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
Understanding The Role Of Host Arih2 In Defence Against Viral Infection And Disease Pathogenesis
Funder
National Health and Medical Research Council
Funding Amount
$537,737.00
Summary
A set of proteins, called E3 ligases, modulate many aspects of immunity. Arih 2 is a novel E3 ligase that limits immune cell activation to maintain the immune system in a quiescent state. The details of how Arih2 functions and its role in immunity to chronic overwhelming infection are the focus of this study. The insights gained from these studies have important implications for our understanding of how immune responses can be promoted during infection or halted in autoimmunity.
Cellular Microenvironments Facilitating The Replication And Propagation Of Flaviviruses
Funder
National Health and Medical Research Council
Funding Amount
$505,279.00
Summary
Flaviviruses are the agents of many mosquito-transmitted infections and many deaths globally each year. The emerging virus West Nile virus (strain New York) is a member of this virus family and shares 99% amino acid homology with the endemic Australian virus Kunjin virus. During virus growth in cells, cellular membrane structures are induced or rearranged by these viruses for their own purpose. That being the production of more virus particles for reinfection of other cells. Using Kunjin virus a ....Flaviviruses are the agents of many mosquito-transmitted infections and many deaths globally each year. The emerging virus West Nile virus (strain New York) is a member of this virus family and shares 99% amino acid homology with the endemic Australian virus Kunjin virus. During virus growth in cells, cellular membrane structures are induced or rearranged by these viruses for their own purpose. That being the production of more virus particles for reinfection of other cells. Using Kunjin virus as a model, and advanced techniques in biochemistry and electron microscopy, we have identified for the first time these membrane structures as the apparent sites of replication of the viral RNA or genetic material, and of the viral proteins involved. We have also observed how new virus particles are able to get out of infected cells and shown how some drugs can prevent this occurring thus limiting their transmission. This research will focus on how the membrane structures are formed in infected cells. The research will determine what cellular components are required by the virus to help it propagate. In particular specific cellular proteins and membrane components that are captured by the virus and moved to different sites in the infected cells. These apparent requirements could possibly lead us to a greater understanding of the complex interactions that occur between the invading virus and the host cells. We aim to directly visualize the process of infection within living cells using new and innovative microscopic techniques. Another of our objectives is to determine the effects of infection on normal cells. The question being whether flavivirus infection disrupts normalcell fuctions like secretion etc. An understanding of these processes, and how the viral RNA is copied into new RNA for more virus particles, will assist in the development of antiviral drugs for treatment of this pathogenic group of viruses.Read moreRead less
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
Several members of the Flaviviridae family are major pathogens of humans including dengue (DEN), yellow fever (YF), tick-borne encephalitis (TBE), Murray valley encephalitis (MVE), Japanese encephalitis (JE), and hepatitis C virus (HCV). An Australian flavivirus Kunjin (KUN), however, appears to be naturally attenuated and does not cause an overt disease in humans. In contrast, genetically and antigenically closely related to KUN, New York strain of West Nile virus (NY WN) has already caused ~50 ....Several members of the Flaviviridae family are major pathogens of humans including dengue (DEN), yellow fever (YF), tick-borne encephalitis (TBE), Murray valley encephalitis (MVE), Japanese encephalitis (JE), and hepatitis C virus (HCV). An Australian flavivirus Kunjin (KUN), however, appears to be naturally attenuated and does not cause an overt disease in humans. In contrast, genetically and antigenically closely related to KUN, New York strain of West Nile virus (NY WN) has already caused ~500 deaths and over 20,000 registered infections since its emergence in North America in 1999, including 223 deaths and 9122 infections in 2003 alone. Recent studies with DEN indicated that flaviviruses may interfere with early steps of IFN-signalling pathway. The type I Interferon (IFN) response is the first line of defence against viral infections and many viruses have developed different strategies to counteract this response in order to ensure their survival in the infected host. In this grant we seek to exploit our extensive understanding of the molecular biology of KUN virus and the contrasting behaviour of KUN and NY WN viruses to gain an understanding of the role of flavivirus-mediated suppression of host anti-viral IFN response in virus-host relationships and its importance in determining virus virulence.Read moreRead less
Roles Of Virus-integrin Interactions And Rotavirus Modulation Of Host Cell Responses In Viral Pathogenesis
Funder
National Health and Medical Research Council
Funding Amount
$474,000.00
Summary
Rotaviruses are the main cause of severe gastroenteritis in children, and cause 1 in 27 Australian children under the age of 5 years to spend time in hospital. There is currently no rotavirus vaccine available. We aim to discover how rotavirus interacts with host cells. This information is necessary to formulate a safe and effective vaccine, or a therapeutic agent that can block virus growth in host cells. Previously, we showed that rotavirus attaches to cells and enters them using several membe ....Rotaviruses are the main cause of severe gastroenteritis in children, and cause 1 in 27 Australian children under the age of 5 years to spend time in hospital. There is currently no rotavirus vaccine available. We aim to discover how rotavirus interacts with host cells. This information is necessary to formulate a safe and effective vaccine, or a therapeutic agent that can block virus growth in host cells. Previously, we showed that rotavirus attaches to cells and enters them using several members of the integrin protein family that are present on the surface of the cells. Integrins are critical for cell adhesion, survival and communication. In this project, we will identify how rotavirus usage of integrins modulates cell functions. This will help us understand how rotavirus causes disease, how virus spreads in the body and how the immune response defends us from rotavirus. Rotavirus binds integrins using particular stretches of protein sequence that we have shown are also present in other human viral pathogens that cause hepatitis, AIDS and measles. We will determine if these other viruses also recognize integrins.Read moreRead less
UNDERSTANDING HEPATITIS C VIRUS-SPECIFIC T CELL TOLERANCE
Funder
National Health and Medical Research Council
Funding Amount
$429,710.00
Summary
Most individuals who are infected with hepatitis C virus (HCV) develop a persistent infection that is lifelong and are at risk of developing serious liver disease, including liver cancer. The evidence suggests that an inadequate immune response is responsible for the inability of the patient to resolve the infection, but it is not clear which stage of the immunological cascade might be targeted. In this project, we will test the hypothesis that HCV antigen induce supressor T cells This will have ....Most individuals who are infected with hepatitis C virus (HCV) develop a persistent infection that is lifelong and are at risk of developing serious liver disease, including liver cancer. The evidence suggests that an inadequate immune response is responsible for the inability of the patient to resolve the infection, but it is not clear which stage of the immunological cascade might be targeted. In this project, we will test the hypothesis that HCV antigen induce supressor T cells This will have the effect of inhibiting the immune response and result in the outcome that we currently recognise as persistent HCV infection.Read moreRead less
Current anti-HIV therapies can't cure HIV because HIV remains silent(latent) in long-lived cells. The HIV life cycle and virus production is linked to activation of the host cell, which is regulated by dendritic cells. This grant will explore how the factors controlling T cell activation and proliferation control virus expression and latency. By understanding how latent infection is established and maintained, these studies will potentially identify new ways to eliminate HIV infection.
Herpesviruses infect us all and cause cancer, blindness, and congenital disability. Developing vaccines requires information from both patients and experimental animals. CD4 T cells seem to suppress directly virus replication, and cells in the nose provide an important way for herpesviruses to get in. We will test whether CD4 T cells can clear nasal infection; what targets they recognize; and how they act. Thus we can establish whether CD4 T cell-directed vaccines might protect against disease.