The Role Of Th17 And Tregs In The Development Of Tolerance And Rejection In A Murine Model Of Renal Allograft Rejection
Funder
National Health and Medical Research Council
Funding Amount
$110,068.00
Summary
In clinical transplantation, rejection remains the greatest problem in determining both short and long-term patient outcomes. Tolerance, the ability of the body to accept a transplant without immunosuppressive drugs, remains an as yet unattained goal. The aim of this project is to examine the mechanisms by which the initial immune response (innate immunity) affects the development of tolerance or rejection in a mouse model of kidney transplantation.
CD39 Protects Against Renal Ischaemic-reperfusion Injury
Funder
National Health and Medical Research Council
Funding Amount
$441,584.00
Summary
In many medical settings, such as heart attacks, strokes, transplantation, heart surgery, shock and infection, the blood supply to an organ may be compromised resulting in damage. The cessation of blood flow depletes the organ of oxygen and generates a number of toxic changes. Re-establishing blood flow to the organ is essential to prevent further damage, however the reestablishment of blood flow itself can be harmful to the organ. The return of blood flow, oxygen and energy can actually promote ....In many medical settings, such as heart attacks, strokes, transplantation, heart surgery, shock and infection, the blood supply to an organ may be compromised resulting in damage. The cessation of blood flow depletes the organ of oxygen and generates a number of toxic changes. Re-establishing blood flow to the organ is essential to prevent further damage, however the reestablishment of blood flow itself can be harmful to the organ. The return of blood flow, oxygen and energy can actually promote more widespread injury - a process known as ischaemia-reperfusion injury (IRI). A greater understanding of IRI should aid in the development of drugs that minimise its impact. The overall aim of this work is to examine the role of a molecule - CD39 - in IRI. This molecule is ideally situated to minimise injury - it is located on cells that line blood vessels and, as such, is able to directly neutralise toxins released in response to this injury. We, therefore, believe that it will be protective in this setting. We have developed animals that express this molecule and have preliminary results to suggest that these animals are protected in experimental models of IRI as well as in several other models including heart transplantation surgery; processes that share many features with IRI. Moreover, mice deplete of this molecule are prone to more severe IRI. We aim to investigate this by using animals both lacking and expressing CD39. Blood flow to the kidneys will be interrupted for 30 minutes and kidney function assessed at 24 and 48 hours. We will then delve into the potential mechanisms underpinning IRI by determining whether the kidney itself or the blood cells afford protection, which has direct clinical implications.Read moreRead less
Many people with organ failure such as heart or kidney disease need a transplant to survive. In the case of kidney failure patients can be kept alive by the artificial kidney however this sort of mechanical traeatment is much less satisfactory than a transplant. Unfortunately most patients who would benefit from a transplant are unable to receive one beacuse of the shortage of living or cadaver donors. A possible solution to this shortage of organs for transplantation is to use animal organs. Pi ....Many people with organ failure such as heart or kidney disease need a transplant to survive. In the case of kidney failure patients can be kept alive by the artificial kidney however this sort of mechanical traeatment is much less satisfactory than a transplant. Unfortunately most patients who would benefit from a transplant are unable to receive one beacuse of the shortage of living or cadaver donors. A possible solution to this shortage of organs for transplantation is to use animal organs. Pigs are the most suitable animal donor. However, a pig-to-human organ is rejected immediatly because of the distance between the species. Over the last 10 years, we and others have been trying to understand which genetic differences are important. It is now clear that there are several important differences. One of these is a Blood Group like molecule in the pig that humans react with immediatly on transplantation. This is called the Gal molecule. We and others have been successful in removing the pig gene that makes this molecule. In addition we have added several human genes to pigs to prevent the early vigorous rejection which usually occurs. Organs from these genetically modified pigs have been tested by transplantation into baboons and monkeys. The transplants which used to be rejected within minutes, now survive for months. However, they organs are still rejected by a process which causes clotting in the transplanted organs. We now understand the mechanism andare making genetically modified pigs with human genes which regulate clotting of human blood. This project will test organs from these pigs by transplantation into baboons. We will also make a special strain of pigs in which all these genetic modifications are assembled. This involves the removal of one pig gene and the addition of 4 or 5 human genes. We think it is highly likely that this combination of genetic modifications will make this strain of pigs much more suitable as organ donors.Read moreRead less