Molecular Interactions Of The Tetraspanins CD37, TSSC6 And CD151 In T Cells
Funder
National Health and Medical Research Council
Funding Amount
$566,575.00
Summary
The tetraspanins are a new type of protein that are found at the surface of cells. Cells of the immune system, such as white blood cells, display at their surface, up to 20 different tetraspanin proteins. However, the precise contributions of these tetraspanin proteins to immunity is still not clear, nor is it clear exactly how tetraspanin proteins differ from one another and why white blood cells need to display so many different tetraspanins. Using genetic technology we have created mice which ....The tetraspanins are a new type of protein that are found at the surface of cells. Cells of the immune system, such as white blood cells, display at their surface, up to 20 different tetraspanin proteins. However, the precise contributions of these tetraspanin proteins to immunity is still not clear, nor is it clear exactly how tetraspanin proteins differ from one another and why white blood cells need to display so many different tetraspanins. Using genetic technology we have created mice which are unable to express certain individual tetraspanin proteins at their cell surface. Excitingly, the immune systems of these mice are not normal, in particular one type of white blood cell, the T cell responds in an exaggerated manner to stimulation. These results suggest a role for tetraspanins in the control and regulation of the immune system. This project will extend these results and work out the precise molecular mechanism by which the tetraspanins exert this control. In the future, a full understanding of how tetraspanins control T cells may ultimately lead to novel ways of controlling the immune system.Read moreRead less
PrtFII, A Streptococcus Pyogenes Fibronectin Binding Protein, And Invasive Diseases.
Funder
National Health and Medical Research Council
Funding Amount
$296,540.00
Summary
Our recent work revealed that, in the Aboriginal population, young age is a risk factor for severe invasive diseases caused by group A streptococcus. For group A streptococcus infection to occur, bacterial attachment is the first step. The bacterium attaches to host cells through interactions involving host fibronectin and the pathogen's fibronectin-binding proteins. We have found that streptococcal strains from severe disease cases are more likely to have the gene for PrtFII, a fibronectin bind ....Our recent work revealed that, in the Aboriginal population, young age is a risk factor for severe invasive diseases caused by group A streptococcus. For group A streptococcus infection to occur, bacterial attachment is the first step. The bacterium attaches to host cells through interactions involving host fibronectin and the pathogen's fibronectin-binding proteins. We have found that streptococcal strains from severe disease cases are more likely to have the gene for PrtFII, a fibronectin binding protein, than those from uncomplicated skin sores. In this application we propose to extend this observation and compare biochemical properties of PrtFII from strains belonging to the above two sets of collections. We hypothesise that PrtFII from invasive strains bind to fibronectin more tightly than the proteins from strains that cause uncomplicated infection. We also will test whether sera from invasive disease cases have lower titre of antibodies to the conserved region of PrtFII than sera from uncomplicated cases. A streptococcal vaccine by necessity has to be a multi-component vaccine to cover a wide spectrum of diseases and epidemiological differences. The study proposed here may provide a basis to argue whether or not to include PrtFII in such a multi-component vaccine.Read moreRead less
Dendritic cells are a very rare type of white blood cell which play a critical role in the initiation of the immune response. They are of particular interest to scientists interested in vaccination, as for a vaccine to work effectively, the vaccine must be presented to the rest of the immune system by the dendritic cell. It has only recently become apparent that there are several types of dendritic cell, and these different types of dendritic cell vary in their ability to present a vaccine to th ....Dendritic cells are a very rare type of white blood cell which play a critical role in the initiation of the immune response. They are of particular interest to scientists interested in vaccination, as for a vaccine to work effectively, the vaccine must be presented to the rest of the immune system by the dendritic cell. It has only recently become apparent that there are several types of dendritic cell, and these different types of dendritic cell vary in their ability to present a vaccine to the immune system. We have already identified some proteins that are expressed on the surface of only one type of dendritic cell. We will explore the possible use of these proteins as a means of delivering a vaccine to only one type of dendritic cell. This project will also identify new genes that are expressed in some types of dendritic cells but not others. These new genes whose expression does differ amongst the dendritic cells are potential targets for manipulating the immune system and ensuring more efficient vaccination.Read moreRead less
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
Co-administration Of DNA Encoding Co-stimulatory Molecules Enhances The Efficacy Of Immune Response To Foreign Antigen
Funder
National Health and Medical Research Council
Funding Amount
$182,000.00
Summary
Vaccines to prevent or treat infectious diseases and some cancers are urgently needed. Infected cells and some cancer cells display unique proteins which the body's immune system can recognises as 'foreign'. The body will then mount an immune response, which, if successful, will eradicate the infected or cancerous cells. Dendritic cells (DCs) initiate the body's immune response by instructing other immune cells to mount a response. For a vaccine to be successful it is important that the vaccine ....Vaccines to prevent or treat infectious diseases and some cancers are urgently needed. Infected cells and some cancer cells display unique proteins which the body's immune system can recognises as 'foreign'. The body will then mount an immune response, which, if successful, will eradicate the infected or cancerous cells. Dendritic cells (DCs) initiate the body's immune response by instructing other immune cells to mount a response. For a vaccine to be successful it is important that the vaccine activates the DCs in the right way. We propose to activate DCs by vaccinating with DNA encoding recently identified costimulatory molecules, as well as DNA encoding the foreign antigen. Our earlier work leads us to believe that this will enhance the immune response, and lead to a more effective state of immunityRead moreRead less