Structural And Functional Studies On The Interaction Between Alpha2-Antiplasmin And Plasmin
Funder
National Health and Medical Research Council
Funding Amount
$280,400.00
Summary
Fibrinolysis is the process by which the body dissolves clots. In this proposal we aim to investigate how the fibrinolysis inhibitor alpha2-antiplasmin interacts with the clot dissolving protease enzyme plasmin. These data will be useful for developing new approaches to accelerate plasmin-mediated clot breakdown.
Regulation Of Lysosomal Proteases By The Intracellular Serpin, PI-6.
Funder
National Health and Medical Research Council
Funding Amount
$152,500.00
Summary
All cells have a graded response to stress. At low levels of stress, intrinsic systems counter the stressor and repair damage. As stress increases and irreparable damage is likely, affected cells suicide in a pre-programmed manner, and are rapidly engulfed by their neighbours to prevent initiation of a deleterious inflammatory response. Finally, if subjected to overwhelming stress, cells may burst and trigger an inflammatory response. Emerging evidence shows that several organelles in the cell a ....All cells have a graded response to stress. At low levels of stress, intrinsic systems counter the stressor and repair damage. As stress increases and irreparable damage is likely, affected cells suicide in a pre-programmed manner, and are rapidly engulfed by their neighbours to prevent initiation of a deleterious inflammatory response. Finally, if subjected to overwhelming stress, cells may burst and trigger an inflammatory response. Emerging evidence shows that several organelles in the cell act as stress sensors and participate in initiating programmed cell death. In particular, it appears that degradative enzymes (proteases) released under stress from waste disposal-recycling organelles (lysosomes) can induce death. This may occur in settings such as infection or cardiovascular disease (e.g. stroke). As part of a defence mechanism to counter low level release of these lysosomal proteases, we propose that some cells produce inhibitors called serpins. In preliminary work we have shown that particular serpins do indeed inactivate a subset lysosomal proteases. We propose to study the role of these serpins in protecting cultured cells from stress and the effects of lysosomal protease release. In addition, we will use mice lacking one of these serpins to evaluate its importance in the physiological response to stresses such as bacterial and viral infection, tumor formation and stroke.Read moreRead less
SERPINB2 IS AN INDUCIBLE HOST FACTOR INVOLVED IN ENHANCING HIV-1 TRANSCRIPTION AND REPLICATION
Funder
National Health and Medical Research Council
Funding Amount
$496,446.00
Summary
SerpinB2 is one of the most abundant proteins made at sites of inflammation. We have shown that HIV-1 infection also induces SerpinB2 and that SerpinB2 then helps the virus to replicate. In this grant we seek to understand how the virus causes this protein to be made and how this protein then increases virus replication. In the human population there are different forms of SerpinB2 and this grant seeks to determine whether these different forms affect HIV-1 replications differently. It may for i ....SerpinB2 is one of the most abundant proteins made at sites of inflammation. We have shown that HIV-1 infection also induces SerpinB2 and that SerpinB2 then helps the virus to replicate. In this grant we seek to understand how the virus causes this protein to be made and how this protein then increases virus replication. In the human population there are different forms of SerpinB2 and this grant seeks to determine whether these different forms affect HIV-1 replications differently. It may for instance be possible that an individual who has a certain form of SerpinB2 may be less susceptable to AIDS following HIV-1 infection.Read moreRead less
The Role Of Proteinase Inhibitor 9 In Cytotoxic Lymphocyte Function
Funder
National Health and Medical Research Council
Funding Amount
$820,136.00
Summary
Cytotoxic lymphocytes eliminate virus-infected or cancerous cells from the body. This is achieved by the release of powerful cytotoxins that kill the abnormal cell. Unless carefully targeted these cytotoxins can damage surrounding normal tissue or the cytotoxic lymphocyte itself, and lead to autoimmune disease. One of the most important cytotoxins is a protease called granzyme B. We have discovered a natural inhibitor of granzyme B that is present in cytotoxic cells and testis. Our studies are a ....Cytotoxic lymphocytes eliminate virus-infected or cancerous cells from the body. This is achieved by the release of powerful cytotoxins that kill the abnormal cell. Unless carefully targeted these cytotoxins can damage surrounding normal tissue or the cytotoxic lymphocyte itself, and lead to autoimmune disease. One of the most important cytotoxins is a protease called granzyme B. We have discovered a natural inhibitor of granzyme B that is present in cytotoxic cells and testis. Our studies are aimed at understanding the role of the inhibitor in human immune and reproductive function. We will also design and evaluate synthetic compounds based on the natural inhibitor that will enable us to easily measure granzyme B levels and control its activity.Read moreRead less
Proteinase Inhibitor 6: A Multifunctional Intracellular Serpin
Funder
National Health and Medical Research Council
Funding Amount
$217,435.00
Summary
We have discovered and characterized an unusual protease inhibitor that is widely distributed in the body. We have shown that the inhibitor is present in immune cells that are responsible for fighting bacterial infection, and that its role is probably to protect these cells against a powerful endogenous protease produced to destroy ingested bacteria. The inhibitor probably has additonal roles because it is present in developing and adult brain, skin and other blood cells. In these tissues we hav ....We have discovered and characterized an unusual protease inhibitor that is widely distributed in the body. We have shown that the inhibitor is present in immune cells that are responsible for fighting bacterial infection, and that its role is probably to protect these cells against a powerful endogenous protease produced to destroy ingested bacteria. The inhibitor probably has additonal roles because it is present in developing and adult brain, skin and other blood cells. In these tissues we have evidence that inhibitor regulates other, unidentified, proteases. The purpose of this grant is to identify these proteases, and to elucidate the physiological significance of the inhibitor by studying mice that lack it.Read moreRead less
Plasminogen activator inhibitor type 2 (PAI-2) or SerpinB2 is a protein that has been extensively studied in the field of cancer prognosis and inflammation. Although it is widely believed that this protein exists outside the cell and inhibits enzymes involved in blood clotting and cell migration, it is becoming increasingly clear that this may not be its primary function. We have identified two important new functions for this protein that are related to activities within the cell. These activit ....Plasminogen activator inhibitor type 2 (PAI-2) or SerpinB2 is a protein that has been extensively studied in the field of cancer prognosis and inflammation. Although it is widely believed that this protein exists outside the cell and inhibits enzymes involved in blood clotting and cell migration, it is becoming increasingly clear that this may not be its primary function. We have identified two important new functions for this protein that are related to activities within the cell. These activities involve regulation of cellular growth and resistence to viral infections. This grant seeks to characterise these different activities and determine how they affect cell behaviour and thereby determine the real role of this protein. Understanding what this protein actually does will have implications for understanding cancer prognosis and antiviral resistance.Read moreRead less