Population Dynamics Of Tissue-specific Effector And Regulatory CD4+ T Cells
Funder
National Health and Medical Research Council
Funding Amount
$394,250.00
Summary
Survival of white blood cells in the body is an active process and is important for the maintainence of a T cell population which can recognise a wide variety of foreign antigens. At present the fate of T lymphocytes which recognise self antigens is unclear. Knowledge of the survival kinetics of self-reactive T lymphocytes and the mechanism by which they are regulated in the normal individual is crucial to be able to control the development of various diseases, including autoimmune diseases. Fro ....Survival of white blood cells in the body is an active process and is important for the maintainence of a T cell population which can recognise a wide variety of foreign antigens. At present the fate of T lymphocytes which recognise self antigens is unclear. Knowledge of the survival kinetics of self-reactive T lymphocytes and the mechanism by which they are regulated in the normal individual is crucial to be able to control the development of various diseases, including autoimmune diseases. From our previous studies of autoimmune gastritis we have generated cell lines of lymphocytes that recognise stomach-specific antigens and with these unique reagents we will perform experiments to determine the fate of these self-reactive T cells in a normal individual. Also we will determine the impact of different amounts of the tissue antigens on the survival and activation of self-reactive T cells, and finally how a special class of lymphocytes, know as regulatory lymphocytes, act in vivo to control the activity of self-reactive T cells. We will use not only classical immunological approaches to address these issues but also state of the art imaging, to visualise the nature of the cell interactions in living tissues. The information arising from this work will underpin strategies to selectively turn off self-reactive lymphocytes that cause disease, will form the basis of clinical development of cell based therapies to treat autoimmune diseases, and the imaging technologies developed in this grant will have wide applicability to the study of a range of immune responses.Read moreRead less
The Function Of Transcription Factor SCL In T Cell Development.
Funder
National Health and Medical Research Council
Funding Amount
$504,750.00
Summary
SCL is a gene which is abnormally expressed in a large percentage of human T cell leukaemias. Mouse models that increase SCL levels have demonstrated that T cell maturation is abnormally affected by SCL. Thus, providing a clue as to how T cell leukemias arise. By utilising recombinant DNA technology we are now able to control SCL levels in T cell maturation. We can either increase the level of SCL using pharmacological reagents or we can genetically remove SCL from maturing T cells. This double- ....SCL is a gene which is abnormally expressed in a large percentage of human T cell leukaemias. Mouse models that increase SCL levels have demonstrated that T cell maturation is abnormally affected by SCL. Thus, providing a clue as to how T cell leukemias arise. By utilising recombinant DNA technology we are now able to control SCL levels in T cell maturation. We can either increase the level of SCL using pharmacological reagents or we can genetically remove SCL from maturing T cells. This double-edged approach will allow us to monitor the effects of SCL on maturing T cells with a precision that has never previously been achieved. Results from this approach will provide new insights into how T cell leukaemia develops and provide the foundation for new rational based treatments.Read moreRead less
Discovery Of Novel T Cell Oncogenes By Using A Functional Retroviral CDNA Library Screen.
Funder
National Health and Medical Research Council
Funding Amount
$692,470.00
Summary
T cells mature in an organ called the thymus which is located on top of the heart. Blood borne T cell precursors enter the thymus after being resident in the bone marrow. T cell leukaemia is a disease where a blood cell that is committed to becoming a T cell is blocked from maturing into a functional cell. Instead, the leukaemic immature T cell uncontrollably divides to make endless non-functional copies of itself. As a result, normal functional T cells are outcompteted and the immune system is ....T cells mature in an organ called the thymus which is located on top of the heart. Blood borne T cell precursors enter the thymus after being resident in the bone marrow. T cell leukaemia is a disease where a blood cell that is committed to becoming a T cell is blocked from maturing into a functional cell. Instead, the leukaemic immature T cell uncontrollably divides to make endless non-functional copies of itself. As a result, normal functional T cells are outcompteted and the immune system is crippled. Patients generally die due to opportunistic infection. The molecular causes of T cell leukaemia are slowly being discovered. Up to 50% of all human T cell leukaemias overexpress SCL-TAL-1. Other T cell leukaemia-causing genes (oncogenes) include Ras and Notch. Current leukaemia treatments include chemotherapy and bone marrow transplants but even these fail ~30% of the time. Consequently, all T cell oncogenes need to be discovered so that disease-specific treatments can be generated. This proposal will utlise a functional retroviral cDNA library screen to uncover novel T cell lineage commitment genes and T cell oncogenes. This will be accomplished by constructing a coloured [GFP] cDNA library (a library of genes) that will be transfected (inserted) into immature T cells that cannot develop down the T cell pathway owing to the lack of a crucial gene (Rag-1). The T cell oncogene Ras and the T cell lineage commitment gene Notch can move cells past the Rag-1 block. If there is a gene in the cDNA library that can compensate for the lack of Rag-1 and allow the cells to mature we will detect it using high speed flow cytometryic cell sorting (like sieving weevils from flour very quickly). Once we find this cell we will isolate the gene using the colour tag. The potential oncogenes uncovered will provide the foundation for next generation drug development that targets each leukaemia based on its cause.Read moreRead less
Epigenetic Regulation Of CD8+ T Cell Function And Memory.
Funder
National Health and Medical Research Council
Funding Amount
$578,171.00
Summary
Upon virus infection, a subset of white blood cells, called killer T cells, are recruited to fight the infection. This proposal aims to examine molecular changes that occur within killer T cells and impart their specific function. We also aim to understand how killer T cells are _programmed� as they establish immunological memory. This proposal will provide insights important for the design and improvement of vaccine strategies to fight pathogens such as influenza, HIV and even tumors.
Memory CD4 T Cells That Harbour The Reservoir Of Latent HIV Infection: Their Antigen Specificity, Function And Frequency Of Antigen-driven Reactivation
Funder
National Health and Medical Research Council
Funding Amount
$453,782.00
Summary
Current antiretroviral therapy for HIV successfully suppresses virus production, but does not completely eliminate the virus from the body. This project will provide essential information on memory CD4 T cells that retain HIV in a latent DNA form. Memory CD4 T cells can be very long-lived, and these latently infected memory cells can give rise to virus during treatment interruption. We will use a novel method to identify which memory CD4 T cells contain latent HIV DNA.
Investigations Into The Biology And Functionality Of The Human T Cell Receptor
Funder
National Health and Medical Research Council
Funding Amount
$424,262.00
Summary
T lymphocytes play a pivotal role in the immune system by recognising virus-infected tissue and tumour cells through the use of specific cell surface receptors called T cell receptors (TCR). This project will study why partcular TCRs are used by the immune system, and will also examine the specificity of T cell recognition by determine the range of molecules an individual T cell can recognise. The work will aid in the development of new intelligent vaccines for cancer and infectious disease.