Targeting Fungal Phospholipid Metabolism For Antifungal Drug Discovery
Funder
National Health and Medical Research Council
Funding Amount
$828,557.00
Summary
Invasive fungal infections are a serious and escalating health problem. They cause severe disease with a high death rate and are very costly to the health system. New antifungal drugs with novel properties are needed now because there are problems with current drugs. This project aims to develop potent new antifungal drugs that are effective in many fungal diseases and are well-tolerated.
Investigating The Interface Between Host Innate Immune Cells And A Fungal Pathogen
Funder
National Health and Medical Research Council
Funding Amount
$578,085.00
Summary
Fungi which infect humans are a major health problem, especially for those with compromised immune systems (eg. AIDS, transplant and cancer patients). These fungi cause disease by evading the immune system whilst deriving nutrients for growth. Some fungi evade the immune system by residing within host cells; a hostile and nutrient poor environment. This project will study a pathway that we have shown is required for growth inside host cells. This knowledge will open new avenues for treatment.
The Role Of Fatty Acid Metabolism In Pathogenicity.
Funder
National Health and Medical Research Council
Funding Amount
$540,075.00
Summary
Fungi which infect humans are a major health problem, especially for those with compromised immune systems (eg. AIDS, transplant and cancer patients). Pathogenic fungi must evade the host s immune system whilst deriving nutrients for growth. Some fungi evade the immune system by residing within host cells. This poses significant challenges to growth due to the nutrient poor environment. By understanding how these fungi adapt to growth inside host cells, new avenues for treatment will emerge.
Molecular Mechanisms Of Intracellular Growth, Survival And Pathogenicity
Funder
National Health and Medical Research Council
Funding Amount
$335,816.00
Summary
Fungi which infect humans are a major health problem, especially for those with compromised immune systems (eg. AIDS, transplant and cancer patients). These fungi cause disease by evading the immune system whilst deriving nutrients for growth. Some fungi evade the immune system by residing within host cells; a hostile and nutrient poor environment. This project will study a pathway that we have shown is required for growth inside host cells. This knowledge will open new avenues for treatment.
Transposable Element Mobility And Chromosomal Rearrangement In The Fungal Pathogen Cryptococcus During Human Infection
Funder
National Health and Medical Research Council
Funding Amount
$322,028.00
Summary
Pathogenic fungi present in the environment have emerged as an increasingly common threat to human health. Cryptococcus neoformans and the closely related species Cryptococcus gattii are the leading causes of life-threatening fungal meningitis, and Australia is one of the few countries where both species are prevalent. Although C. neoformans is an increasingly common cause of infection in immunocompromised patients such as those suffering from AIDS, approximately one in four infected individuals ....Pathogenic fungi present in the environment have emerged as an increasingly common threat to human health. Cryptococcus neoformans and the closely related species Cryptococcus gattii are the leading causes of life-threatening fungal meningitis, and Australia is one of the few countries where both species are prevalent. Although C. neoformans is an increasingly common cause of infection in immunocompromised patients such as those suffering from AIDS, approximately one in four infected individuals has no apparent immune system defect. For patients with AIDS, in the absence of antiretroviral therapy cryptococcal infection is incurable and requires lifelong treatment with antifungal medication to keep the infection in check. During infection, Cryptococcus is under tremendous stress enforced not only by the immune system and the presence of antifungals, but also by the high temperature, nutrient limiting environment encountered in the host. The proposed research will reveal how Cryptococcus evolves in this environment to enable persistence of infection despite medical intervention. I propose that naturally occurring mobile genetic elements present in the Cryptococcus genome cause chromosomal rearrangements during long term infection to produce gene deletions and duplications that facilitate survival. By characterising these changes and the genes associated with them, the research will identify novel genes involved in pathogenesis and will increase our understanding of the infection process. The expected outcome of this project is a detailed understanding of the roles mobile element movement and chromosomal rearrangement play in Cryptococcus during infection, and how these affect genes that contribute to the pathogenic process. The fundamental knowledge gained from this study will facilitate studies designed to combat infections in the clinical setting, provide new drug targets and help foster the development of more effective therapies.Read moreRead less
Cryptococcal Phospholipases: Structure, And Potential Targets For Therapeutics
Funder
National Health and Medical Research Council
Funding Amount
$511,650.00
Summary
