Major Xenoantigens For Neovascularised Porcine Xenografts: The Role Of PERV And MHC In Rejection And Tolerance
Funder
National Health and Medical Research Council
Funding Amount
$504,750.00
Summary
Cross-species transplants (xenografts) of pig organs which use donor pig blood vessels are rejected by antibody which recognises a special target (xenoantigen) on the pig blood vessels; other pig tissue transplants (cellular transplants) which use recipient (not donor pig) blood vessels, are rejected by white blood cells called CD4 T cells. The pig targets recognised by the xenoreactive CD4 T cells are unknown. We plan to identify the major target(s) involved in cellular xenograft rejection. Thi ....Cross-species transplants (xenografts) of pig organs which use donor pig blood vessels are rejected by antibody which recognises a special target (xenoantigen) on the pig blood vessels; other pig tissue transplants (cellular transplants) which use recipient (not donor pig) blood vessels, are rejected by white blood cells called CD4 T cells. The pig targets recognised by the xenoreactive CD4 T cells are unknown. We plan to identify the major target(s) involved in cellular xenograft rejection. This information can then be used to specifically remove or disable only those CD4 T cells capable of recognising the pig tissue and hence facilitate xenograft survival or tolerance without immunosuppression. In this way, the remainder of the CD4 T cell population and immune system is preserved intact. Recent studies have demonstrated that a pig virus (PERV) can be transmitted from pig tissue xenografts to recipient tissues. Our studies have also suggested that the process of xenograft rejection and the immunological recognition of transplant recipient cells infected with the pig virus, are closely related. We plan to investigate this relationship and ascertain whether the immunological destruction of the pig tissue xenograft is largely due to an immune response generated against the pig virus(es) it carries. As an extension of this concept, we will investigate whether long-term xenograft survival (tolerance) is associated with lack of immune reactivity to the pig virus and hence a continual capacity for pig virus to be transmitted to host tissues. This outcome could result in the development of unwanted disease(s) in transplant patients. To prevent these problems, our studies will determine whether it will be essential for such pig virus to be eliminated from the donor pig tissue before transplantation, e.g. by the development of potent anti-viral agents and-or via the development of pig herds that have been genetically engineered to be pig virus (PERV)-deficient.Read moreRead less
Periodontal Mesenchymal Stem Cells For Periodontal Regeneration
Funder
National Health and Medical Research Council
Funding Amount
$358,000.00
Summary
Dental diseases affecting the gums (periodontal disease) are extremely prevalent in our society. The effects of periodontal disease can be particularly severe as loss of support for the teeth leads to loose teeth and severely compromised masticatory function. If left untreated, the associated pain and loss of function may necessitate extraction of the teeth. We have recently identified cells residing in the periodontal ligament which may be adult stem cells. This project will further characteriz ....Dental diseases affecting the gums (periodontal disease) are extremely prevalent in our society. The effects of periodontal disease can be particularly severe as loss of support for the teeth leads to loose teeth and severely compromised masticatory function. If left untreated, the associated pain and loss of function may necessitate extraction of the teeth. We have recently identified cells residing in the periodontal ligament which may be adult stem cells. This project will further characterize these cells and explore whether they can be used to restore periodontal tissues damaged by periodontal disease.Read moreRead less
Opioid Actions On Sensory Neuron Excitability In Vitro
Funder
National Health and Medical Research Council
Funding Amount
$241,018.00
Summary
Morphine and related drugs are very widely used for pain relief, although the way they affect the pain-sensitive cells in the body is not well understood. Use of morphine for extended periods of time often makes morphine less effective for pain relief, which makes it necessary to increase the dose of morphine given. This leads to an increase in the unwanted side effects of morphine, and can eventually lead to morphine becoming ineffective in controlling pain. This study is designed to examine ho ....Morphine and related drugs are very widely used for pain relief, although the way they affect the pain-sensitive cells in the body is not well understood. Use of morphine for extended periods of time often makes morphine less effective for pain relief, which makes it necessary to increase the dose of morphine given. This leads to an increase in the unwanted side effects of morphine, and can eventually lead to morphine becoming ineffective in controlling pain. This study is designed to examine how morphine affects pain-sensitive cells, and to determine how continued use of morphine changes the way pain-sensitive cells respond to morphine. We hope that by understanding how morphine works on pain-sensitive cells, we can understand why it does not work so well after continued use. This information should enable us to design better forms of pain relief than we have now.Read moreRead less
Cellular And Molecular Events During Antigen Dependent B Cell Differentiation
Funder
National Health and Medical Research Council
Funding Amount
$283,329.00
Summary
