Last year an estimated 3.1 million people died of AIDS (source: UNAIDS, Dec 2002) equivalent to the number killed by tuberculosis and malaria combined. AIDS-related opportunistic infections (OIs) are the main cause of death for AIDS patients, especially in resource constrained countries where access to antiretroviral and antibiotic therapy is limited. Attempts to limit the epidemic have failed and new foci have emerged in Eastern Europe, Central Asia and, of particular relevance for us, South Ea ....Last year an estimated 3.1 million people died of AIDS (source: UNAIDS, Dec 2002) equivalent to the number killed by tuberculosis and malaria combined. AIDS-related opportunistic infections (OIs) are the main cause of death for AIDS patients, especially in resource constrained countries where access to antiretroviral and antibiotic therapy is limited. Attempts to limit the epidemic have failed and new foci have emerged in Eastern Europe, Central Asia and, of particular relevance for us, South East Asia, underlining the fact that safe and effective treatment for AIDS-related OIs will be a global health priority for the foreseeable future. People with healthy immune systems do not get OIs since the germs that cause such infections are efficiently ingested and subsequently destroyed by cells called macrophages. We have discovered that the virus that causes AIDS, HIV-1, interferes with the ability of macrophages to ingest opportunistic pathogens by the 2 most important mechanisms used for this purpose. We believe that this is the direct cause for the susceptibility of AIDS patients to many of the opportunistic pathogens that cause their OIs. The purpose of this grant will be to understand the biochemical basis underlying these 2 defects in macrophage function. This will help in the design of safe, adjunctive therapies aimed at improving macrophage function and reducing the risk of HIV-infected individuals developing AIDS-related OIs.Read moreRead less
Phagocytic Clearance And Immune Activation In Malaria
Funder
National Health and Medical Research Council
Funding Amount
$564,644.00
Summary
Macrophage white blood cells clear malaria infected cells by eating them, by three routes- by recognising ANTIBODIES or COMPLEMENT on the cell surface, or by the cell BINDING directly to the macrophage. Each has different results, such as amounts of cytokines produced. Cytokines clear malaria; in excess they can cause fatal immune pathology. We will investigate how variations in amount of antibody and complement and route of uptake of malaria infected cells might determine malaria outcome.
Evaluation Of Orally Active Anti-inflammatory C5a Receptor Antagonists In A Transgenic Rat Motor Neurone Disease Model
Funder
National Health and Medical Research Council
Funding Amount
$533,578.00
Summary
Motor neurone disease is a rapidly progressive and incurable disease, usually ending in death within 3-5 years of diagnosis. The disease usually arrives without warning, and results in a progressive loss of muscle control. There is no effective treatment, and available drugs increase life span by a few weeks at best. There is evidence that the disease involves an inflammatory component, but available anti-inflammatory drugs are ineffective. We have developed a new class of anti-inflammatory drug ....Motor neurone disease is a rapidly progressive and incurable disease, usually ending in death within 3-5 years of diagnosis. The disease usually arrives without warning, and results in a progressive loss of muscle control. There is no effective treatment, and available drugs increase life span by a few weeks at best. There is evidence that the disease involves an inflammatory component, but available anti-inflammatory drugs are ineffective. We have developed a new class of anti-inflammatory drugs, known as C5a antagonists, and in preliminary experiments have shown they are therapeutically effective in a transgenic rat model of motor neurone disease. We propose to investigate in more detail how these drugs work in the rat model, and demonstrate that a specific inflammatory pathway, which we can now block, is responsible for some of the disease's progression. This work may lead to an entirely new class of drugs being used to treat patients with this drastic disease.Read moreRead less
Biology Of The Novel C-type Lectin Receptor DCL-1 In Innate And Adaptive Immune Response
Funder
National Health and Medical Research Council
Funding Amount
$439,500.00
Summary
The innate immune system is the first line of defense in protecting the body from infection. Phagocytic (meaning eating) white blood cells, which include dendritic cells and macrophages are equipped with cell surface proteins These bind the many types of microbes that cause infection, allowing the phagocytes to destroy them (innate immune response). Furthermore, dendritic cells and macrophages have mechanisms to activate additional specific responses (adaptive immune response) mediated by lympho ....The innate immune system is the first line of defense in protecting the body from infection. Phagocytic (meaning eating) white blood cells, which include dendritic cells and macrophages are equipped with cell surface proteins These bind the many types of microbes that cause infection, allowing the phagocytes to destroy them (innate immune response). Furthermore, dendritic cells and macrophages have mechanisms to activate additional specific responses (adaptive immune response) mediated by lymphocytes (T and B cells). We have discovered a cell surface protein, termed DCL-1, which may play a role in uptake of microbes by phagocytes and activation of innate and adaptive immune responses. This project will examine the mechanisms whereby DCL-1 mediates these immune responses. Understanding the mechanism may allow us to exploit DCL-1 for tumor immunotherapy.Read moreRead less
The C-type Lectin, Mincle, Is A Macrophage Receptor For Candida Albicans.
