Regulation Of TNF And SFK Signalling In Immune Cells By TCPTP
Funder
National Health and Medical Research Council
Funding Amount
$454,023.00
Summary
Tumour necrosis factor (TNF) is a potent proinflammatory cytokine that plays an important role in immunity and inflammation. TNF acts on the cell surface to activate two key cellular communication or signalling pathways: the mitogen-activated protein kinase (MAPK) pathway and the nuclear factor kappaB (NFkappaB) pathway. The relative activation of the two pathways can dictate whether cells live and proliferate or differentiate or otherwise die in response to TNF, and therefore determine the natu ....Tumour necrosis factor (TNF) is a potent proinflammatory cytokine that plays an important role in immunity and inflammation. TNF acts on the cell surface to activate two key cellular communication or signalling pathways: the mitogen-activated protein kinase (MAPK) pathway and the nuclear factor kappaB (NFkappaB) pathway. The relative activation of the two pathways can dictate whether cells live and proliferate or differentiate or otherwise die in response to TNF, and therefore determine the nature of the immune or inflammatory response. The T-cell protein tyrosine phosphatase (TCPTP) is known to be important in the immune system and serves as a negative regulator of inflammation. Our preliminary studies have identified TCPTP as a selective regulator of TNF-induced MAPK but not NFkappaB signaling. TCPTP exerts its effects by inactivating Src family kinases (SFK) which are themselves integral to immune and inflammatory responses. In this proposal we will elucidate the molecular basis for TCPTP function in TNF- signalling and characterise the role of TCPTP in TNF and SFK functions in immune cells, in particular T-cells.Read moreRead less
The establishment of an immune system that is able to distinguish between self and non-self is of fundamental importance for good health and survival. How this specificity is achieved has been an area of intense investigation for many years because a breakdown of this process leads to the development of autoimmune diseases, such as diabetes, or an inability to fight pathogenic organisms. It has been known for many years that the development T cells, a subset of cells involved in mounting immune ....The establishment of an immune system that is able to distinguish between self and non-self is of fundamental importance for good health and survival. How this specificity is achieved has been an area of intense investigation for many years because a breakdown of this process leads to the development of autoimmune diseases, such as diabetes, or an inability to fight pathogenic organisms. It has been known for many years that the development T cells, a subset of cells involved in mounting immune responses, occurs in the thymus. The thymus produces large numbers of immature T cells (called thymocytes) from which a small number receive the appropriate signals to survive and develop into mature T cells. These tailor-made T cells can then enter the blood and peripheral lymphoid organs where they fight infectious organisms without reacting against host (i.e. self) tissues. The work for this project is aimed at determining how proteins inside thymocytes transmit signals that determine whether thymocytes either survive, and develop into T cells, or are eliminated because they react too strongly with self proteins. We have established that a protein called c-Cbl is central to this process as it regulates the initial strength of the signal that determines the fate of thymocytes. Our aim is to identify the putative key protein regulated by c-Cbl that can sense when a signal is too strong following the binding of a thymocyte to a self protein and directs a cell death signalling response. From this critical point of signal splitting we also aim to identify proteins that relay the death signal to the nucleus where they trigger the production of well-characterised proteins required to mediate cell death. By identifying the proteins in this signalling pathway we will have a greater capacity to control the magnitude of immune responses and therefore be able to lessen tissue damage caused by autoimmune reactions.Read moreRead less