A New Insight Into Hepatitis B Infection:the HBV Fusion Peptide
Funder
National Health and Medical Research Council
Funding Amount
$288,210.00
Summary
Three hundred and fifty million people worldwide and 250,000 in Australia are chronically infected with hepatitis B virus (HBV). Without intervention, one third will die as a direct result of this infection through cirrhosis, liver failure and liver cancer, but current therapies are inadequate. New antiviral treatments requiring the identification of new antiviral targets are needed to combat the disease but a major obstacle to the study of HBV is the lack of a cell culture system. As a result n ....Three hundred and fifty million people worldwide and 250,000 in Australia are chronically infected with hepatitis B virus (HBV). Without intervention, one third will die as a direct result of this infection through cirrhosis, liver failure and liver cancer, but current therapies are inadequate. New antiviral treatments requiring the identification of new antiviral targets are needed to combat the disease but a major obstacle to the study of HBV is the lack of a cell culture system. As a result nothing is known about how HBV enter and fuses with the host liver cell but we have made significant progress with the identification of the entry and fusion events of the related duck hepatitis B virus, using the duck infection model. This knowledge is now ready for application to the medically important HBV by use of primary human liver cells and the techniques developed in the duck hepatitis B virus model.Read moreRead less
Characterisation Of Anti-HBs Responses In Patients Undergoing Functional Hepatitis B Cure: Implication For Future Therapies
Funder
National Health and Medical Research Council
Funding Amount
$723,649.00
Summary
The hepatitis B virus causes liver cirrhosis and liver cancer. There is no cure for hepatitis B. However, a small number of patients can naturally rid themselves of the virus. We have identified 14 of these individuals and discovered that they have a unique immune response that is responsible for these “natural” cures. We plan to characterise this immune response and turn it into a therapeutic vaccine which can be used to cure patients who are still chronically infected.
Chronic Active Viral Persistence Versus Host Immune Mediated Pathology: An Analysis And Manipulation Of The Balance.
Funder
National Health and Medical Research Council
Funding Amount
$418,658.00
Summary
Our robust ability to mount an immune response and clear infections is tempered by the possibility of promoting autoimmunity. Several host genes regulate immunity. Viruses like HIV have exploited these to abrogate antiviral immunity. This project attempts to define host factors that promote chronic infection. This will be extremely valuable in understanding the vulnerabilities of our immune system and provide an insight into how we can treat chronic infections.
Clearing Chronic Infectious Diseases – Enhancing Host Immune Effector Function
Funder
National Health and Medical Research Council
Funding Amount
$92,314.00
Summary
Chronic infections produced by pathogens such as HIV, overwhelm our immune system leading to an exhausted state where cells responsible for the clearance of invading microorganisms are unable to respond effectively. We have recently identified a highly promising therapeutic target that enhances immune effector function. We seek to understand the underlying mechanism, and to explore the therapeutic potential of this approach for the treatment of a broad range of pathogens, including those respons ....Chronic infections produced by pathogens such as HIV, overwhelm our immune system leading to an exhausted state where cells responsible for the clearance of invading microorganisms are unable to respond effectively. We have recently identified a highly promising therapeutic target that enhances immune effector function. We seek to understand the underlying mechanism, and to explore the therapeutic potential of this approach for the treatment of a broad range of pathogens, including those responsible for chronic disease.Read moreRead less
Worldwide >360 million people have chronic hepatitis B virus (HBV) infection that imparts a 25% lifetime risk of death due to serious liver disease. Current therapies for chronic HBV reduce levels of virus replication but fail to target the stable, nuclear episome, covalently closed circular DNA (cccDNA). The current study will determine what is required to eliminate cccDNA and how current therapies for chronic HBV infection should be modified to achieve this aim.
ANTIVIRAL DRUG RESISTANT HBV: PATHOGENIC AND ONCOGENIC SIGNIFICANCE OF THE ALTERED VIRAL ENVELOPE
Funder
National Health and Medical Research Council
Funding Amount
$509,284.00
Summary
We aim to investigate the consequences of long-term therapy for hepatitis B on liver cancer progression. We propose that antiviral therapy is associated with persistent expression and accumulation of potentially oncogenic surface proteins in the liver. This can dramatically alter the viral lifecycle, particularly the HBsAg secretion pathway, which can cause serious effects in the host hepatocyte biology, including promoting pathways to tumour formation.
Protein Topogenesis And The Assembly/disassembly Of The Enveloped Hepatitis B Virus.
