Inhibitors Of Bacterial Protein Synthesis - A New Class Of Antibiotics
Funder
National Health and Medical Research Council
Funding Amount
$120,000.00
Summary
Pioneering work by CSIRO scientists has identified specific peptide motifs in the DNA replication machinery of bacteria that are critical for the correct functioning of the organism. In collaboration with CI Alewood potent (Kd ~ nM) lead compounds that inhibit bacterial DNA replication have been designed and synthesised. Through the application of a number of novel bioinformatics approaches to the analysis of the complete genome sequences of bacteria, the key sites of interaction of a number of ....Pioneering work by CSIRO scientists has identified specific peptide motifs in the DNA replication machinery of bacteria that are critical for the correct functioning of the organism. In collaboration with CI Alewood potent (Kd ~ nM) lead compounds that inhibit bacterial DNA replication have been designed and synthesised. Through the application of a number of novel bioinformatics approaches to the analysis of the complete genome sequences of bacteria, the key sites of interaction of a number of protein families (DNA synthesis and repair enzymes) with the beta subunit of bacterial DNA Polymerase III have been identified. The nature of the sites, and preliminary experimental data, suggests that the approach will be generally applicable to all species of bacteria. In addition a wide range of novel assays for the identification of inhibitors of the interaction of proteins with the beta subunit have been developed. In this proposal we wish to demonstrate that our in vitro nanomolar inhibitors of the beta subunit can inhibit bacterial cell growth. The development program proposes to develop methods and strategies to gain bacterial cell entry of inhibitors of the interaction of proteins with the beta subunit of bacterial DNA Polymerase III. Proof of concept will be demonstrated by inhibition of bacterial cell growth. Stable compounds with good binding characteristics and able to be taken up by cells will be developed based on structure-function assay results, structural studies and modelling of inhibitors bound to the target. Antimicrobial activity of compounds will be demonstrated in standard FDA approved NCLLS (National Centre of Clinical Laboratory Standards USA) tests. Spectrum of activity will be demonstrated by testing compounds against bacterial species representative of the range of pathogenic organisms in standard FDA assays.Read moreRead less
Evaluation Of Factor Va From The Venom Of The Australian Brown Snake As A Topical And Systemic Anti-bleeding Agent
Funder
National Health and Medical Research Council
Funding Amount
$113,742.00
Summary
Anti-bleeding agents are important pharmaceuticals for use in truama, surgery and several medical conditions to reduce blood loss and the need for blood transfusion. Some Australian snakes contain in their venom a powerful blood clotting agent. This agent mimics the human clotting machinery. In this project, we plan to test purified components of snake venom for an ability to clot human blood. We will undertake laboratory test-tube experiments as well as using an animal model after ethical appro ....Anti-bleeding agents are important pharmaceuticals for use in truama, surgery and several medical conditions to reduce blood loss and the need for blood transfusion. Some Australian snakes contain in their venom a powerful blood clotting agent. This agent mimics the human clotting machinery. In this project, we plan to test purified components of snake venom for an ability to clot human blood. We will undertake laboratory test-tube experiments as well as using an animal model after ethical approval. This project seeks to capture some of the genetic blueprint of an Australian snake, for human benefit by developing a new therapeutic agent based on a venom component. If the experiments are successful, the next stage will be further testing of efficacy and toxicity before seeking approval for clinical trials. The research is supported by the Australian pharmaceutical company QRx Pharma Pty Ltd who will work with Uniquest Pty Ltd to protect intellectual property generated in the project.Read moreRead less
Synthesis And Purification Of Flavivirus-specific Antiviral Factor Mrasal
Funder
National Health and Medical Research Council
Funding Amount
$140,000.00
Summary
In this proposal we suggest to develop an anti-flaviviral compound based on naturally occurring host factors associated with inborn flavivirus resistance observed in mice. We propose to synthesise and purify a mouse protein factor encoded by a gene (Mrasal), which we have previously mapped by mouse genetics and positional cloning to a narrow 300 kb chromosomal region on mouse chromosome 5 carrying flavivirus resistance locus (Flv). When this mouse gene was isolated, sub cloned into a mammalian e ....In this proposal we suggest to develop an anti-flaviviral compound based on naturally occurring host factors associated with inborn flavivirus resistance observed in mice. We propose to synthesise and purify a mouse protein factor encoded by a gene (Mrasal), which we have previously mapped by mouse genetics and positional cloning to a narrow 300 kb chromosomal region on mouse chromosome 5 carrying flavivirus resistance locus (Flv). When this mouse gene was isolated, sub cloned into a mammalian expression vector pcDNA3tag and transiently transfected and expressed in cos-7 and Vero cells, its product conferred antiviral effect to a flavivirus Murray Valley encephalitis (MVE), but not to a non-flavivirus encephalomyocarditis virus (EMCV). Mrasal protein operates as an antiviral host factor and confers a flavivirus specific resistance at the cellular level. It could be directly used for the treatment-cure of acute flavivirus infections in vivo. Our aims are to produce and purify the Mrasal protein for the in vivo delivery as a therapeutic compound into susceptible mice during the acute phase of flavivirus infection: 1. To synthesise and purify Mrasal protein using baculovirus system. 