Influence Of TCR Signals From Contact With Self-MHC Ligands On Naive T Cell Survival
Funder
National Health and Medical Research Council
Funding Amount
$418,658.00
Summary
A diverse repertoire of naive T cells constitutes a critical part of the adaptive immune system and protects hosts from various infections and cancer. T cells are stably maintained at a constant number in the periphery by mechanisms that are not clearly understood. This proposal will shed light on how the immune system preserves a diverse na�ve T cell pool able to respond against various foreign antigens, while preventing their harmful auto-reactivity to self antigens.
T cells are a central component of the immune system and without T cells the body is very vulnerable to infections. One subgroup of T cells is the killer T cells that are important for identifying and killing cells infected by viruses and bacteria. The immune system works to maintain T cell numbers at a fairly constant level and part of this process includes sending signals to the killer T cells from other cells via cell surface protein interactions and soluble mediators, such as cytokines. We h ....T cells are a central component of the immune system and without T cells the body is very vulnerable to infections. One subgroup of T cells is the killer T cells that are important for identifying and killing cells infected by viruses and bacteria. The immune system works to maintain T cell numbers at a fairly constant level and part of this process includes sending signals to the killer T cells from other cells via cell surface protein interactions and soluble mediators, such as cytokines. We have been studying killer T cells, which are missing a protein SOCS1. SOCS1 is important for switching off the signals generated by a group of cytokines. As a consequence of being unable to correctly regulate cytokine signals these killer T cells multiply inappropriately and contribute to disease development. Our current work is aimed at achieving a better understanding of the particular interactions between killer T cells and other immune system cells and the soluble factors that deliver important signals for maintaining killer T cells in the immune system. The ability to better understand the factors controlling the maintenance of killer T cells will enable us to more intelligently target the immune system ,which is important for improving vaccine strategies and cancer immunotherapy as well as for controlling T cells that are activated inappropriately, such as in autoimmune disease.Read moreRead less
Viral Reservoirs:Role Of Naive T-cells In The Pathogeneisis Of T-cell Decline And Longterm Persistence Of HIV Infection.
Funder
National Health and Medical Research Council
Funding Amount
$85,716.00
Summary
Despite dramatic advances in treatment for HIV infection, HIV cannot be cured. The main reason why cure is not possible is because HIV can persist in long lived cells and these infected cells are not recognised by the immune system. This project will examine the role of a particular type of infection fighting cell, the naive T-cell, in long term persistence of HIV. The project will determine how naive T-cells are infected with HIV and what happens to these cells following HIV treatment.
Regulation Of Natural Killer Cell Homeostasis By Multiple Components Of The Immune System
Funder
National Health and Medical Research Council
Funding Amount
$327,151.00
Summary
Differentiation and homeostasis of immune cell populations such as CD4 and CD8 T cells and dendritic cells has been key to understanding their function during inflammation. In contrast, late stage natural killer (NK) cell differentiation has largely been ignored. Given the key role of NK cells in providing innate effector immunity and shaping adaptive responses, a better understanding of the cues that regulate their differentiation is clearly warranted.
CD4+ T-cells In HIV - Regulator Or Target Of Viral Infection: A Modelling Approach
Funder
National Health and Medical Research Council
Funding Amount
$319,740.00
Summary
T-cell loss due to HIV infection causes immunodeficiency. Since virus grows faster if more T-cells are available and preferentially infects dividing cells, we want to understand how replacement, division and death of uninfected T-cells affect the progress of HIV infection and T-cell recovery during drug therapy. The results of our study will lead to a better understanding of HIV disease, and may assist in the development of novel treatment regimes optimising T-cell numbers during infection.
