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
This application proposes to study in detail the main target cell for HIV infection, namely CCR5+ CD4 T lymphocytes. After 30 years of the pandemic, fundamental knowledge of these cells, such as locations in the body, differentiation from other lymphocytes, and survival, is still lacking. These attributes determine whether or not they will be infected by HIV, whether this can be prevented by vaccines or CCR5 blocking drugs, and whether their long-term survival results in an inability to eradicat ....This application proposes to study in detail the main target cell for HIV infection, namely CCR5+ CD4 T lymphocytes. After 30 years of the pandemic, fundamental knowledge of these cells, such as locations in the body, differentiation from other lymphocytes, and survival, is still lacking. These attributes determine whether or not they will be infected by HIV, whether this can be prevented by vaccines or CCR5 blocking drugs, and whether their long-term survival results in an inability to eradicate HIV.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
Using Single-cell Genomics To Resolve Functional Diversification By CD4+ T Cells In Vivo
Funder
National Health and Medical Research Council
Funding Amount
$1,048,096.00
Summary
During immune responses, individual CD4+ T cells multiply and produce hundreds of descendants, with close relatives within a family often developing very different skills. How such differences emerge from one ancestor remains unclear. We use new methods to look at individual CD4+ T cells in unprecedented detail, allowing us to see how close relatives begin to grow apart. Using this, we hope to find novel ways of educating CD4+ T cells to prevent infectious and immune-mediated diseases.
CD4+ T Cell-independent Immunity Against Salmonellae
Funder
National Health and Medical Research Council
Funding Amount
$550,226.00
Summary
Salmonella typhimurium is an important pathogen in both developed and developing countries where it causes significant HIV-linked morbidity. There is a pressing need to understand how immunity might be established against this organism that will function when the patient is immunocompromised either through age or through a comorbidity like HIV.