Funder
National Health and Medical Research Council
Funding Amount
$465,210.00
Summary
The yeast Candida albicans is an important opportunistic infection that causes both mucosal and disseminated disease in patients whose innate or adaptive immune responses are impaired Infection and proliferation results in fungal colonisation of the tissues, and a variable degree of tissue damage. The latter is determined both by the virulence properties of the organism and by the genetic makeup of the host. This large, extracellular pathogen is eradicated from the body predominantly by acavenge ....The yeast Candida albicans is an important opportunistic infection that causes both mucosal and disseminated disease in patients whose innate or adaptive immune responses are impaired Infection and proliferation results in fungal colonisation of the tissues, and a variable degree of tissue damage. The latter is determined both by the virulence properties of the organism and by the genetic makeup of the host. This large, extracellular pathogen is eradicated from the body predominantly by acavenger (phagocytic) cells, which are also important in determining the severity of the associated tissue lesions. A phagocytic cell that is central to both innate and adaptive immune responses is the macrophage, which not only takes up and kills the yeast, but also is capable of of killing and digesting it, and presenting the components to cells of the adaptive immune system. This project is based on the postulate that the outcome and severity of infection is determined, at least in part, by the early functional response of the macrophage to the overall virulence properties of the yeast. The response is initiated by interactions with cell-surface receptors, and this study will show that a novel macrophage receptor, Mincle, is an important part of the innate immune response to fungal infections. We have shown that it is associated with differences in susceptibility to yeast infections in inbred mouse strains; it can discriminate between different isolates of the yeast; and it initiates the inflammatory signalling cascade. Our project will define the specific role of this receptor in fungal infection. The results will be important in understanding the basic biology of host resistance, and will offer new opportunities for therapeutic intervention by selectively blocking or modifying different activation pathways.Read moreRead less
Role Of Complement Factor H And Related Proteins In Regulating Complement Activation And Microbial Pathogenesis
Funder
National Health and Medical Research Council
Funding Amount
$377,036.00
Summary
A group of proteins in blood called Complement are activated in the presence of foreign cells or organisms and this generally results in their destruction. It is important to direct this destructive activity against foreign and not self tissue. This is achieved by a further family of proteins, including factor H, which regulate complement activity and how these proteins work is the principal focus of this project. There are many diseases in which damage results from inadvertent complement damage ....A group of proteins in blood called Complement are activated in the presence of foreign cells or organisms and this generally results in their destruction. It is important to direct this destructive activity against foreign and not self tissue. This is achieved by a further family of proteins, including factor H, which regulate complement activity and how these proteins work is the principal focus of this project. There are many diseases in which damage results from inadvertent complement damage and the regulatory proteins have therapeutic potential in this area. In addition many bacteria and other microorganisms, which should be destroyed by complement, escape by binding regulatory proteins. Understanding how this is achieved may reveal new targets for vaccine development. Knowledge of how the production of factor H and related proteins will help understand how inflammation occurs and how it might be controlled.Read moreRead less
Defining The Molecular Regulators Of Apoptotic Cell Disassembly And Their Role In Cell Clearance And Lupus-like Autoimmune Disease
Funder
National Health and Medical Research Council
Funding Amount
$773,848.00
Summary
In humans, billions of cells will die daily as part of normal turnover in various organs. It is vital that dying cells are rapidly removed as their accumulation has been linked to autoimmunity and inflammation. To aid efficient removal of dead cells, dying cells can disassemble into smaller fragments for neighbouring cells to engulf. We aim to understand the machinery that controls how dying cells can disassemble into smaller pieces and their function in cell clearance and autoimmunity.
Role Of The Microglial Adaptor Molecule TYROBP In Alzheimer’s Disease Pathology
Funder
National Health and Medical Research Council
Funding Amount
$469,433.00
Summary
Immune activation characterizes Alzheimer’s disease (AD) brains; however, how it impacts AD progression is not understood. Our previous studies in AD brains identified the immune molecule TYROBP, pointing at both beneficial and detrimental effects triggered by this molecule. Here, we aim to understand in detail how TYROBP is involved in AD and how we can enhance its beneficial effects and decrease its unintended actions.