published in our lab by Dr. Bernd Stadelmayer. This technique was applied to study viral transcript in a context of DDX5/17 depletion. Furthermore, DDX5/17 belong to the insulator complex CCCTC-binding protein (CTCF). We therefore investigated the role of CTCF in cccDNA biology and viral RNA metabolism. In HBV infected HepG2-NTCP and Primary Human Hepatocytes, siRNA knockdown of DDX5/17 led to a shortening of all the viral transcripts, together with an increase in viral transcript levels and viral particles accumulation in the cytoplasm, without affecting the global level of cccDNA. Next and third generation sequencing allowed the identification of alternative splicing of pgRNA-derived spliced variants and differential usage of polyadenylation site during HBV RNA transcription. Moreover, RNA immunoprecipitation of DDX5 and DDX17 revealed that both of these proteins are directly associated to the viral transcripts and recruit two factors, CPSF6 and NUDT21, involved in alternative polyadenylation site choice. Moreover, we identified CTCF binding sites on HBV genome and by site directed mutagenesis we showed that mutations in CTCF binding sites affect CTCF and DDX5/17 recruitment to cccDNA and subsequently impact HBV RNA processing. Altogether, our data highlight an essential role of DDX5 and DDX17 in the fine tuning of HBV RNA processing, in complex with the insulator protein CTCF and termination factors at the interface between cccDNA and HBV transcripts
BHARTI. "A NOVEL DTMOS BASED CCCDCC WITH ITS APPLICATIONS." Thesis, 2019. http://dspace.dtu.ac.in:8080/jspui/handle/repository/16729.
Full textTSENG, CHIA-WEI, and 曾家維. "The research of“the supernatural phenomenon”in "The Gods"." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/ccc3ca.
Full text玄奘大學
中國語文學系碩士在職專班
104
Abstract "The Gods"from Xu Xuan is a collection of Zhiguai XiaoShuowhich is about spirits. It brought down the root of Six Dynasties and Chinese, while opening for the trend of sketch-novel after Song Dynasty. This thesis will study the representation of different contexts phenomenon. This paper first discoursed the writer of "The Gods", his family story, evaluation and formation of the book. To understand the course of compiling "The Gods" by finding out the growth background of Xu Xuan. He was a simple, lenient man with few desires. As born in a queasy time between Five Dynasties and Song Dynasty, therefore he had been demoted for three times in his lifetime. Since the status of demoted minister, he was always trembling. Secondly, research about dreams in "The Gods" would be discoursed as well. Dreams, are mysterious, unpredictable and inseparable with human kinds since long time ago. From the research of dreams in "The Gods", it was believed that dream was the communication bridge which connected human and gods. Besides, fame and fortune were controlled by gods while living time of human was already fixed. After that, the book discussed the supernatural faith in Five Dynasties from "The Gods". This chapter discussed the relation of spirits and religion, as spirits were usually used by religion to promote doctrine. Both Taoism and Buddhism believed in Karma and Buddhist has even developed‘The Six Samsara’ cogitation. By the spirits and ghosts in "The Gods",it has an alternative beauty experience. "The Gods" recorded rare but real animals. By the fantastic and eccentric stories in "The Gods",it presents the earthling chasing for wealth. Finally, the conclusion is that the "The Gods" written by Xuan Xu having deep religious meanings and being a classic of the Supernatural Stories in the early Song Dynasty. It impacts the later novels of gods and spirits, and has an important place in the development history of the novels.
Hung-ChengKo and 柯泓丞. "A Study of the Internet Services of Smart Vehicles Based on Technology Acceptance Model." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/cccpch.
Full textLiu, Yu-Chih, and 柳育志. "Establishment of Hepatitis B Virus cccDNA-producing Lines and Its Applications." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/14489670687144579283.
