Study Of Papillomavirus DNA Encapsidation And Formation Of Infectious Virions
Funder
National Health and Medical Research Council
Funding Amount
$214,053.00
Summary
Papillomavirus (PV) is a sexually-transmitted virus that is a major cause of cervical cancer. Our study will determine how PV is able to form new virus particles inside infected cells. This is a critical part of the virus life-cycle, and a better understanding of this process may allow it to be trageted by anti-viral treatments. In addition, we will develop a method to create non-harmful virus particles which we will use to study human immune responses to the virus.
RECOMBINANT MALARIAL PYRIMIDINE ENZYMES AS DRUG TARGETS
Funder
National Health and Medical Research Council
Funding Amount
$229,750.00
Summary
Malarial parasites have now developed resistance to most of the available drugs and there is an urgent need for drugs with new mechanisms of action. Institutions collaborating on the Malarial Genome Project have sequenced the majority of DNA in the 14 chromosomes. The nucleotide sequence available on the internet contains thousands of open reading frames (ORFs) which encode proteins essential for survival of the parasite. Many of these proteins are enzymes which are suitable targets for drug dev ....Malarial parasites have now developed resistance to most of the available drugs and there is an urgent need for drugs with new mechanisms of action. Institutions collaborating on the Malarial Genome Project have sequenced the majority of DNA in the 14 chromosomes. The nucleotide sequence available on the internet contains thousands of open reading frames (ORFs) which encode proteins essential for survival of the parasite. Many of these proteins are enzymes which are suitable targets for drug development. A knowledge of the molecular architecture of the active site of such enzymes provides a template for drug design. The malarial parasite, Plasmodium falciparum, can only synthesise pyrimidine nucleotides for DNA via the de novo pyrimidine pathway. We have cloned the genes encoding three of the enzymes of the de novo pathway using sequence information from the Malarial Genome Project. Dihydroorotase, orotate phosphoribosyltransferase, and OMP decarboxylase, catalyse reactions 3, 5 and 6 of the pathway. We have expressed these enzymes in the bacterium Escherichia coli enabling large-scale production of these drug targets. We propose to characterise the catalytic and inhibitory properties of these enzymes, and grow protein crystals for determination of atomic structures by x-ray diffraction. The structures will provide templates for rational design of new antimalarial drugs. In a second approach for develoment of new drugs, the 3 malarial enzymes will be screened against chemical libraries for inhibition of catalytic activity. The initial screen will utilise a high throughput Biacore 3000 instrument which detects strong interactions between a target enzyme and candidate inhibitors. A thorough knowledge of the catalytic mechanisms, the three-dimensional structures and novel first generation inhibitors of these 3 malarial target enzymes, will provide a strong basis for development of new antimalarial drugs.Read moreRead less
Development Of Improved Vaccine Strategies For Measles Using Plant-derived Edible Vaccines
Funder
National Health and Medical Research Council
Funding Amount
$331,980.00
Summary
Measles is a highly contagious viral disease that is contracted via the respiratory tract. Severe infection may lead to complications such as otitis media, pneumonia, encephalitis. Despite our current vaccination strategy outbreaks still occur in Australia and measles is a major problem in developing countries. In developing nations the case fatality rate of measles is several hundred times that of developed nations. Over 800,000 children still die each year due to measles. Problems with the cur ....Measles is a highly contagious viral disease that is contracted via the respiratory tract. Severe infection may lead to complications such as otitis media, pneumonia, encephalitis. Despite our current vaccination strategy outbreaks still occur in Australia and measles is a major problem in developing countries. In developing nations the case fatality rate of measles is several hundred times that of developed nations. Over 800,000 children still die each year due to measles. Problems with the current vaccination strategy are: a) doesn't work in children less than 1 year of age, b) must be kept cold c) must be given by injection. We believe that a plant derived edible vaccine for measles will address the limitations of currently available vaccine i.e. we can give it children under the age of 1 year, it can be eaten and doesn't have to be kept cold.Read moreRead less
Though vaccination has had a major impact on the number of persons becoming infected, chronic infection with the hepatitis B virus (HBV) still remains a major worldwide problem, with 350 million people chronically infected. The existence of HBV vaccine escape mutants and the fact that 5% of vaccinees fail to respond implies that HBV will remain a significant public health problem for the foreseeable future. Current treatments for chronic HBV infection have a low success rate (~20%) and patients ....Though vaccination has had a major impact on the number of persons becoming infected, chronic infection with the hepatitis B virus (HBV) still remains a major worldwide problem, with 350 million people chronically infected. The existence of HBV vaccine escape mutants and the fact that 5% of vaccinees fail to respond implies that HBV will remain a significant public health problem for the foreseeable future. Current treatments for chronic HBV infection have a low success rate (~20%) and patients with chronic infection are expected to die prematurely due to chronic liver disease or primary liver cancer. Interestingly, exposure to HBV can lead to either acute resolving or chronic HBV infection. Like chronic infections, acute infections involve spread of virus to virtually every hepatocyte, followed by rapid clearance of the virus mediated by the host immune response. Our immediate aim is to study the resolution of acute HBV infections to determine how the stable intracellular viral genome, covalently closed circular DNA (cccDNA), is cleared from the nucleus of infected hepatocytes. Our broad long-term aim is to develop new and effective treatments for chronic HBV infection based on a better understanding of how acute HBV infections are resolved by the host. Based on our previous work we believe that clearance of cccDNA requires hepatocyte death, together with compensatory proliferation of other infected hepatocytes. We will perform detailed studies in duck hepatitis B virus (DHBV) infected ducks to determine if hepatocyte death and compensatory proliferation are essential to clear the infection, or if mechanisms exist for clearance that do not involve cell destruction.Read moreRead less