Mechanisms Of Immune Modulation By Varicella Zoster Virus During Cutaneous Infections
Funder
National Health and Medical Research Council
Funding Amount
$570,446.00
Summary
Varicella zoster virus (VZV) is a herpesvirus which infects up to 90% of the population. VZV causes two skin diseases: chicken pox (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. Shingles aff ....Varicella zoster virus (VZV) is a herpesvirus which infects up to 90% of the population. VZV causes two skin diseases: chicken pox (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. Shingles affects many elderly individuals and a major complication is prolonged severe pain or post-herpetic neuralgia (PHN), which can be severely debilitating and often requires follow-up medical care for months or even years after the initial attack. Despite its significant impact on the community, little is known about how this virus functions and causes disease. This project aims to improve our understanding of how VZV infection of the skin affects the function of specialised skin cells in order to provide novel information for the development of therapies aimed at lessening the impact of VZV disease on the community. This project has three main components: (1) To determine what the differences are in the types of immune cells present in infected skin from chicken pox and shingles sufferers. (2) To assess the impact of VZV infection on the ability of specialised immune cells (called dendritic cells) to function properly (3) To identify which parts of the virus (called genes) code for functions that interfere with the proper function of specialised immune cells (dendritic cells)Read moreRead less
Immunopathogenesis Of Varicella Zoster Virus Infection
Funder
National Health and Medical Research Council
Funding Amount
$346,250.00
Summary
Varicella zoster virus (VZV) is a herpesvirus which infects up to 90% of the population. VZV causes chicken pox (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. Shingles affects many elderly i ....Varicella zoster virus (VZV) is a herpesvirus which infects up to 90% of the population. VZV causes chicken pox (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. Shingles affects many elderly individuals and a major complication is prolonged severe pain or post-herpetic neuralgia (PHN), which can be severely debilitating and often requires follow-up medical care for months or even years after the initial attack. Despite its significant impact on the community, little is known about how this virus functions and causes disease. This project aims to improve our understanding of how VZV infection affects specialised human cells in order to provide novel information for the development of therapies aimed at lessening the impact of VZV disease on the community. This project has four components: (1) We will continue studies which have shown that VZV causes programmed cell death (apoptosis) in human skin cells (fibroblasts) but not human nerve cells (neurons). We aim to identify viral genes responsible for the cell-type specific modulation of apoptosis in human neurons and fibroblasts (2) We will examine human sensory ganglia (clusters of human nerve cells) during shingles and determine what immune cells are present and whether neurons are undergoing apoptosis (3) To assess the impact of VZV infection on the ability of specialized immune cells (called dendritic cells) to mature properly (4) We have shown that VZV may actively avoid immune detection by interfering with the function of dendritic cells. We aim to identify the mechanism responsible for the virus interfering with the expression of immune molecules which are essential for our immune system.Read moreRead less
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.
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
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
Herpesviruses infect most Australians and cause recurrent ulcers, birth defects and cancer. Infection lasts lifelong, and spreads to close contacts without obvious clinical signs. Thus disease is hard to prevent. However we can learn much from related animal infections. We have shown that both mouse and human herpesviruses enter mice via cells in the nose. Thus human infections might follow the same route. We will define what body defences work here and whether vaccines can prevent infection.
Human ?-herpesviruses persist for life, cause cancers and emerge with particular virulence when the immune system is weak. Vaccination against them is therefore an important health priority. We have shown for a related ?-herpesvirus of mice that live vaccines protect. Antibody seems to play a major role. We will test whether safer, recombinant vaccines are also sufficient to elicit protective antibody. Thus we can establish a viable strategy for preventing virus-induced human cancers.
Transport And Egress Of Herpes Simplex Virus In Neurones
Funder
National Health and Medical Research Council
Funding Amount
$592,023.00
Summary
Herpes simplex virus (HSV) enters the human body via the skin before entering the termini of nerve cell processes. It is transported along these processes to the body of the nerve cell. HSV lies dormant within these nerve cell bodies near the spinal cord in most people. Intermittently the virus reactivates and is transported back down the nerve cell processes to the skin where it causes blisters-ulcers or is shed without causing symptoms. The aim of this grant is to determine how HSV is transpor ....Herpes simplex virus (HSV) enters the human body via the skin before entering the termini of nerve cell processes. It is transported along these processes to the body of the nerve cell. HSV lies dormant within these nerve cell bodies near the spinal cord in most people. Intermittently the virus reactivates and is transported back down the nerve cell processes to the skin where it causes blisters-ulcers or is shed without causing symptoms. The aim of this grant is to determine how HSV is transported within nerve cells at the molecular level. Recent discoveries have shown how virus transport in nerve cells is dependent on interactions between specific viral proteins and cellular motor proteins and how the virus escapes from nerves to infect skin and cause disease. Such information on viral transport will allow development of inhibitors of this process which may be candidates for use as antivirals for control of recurrent herpes simplex. In addition, this information will allow the virus to be exploited for use in gene therapy to introduce DNA into human nerve cells to correct genetic abnormalities. Finally this data will assist in understanding similar mechanisms for other viruses transported in nerve cells such as those causing shingles and rabies.Read moreRead less
Viral infections of the gut are one of the most debilitating infections one can suffer from. Noroviruses are the most common causative agents of viral-associated gastroenteritis but unfortunately little is known regarding their biology and pathogenesis. Our study aims to investigate the replication and pathogenesis of a mouse norovirus to shed light on similar aspects relating to human norovirus infection. We aim to understand how virus infection in cells leads to disease symptoms.
Influenza A Virus PB1-F2 Protein: A Putative Virulence Factor And Initiator Of Inflammation
Funder
National Health and Medical Research Council
Funding Amount
$474,718.00
Summary
Influenza virus produces a protein of undefined function called PB1-F2. Infection of mice with virus expressing PB1-F2 from virulent strains causes severe lung inflammation, while PB1-F2 from milder seasonal viruses does not. We will examine how PB1-F2 influences virulence of human influenza in the ferret, which exhibits the same illness as humans. This work will help understand the disease severity of newly evolved influenza viruses of humans and the role of PB1-F2 in mediating this.