The Role And Function Of Macrophages In Cellular Xenograft Rejection
Funder
National Health and Medical Research Council
Funding Amount
$323,250.00
Summary
The long term objective of this project is to develop pig insulin secreting tissue as a treatment for type 1 diabetes. At present the main barrier to this is rejection. In paricular a type of white blood cell called macophages has an important role in causing the rejection seen in xenotransplantation (the transplantation of pig tissue into humans). Our reseach group has made novel observations which show that the way macrophages respond to a xenotransplant is different to the way it behaves to t ....The long term objective of this project is to develop pig insulin secreting tissue as a treatment for type 1 diabetes. At present the main barrier to this is rejection. In paricular a type of white blood cell called macophages has an important role in causing the rejection seen in xenotransplantation (the transplantation of pig tissue into humans). Our reseach group has made novel observations which show that the way macrophages respond to a xenotransplant is different to the way it behaves to the transplant of an organ from the same species. In the rejection of pig insulin secreting tissue, macrophages are able to respond in the absence of ongoing signals from T cells. This project aims to identify the receptors on macrophages that are responsible for this response. In particular those receptors that are important for facilitating the migration of macrophages to the transplant site and the receptors that allow macrophages to distinguish self from non-self will be analysed. Hopefully these receptors will be used as targets for new therapeutic agents that could be used to prevent the strong rejection response that occurs when pig insulin secreting tissue is transplanted into humans.Read moreRead less
Immunobiology Of Carbohydrate Antigens In Xenotransplantation
Funder
National Health and Medical Research Council
Funding Amount
$563,554.00
Summary
Xenotransplantation, the transplanting of organs from other species, is now seen as a viable solution to the problem of lack of supply of suitable human donors. The recent production of genetically engineered pigs represented a critical step towards clinical xenotransplantation. However, other sugars still remain that cause rejection. This project examines the consequences of these sugars.
Intravascular Coagulopathy In Discordant Xenotransplantation
Funder
National Health and Medical Research Council
Funding Amount
$447,750.00
Summary
The successful treatment of many conditions in which the relevant organ has failed completely and irreversibly is to replace that organ with a new one ie. to perform a transplant. It is well known that there are far fewer organs available for transplantation than the number needed. This means that for those conditions where a supportive treatment is available, eg. the artificial kidney, patients must be maintained by that method, however for other organs such as hearts, lungs and livers, there i ....The successful treatment of many conditions in which the relevant organ has failed completely and irreversibly is to replace that organ with a new one ie. to perform a transplant. It is well known that there are far fewer organs available for transplantation than the number needed. This means that for those conditions where a supportive treatment is available, eg. the artificial kidney, patients must be maintained by that method, however for other organs such as hearts, lungs and livers, there is no mechanical substitute. If these patients do not receive a transplant, they die. A solution to this problem is to use organs from animals. This is called xenotransplantation. The pig is the most suitable donor, however despite many similarities to humans which make it suitable, there are many differences which are still to be overcome before clinical application is possible. These differences are at a very fine molecular level and prevent the normal integration of the organ into the new recipient. The result is that the new organ is rejected within minutes. This process is called hyperacute rejection and by research into its mechanism it was found to be due to just a few differences. We and others have genetically modified pigs so that they have the human components and this has completely prevented this form of rejection. However,we have found a second barrier which causes a rejection response after a few days. It is now known that a major component of the cause of this second barrier is a few differences in the clotting system. We propose to make further genetic modifications which we think will prevent this rejection. This project proposes to examine various genetic modifications and test their effect in small animal models before going on to make and test pigs in which human anti-clotting genes have been inserted. . If we are successful, the possibility of replacing failed human organs with animal organs will be a step closer.Read moreRead less
Intravascular Coagulopathy In Discordant Xenotransplantation
Funder
National Health and Medical Research Council
Funding Amount
$227,036.00
Summary
