Current combination antiviral therapy can't cure an HIV infection because long-lived T-cells carrying latent HIV DNA can rekindle the infection when drugs are removed. We will study elements in HIV genetic code that control expression of HIV proteins from latent HIV. A detailed molecular understanding of the structure and function of these HIV RNA elements and the viral and host cell factors that interact with them will expose new targets for therapy of latent HIV.
Molecular Mechanisms Of Varicella Zoster Virus Interactions With Key Target Cells
Funder
National Health and Medical Research Council
Funding Amount
$421,650.00
Summary
Varicella zoster virus (VZV) is a herpesvirus which infects up to 90% of the population. VZV causes chickenpox (varicella) predominantly in childhood and shingles (herpes zoster) in middle to old age people. Whilst VZV usually causes relatively mild disease in healthy individuals, VZV still causes significant morbidity in children and adults. VZV causes life-threatening disease in immunocompromised individuals such as patients who are elderly or have HIV disease . Herpes zoster affects many eder ....Varicella zoster virus (VZV) is a herpesvirus which infects up to 90% of the population. VZV causes chickenpox (varicella) predominantly in childhood and shingles (herpes zoster) in middle to old age people. Whilst VZV usually causes relatively mild disease in healthy individuals, VZV still causes significant morbidity in children and adults. VZV causes life-threatening disease in immunocompromised individuals such as patients who are elderly or have HIV disease . Herpes zoster affects many ederly individuals and a major complication is prolonged severe pain or post-herpetic neuralgia (PHN), both severely debilitating and which often requires follow-up medical care for months or years after the initial attack. Despite its significant impact on the community, little is known about the molecular details of how this virus functions. This project aims to improve our understanding of how VZV infection affects specialised human cells in order to make further advances in antiviral therapies as well improve vaccine design for the treatment or prevention of VZV disease and the crippling complication of PHN. This project has four components: (1) We will continue studies which have shown that VZV may actively avoid detection by the immune system. We aim to identify the mechanism and viral genes responsible for interfering with the expression of molecules which are essential for our immune system. (2) We will determine whether VZV infection of specialised immune cells (called dendritic cells) will affect their ability to function and interact with other immune cells (called T cells). (3) We will examine how VZV interacts in human nerve cells (neurons) and whether infected neurons undergo specially programmed cell death (apoptosis). (4) We will examine how different human cells change when they are infected with VZV. A new and exciting technology called DNA microarray now makes it possible to examine the expression of many thousands of genes in one experiment.Read moreRead less
Control Of Viral Replication By Non-coding Viral RNA
Funder
National Health and Medical Research Council
Funding Amount
$502,270.00
Summary
In 25 years since identified, HIV-AIDS deaths have exceeded 30 million and 40 million more are now living with HIV. The toll will soon far surpass any other infectious disease epidemic in history, or even military deaths from war in the past century. While effective combination drug therapies are available, multi-drug resistant HIV strains are commonly transmitted, leaving some patients with limited treatment options. New classes of drugs aimed at different steps in virus replication are urgentl ....In 25 years since identified, HIV-AIDS deaths have exceeded 30 million and 40 million more are now living with HIV. The toll will soon far surpass any other infectious disease epidemic in history, or even military deaths from war in the past century. While effective combination drug therapies are available, multi-drug resistant HIV strains are commonly transmitted, leaving some patients with limited treatment options. New classes of drugs aimed at different steps in virus replication are urgently needed. We have discovered that viral RNAs that do not code for protein serve important functions in HIV replication. We will study the molecular mechanisms these non-coding (intron) RNAs previously considered junk use to support of HIV gene expression and assess their potential as drug targets. First, we will investigate the role of these junk RNA loops, or lariat introns, produced in large amounts during the HIV replication cycle. Retroviruses employ RNA splicing to make mRNA for envelope and regulatory accessory genes. The complex alternative RNA splicing pattern of HIV spawns several non-coding lariats, including the lariat-intron that contains much of the removed env coding sequence. We have made the counterintuitive finding that the env-lariat dramatically enhances expression of Env protein. We will examine how this occurs and the involvement of the new class of gene-expression controlling micro-RNAs in this process. We will test for functional activity from the other lariat-introns that are produced by HIV. Second, we will characterise the mRNA-element required for efficient expression of the HIV envelope glycoprotein, Env gp160, which is essential for virus binding and entry during infection. This RNA-element directs the cell protein translation machinery to commence protein synthesis at the start of the Envgp160 rather than at upstream start sites for Vpu and Rev. We will determine how this RNA element works, its structure, and how it might be inactivated.Read moreRead less
Viral And Host Cell Gene Expression During The Establishment And Maintenance Phases Of Human Cytomegalovirus Latency
Funder
National Health and Medical Research Council
Funding Amount
$149,250.00
Summary
Human cytomegalovirus (CMV) is a herpesvirus which infects a majority of the population. HCMV is a significant cause of serious, life-threatening disease in neonates and in people who are immunosuppressed. Transplant recipients such as bone marrow, kidney and heart transplant patients are particularly at risk of developing CMV disease. Like other herpesviruses, after initial infection CMV can establish a life-long latent infection. During latency, the virus remains dormant in the human body and ....Human cytomegalovirus (CMV) is a herpesvirus which infects a majority of the population. HCMV is a significant cause of serious, life-threatening disease in neonates and in people who are immunosuppressed. Transplant recipients such as bone marrow, kidney and heart transplant patients are particularly at risk of developing CMV disease. Like other herpesviruses, after initial infection CMV can establish a life-long latent infection. During latency, the virus remains dormant in the human body and no infectious virus is made. However, when conditions are right the virus can awaken (ie reactivate) from its latent state, producing new infectious virus and disease. It is in immunosuppressed individuals such as transplant patients that viral latency and reactivation are of most medical concern, yet viral latency remains very poorly understood. The overall aim of these studies is to provide a much better understanding of how CMV latency is established and maintained, with the ultimate goal of making advances for the design of anti-viral therapies to disrupt these processes. This project has three major components: Firstly, we aim to identify and characterise viral gene expression during the establishment of latency and these findings will have profound implications to our understanding of latency. Secondly, we will examine how human cells are affected when they become latently infected. A new and exciting technology called DNA microarray now makes it possible to examine the expression of many thousands of genes in a single experiment. For the first time, we will be able to determine how the cell changes during the establishment and maintenance phases of latency. Thirdly, we will apply microarray technologies to determine how human cell genes are altered in response to the expression of individual viral genes that are active during the latent phase of infection.Read moreRead less
