Human immunodeficiency virus type 1 (HIV-1) causes AIDS and, to date, has infected approximately 20 thousand people in Australia and more than 40 million worldwide. People infected with HIV-1 first experience a period of 5-7 years where they remain healthy, ofter assisted by the use of anti-HIV-1 drugs, and this period is referred to as the asymptomatic period. After this period, infected individuals become sick due to their immune system being destroyed, and this is referred to as AIDS. Researc ....Human immunodeficiency virus type 1 (HIV-1) causes AIDS and, to date, has infected approximately 20 thousand people in Australia and more than 40 million worldwide. People infected with HIV-1 first experience a period of 5-7 years where they remain healthy, ofter assisted by the use of anti-HIV-1 drugs, and this period is referred to as the asymptomatic period. After this period, infected individuals become sick due to their immune system being destroyed, and this is referred to as AIDS. Research into how HIV-1 causes AIDS has shown us that the virus changes over time to make itself better able to kill cells of the immune system, by at least 2 mechanisms. The first mechanism, which is the best characterised one, is where the virus changes the way it infects cells, whereby it can infect many more cells in the body by taking advantage of an alternate receptor molecule on the cell called CXCR4. This molecule is very widely expressed on immune cells, and thus the virus can now infect and kill many more cells. However, in about 50% of infected people who eventually get AIDS, the virus does not change this way. The virus instead uses it's original receptor to infect cells, called CCR5. Our preliminary studies, as well as other published reports, suggest that the virus changes itself another way to make it kill immune cells better, without using CXCR4. However, the mechanism by which HIV-1 does this is poorly understood. This proposal aims to better understand this mechanism. We expect to find that, in this group of patients, the Env proteins on the virus change to be able to bind CCR5 more tightly, and thus be able to use fewer molecules of CCR5 to infect cells. We believe that these forms of the virus are now better able to kill immune cells, leading to AIDS. This study will contribute to a greater understanding of how HIV-1 causes AIDS, which is necessary for the development of new drugs to treat HIV-1 infection.Read moreRead less
Retroviral Recombination, RNA Dimers & Multiple Drug Resistant HIV-1
Funder
National Health and Medical Research Council
Funding Amount
$405,017.00
Summary
The emergence of multiple drug resistant strains of HIV-1 has threatened the continue success of current clinical treatment to suppress virus propagation. Retroviruses, such as HIV-1, can reshuffle its two copies of genetic materials during the viral replication process, which leads to the production of offspring viruses that contain a mixture of the parental genetic materials. This process of genetic information reshuffling is believed to be important for the generation of multiple drug resista ....The emergence of multiple drug resistant strains of HIV-1 has threatened the continue success of current clinical treatment to suppress virus propagation. Retroviruses, such as HIV-1, can reshuffle its two copies of genetic materials during the viral replication process, which leads to the production of offspring viruses that contain a mixture of the parental genetic materials. This process of genetic information reshuffling is believed to be important for the generation of multiple drug resistant strains of HIV-1. The objective of this proposal is to define the parameters that regulate the reshuffling of HIV-1 genetic materials and to design novel tools to inhibit the production of multiple drug resistant HIV-1.Read moreRead less
Molecular Studies Of The Astrocyte Reservoir Of HIV-1 In The Central Nervous System
Funder
National Health and Medical Research Council
Funding Amount
$592,661.00
Summary
HIV infects the brain causing dementia in 10-20% patients. Strategies aimed at eradicating HIV infection fail to take into account CNS infection. Understanding the way in which HIV enters, infects and replicates in the brain is pivotal in development of drugs to prevent brain infection and dementia. Our studies have shown that HIV infection of the brain involves mechanisms distinct to those observed for blood and other organs. This study seeks to clarify such mechanisms.