The Role Of Interleukin-21 In The Pathogenesis Of Autoimmune Diabetes
Funder
National Health and Medical Research Council
Funding Amount
$519,000.00
Summary
T cells are a component of our blood (white blood cells) and a major component of the body's defense system against infection, known as immunity. Without T cells, we would fail to resist infection by foreign agents, such as viruses, bacteria and fungi. Autoimmune (type 1) diabetes is a disease in which T cells attack our own pancreatic islet self tissues as if they were foreign. T cells that react against the islets of the pancreas cause destruction of the insulin producing beta cells so that th ....T cells are a component of our blood (white blood cells) and a major component of the body's defense system against infection, known as immunity. Without T cells, we would fail to resist infection by foreign agents, such as viruses, bacteria and fungi. Autoimmune (type 1) diabetes is a disease in which T cells attack our own pancreatic islet self tissues as if they were foreign. T cells that react against the islets of the pancreas cause destruction of the insulin producing beta cells so that the pancreas can no longer make insulin. Diabetes is a life-threatening disease because insulin is a hormone that enables people to get energy from food. Type 1 diabetes is usually diagnosed in childhood and insulin must be administered daily by injection or through a pump in order to survive. Unfortunately, taking insulin doesn t cure diabetes and people continue to suffer from an extensive list of complications affecting most vital organs. Interleukin-21 (IL-21) is a soluble protein that is produced by cells enabling them to communicate with other cells. IL-21 helps cells to produce factors that cause inflammation and assist in clearance of viruses and bacteria from the body. However, our studies show that IL-21 is a major factor in the development of the T cells that destroy beta cells and cause diabetes. Our studies show that IL-21 is over-expressed in an important murine model of spontaneous type-1 diabetes. We have isolated the T cells that cause diabetes and show that they are distinguished from other T cells by very high levels of the receptor for IL-21. This project focuses on the IL-21-responsive T cells that cause diabetes and aims to determine the mechanisms by which the cytokine IL-21 causes destructive immune responses and ways to modulate its production. This project applies basic science to the important public health issue of type 1 diabetes for the development of therapeutic intervention strategies.Read moreRead less
Determining The Role Of Rel/NF-kB Transcription Factors In CD8 T Cell Homeostasis.
Funder
National Health and Medical Research Council
Funding Amount
$426,500.00
Summary
NF-kB proteins comprise a family of transcription factors that regulate key genes involved in immune responses, inflammation, cell death and proliferation. This family of proteins are potential drug targets for treatment of various diseases. How and when such inhibitors are used in clinical situations depends on understanding how and which cells of the immune system are specifically affected by the absence of NF-kB proteins. In a number of treatment settings intercurrent viral infections occur f ....NF-kB proteins comprise a family of transcription factors that regulate key genes involved in immune responses, inflammation, cell death and proliferation. This family of proteins are potential drug targets for treatment of various diseases. How and when such inhibitors are used in clinical situations depends on understanding how and which cells of the immune system are specifically affected by the absence of NF-kB proteins. In a number of treatment settings intercurrent viral infections occur frequently and therefore there is an even greater need to understand how the immune system may be affected or compromised in response to the primary treatment. This work will provide insights into the cellular and molecular mechanisms affected by the absnece of a particular NF-kB family member (NF-kB1) in CD8 T cells during normal T cell homeostasis and when challenged with viruses. What we learn from our experiments could have important implications for the development of vaccines.Read moreRead less
The Generation, Fate And Functional Potential Of Recent Thymic Emigrants
Funder
National Health and Medical Research Council
Funding Amount
$318,856.00
Summary
A particular kind of white blood cell, called a T lymphocyte, is responsible for controlling our immune responses to foreign invaders. These cells develop in the thymus, where they learn to distinguish between foreign invaders and self tissue, before emigrating to other organs. The regulation of this process is important to maintain a pool of T lymphocytes in the body. It is important that T lymphocytes do not respond against self tissue, as this can lead to a Oself destructO disease called auto ....A particular kind of white blood cell, called a T lymphocyte, is responsible for controlling our immune responses to foreign invaders. These cells develop in the thymus, where they learn to distinguish between foreign invaders and self tissue, before emigrating to other organs. The regulation of this process is important to maintain a pool of T lymphocytes in the body. It is important that T lymphocytes do not respond against self tissue, as this can lead to a Oself destructO disease called autoimmunity. Since these developing T lymphocytes will not see all kinds of self tissue while in the thymus, we propose that their education to prevent self-tissue reactivity may continue for some time after they leave the thymus.Read moreRead less
Regulation Of T Cell Effector Function In Peripheral Tissues
Funder
National Health and Medical Research Council
Funding Amount
$698,550.00
Summary
Protection from infections relies on different types of immune cells. While some of these cells are found in the blood, others reside in peripheral tissues such as the skin. We will analyse the function of these peripheral immune cells to understand how they work to fight off infections. We will also investigate how so-called memory cells that permanently reside in peripheral tissues can protect from re-infection with similar bacteria or viruses.