Mortality and morbidity from invasive fungal infections have increased substantially over the past two decades, especially in immunocompromised patients, such as those with AIDS. Antifungal drugs marketed at present are not very effective or are toxic. There is a need to identify new metabolic and structural targets, some of which are responsible for fungal virulence, as potential areas for development of new drugs. One such virulence factor discovered in our laboratory is an enzyme secreted by ....Mortality and morbidity from invasive fungal infections have increased substantially over the past two decades, especially in immunocompromised patients, such as those with AIDS. Antifungal drugs marketed at present are not very effective or are toxic. There is a need to identify new metabolic and structural targets, some of which are responsible for fungal virulence, as potential areas for development of new drugs. One such virulence factor discovered in our laboratory is an enzyme secreted by the pathogenic fungus, Cryptococcus neoformans, which is acquired by inhalation into the lungs where it can cause lesions, and eventually spreads to other parts of the body, including the brain (median mortality, 17%). This enzyme breaks down cell membranes, aiding invasion into the host lungs and other tissues, and is called phospholipase B (PLB). It is also produced by several other pathogenic fungi, and is different from human phospholipases. In this project we aim to understand how the PLB is constructed, so that we can work out where the cell membrane components bind to it. We will then design drugs which can bind to the PLB enzyme in place of membrane components and in this way block its harmful effects. We will test the effects of such drugs to make sure they do not interfere with human enzyme systems. Inhibitory compounds may also be able to kill the cryptococcal cells, especially if administered together with currently used therapies. Drugs developed to treat Cryptococcus will then be applicable to other systemic fungal infections - a major advance in the treatment of fungal disease, and a saving of some A$60,000 per patient (estimated from a recent U.S. study).Read moreRead less
Fungal Phospholipases: A Novel Drug Discovery Platform
Funder
National Health and Medical Research Council
Funding Amount
$588,679.00
Summary
Invasive fungal infections are a serious and escalating health issue. They cause severe disease with a high death rate and are very costly to the health system. This is especially the case in immunocompromised patients, such as those with blood malignancies, organ transplant recipients and AIDS. The number of currently available drugs for the treatment of fungal infections is limited and they are, in general, either not very effective or toxic. The development of fungal strains resistant to thes ....Invasive fungal infections are a serious and escalating health issue. They cause severe disease with a high death rate and are very costly to the health system. This is especially the case in immunocompromised patients, such as those with blood malignancies, organ transplant recipients and AIDS. The number of currently available drugs for the treatment of fungal infections is limited and they are, in general, either not very effective or toxic. The development of fungal strains resistant to these drugs is also becoming problematic. There is an urgent need to discover and develop new drugs effective against fungal infections through identifying new targets in the fungal cell and-or targets that prevent the spread of infection in the human host. We were the first to describe an enzyme, phospholipase B (PLB1), which is secreted by the medically important fungus, Cryptococcus neoformans, and is important in invasion of human tissue by the fungus. It is also important in remodelling of membranes in the fungal cell. This enzyme is sufficiently different from human phospholipases to be a good target for antifungal drugs. In this project, we aim to synthesise and test molecules which should inhibit the activity of PLB and in this way block its harmful effects. We will test the effects of such drugs to make sure they do not interfere with human enzyme systems. Inhibitory compounds may also be used to kill the fungal cells, especially if administered together with currently used therapies. The design and development of new antifungal drugs with a novel mode of action represents a major advance in the treatment of fungal disease, and a saving of some A$60000 per affected patient (estimated from a recent US study).Read moreRead less
Regulation Of Secretion Of The Fungal Virulence Determinant, Phospholipase B
Funder
National Health and Medical Research Council
Funding Amount
$487,500.00
Summary
Serious systemic infections due to fungi have increased dramatically in the past few years, especially in people with poorly functioning immune systems. Treatment of these conditions is problematic because the few drugs which are available are not highly effective, and-or cause significant side-effects. Little is understood of how fungi cause disease, and this problem must be addressed if these infections are to be contained. We have discovered that the enzyme, phospholipase B (PLB), is secreted ....Serious systemic infections due to fungi have increased dramatically in the past few years, especially in people with poorly functioning immune systems. Treatment of these conditions is problematic because the few drugs which are available are not highly effective, and-or cause significant side-effects. Little is understood of how fungi cause disease, and this problem must be addressed if these infections are to be contained. We have discovered that the enzyme, phospholipase B (PLB), is secreted by the disease-causing fungus, Cryptococcus neoformans, and that it is important in enabling the fungus to invade the host's cells and spread around the body from the lungs to the brain, where it can cause meningoencephalitis. PLB is also produced by other disease-causing fungi. The mechanism of PLB secretion is completely unknown. In this project we aim to determine the pathways involved in PLB secretion with the intention of exploiting steps unique to pathogenic fungi, for the future design of new anti-fungal drugs.Read moreRead less