Molecular Studies Of The Astrocyte Reservoir Of HIV-1 In The Central Nervous System
Funder
National Health and Medical Research Council
Funding Amount
$533,828.00
Summary
Human immunodeficiency virus type 1 (HIV-1) causes AIDS and, to date, has infected approximately 20 thousand people in Australia and more than 40 million worldwide. HIV infects the central nervous system and causes HIV associated dementia in 10-20% of patients with AIDS. Despite the introduction of highly active antiretroviral therapy the prevalence in Australia continues to rise and studies have shown that the incidence has been under represented in the South east Asian region. Infection of the ....Human immunodeficiency virus type 1 (HIV-1) causes AIDS and, to date, has infected approximately 20 thousand people in Australia and more than 40 million worldwide. HIV infects the central nervous system and causes HIV associated dementia in 10-20% of patients with AIDS. Despite the introduction of highly active antiretroviral therapy the prevalence in Australia continues to rise and studies have shown that the incidence has been under represented in the South east Asian region. Infection of the CNS has two major implications for the treatment of AIDS patients. Firstly, HIV-associated dementia is the most common cause of dementia in people under 40 and this continuing increase in the number of young adults with dementia is placing increased pressure on health resources in the community. Secondly, strategies aimed at eradicating HIV infection from AIDS patients have thus far have failed to take into account the important and unique viral reservoir present in the CNS of an infected patient. The mechanisms involved in HIV-1infection of the brain remain unclear. Understanding the mechanisms by which HIV enters, infects and replicates the brain, are pivotal to the development of regimes to prevent infection of the brain in the first instance as well as development of targeted drug therapy to prevent dementia. Our preliminary studies have shown that HIV infection of the brain involves unique HIV virus and cellular mechanism distinct to those observed for the blood and other organs. This study seeks to clarify such mechanisms. This study will contribute to a greater understanding of how HIV-1 enters the brain and causes dementia, both of which are essential to the development of new drugs to treat HIV-1 infection.Read moreRead less
The diversity of HIV quasispecies within a single AIDS patient is far greater than the global diversity of influeneza annually, highlighting the enormous burden HIV imposes on the immune network. The capacity of HIV-1 to evolve quickly has significantly impaired our effort to produce effective vaccine and long lasting treatment strategy. This project utilizes multidisciplinary approaches to delineate determinants that drives the diversification of HIV-1.
Mechanisms Of HIV Binding, Uptake, Trafficking And Infection In Dendritic Cells
Funder
National Health and Medical Research Council
Funding Amount
$144,250.00
Summary
HIV is the fourth greatest killing disease in the world. Currently there are more than 40 million people infected with the virus and it is spreading through Asia, especially India and China. The priorities are vaccines and new antiviral strategies to complement the existing ones and provide alternatives in the event of toxicity and viral resistance to existing drugs. HIV infects three types of body cells, CD4 lymphocytes, macrophages and dendritic cells. Dendritic cells are the key cells which n ....HIV is the fourth greatest killing disease in the world. Currently there are more than 40 million people infected with the virus and it is spreading through Asia, especially India and China. The priorities are vaccines and new antiviral strategies to complement the existing ones and provide alternatives in the event of toxicity and viral resistance to existing drugs. HIV infects three types of body cells, CD4 lymphocytes, macrophages and dendritic cells. Dendritic cells are the key cells which normally act as sentinels at the surfaces of the body picking up microbes digesting them and transferring their products to lymph nodes where the immune response is stimulated. HIV uses this pathway to enter the body and particularly to enter CD4 lymphocytes and lymph nodes and undergo explosive replication. This project is aimed at identifying new proteins which the virus uses to bind to these cells and also the pathways which the virus uses within the cells to be transferred to CD4 lymphocytes. Such knowledge should allow the design of new antiviral strategies and may also assist in developing HIV vaccines.Read moreRead less
Drug Resistance Mutations In The Connection Subdomain Of The HIV-1 Reverse Transcriptase
Funder
National Health and Medical Research Council
Funding Amount
$376,710.00
Summary
