Genetic Adaptations Of Mycobacterium Tuberculosis For Intracellular Survival
Funder
National Health and Medical Research Council
Funding Amount
$187,677.00
Summary
Tuberculosis (TB) remains a significant global public health problem and new approaches to its treatment and prevention are urgently needed. The disease is caused by infection with Mycobacterium tuberculosis, a slow growing organism that lives within cells. How it adapts to survive in this intracellular environment is unknown. Recently the complete genome of M. tuberculosis was sequenced and new techniques developed for manipulating its genes. We plan to use these techniques to identify genes th ....Tuberculosis (TB) remains a significant global public health problem and new approaches to its treatment and prevention are urgently needed. The disease is caused by infection with Mycobacterium tuberculosis, a slow growing organism that lives within cells. How it adapts to survive in this intracellular environment is unknown. Recently the complete genome of M. tuberculosis was sequenced and new techniques developed for manipulating its genes. We plan to use these techniques to identify genes that are more active within the cells. Genes are controlled by short sequences of preceding DNA called promoters. If these promoters are randomly placed in front of readily identifiable reporter genes and inserted into a suitable host strain, it is possible to select for those promoters expressed only inside cells and then identify the promoter and its gene by sequence analysis. We plan to use two types of reporter genes. First, we shall place the M. tuberculosis DNA containing promoters before the gene for a naturally fluorescent protein within the M. bovis BCG host strain and then infect macrophages. If the promoters are switched on inside the cell, the macrophages will become green and can be selected and the promoter identified. After several rounds of selection the promoter is isolated and identified. Second, we shall select the promoters by their ability to produce a protein that is on the surface of the bacterium. We will use these intracellular genes to make better vaccines against TB. Genes that enhance intracellular survival may contribute to the virulence of the TB organism. By removing these genes we can make an attenuated organism suitable as a vaccine. We will test for reduced virulence by growth inside cells in mice. We will also use the intracellular promoter to improve the current BCG vaccine. Proteins expressed inside the cell may also be targets for new TB drugs.Read moreRead less
The Role Of Transcription Factors In Regulating The First Round Of Gene Expression In The Early Embryo.
Funder
National Health and Medical Research Council
Funding Amount
$348,931.00
Summary
Assisted reproductive technologies result in a high incidence of multiple births. This is and adverse outcome that requires correction. It stems from the common transfer of several embryos due to the low chance of an individual embryo made by IVF resulting in a baby. This project will determine the normal pattern of gene expression in the embryo and define: (1) how it is adversely changed as a consequence of IVF; and (2) the extent that these changes are a cause of the low embryo viability.
Mechanisms Of P53 Induced Embryopathy After In Vitro Fertilisation.
Funder
National Health and Medical Research Council
Funding Amount
$483,737.00
Summary
Assisted reproductive technologies (ART) cause many embryos not to survive to birth. We have shown that IVF causes increased expression of protein normally involved in stopping cells from dividing. This is a major cause of embryo death after IVF. This project will determine how this protein acts to cause embryonic death and assess strategies to prevent it.