Novel Use Of Fungal Entomopathogens For Sustainable Control Of Mosquito-borne Viruses
Funder
National Health and Medical Research Council
Funding Amount
$605,993.00
Summary
Mosquito-born viruses such as Dengue, Ross River and Barmah Forest are increasing in regional significance. At a broader scale, an estimated 2.5 billion people live in areas at risk of epidemic Dengue transmission. Chemical insecticides are the mainstay of current mosquito control throughout many parts of the world. However, problems of insecticide resistance, environmental contamination and risks to human health, mean that chemical pesticides have not provided a universal solution, either as ou ....Mosquito-born viruses such as Dengue, Ross River and Barmah Forest are increasing in regional significance. At a broader scale, an estimated 2.5 billion people live in areas at risk of epidemic Dengue transmission. Chemical insecticides are the mainstay of current mosquito control throughout many parts of the world. However, problems of insecticide resistance, environmental contamination and risks to human health, mean that chemical pesticides have not provided a universal solution, either as outdoor sprays, residual house sprays or as insecticide treated nets. This creates a pressing need for practical alternatives. Building on approaches and technologies developed for control of locusts in Australia and Africa, we have recently discovered that the ability of mosquitoes to transmit malaria can be substantially reduced with insect fungal pathogens used as biological pesticides. We found that exposure to biopesticide-treated surfaces reduced the number of mosquitoes able to transmit malaria 80-fold. Other supporting data from semi-field trials confirm the feasibility of infecting mosquitoes under real field conditions. Together, these results represent a significant advance in the development of a cheap and sustainable biological alternative to chemical insecticides for disease control. We now wish to extend this research to explore the potential for use of fungal pathogens in control of mosquito-borne viruses. Preliminary studies already confirm that we can infect the key mosquito species responsible for transmitting Dengue. The aim of the current project is to conduct a more comprehensive evaluation of a wider range of fungal isolates to identify strains with the greatest potential to stop transmission of mosquito-borne viruses. The longer term goal is to translate this research into a practical product. Such a product would offer a cheap, environmentally friendly disease control measure, with reduced potential for resistance evolution.Read moreRead less
The Clinical Value Of Serology And Molecular Tests For Diagnosing Invasive Aspergillosis In At-risk Hematology Patients
Funder
National Health and Medical Research Council
Funding Amount
$1,095,500.00
Summary
Aspergillus is a fungus found in soil, on farms and on construction sites. In those whose immune system is impaired it causes severe infection. The people who are particularly at high-risk of Aspergillus infection (called Invasive Aspergillosis) are those with acute leukaemia on chemotherapy or post bone marrow transplantation. Currently 15% of those at high-risk get Invasive Aspergillosis and 58-93% of those infected die. The main reason for this high death rate is that our current diagnostic t ....Aspergillus is a fungus found in soil, on farms and on construction sites. In those whose immune system is impaired it causes severe infection. The people who are particularly at high-risk of Aspergillus infection (called Invasive Aspergillosis) are those with acute leukaemia on chemotherapy or post bone marrow transplantation. Currently 15% of those at high-risk get Invasive Aspergillosis and 58-93% of those infected die. The main reason for this high death rate is that our current diagnostic tests are not good at detecting infection or often only detect the infection at advanced stages when treatment is ineffective. Because of the limitations of current diagnostic tests the current practice is to give empiric antifungal therapy (EAFT) early to treat Invasive Aspergillosis. However studies have demonstrated that this therapy has only resulted in a minor reduction in the mortality rates and it causes significant drug toxicity. It is a suboptimal treatment modality. New tests have been developed to diagnose Invasive Aspergillosis. These tests are for the detection of an Aspergillus protein in blood and for the detection of Aspergillus DNA in the blood. Available data suggests that these new tests are sensitive in the detection of Invasive Aspergillosis. Also other studies suggest that these new tests make an early diagnosis and seem to be able to monitor responses to treatment. However no study has been performed to date which demonstrates that the use of these tests can impact on important patient outcomes. This trial is designed to determine whether the use of the new tests to guide therapy will help improve treatment of Invasive Aspergillosis, reduce drug toxicity and reduce the death rate in the high-risk patients as compared with the current standard method of diagnosis and treatment with EAFT. If the trial is successful then this represents a significant advancement in the treatment and survival of leukaemic and bone marrow transplantation patients.Read moreRead less