The immune system plays an important role in protecting the host from viral and bacterial infections, and inhibits cancer onset and progression. Unfortunately the immune system can sometimes lose specificity and attack the host resulting in autoimmune diseases such as diabetes. This research team has played a vital role in characterising the specific activities of immune cells and the associated factors. By understanding these complex processes the team aims to harness the unique therapeutic pro ....The immune system plays an important role in protecting the host from viral and bacterial infections, and inhibits cancer onset and progression. Unfortunately the immune system can sometimes lose specificity and attack the host resulting in autoimmune diseases such as diabetes. This research team has played a vital role in characterising the specific activities of immune cells and the associated factors. By understanding these complex processes the team aims to harness the unique therapeutic properties of our own immune system and translate their findings into the clinic.Read moreRead less
Heterogeneous Nuclear Ribonucleoprotein Role In Alternative RNA Splicing And Human Disease
Funder
National Health and Medical Research Council
Funding Amount
$254,250.00
Summary
Control of the use of DNA, gene expression, is vital to all living organisms, especially in development and disease. The information in the genes of DNA is transferred to an intermediate molecule, mRNA, in a process called transcription. The genetic information in the mRNA is subsequently used, in the process called translation, to make the protein encoded by the original gene. The switching on and off of DNA appears to be most frequently controlled at the transcription step but recently it has ....Control of the use of DNA, gene expression, is vital to all living organisms, especially in development and disease. The information in the genes of DNA is transferred to an intermediate molecule, mRNA, in a process called transcription. The genetic information in the mRNA is subsequently used, in the process called translation, to make the protein encoded by the original gene. The switching on and off of DNA appears to be most frequently controlled at the transcription step but recently it has become apparent that there are many post-transcriptional events that govern how efficiently the genetic information is ultimately converted to protein molecules. An important step is the cutting out of parts (introns) of the RNA molecule that is copied from DNA, and splicing of the retained sections (exons). During this process the RNA may also lose one or more of its exons. As a result of this variable retention of exons a single gene may produce many isoforms of the protein it encodes. By this mechanism the roughly 30,000 genes in the human genome can give rise to potentially hundreds of thousands of proteins. RNA splicing connects to cancer in two ways. First, changes in the concentrations of the proteins that control splicing may change the isoforms, resulting in changes that lead to uncontrolled cell proliferation. Secondly, DNA mutations that affect the splicing process can also vary the ratios of the isoforms produced from a gene: if this occurs in a protein that is involved in the growth of cells this too may lead to cancer. In this project we will study the molecular mechanism of this alternative splicing, and particularly a group of proteins that generally favour the excision of some exons, with a focus on cancer cells. Recent publications have highlighted the potential for the therapeutic use of drugs that target the splicing apparatus: it is anticipated that studies of alternative splicing will underpin development of new therapeutic agents.Read moreRead less
The Role Of CXCR3 Chemokines In Hepatitis C And Other Forms Of Viral Hepatitis
Funder
National Health and Medical Research Council
Funding Amount
$457,267.00
Summary
The majority of individuals infected with hepatitis C virus (HCV) show a slow progression of liver disease over a period of 10-20 years. This liver disease is primarily a result of the host immune response to liver cells (hepatocytes) infected with HCV. As part of this immune response there in an increase in the number of immune cells that infiltrate the liver. To date we do not fully understand the mechanims that attract these cells to the liver but a class of molecules called chemokines is the ....The majority of individuals infected with hepatitis C virus (HCV) show a slow progression of liver disease over a period of 10-20 years. This liver disease is primarily a result of the host immune response to liver cells (hepatocytes) infected with HCV. As part of this immune response there in an increase in the number of immune cells that infiltrate the liver. To date we do not fully understand the mechanims that attract these cells to the liver but a class of molecules called chemokines is the most likely candidate. Thus a greater understanding of the chemokines expressed in the liver, their modulation and role in attracting immune cells to the liver in HCV-related liver disease will help us understand the basic mechanisms of liver disease with the possibility of development of novel therapeutic strategies. In pilot studies we have shown that the chemokine interferon-inducible T cell alpha chemoattractant (I-TAC) is significantly increased in the liver of persons infected with HCV. I-TAC is a member of the CXCR3 ligand chemokine family that attracts lymphocytes to sites of inflammation and as such may play an important role in hepatitis C. We have also shown that hepatocytes express I-TAC and that HCV can upregulate expression of I-TAC in a laboratory model of HCV replication. This proposal plans to determine the molecular mechanisms of I-TAC expression in response to HCV replication and to investigate if I-TAC expression is unique for hepatits C or a general feature of viral infections of the liver. We also plan to determine the the role of I-TAC and other CXCR3 ligand family members in a mouse model of viral hepatitis through the use of CXCR3 ligand antagonists. These experiments will enhance or knowledge of the role of the CXCR3 ligands in hepatitis C and viral hepatitis in general.Read moreRead less