The successful treatment of many conditions in which the relevant organ has failed completely and irreversibly, is to replace that organ with a new one ie. to perform a transplant. It is well known that there are far fewer organs available for transplantation than the number needed. This means that for those conditions where a supportive treatment is available, eg. the artificial kidney, patients must be maintained by that method, however for other organs such as hearts, lungs and livers, there ....The successful treatment of many conditions in which the relevant organ has failed completely and irreversibly, is to replace that organ with a new one ie. to perform a transplant. It is well known that there are far fewer organs available for transplantation than the number needed. This means that for those conditions where a supportive treatment is available, eg. the artificial kidney, patients must be maintained by that method, however for other organs such as hearts, lungs and livers, there is no mechanical substitute. If these patients do not receive a transplant, they die. A solution to this problem is to use organs from animals. This is called xenotransplantation. The pig is the most suitable donor, however despite many similarities to humans which make it suitable, there are many differences which are still to be overcome before we can use xenotransplants clinically. These differences are at a very fine molecular level and prevent the normal integration of the organ into the new recipient. The result is that the new organ is rejected within minutes. This process is called hyperacute rejection and by research into its mechanism it was found to be due to just a few differences. We and others have genetically modified pigs so that they have the human genes and this has completely prevented this form of rejection. However,we have found a second barrier which causes a rejection response after a few days. It is now known that a major component of the cause of this second barrier is a few differences in the clotting system. We propose to make further genetic modifications which we think will prevent this rejection. This project proposes to examine various genetic modifications and test their effect in small animal models before going on to make and test pigs into which human genes have been inserted. If we are successful, the possibility of replacing failed human organs with animal organs will be a step closer.Read moreRead less
Cross-reactive Anti-viral T Cells Mediate Allograft Rejection In Lung Transplantation.
Funder
National Health and Medical Research Council
Funding Amount
$379,563.00
Summary
In solid organ transplantation chronic viral infections can play a major role in causing graft dysfunction and-or loss. This study investigates the role of a specific population of immunological cells. These specific anti-viral immune cells are key controllers of viral infections and have also been implicated in mediating the destruction and-or rejection of a transplanted graft.
Gene Transfer For Corneal Transplantation And Limbal Stem Cell Transplantation
Funder
National Health and Medical Research Council
Funding Amount
$743,463.00
Summary
The cornea is the clear window at the front of the eye. Corneal disease is the second most common reason for blindness in the world. It is sometimes made worse by additional disease affecting the ocular surface. Replacement of a damaged cornea, or of the elements that maintain a normal ocular surface, is possible by transplantation of tissue (either the cornea or the limbus) from a donor eye. The alternative, an artificial cornea, has never yet been reported to function nearly as well as does a ....The cornea is the clear window at the front of the eye. Corneal disease is the second most common reason for blindness in the world. It is sometimes made worse by additional disease affecting the ocular surface. Replacement of a damaged cornea, or of the elements that maintain a normal ocular surface, is possible by transplantation of tissue (either the cornea or the limbus) from a donor eye. The alternative, an artificial cornea, has never yet been reported to function nearly as well as does a successful corneal graft, because the interface between the patient and the prosthesis breaks down and serious problems such as infection are common. Transplantation of the cornea is very successful in some patients but in a sizable subgroup, the graft will fail because of an unwanted immune response. Rejection is the usual cause of a graft failure. Grafts to repair a damaged ocular surface also fail from rejection. Overcoming an unwanted immune response would improve the outcome of corneal transplantation by as much as thirty percent. Overcoming the twin problems of corneal graft rejection and ocular surface disease would make transplantation a feasible option for millions of blind individuals. Novel approaches to abrogation of the immune response to ocular tissue grafts are required, because the many developments in immunosuppression that have improved the survival of other types of transplants have not improved the outcome for grafts in the eye. The immunobiology of the eye is sufficiently different from that of solid organs to demand a different approach. We plan to investigate the use of localised gene transfer to donor eye tissue prior to transplantation, to improve corneal graft and limbal graft outcome.Read moreRead less