Structural Basis Of Influenza A Virus-specific CD8+ T Cell Receptor Diversity
Funder
National Health and Medical Research Council
Funding Amount
$469,500.00
Summary
Viral infection results in the activation and proliferation of virus-specific T cells that mediate clearance of virally infected cells. Recognition of virally infected cells is meditated by presentation of peptide fragments complexed to Major histocompatibility complex (MHC) class I glycoproteins. Virus-specific T cells recognise these viral protein fragments via a specific receptor expressed at the T cell surface. This proposal plans to examine the structural factors that determine influenza-sp ....Viral infection results in the activation and proliferation of virus-specific T cells that mediate clearance of virally infected cells. Recognition of virally infected cells is meditated by presentation of peptide fragments complexed to Major histocompatibility complex (MHC) class I glycoproteins. Virus-specific T cells recognise these viral protein fragments via a specific receptor expressed at the T cell surface. This proposal plans to examine the structural factors that determine influenza-specific T cell receptor recognition. From these studies, we plan to determine how these structural factors can influence the diversity of virus-specific T cells that are generated after viral infection. The conclusions from these studies will enable us to determine why some virus-specific T cell responses are not diverse and what are the consequences for virus-specific T cell immunity. This has implications for the development of novel vaccine strategies designed to induce immunity against both viral and tumour challenge.Read moreRead less
Chromatin Remodelling And Transcriptional Regulation Of CD8 T Cell Effector Gene Expression
Funder
National Health and Medical Research Council
Funding Amount
$531,696.00
Summary
A major role for cytotoxic, or killer, T cells is the recognition and removal of virus infected or tumor cells from a host. Upon recognition of a target host cell, killer T cells deliver a package of proteins, termed granzymes, that mediate the removal of these virus infected and tumor cells. Naive killer T cells need to be activated to start producing these effector molecules. This proposal plans to examine the factors that regulate both induction and maintanence of cell specific expression of ....A major role for cytotoxic, or killer, T cells is the recognition and removal of virus infected or tumor cells from a host. Upon recognition of a target host cell, killer T cells deliver a package of proteins, termed granzymes, that mediate the removal of these virus infected and tumor cells. Naive killer T cells need to be activated to start producing these effector molecules. This proposal plans to examine the factors that regulate both induction and maintanence of cell specific expression of these effector molecules. We plan to identify the molecular events that occur within a cells genome to turn on granzyme gene expression and how these factors influence subsequent killer T cell function. The conclusions from these studies will enable us to determine why some killer T cell responses are not effective and what can be done to improve killer T cell function. This has implications for the development of novel vaccine strategies designed to induce immunity against both viral and tumour challenges.Read moreRead less
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
Immunodominance In Vaccinia Virus And Recombinant Vaccinia Vaccines
Funder
National Health and Medical Research Council
Funding Amount
$388,455.00
Summary
When confronted with an invading microbe, the human immune system does not recognise its overall shape. Instead, the microbe is chopped up into tiny fragments, called peptides, and these can be recognised by special cells of the immune system called T cells which orchestrate a response. We have a good understanding of this chopping process and can predict many of these peptides, but this is only part of the story. Not all peptides will be recognized by a T cell. Further, through processes we do ....When confronted with an invading microbe, the human immune system does not recognise its overall shape. Instead, the microbe is chopped up into tiny fragments, called peptides, and these can be recognised by special cells of the immune system called T cells which orchestrate a response. We have a good understanding of this chopping process and can predict many of these peptides, but this is only part of the story. Not all peptides will be recognized by a T cell. Further, through processes we do not understand well, T cells that recognize only a few out of the many peptides will dominate an entire immune response. As a result, immune responses are focused in such a way that they recognize only a tiny portion of an invading microbe. Focusing of immune responses also occurs during immunization with vaccines. Some new, genetically engineered vaccines use a harmless microbe to carry small parts of more dangerous pathogens. The parts chosen will not cause any disease by themselves, so the whole vaccine is safe. Vaccines built in this way are in clinical trials for diseases such as AIDS and malaria, but do not work as well as was hoped. These new vaccines are largely made up of the carrier and the parts of the microbe we wish to immunize against (e.g. a part of the AIDS virus) will be only a small fraction of the whole vaccine. Ideally we would like the immune system to focus on this small part of our choosing, but the few studies done suggest that this is not the case. In this project we will study vaccines that use a carrier called vaccinia virus. We will test to what extent immune responses are focused inappropriately. We will then genetically alter the virus and use new immunisation strategies to try and shift the focus of the immune response so that it targets the right parts of the vaccine. The ultimate aim is to improve vaccines, but in the process we may learn more about how the immune system chooses its targets.Read moreRead less
HIV currently infects ~40 million people world-wide, causing ~3 million deaths in 2003, mainly in the world's poorest countries. A cheap, effective vaccine seems the best means of preventing the spread of the epidemic. The two main approaches to vaccination are either to make antibodies (which bind to and inactivate the virus), or killer T cells (which kill infected cells). Many of these vaccines are now being tested in monkeys. The results of killer T cell vaccination trials have been both enco ....HIV currently infects ~40 million people world-wide, causing ~3 million deaths in 2003, mainly in the world's poorest countries. A cheap, effective vaccine seems the best means of preventing the spread of the epidemic. The two main approaches to vaccination are either to make antibodies (which bind to and inactivate the virus), or killer T cells (which kill infected cells). Many of these vaccines are now being tested in monkeys. The results of killer T cell vaccination trials have been both encouraging and disappointing. The vaccines do not appear able to prevent the monkeys from getting infected with the virus. However, in many cases even though the monkeys become infected with HIV, they do not get the usual disease associated with AIDS, and hence live with rather than die from this infection. The aims of this project are to use statistical analysis, and more complex mathematical and computer models to try to analyse the data generated by these vaccine trials and to understand how these partially effective vaccines help control virus. For example, even if a vaccine does not prevent infection, we can investigate whether it slowed viral growth, or increased killing of infected cells, and if so, whether an increase in this response could be effective. In preliminary work we have analysed data from a vaccination trial performed in Boston. The results of this study suggest that the reason vaccinated monkeys still become infected is that the killer T cells produced by the vaccine do not appear to activate for the first 10 days of infection. In these first 10 days the virus grows normally and is able to establish a foothold for continuing infection. By contrast, we find that antibodies act extremely early after infection. The methods we propose have not been used before to study vaccines, and by studying the kinetics of the virus and immune response from a large number of vaccine trials we hope to help identify the optimal vaccine design.Read moreRead less
Exploiting the lymphatic system for next generation vaccine development . Vaccination is the most successful and cost-effective means of combating infectious diseases. This project will look at how vaccine adjuvants work and will help the development of new vaccines against infections in both animals and man. It will also promote the training of Australian scientists in the field of vaccine research and development.