Funder
National Health and Medical Research Council
Funding Amount
$197,884.00
Summary
An estimated 350 million people worldwide, and 250,000 in Australia, are chronically infected with the hepatitis B virus (HBV). Without intervention, one third will die as a direct result of this infection through cirrhosis, liver failure and liver cancer, but current treatments are inadequate. A major obstacle to the study of this virus is the lack of a cell culture infection system. We have used the duck hepatitis B virus (DHBV) model to study the events leading up to assembly of the virus in ....An estimated 350 million people worldwide, and 250,000 in Australia, are chronically infected with the hepatitis B virus (HBV). Without intervention, one third will die as a direct result of this infection through cirrhosis, liver failure and liver cancer, but current treatments are inadequate. A major obstacle to the study of this virus is the lack of a cell culture infection system. We have used the duck hepatitis B virus (DHBV) model to study the events leading up to assembly of the virus in a way which prepares the viral envelope or outer coat for its foray into a new host cell. The project will examine the specific interactions of two proteins, the large and the small envelope protein, in addition to a third envelope protein we have recently discovered, which together make up the viral envelope. This will reveal which envelope components are required to make up the specific structures known to be essential for the disruption of the host cell membrane and subsequent entry of the virus to a new cell. An understanding of the changes that occur to the viral envelope upon entry will enable development of strategies for the inhibition or blocking of this change, thus identifying targets for the development of new antiviral agents. Because HBV is just one of many viruses which have an envelope, all of which must enter the cell in some way, our studies of HBV will also provide new clues with respect to the replication of other viruses such as measles, influenza and HIV. A related part of the study will examine the orientation of the large envelope protein within the virus particle and how it changes its orientation to assume its many important functional roles, in the late stages of particle assembly. Expanding on our finding that the small protein is essential to the orientation of the large protein, this study will reveal the mechanism of a unique method of protein transport which may have wider implications in cell biology.Read moreRead less
The Role Of Stellate Cells In Fibrosis And Liver Disease Progression In HIV-Hepatitis B Co-infection
Funder
National Health and Medical Research Council
Funding Amount
$157,292.00
Summary
Liver related mortality is the commonest cause of non-AIDS death in HIV infected individuals on treatment. With HIV, HBV liver damage is accelerated and liver-related mortality increased. Understanding how and why is critical to management. I will examine the role of hepatic stellate cells using in vitro models and directly ex vivo from infected patient biopsy tissue. I will investigate the activated of these cells by HIV and HBV infection, thus promoting scar formation with liver injury.
Novel Bioinformatic Methods To Determine The Link Between Genomic Complexity Of Hepatitis Viruses And Liver Disease Phenotypes
Funder
National Health and Medical Research Council
Funding Amount
$605,859.00
Summary
Bioinformatics is a discipline concerned with the study of how information is stored and used in biological systems. Here we develop bioinformatic tools to study how hepatitis viruses evolve during an infection and how these infections cause severe liver diseases.
Title: Structure of hepadnaviral pre-genomic RNA. We aim to study the replication strategy of human hepatitis B virus (HBV), a member of the hepadnavirus family. Hepadnaviruses infect hepatocytes in the liver and are released in high numbers into the bloodstream. Infection is transmitted by blood or sexual contact. Hepadnaviruses cause acute and chronic infection with varying degrees of liver disease. The HBV DNA genome is formed by copying of a viral pre-genome made of RNA, into DNA. This proce ....Title: Structure of hepadnaviral pre-genomic RNA. We aim to study the replication strategy of human hepatitis B virus (HBV), a member of the hepadnavirus family. Hepadnaviruses infect hepatocytes in the liver and are released in high numbers into the bloodstream. Infection is transmitted by blood or sexual contact. Hepadnaviruses cause acute and chronic infection with varying degrees of liver disease. The HBV DNA genome is formed by copying of a viral pre-genome made of RNA, into DNA. This process is called reverse transcription and is performed by the viral polymerase. Reverse transcription occurs within viral nucleocapsids made of core antigen. After formation of the new viral DNA genome, nucleocapsids are enveloped in surface antigen and are released from the cell. It is assumed that 1 copy of HBV pre-genomic RNA is packaged within each viral nucleocapsid. However, members of the retrovirus family that have common evolutionary origins to hepadnaviruses and also replicate via reverse transcription, contain 2 copies of RNA. The human immunodeficiency virus (HIV), the AIDS virus, is a well-studied example. In HIV infection 2 RNA genomes are packaged into each nucleocapsid and form a dimeric RNA genome. The HIV RNA is able to fold into a series of stem loops that promote formation of dimers. During the reverse transcription step in HIV replication, the polymerase switches templates and forms new combined strains of virus. The project aims to determine if 2 copies of pre-genomic RNA are packaged into HBV nucleocapsids. HBV pre-genomic RNA is able to form stem loop structures similar to those in HIV and has the potential to form dimeric RNA. If 2 copies of HBV pre-genomic RNA are packaged this will allow us to redefine the viral replication strategy and to develop a greater understanding of the relationships between hepadnaviruses and retroviruses. The formation of dimers will also provide a mechanism for recombination between HBV strains.Read moreRead less