2. To encapsulate the protein into liposomes ready to be used in mice. 3. To perform initial testing in a limited number of susceptible mice.Read moreRead less
Activated Protein C As A Promoter Of Wound Healing
Funder
National Health and Medical Research Council
Funding Amount
$391,650.00
Summary
The healing of wounds is a complex process involving a number of stages, including coagulation, inflammation, remodelling and finally development of full strength skin. Impaired wound healing and-or skin ulcers occur in patients with peripheral arterial occlusive disease, deep vein thrombosis, diabetes, pressure sores and burns. Despite intense investigation, the precise mechanisms associated with impaired healing are poorly understood. APC is a serine protease that plays a central role in physi ....The healing of wounds is a complex process involving a number of stages, including coagulation, inflammation, remodelling and finally development of full strength skin. Impaired wound healing and-or skin ulcers occur in patients with peripheral arterial occlusive disease, deep vein thrombosis, diabetes, pressure sores and burns. Despite intense investigation, the precise mechanisms associated with impaired healing are poorly understood. APC is a serine protease that plays a central role in physiological anticoagulation. APC potently activates gelatinase A, an enzyme that plays a prominent role during the remodelling phase of wound healing and angiogenesis. Our preliminary experiments provide very strong evidence that APC accelerates wound healing using both cultured cells and a rat skin wounding model. There are three aims to this study. The first will use cell culture techniques to investigate the mechanisms of action of APC during wound healing. Secondly, we will expand our pilot studies on the effect of APC as a promoter of wound healing in vivo. These studies will examine the exact dosing and timing regime for APC, using a rat wound healing model. In addition, we will test the effect of APC on slow healing wounds, present in diabetic rats. Thirdly, we will determine whether APC is quantitatively or functionally deficient in human wound fluid derived from slow-healing wounds compared to wounds that heal normally. This is the first time that APC has been implicated in wound healing. It is envisaged that this work will ultimately lead to a novel topical treatment of APC to accelerate slow-healing wounds.Read moreRead less
Targeting Protein Kinase C In Diabetes Management Using Novel Polyunsaturated Fatty Acids
Funder
National Health and Medical Research Council
Funding Amount
$150,000.00
Summary
PKC regulates a diverse range of cellular processes in an isozyme-specific manner. There is strong recent evidence to implicate PKC, especially PKC _, in mediating the actions of glucose in diabetes. This includes the action of glucose in renal glomeruli, retina, aorta and heart of diabetic animals and in cultured cells from these organs. More importantly, inhibition of PKC_ with the PKC_-specific inhibitor, LY333531, blocks the actions of glucose. Recently, our research group designed and synth ....PKC regulates a diverse range of cellular processes in an isozyme-specific manner. There is strong recent evidence to implicate PKC, especially PKC _, in mediating the actions of glucose in diabetes. This includes the action of glucose in renal glomeruli, retina, aorta and heart of diabetic animals and in cultured cells from these organs. More importantly, inhibition of PKC_ with the PKC_-specific inhibitor, LY333531, blocks the actions of glucose. Recently, our research group designed and synthesised a family of novel polyunsaturated fatty acids. One of these, MP5 (_-oxa- 21:3n-3), inhibited high glucose-induced activation of PKC? in cultured mesangial cells as well as in glomeruli of diabetic rats in a relatively selective manner. The overall aim of this proposal is to evaluate the potential for a chemically engineered novel polyunsaturated fatty acid, MP5 (_-oxa-21:3n-3), to treat pathogenesis associated with diabetes by targeting the PKC system. The specific aims are to: 1. Characterise the effects of MP5 on glucose- or advanced glycosylation end product-stimulated activation of protein kinase C (PKC). 2. Determine whether esterification of MP5 into diacylglycerol is essential for the action of MP5 3. Investigate whether MP5 is efficacious at preventing the actions of glucose in vitro e.g. glucose stimulated TGF_ production in mesangial cells, and in vivo in streptozotocin-diabetic rRead moreRead less
Kunjin Replicons For Gene Therapy And Protein Manufacture
Funder
National Health and Medical Research Council
Funding Amount
$310,000.00
Summary