Full text國立陽明大學
微生物暨免疫學研究所
89
Chronic hepatitis B (CHB) is one of the most serious viral infections in humans worldwide. Virus persistence in CHB patient relies on maintaining a pool of covalently closed circular DNA (cccDNA) in the nuclei of infected hepatocytes, which presumably is the template of HBV gene expression. (-)-2’, 3’-thiacytidine (lamivudine; 3TC), an approved oral drug, is a nucleoside analogue which effectively inhibits the replication of HBV in CHB patients. However, it has been showed that cessation of drug treatment resulted in rapid rebound of HBV DNA in the patients’ sera. In vitro studies suggested that the cccDNA might be responsible for the reappearance of HBV DNA. To get insight into the understanding of the persistence of the HBV cccDNA, two classes of HBV producing lines, based on the RT-PCR analysis were established by transfecting BclI-bearing 1.3-fold HBV genome into HepG2 cells (The BclI site would present on the 3’end of all HBV mRNAs if their transcribed from cccDNA but not from introduced DNA template). Class one cell (clone 1.3.ES11) is characterized by containing BclI site at the 3’end at all HBV mRNAs. In the class two cell (clone 1.3.ES2 and 1.3.ES8), the produced mRNAs are mixture products in which the 3’end of HBV mRNAs either contained BclI site or did not. Southern blot analysis of the genomic DNA suggested that all clones contained intact 1.3-fold HBV genome with one integrated site (clone 1.3.ES2 and 1.3.ES11) or two sites (1.3.ES8). However, BclI restriction and Southern analysis of 1.3.ES11 genomic DNA generated an HBV-containing fragment with size approximately 3.2 kb, suggesting that the 3’end of the 1.3-fold HBV genome contain a BclI site. This finding may account for the fact that the 3’ end of all HBV mRNAs derived from 1.3.ES11 cells contains the BclI site. Southern analysis of Hirt supernatants prepared from 1.3.ES2 and 1.3.ES8 cells clearly indicated that this two cell lines produced cccDNA, as evidenced by band shifting after digesting with EcoRI and resistant to heat denaturation. We have established HBV cccDNA-producing lines. Class two cells are being used to assess the effects of proliferating or arrested cells treated with or without lamivudine on the maintenance of cccDNA. In the next, the more detailed study of cccDNA might be accomplished in this cell culture system.
Kaldine, Haajira. "Liver-targeted transcription activator-like effector repressors that inactivate HBV cccDNA." Thesis, 2017. https://hdl.handle.net/10539/24730.
Full textThe hepatitis B virus (HBV) continues to be a global health threat as chronic infection may lead to cirrhosis and hepatocellular carcinoma (HCC). Current treatments are limited in efficacy and do not target the stable HBV covalently closed circular DNA (cccDNA) minichromosome which forms the template for viral replication and is responsible for persistence of the infection. Using gene editing technologies to disable cccDNA presents a potential approach for treating HBV infection. Transcription activator-like effector (TALE) proteins provide specific and adaptable DNA binding modules, which can be used to generate engineered proteins capable of modifying DNA. Transcription activator-like effector nuclease (TALEN) mediated cleavage of cccDNA has been shown to effectively inhibit HBV replication. However, the approach to transcriptionally silence cccDNA, instead of cleaving it, may overcome the risk of unwanted host DNA cleavage. Repressor transcription activator-like effectors (rTALEs), which target and transcriptionally silence genes, have shown potential as antiviral agents. Here we generated Krüppel-associated box (KRAB)-based rTALEs targeted to the surface open reading frame (ORF) and HBx promoter region of HBV cccDNA to inhibit transcription. The rTALEs were placed under the transcriptional control of the liver-specific modified murine transthyretin (mTTR) promoter, to restrict activity to hepatocytes thereby reducing the potential for off-target activity. In vitro the mTTR-driven rTALEs were shown to tissue specifically decrease secreted HBV surface antigen (HBsAg) levels by 63 - 92 %. Additionally, the mTTR-driven rTALEs were shown to tissue specifically decrease surface mRNA levels by 65 – 81 % and pregenomic RNA levels by 60 - 76 %. These results indicate that the KRAB domain was able to effectively suppress transcription from the basic core, Pre-S1 and/or vi Pre-S2 promoters which otherwise regulates HBV transcription. Furthermore, the observed inhibition was not associated with cytotoxicity or off-target effects. The work presented here is a proof-of-concept study demonstrating that highly specific transcriptional repressors designed to target and inhibit HBV viral replication without altering the genetic sequence or causing mutations in the host genome may be a promising antiviral approach. The capabilities of this technology to directly target cccDNA and inhibit its transcription, could contribute to addressing a global health problem.
LG2018
Ching-YuBao and 包慶瑜. "Regulation of hepatitis B virus cccDNA replication and potential therapeutic strategy." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/m8849a.
Full textBloom, Kristie Michelle. "Inactivation of hepatitis B virus CCCDNA using engineered transcription activator-like affector nucleases." Thesis, 2014.