C-JUN TARGETING STRATEGIES AS NOVEL CARDIOPROTECTIVE AGENTS IN ISCHAEMIA-REPERFUSION INJURY
Funder
National Health and Medical Research Council
Funding Amount
$361,148.00
Summary
Acute myocardial infarction (AMI) and its sequelae are an increasing problem in terms of morbidity, mortality and healthcare costs in Australia and the industrialised world; in the USA this is estimated annually at 900,000 and 225,000 patients and US$60 billion, respectively. Current treatment for AMI includes mechanical (percutaneous coronary intervention) or thrombolytic therapy; however, these approaches are directed primarily at epicardial arteries rather than the myocardium and are, therefo ....Acute myocardial infarction (AMI) and its sequelae are an increasing problem in terms of morbidity, mortality and healthcare costs in Australia and the industrialised world; in the USA this is estimated annually at 900,000 and 225,000 patients and US$60 billion, respectively. Current treatment for AMI includes mechanical (percutaneous coronary intervention) or thrombolytic therapy; however, these approaches are directed primarily at epicardial arteries rather than the myocardium and are, therefore, suboptimal. Strategies aimed at directly protecting cardiomyocytes from ischaemia-reperfusion injury, reducing leukocyte recruitment and myocardial cell death, would complement current approaches restoring epicardial artery flow and are keenly sought. This project will demonstrate the capacity of two separate gene-silencing strategies (DNAzymes and siRNA to suppress the expression of the immediate-early gene, c-Jun in cardiomyocytes and reduce infarct size, left ventricular dysfunction, apoptosis, inflammation, production of reactive oxygen species, angiogenesis and fibrosis in the injured rat myocardium. It will also shed light on the molecular mechanisms underlying c-Jun-mediated myocardial inflammation. As such, these studies will provide important proof of principle evidence for these small molecule nucleic acid agents as potential therapeutic tools as cardioprotective agents in ischaemia-reperfusion injury.Read moreRead less
Controlling the rate of transcription and translation of Rubisco transgenes effectively in higher-plant plastids. Genetic transformation of the circular genome of the plastids provides a containable means for modifying plant growth by manipulating photosynthesis. Although the transformation mechanism is precise, predicting the level of foreign gene expression is difficult because the amounts of messenger RNA and protein produced by foreign genes in plastids varies widely, even when the protein a ....Controlling the rate of transcription and translation of Rubisco transgenes effectively in higher-plant plastids. Genetic transformation of the circular genome of the plastids provides a containable means for modifying plant growth by manipulating photosynthesis. Although the transformation mechanism is precise, predicting the level of foreign gene expression is difficult because the amounts of messenger RNA and protein produced by foreign genes in plastids varies widely, even when the protein assembles without difficulty. This project will devise strategies for controlling this variability that will facilitate attempts to exploit plastid transformation for transplanting better versions of the photosynthetic CO2-fixing enzyme, Rubisco, into plants to improve their growth efficiency in terms of water, fertiliser and light use.Read moreRead less
Defining New Building Blocks for the Construction of Artificial Genetic Circuits. By characterising the components of a natural genetic switch, we will make available a set of well defined genetic building blocks for construction of rationally designed biological circuits. The ability to build such circuits would have significant economic benefit in areas such as metabolic engineering, to improve the efficiency of production of natural compounds from micro-organisms, and in biomedicine, for the ....Defining New Building Blocks for the Construction of Artificial Genetic Circuits. By characterising the components of a natural genetic switch, we will make available a set of well defined genetic building blocks for construction of rationally designed biological circuits. The ability to build such circuits would have significant economic benefit in areas such as metabolic engineering, to improve the efficiency of production of natural compounds from micro-organisms, and in biomedicine, for the controlled release of therapeutic compounds. The involvement of Honours and Ph.D students in this project will expose the next generation of Australian scientists to this emerging discipline. International collaboration leading to publications in high impact scientific journals will enhance Australia's scientific reputation.Read moreRead less
Practical strategies for engineering the CO2-fixing enzyme, Rubisco, whose subunits are encoded in different subcellular compartments. My recent replacement of the plant CO2-fixing enzyme, Rubisco, with a less efficient bacterial version, with a single type of subunit encoded by a single gene, demonstrated the feasibility of replacing Rubisco. This encourages ongoing attempts to replace plant Rubisco with more efficient versions that would allow the plants to grow with less water, fertiliser or ....Practical strategies for engineering the CO2-fixing enzyme, Rubisco, whose subunits are encoded in different subcellular compartments. My recent replacement of the plant CO2-fixing enzyme, Rubisco, with a less efficient bacterial version, with a single type of subunit encoded by a single gene, demonstrated the feasibility of replacing Rubisco. This encourages ongoing attempts to replace plant Rubisco with more efficient versions that would allow the plants to grow with less water, fertiliser or light. The most efficient Rubiscos are more complex, with two different types of subunits which, in plants, are encoded in different subcellular compartments (nucleus and plastid). This proposal addresses the challenges associated with complementary engineering both genomes to substitute foreign Rubiscos into higher-plant chloroplasts.Read moreRead less