Enhanced Translation Of Epstein-Barr Virus Nuclear Protein, EBNA1, As A Target For T Cell-based Immunotherapy.
Funder
National Health and Medical Research Council
Funding Amount
$276,598.00
Summary
Epstein-Barr virus, (EBV) is a human herpesvirus associated with a range of human cancers. EBNA1, an important EBV antigen, was thought to be immunologically silent however, recent studies from our laboratory show that EBNA1 is recognized by our body's defence system and these observations raise the possibility that EBNA1 may be an exploitable, immuno-therapy target for treating EBV-associated cancers.
A Proteome-wide Approach To Anti-viral Immunity And Vaccine Development
Funder
National Health and Medical Research Council
Funding Amount
$622,655.00
Summary
We know that many parts of viruses are displayed to the immune system, but at present the exact fragments are difficult to predict, we do not know all the genes in our bodies that control this process and we also need better methods to study the way some viruses (e.g. the cold sore virus) avoid detection. This project will study these problems with the overall goal of improving vaccine design, understanding immune deficiency and how viruses fight back against our immune system.
Mechanisms Regulating Antigen Presentation During Primary And Recall Responses Of T Cells Following Pathogen Infection
Funder
National Health and Medical Research Council
Funding Amount
$441,364.00
Summary
The primary role of the immune system is the containment of pathogens, cancer cells and infections. This depends on generating long-lived memory CD8+ killer T lymphocytes. Generally this process is achieved efficiently in acute infections in which the pathogen grows relatively rapidly. However, pathogens such as herpes viruses and tuberculosis grow more slowly, fail to efficiently activate the killer T cells such that they elude the immune system and are never completely removed from the body. T ....The primary role of the immune system is the containment of pathogens, cancer cells and infections. This depends on generating long-lived memory CD8+ killer T lymphocytes. Generally this process is achieved efficiently in acute infections in which the pathogen grows relatively rapidly. However, pathogens such as herpes viruses and tuberculosis grow more slowly, fail to efficiently activate the killer T cells such that they elude the immune system and are never completely removed from the body. These latter infections result in persistent or chronic infections. Our work will endeavour to unravel the mechanisms that underlie how a killer T cell is effectively activated and the factors that contribute to failure of these cells to be similarly activated in a persistent infection. The central aim of the studies described in this proposal is to understand the mechanisms utilized by different pathogens to generate the diverse population of memory killer T cells that allow us to respond to the plethora of pathogens we might encounter every day. These studies will improve our understanding of how antigen presenting cells and killer T lymphocytes ensure an immune response is maintained and may identify checkpoints that could be targeted to modulate the immune response when it goes wrong.Read moreRead less
Systematically Exploring The Contribution Of Immunoproteasome To Immunodominance And T Cell Function
Funder
National Health and Medical Research Council
Funding Amount
$499,860.00
Summary
Vaccine will help us to fight both infectious diseases and malignancy. However, there are few successful vaccines for infectious agents and there is simply no vaccine to cure any tumor at the moment. So, it is essential for us to learn the basics related to vaccine development. Killer T cells eliminate tumour cells or virally infected host cells by recognising fragments (epitopes) derived from tumour- or virus-derived proteins displayed on a host molecule called MHC. Normally multiple epitopes a ....Vaccine will help us to fight both infectious diseases and malignancy. However, there are few successful vaccines for infectious agents and there is simply no vaccine to cure any tumor at the moment. So, it is essential for us to learn the basics related to vaccine development. Killer T cells eliminate tumour cells or virally infected host cells by recognising fragments (epitopes) derived from tumour- or virus-derived proteins displayed on a host molecule called MHC. Normally multiple epitopes are generated as part of the protein recycling program referred as proteine degradation which is mainly conducted by bundled enzyme complex, called proteasome. Two major forms of proteasomes are expressed by most cells. One called house-keeping proteasome and the other, which replaces the house-keeping one during viral infections is called immunoproteasome. The role that the immunoproteasome plays during anti-viral and anti-tumoral immune responses is not fully understood. In addition, the immunoproteasome is also expressed by a few cell types that do not suppose to need it if its function is entirely to generate better epitopes for MHC to display. In this project, we will sytematically explore the contribution of the immunoproteasome to overall anti-viral and anti-tumoral immune responses in three mouse model systems. The shared feature of these systems is that multiple killer T cell epitopes have been defined, which could potentially provide us with very sensitive assessments. The three systems are anti-influenza, anti-vaccinia virus and anti-tumor antigen (NY-ESO-1) mouse models.Read moreRead less
Antigen Dose And TCR Repertoire In CD8+ T Cell Immunodominance Hierarchies
Funder
National Health and Medical Research Council
Funding Amount
$558,920.00
Summary
The CD8+, or killer , T lymphocytes (white blood cells) are the hit men of immunity, recirculating continually around the body to eliminate other cells that are dangerous because they are cancerous or infected with a virus. A major difficulty is that killer T cells also exert selective pressures that cause viruses and tumours to mutate and thus avoid immune control. This is a particularly serious problem for RNA viruses that readily mutate as they divide. These include the human immunodeficiency ....The CD8+, or killer , T lymphocytes (white blood cells) are the hit men of immunity, recirculating continually around the body to eliminate other cells that are dangerous because they are cancerous or infected with a virus. A major difficulty is that killer T cells also exert selective pressures that cause viruses and tumours to mutate and thus avoid immune control. This is a particularly serious problem for RNA viruses that readily mutate as they divide. These include the human immunodeficiency virus (HIV) that causes AIDS and, while the mutations that are most important with influenza viruses are those that modify viral surface proteins recognized by antibodies, such T cell escape mutants can also be a problem with influenza. The other reason why there is particular interest in promoting CD8+ T cell-mediated immunity to influenza is that the killer T cells are very cross-reactive. We have shown that vaccination approaches that prime mouse CD8+ T cells to resist influenza A viruses circulating currently in humans will also protect against the highly lethal, and dangerous H5N1 bird 'flu. The present flu vaccines only stimulate antibodies, so there is interest in the possibility of a major re-design. The CD8+ T cells recognize tiny elements (peptides) of the virus or tumour bound in the tip of our own transplantation, or class I major histocompatibility complex (MHCI) molecules. These pMHCI complexes are called epitopes. The focus here is on the use of novel genetic engineering strategies to find out how, when the virus mutates to disrupt the major epitopes seen by killer T cells, other minor epitopes can be abnormally emphasized in a way that promotes effective immune control. As we work on this with the relatively simple and safe influenza model we will concurrently develop strategies that may be of value in HIV and tumour immunity. Solving this problem could prove to be a substantial advance in the design of vaccines and immunotherapy approaches.Read moreRead less