This grant seeks to provide proof of concept (PoC) for the use of the Kunjin replicon technology for gene therapy and protein production. (A) Protein production. Two Kunjin replicon constructs expressing green fluorescent protein (GFP) and secreted alkaline phosphatase (SEAP) are to be constructed and protein production monitored using FACS and SEAP bioactivity reporter kit (Roche), respectively. Protein production and biological activity of the proteins will be monitored in transient transfecti ....This grant seeks to provide proof of concept (PoC) for the use of the Kunjin replicon technology for gene therapy and protein production. (A) Protein production. Two Kunjin replicon constructs expressing green fluorescent protein (GFP) and secreted alkaline phosphatase (SEAP) are to be constructed and protein production monitored using FACS and SEAP bioactivity reporter kit (Roche), respectively. Protein production and biological activity of the proteins will be monitored in transient transfections and over an extended time period. Several cell lines, culture conditions and Kunjin replicon vector modifications will be tested. Arrangements have also been made to send the constructs to Roche, GSK, Eli Lilly, and Exelixis for side by side comparisons of this system with existing proprietary protein production echnologies. (B) Gene therapy. Two PoC gene therapy systems are proposed to be used for evaluation of Kunjin replicon vectors. (i) Tumours expressing granulocyte macrophage colony stimulating factor (GMCSF) by transfection cause the generation of anti-tumour CD8 T cells and subsequent tumour rejection. Current approaches include adoptive transfer of adeno-GM-CSF transfected tumour cells, a costly and laborious process resulting in only transient expression (Can. Imm. Immunother 2001 50:373). We intend to inject Kunjin replicon virus like particles into growing s.c. B16 melanomas and expect to see a high infection rate, a sustained high-level expression of GMCSF, and rejection of the tumour. In contrast to Kunjin, nearly all humans have antibody responses to adenovirus, and very high titres of adenovirus are required to obtain high infection and GM-CSF expression. Both factors limit adenovirus use in vivo. (ii) Transplant rejection can be inhibited by expression in the graft of CTLA4-Fc a reagent that blocks T cell co-stimulation enhancing allo-graft acceptance (Transplantation 2000 69:1806). High-level expression for over 100 days is expected to correlate with optimal graft acceptance. Our ability to use Kunjin to express beta galactosidase for several months in vivo without inflammation illustrates the potential for this approach (CIB ref 15). Initially we intend to use P815 cells injected i.p. into C57BL-6, where they are usually rejected within a few days. In contrast, P815 cells with Kunjin replicon-mediated CTLA4-Fc expression should survive for an extended period. Graft survival is easily monitored using FACS and anti-H-2d antibodies.Read moreRead less
Proof Of Concept Studies On A Novel Class Of Antibiotics
Funder
National Health and Medical Research Council
Funding Amount
$199,700.00
Summary
The rise of drug-resistant superbugs is a major healthcare concern in hospitals across the world. New antibiotics are needed to combat infections caused by bacteria that are resistant to current drugs. One collaborative team of researchers is addressing the issue. They have discovered a new compound effective against Staphylococcus aureus, the cause of Golden Staph. Using a combination of scientific disciplines the team are now developing this compound into a new antibiotic.
Pre-clinical Assessment Of Novel Growth Factor Complexes As A Topical Agent In The Treatment Of Deep
Funder
National Health and Medical Research Council
Funding Amount
$156,870.00
Summary
Healing of deep burns, unlike that of superficial injuries, often resolves with scarring. Scarring is reduced with rapid closure of burns. The CIs have discovered and patented novel growth factor complexes that stimulate the growth and migration of keratinocytes, cells derived from skin. Hence these complexes hold therapeutic potential for wounds that require rapid closure such as deep burns. This application will provide pre-clinical, proof-of-principle data to facilitate future patient trials.
Development Of Inhibitors Of PKCzeta For Targeting Vascular Leak
Funder
National Health and Medical Research Council
Funding Amount
$335,113.00
Summary
Vascular leak (permeability) is a chief pathophysiological mechanism of many inflammatory diseases and cancer. Effective methods of reducing vascular permeability are likely to reduce or prevent morbidity. At present there are no potent broad spectrum inhibitors of vascular permeability. This application focuses on the development of such inhibitors.
Stage II In The Development Of Eph/ephrin Based Tumor Targeting Reagents: Optimisation Of Drug Efficacy And Delivery
Funder
National Health and Medical Research Council
Funding Amount
$204,125.00
Summary
In the final stage of cancer, including melanoma, tumor cells gain the ability to spread, a process called metastasis. Altered communication between cancer and normal cells is one of the causes of this invasive characteristic. We have started the development of novel agents that target and modulate proteins on the cell surface that control these properties and are found in metastatic tumors. We propose to refine the targeting and killing properties of these agents for early clinical testing.