Human immunodeficiency virus type 1 (HIV-1) infections can be controlled with antiretroviral drugs. In the majority of patients on antiretroviral therapy the virus mutates and is no longer inhibited by the drug. The emergence of drug-resistant HIV-1 is one of the major factors that lead to loss of drug efficacy in patients. Mutations that confer drug resistance have been defined and are specific for different drug classes. Genotype assays that are used to predict drug resistance are routinely us ....Human immunodeficiency virus type 1 (HIV-1) infections can be controlled with antiretroviral drugs. In the majority of patients on antiretroviral therapy the virus mutates and is no longer inhibited by the drug. The emergence of drug-resistant HIV-1 is one of the major factors that lead to loss of drug efficacy in patients. Mutations that confer drug resistance have been defined and are specific for different drug classes. Genotype assays that are used to predict drug resistance are routinely used to guide therapeutic decisions in the treatment of HIV-1 infected individuals. For drugs that target the HIV-1 reverse transcriptase (RT), commonly used genotype kits normally analyse mutations in the first 240 out of 560 amino acids of the reverse transcriptase. This ignores the impact of mutations in other regions of the enzyme, which are potentially important in drug resistance. Recently, mutations that inhibit ribonuclease H function of the HIV-1 RT have been shown to confer high-level resistance to zidovudine, providing the precendent that mutations beyond codon 240 can confer drug resistance. Our analysis of a different region to ribonuclease H called the connection subdomain has demonstrated the presence of mutations that are highly prevalent in drug-treated versus drug naive patients. In this study we will use in vitro assays to define the effect of these mutations on drug resistance and viral fitness . We will also determine the mechanism by which these mutations confer drug resistance. Finally, using our unique database consisting of over 20,000 genotyped samples , we will establish the role of these mutations in the patient. This study is anticipated to identify clinically significant mutations that are present in the RT connection subdomain. Additionally, this study will lead to the development of more accurate genotype assays which will improve the clinical management of HIV infected individuals.Read moreRead less
Both human and viral genetic materials (ribonucleic acids, RNA) are made up of 4 different basic residues, namely A, U, G and C. Combination of any three of these ribonucleic acids residues is known as codon , which is essential to target one of the twenty amino acids to the host cell machinery for the making of proteins. Eighteen out of these twenty amino acids can be represented by more than one codon during the making of proteins. Interestingly, human and viral proteins, such as HIV-1, utilis ....Both human and viral genetic materials (ribonucleic acids, RNA) are made up of 4 different basic residues, namely A, U, G and C. Combination of any three of these ribonucleic acids residues is known as codon , which is essential to target one of the twenty amino acids to the host cell machinery for the making of proteins. Eighteen out of these twenty amino acids can be represented by more than one codon during the making of proteins. Interestingly, human and viral proteins, such as HIV-1, utilise two completely different subsets of codons (codon bias) for the synthesis of their respective proteins. The objective of this proposal is to delineate the functional requirement of this codon bias in HIV-1 replication cycle. Results from this work will identify novel elements that may be used for the design of novel antiretroviral strategy. Furthermore, lesson learned from this project will also provide important clues to improve the efficacy and safety of the design of current retroviral gene delivery vector.Read moreRead less
Impact Of HIV Infection And Treatment With Highly Active Retroviral Therapy On Reverse Cholesterol Transport
Funder
National Health and Medical Research Council
Funding Amount
$339,375.00
Summary
HIV has been found to be associated with increased risk of cardiovascular diseases. The introduction of new treatment for HIV resulted in a dramatic improvement in morbidity and mortality of HIV-infected patients, but paradoxically cardiovascular complications became more frequent and severe. It is not currently clear whether increased cardiovascular risk is due to long lasting HIV or due to the impact of therapy. In both cases a major complication of HIV and-or therapy is rapid development of a ....HIV has been found to be associated with increased risk of cardiovascular diseases. The introduction of new treatment for HIV resulted in a dramatic improvement in morbidity and mortality of HIV-infected patients, but paradoxically cardiovascular complications became more frequent and severe. It is not currently clear whether increased cardiovascular risk is due to long lasting HIV or due to the impact of therapy. In both cases a major complication of HIV and-or therapy is rapid development of atherosclerosis. Atherosclerosis is the cause of more than half of heart diseases, which is a leading cause of death in Western societies. Atherosclerosis develops when cholesterol is deposited within artery walls, causing the formation of a fatty plaque and restricting blood flow. The mechanism behind the effect of HIV and its treatment on development of atherosclerosis is unknown. This project is designed to investigate how and why HIV infection and its treatment results in this increased risk of cardiovascular disease.Read moreRead less