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
The Human Immunodeficiency Virus (HIV) is a virus that infects and kills the cells of your immune system. This infection eventually leads to the Acquired Immune Deficiency Syndrome (AIDS). An important aspect in preventing infection is to study how HIV enters immune cells and how infection spreads. Our lab is researching drugs to block the entry of HIV in immune cells, which can hopefully be used together with existing anti-HIV drugs to slow down the spread of the virus and the onset of AIDS.
Consequences Of Disulfide Exchange In CD4 For Function
Funder
National Health and Medical Research Council
Funding Amount
$332,580.00
Summary
CD4 is a particular type of receptor on the surface of immune cells that participates in our response to infection. CD4 is also the primary receptor for the HIV virus which causes AIDS. We have discovered that a particular type of chemistry is occurring in CD4. This chemistry, which is known as redox chemistry, changes the shape of CD4. The shape change appears to be controlled by the immune cell. We have suggested that the redox chemistry in CD4 is important for controlling how immune cells res ....CD4 is a particular type of receptor on the surface of immune cells that participates in our response to infection. CD4 is also the primary receptor for the HIV virus which causes AIDS. We have discovered that a particular type of chemistry is occurring in CD4. This chemistry, which is known as redox chemistry, changes the shape of CD4. The shape change appears to be controlled by the immune cell. We have suggested that the redox chemistry in CD4 is important for controlling how immune cells respond to infection and how the HIV virus infects immune cells. Moreover, we have designed a small synthetic compound that blocks the redox chemistry in CD4 and prevents HIV infection in the test tube. We propose to investigate how the redox chemistry in CD4 controls the function of immune cells and infection by HIV.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
AIDS is caused by the human immunodeficiency virus type 1 (HIV-1). Long-term HIV infection leads to increased incidence of Kaposi's sarcoma, AIDS dementia complex, and immune dysfunctions. The HIV-1 Tat protein has been linked to disease progression. However, Tat is predominantly found in the cell nucleus while measurable levels in patient serum. This is not believed to be a passive event caused by dying cells. Here we will investigate how Tat is released by HIV-1 infected cells.
HOST CELL FACTORS INCREASE THE EFFICIENCY OF HIV-1 REVERSE TRANSCRIPTION
Funder
National Health and Medical Research Council
Funding Amount
$636,919.00
Summary
We have found that when human immunodeficiency virus (HIV) infects a cell, it uses functions of the host to better infect. At this point, we do not know the identity of the host cell factors involved. If we are able to identify the factors we might be able to specifically target them without affecting normal cell functions. This approach has the advantage that it minimises the opportunities for the virus to develop drug resitance, which is increasingly a problem with HIV.
Silent Mutations In The HIV-1 Reverse Transcriptase Selected During Antiretroviral Therapy
Funder
National Health and Medical Research Council
Funding Amount
$555,325.00
Summary
This project seeks to determine the role of silent mutations in the HIV reverse transcriptase that are selected during drug therapy in HIV infected individuals on HIV fitness, reverse transcriptase function and the emergence of drug resistance. This study will increase our understanding of the mechanisms by which the virus evades the effects of antiretrovirals and will provide a rationale for deciding on the best drug combinations for use in patients infected with specific HIV strains (clades).
Prevention Of HIV-1 Infection By Adeno Associated Virus Vector-delivered Broadly Neutralizing Antibodies Or Antibody-like Molecules
Funder
National Health and Medical Research Council
Funding Amount
$875,854.00
Summary
A promising neutralizing molecule has boosted hopes of an HIV vaccine. It remains unknown how well this molecule prevents HIV infection under conditions reflecting “real world” exposure, including exposure to HIV in the form of cells carrying virus or free-floating virus in the presence of semen. We will assess this molecule for their ability to inhibit transmission of HIV-like viruses under these conditions. These experiments will define requirements to protect against HIV infection.