Find full textMitra, Bidisha. "Biological Functions of Intracellular Hepatitis B e Antigen." Diss., 2019. http://hdl.handle.net/1805/21091.
Full textThe function(s) of the intracellular form of HBeAg, previously reported as the preCore protein intermediate (p22) without the N-terminal signal peptide, remains elusive. Here, we propose to elucidate the translocation of p22 during its formation from endoplasmic reticulum (ER) to cytosol, how it differs from core in its inability to form a capsid and the biological functions of cytoplasmic and nuclear p22. Firstly, we have identified that a portion of p22, after the cleavage of its signal peptide in ER, is released back into the cytosol through an ERAD-independent mechanism, as neither wildtype nor dominant-negative p97 affected the ER-to-cytosol translocation of p22 or ER-Golgi secretion of HBeAg. Secondly, despite sharing the same sequence with core protein except for the extended 10 amino acid precore region at the N-terminus, we observed that p22 wildtype and C-7Q mutant are unable to form a capsid. Thirdly, we report that p22 but not the secreted HBeAg significantly reduced interferon stimulated response element (ISRE) activity and expression of interferon stimulated genes (ISGs) upon interferon-alpha (IFN- α) stimulation. Furthermore, in line with this, RNA-seq analysis of ISG induction profile from IFN-α treated patients showed that HBeAg(+) patients exhibited reduced and weak antiviral ISG upregulations compared to HBeAg(-) patients. Further, mechanistic study indicated that while p22 did not alter the total STAT1 or p-STAT1 levels in IFN-α treated cells, it blocked the nuclear translocation of p-STAT1 by interacting with karyopherin α1, indicating that the cytoplasmic p22 may impede JAK-STAT signaling to help the virus evade host innate immune response and cause resistance to IFN therapy in patients. Additionally, nuclear p22 and nuclear core were found to interact with the promoter regions (ISRE – containing) of ISGs, suggesting a new mechanism of inhibition of ISG expression upon stimulation. Finally, we found that the nuclear p22 can bind to cccDNA minichromosome and affects cccDNA maintenance and/or transcription. Thus, our results indicate that there is a novel ER sorting mechanism for the distribution of the intracellular and secretory HBeAg, and the intracellular HBeAg may contribute to HBV persistence by interfering with IFN-α elicited JAK-STAT signaling and regulating cccDNA metabolism.
"Functional characterization of CCCTC-binding factor (CTCF) in the pathogenesis of hepatocellular carcinoma." 2013. http://library.cuhk.edu.hk/record=b5884412.
Full textThesis (Ph.D.)--Chinese University of Hong Kong, 2013.
Includes bibliographical references (leaves 154-187).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstract also in Chinese.
Tang, Jyh-Bing, and 湯智斌. "Identification of a tyrosine-phosphorylated CCCTC-binding nuclear factor in capacitated mouse spermatozoa." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/54376424667220781625.
Full text國立臺灣大學
生化科學研究所
94
The molecular basis of mammalian sperm capacitation, the process to acquire the ability to fertilize the oocyte in the female genital tract in a time-dependent manner, either in vivo in the female reproductive tract or in vitro, is poorly understood. It is well known that sperm capacitation is associated with a cyclic AMP-dependent increase in tyrosine phosphorylation of a subset of proteins. We resolved the phosphoproteins in the cell lysate of mouse sperm after capacitation by two-dimensional gel electrophoresis. Among the protein targets, one tyrosine-phosphorylated 130-kDa protein spot was trypsin-digested, and six oligopeptide sequences were further established from the trypsin digests by mass spectral analysis. These data were completely confirmed in a CCCTC-binding nuclear factor (CTCF), a widely expressed and highly conserved nuclear factor. Although we were unable to determine the exact site of phosphorylation of CTCF for the time being, we did demonstrate, using a cross-immunoprecipitation approach, that this protein is tyrosine phosphorylated during capacitation. Both an anti-phosphotyrosine antibody and an anti-CTCF antibody showed immunoreactivity to a 130-kDa component in the immunoprecipitates obtained after incubation of the cell lysate from the capacitated sperm using another anti-CTCF antibody. The data support the presence of a tyrosine-phosphorylated CTCF in the capacitated mouse sperm. Immunolocalization of the CTCF revealed fluorescent staining in the acrosome region in both capacitated and incapacitated sperm. The electrophoretic mobility shift assay, using a CTCF target sequence 5’-GGCGGCGCCGCTAGGGGTCTCTCT-3’ found in the promoter of the amyloid
Zimmerman, Kimberley Anne. "Designed zinc finger proteins as novel therapeutics inhibiting the transcription of hepatitis B and duck hepatitis B viruses." Phd thesis, 2010. http://hdl.handle.net/10048/1367.
