Viral And Cellular Factors Affecting Early Steps In HIV Reverse Transcription
Funder
National Health and Medical Research Council
Funding Amount
$465,750.00
Summary
One of the key events in the life cycle of HIV is the conversion of viral RNA into a double stranded DNA intermediate. This process, called reverse transcription, is carried out by the viral enzyme reverse transcriptase (RT) in conjunction with other viral and cellular factors. While HIV RT has been extensively studied and RT inhibitors have been used in anti-retroviral therapy for HIV patients, other viral and cellular factors essential for efficient HIV reverse transcription have not been prop ....One of the key events in the life cycle of HIV is the conversion of viral RNA into a double stranded DNA intermediate. This process, called reverse transcription, is carried out by the viral enzyme reverse transcriptase (RT) in conjunction with other viral and cellular factors. While HIV RT has been extensively studied and RT inhibitors have been used in anti-retroviral therapy for HIV patients, other viral and cellular factors essential for efficient HIV reverse transcription have not been properly investigated and may represent a new class of anti-HIV targets.This project, based on our long standing (>10 years) research interest and experience, aims at identification of the viral and cellular factors particularly involved in the early steps of HIV reverse transcription.We have obtained preliminary data which lead to hypotheses regarding what kind of viral and cellular factors might be involved and their possible modes of action. Experiments have been designed to specifically prove or disprove these hypotheses. Thus this project will help us achieve a more comprehensive understanding on how HIV uses other viral and cellular factors, in addition to RT, to accomplish one of the mandatory stage of its growth (reverse transcription); and identify viral and cellular factors which can be further explored as new targets for anti-retroviral therapy. This is particularly important, as HIV resistance to current drug therapy has emerged as one serious issue facing HIV patients, and the HIV care communities.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.
Envelope Glycoprotein Determinants Underlying Cytopathicity Of CCR5-restricted Human Immunodeficiency Virus Type 1
Funder
National Health and Medical Research Council
Funding Amount
$428,602.00
Summary
HIV weakens the immune system causing AIDS, but the mechanism by which HIV does this are poorly understood. This proposal aims to define these mechanisms. We expect that HIV evolves in infected people, becoming better able to infect and kill cells of the immune system, and that this results from specific genetic changes in the virus. This study will contribute to a greater understanding of how HIV causes AIDS, which is necessary for the development of new drugs to treat HIV infection.
The Role Of Vif In Enhancing HIV Replication And Effecting The Integrity Of The Replication Complexes Of HIV
Funder
National Health and Medical Research Council
Funding Amount
$260,200.00
Summary
HIV-AIDS is still one of the leading causes of infectious human fatality worldwide. The genome of HIV encodes six viral accessory proteins that are necessary for viral replication and infection. One of these genes, viral infectivity factor (vif), is essential for production of infectious virus. Exactly how this viral protein works within the cell is not clear at present. Current literature suggests that Vif acts in some way to enhance reverse transcription, one of the early stages of the viral l ....HIV-AIDS is still one of the leading causes of infectious human fatality worldwide. The genome of HIV encodes six viral accessory proteins that are necessary for viral replication and infection. One of these genes, viral infectivity factor (vif), is essential for production of infectious virus. Exactly how this viral protein works within the cell is not clear at present. Current literature suggests that Vif acts in some way to enhance reverse transcription, one of the early stages of the viral life cycle. We aim to investigate the action of Vif in stabilizing early HIV reverse transcription complexes to understand how it acts to enhance HIV replication and viral infection. The early stages of HIV replication are critical for establishing infection and hence ideal targets for therapeutic intervention. This research will help understand how Vif works in a cell and affects the infectivity of HIV viral particles and may be suggestive of potential targets for development of anti-viral drugs.Read moreRead less
Gene therapy is a novel form of medical treatment in which healthy genes are used to replace defective genes in cells. It is sobering to realise that in the next few years the whole human DNA sequence will be known. Consequently the already large list of genes which are known to cause disease will be greatly expanded through the application of molecular genetics. Surprisingly, however, treatments based on the correction of disease genes in the cells of a patient are not keeping up with expectati ....Gene therapy is a novel form of medical treatment in which healthy genes are used to replace defective genes in cells. It is sobering to realise that in the next few years the whole human DNA sequence will be known. Consequently the already large list of genes which are known to cause disease will be greatly expanded through the application of molecular genetics. Surprisingly, however, treatments based on the correction of disease genes in the cells of a patient are not keeping up with expectations. In attempting to achieve clinically relevant results, viruses (masters of forcing infected cells to do their bidding) have been harnessed to deliver healthy genes into diseased cells. The problem has been that the modified, safe viruses used clinically have not been efficient at achieving sustained production of healthy genes in sufficient numbers of cells. In the studies described , we will attack this problem using a number of different, but complementary approaches. Our main focus will be to facilitate efficient virus entry of appropriate target cells. We have recently been successful in cloning the receptors for two important viruses which can enter human cells. Identification of these receptors gives us clues to methods of improving virus entry. Now that we know the identity of these receptors, we can create tools to define the type of cells that these viruses can readily target.Read moreRead less