Full textVirology
Bloom, Kristie Michelle. "The design and application of a real-time PCR assay to assess rcDNA and cccDNA produced by HBV during infection." Thesis, 2010. http://hdl.handle.net/10539/8576.
Full textChou, Yu-Chi, and 周祐吉. "Elucidation of transcriptional regulation on hepatitis B virus cccDNA and anti-viral effect of transforming growth factor-beta1 on HBV replication." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/31086204988499485215.
Full text國立陽明大學
微生物及免疫學研究所
93
In the first part of this thesis, we have evaluated the transcriptional efficiency of covalently closed circular DNA by using a RT-PCR combined with restriction enzyme digestion method. Virus persistence in chronic hepatitis B patient is manifested by sustaining a pool of covalently closed circular DNA (cccDNA) in the nucleus of the infected hepatocytes that presumably serves as a template for HBV genes expression. We used a modified 1.3-fold HBV genome, with a BclI-genetic marker embedded in the 5’-end redundancy region, to examine the transcriptional activity of cccDNA and the regulatory effect of HBx protein on the transcriptional activity. After harvesting total RNA from transfected cells or stable lines, we specifically monitored the transcription ability of cccDNA by using a RT-PCR combined with restriction enzyme digestion method. With this approach, we have found that (1) RT-PCR combined with digestion by BclI marker is highly specific and can distinguish transcripts originating from cccDNA from those originating from an integrated viral genome; (2) the transcriptional ability of cccDNA was shown to be less efficient than that from integrated viral genome; (3) the transcriptional activity of the cccDNA was significantly regulated by the HBx protein, a potential transcription activator. Accordingly, this information may provide a meam to further examine the transcriptional regulation of cccDNA and possibly, a very useful tool in the development of a cure for patients with a chronic HBV infection. In the second part of this thesis, we focused on the elucidation of the anti-viral effect of Transforming Growth Factor-beta1 on HBV replication. The replication of hepatitis B virus (HBV) has been reported to be suppressed by several cytokines, such as alpha/beta interferon (IFN-□/□), gamma interferon (IFN-□), and tumor necrosis factor alpha (TNF-□). Here we described that transforming growth factor beta 1 (TGF-□1), one of the cytokines elevated in hepatitis, has potential antiviral activities to decrease HBV replication in vitro. Using a virion-producing cell line derived from HepG2, we showed that TGF-□1 could suppress HBV replication as demonstrated by dramatically reduction of extracelluar and intracellular nucleocapsid. Concurrently, the cytosolic viral replicative intermediates were significantly diminished after TGF-□1 treatment. Furthermore, we also have evidence suggests that TGF-□1 can suppress HBV particle assembly by interfering with pgRNA transcription and HBc translation. RNase protection analysis revealed that TGF-□1 inhibited viral replication primarily by downregulating the expression of pregenomic RNA (pgRNA), as well as hepatocyte nuclear factor(s). Following the attenuation of viral transcripts by TGF-□1, we found that the HBc protein synthetic rate was also reduced due to the failure of ribosome engagement. Taking together, our data demonstrated that the antiviral effect of TGF-□1 was primarily due to both the transcriptional and translational controls, and suggest that elevated TGF-□1 may play a critical role in suppressing viral replication in chronic hepatitis.
Metzler, Frauke [Verfasser]. "Die Quantifizierung von cccDNA bei Patienten mit chronischer Hepatitis-B-Virusinfektion unter antiviraler Therapie und Korrelation zu serologischen und histologischen Parametern / vorgelegt von Frauke Metzler." 2005. http://d-nb.info/974107824/34.
Full textRen, Shaotang [Verfasser]. "Hepatitis B virion and cccDNA formation in primary tupaia hepatocytes and human hepatoma cell lines upon HBV genome transduction with replication defective adenovirus vectors and in vivo infection of tupaias / von Shaotang Ren." 2000. http://d-nb.info/961156007/34.
Full textReid, Heather A. "The Storie of Asneth and its literary relations: the Bride of Christ tradition in late Medieval England." Thesis, 2011. http://hdl.handle.net/1828/3518.
Full textGraduate