The immune system is essential for protecting us against invasion from without by viruses and bacteria and invasion from within by cancer cells. Among the white blood cells making up this system are those responsible for producing antibodies. To ensure that all possible infections and tumours can be recognised, the body needs to manufacture a very large number of these cells on a continuous basis. The aim of this project is to work out the mechanism responsible for controlling their production a ....The immune system is essential for protecting us against invasion from without by viruses and bacteria and invasion from within by cancer cells. Among the white blood cells making up this system are those responsible for producing antibodies. To ensure that all possible infections and tumours can be recognised, the body needs to manufacture a very large number of these cells on a continuous basis. The aim of this project is to work out the mechanism responsible for controlling their production and function using a novel experimental system. By pinpointing the different stages involved in antibody production in the normal host we should be in a better position to make longer lasting vaccines in the future and to understand what goes wrong with these white cells in disease. In particular, the results should shed light on the chronic form of leukaemia called myeloma and some of the autoimmune disorders like the rheumatic diseases which occur when the antibodies being produced attack our own tissues.Read moreRead less
Opioid Actions On Identified Sensory Neurons In Vitro
Funder
National Health and Medical Research Council
Funding Amount
$371,850.00
Summary
Opioids (in particular morphine) are the gold standard drugs for the relief of most types of moderate to severe pain. Despite the effectiveness of opioids and other analgesics, many people still suffer unrelieved pain. There are 2 main reasons for this. Firstly, there are some types of pain that are refractory to currently used analgesics from the outset, and secondly, chronic conditions may require escalating doses of analgesics for adequate pain relief, and these does may increase until side e ....Opioids (in particular morphine) are the gold standard drugs for the relief of most types of moderate to severe pain. Despite the effectiveness of opioids and other analgesics, many people still suffer unrelieved pain. There are 2 main reasons for this. Firstly, there are some types of pain that are refractory to currently used analgesics from the outset, and secondly, chronic conditions may require escalating doses of analgesics for adequate pain relief, and these does may increase until side effects become intolerable. My studies will provide insight into the reasons that underlie the differential effectiveness of opioids in acute pain conditions, as well as the reasons why opioids lose their effectiveness over time. These studies will also identify molecular targets that may be important for developing analgesics for specific pain conditions. Because the head is the source of many familiar painful conditions, including tooth pain, migraine and temporomandibular disorders, I will be using neurons from the trigeminal ganglion, the part of the nervous system which supplies the sensory innervation to the structures involved in these pain states. By using mice as experimental animals, I will be able to investigate the contribution of neurons that innervate specific parts of the head to these pain states, and study how chronic morphine treatment affects the behavior of these cells. I hope that these studies will provide a basis for designing strategies that improve the effectiveness of existing analgesics, and perhaps lead to the identification of new, better pain relievers.Read moreRead less
Tolerogenic Dendritic Cells In Common Marmoset Renal Transplantation
Funder
National Health and Medical Research Council
Funding Amount
$162,756.00
Summary
ORGAN TRANSPLANT PATIENTS currently need life-long immune suppressing drugs to prevent rejection, often using 15 medications a day, costing Australia $52M in 2002. These drugs increase risks of infection and cancer. 90% of patients develop some form of cancer over 30 years. They also cause non-specific side effects including high blood pressure, diabetes and osteoporosis. The average lifespan of a kidney transplant is 8-15 years. Major causes of kidney transplant loss are rejection and drug toxi ....ORGAN TRANSPLANT PATIENTS currently need life-long immune suppressing drugs to prevent rejection, often using 15 medications a day, costing Australia $52M in 2002. These drugs increase risks of infection and cancer. 90% of patients develop some form of cancer over 30 years. They also cause non-specific side effects including high blood pressure, diabetes and osteoporosis. The average lifespan of a kidney transplant is 8-15 years. Major causes of kidney transplant loss are rejection and drug toxicity. TRANSPLANTS ARE REJECTED when a recipient's immune system sees the kidney as foreign. Immune suppressing drugs prevent rejection by stopping the reaction to foreign tissues, but this causes increased infection and cancer risk. IMMUNE TOLERANCE means the recipient's immune system sees a transplant not as foreign but as part of itself, no longer reacting to it. If tolerance could be achieved for transplants, patients wouldn't need to use immune suppressing drugs. Costs of immune suppression would be nil. Tolerance is the best long-term solution for patients needing transplants. Tolerance has been achieved in various ways in mice models. DENDRITIC CELLS can be used to induce tolerance as they can silence a recipient's immune system, preventing it from seeing transplant tissues as foreign. We have shown in mice that a single infusion of a certain type of dendritic cells caused prolonged transplant tolerance without needing immune suppression. This project aims to use dendritic cells to induce tolerance in a marmoset model - a required step before allowing this therapy to be done in humans. PRIMATES like MARMOSETS have close genetic identity to humans and are ideal transplant models as their immune systems react much more like humans than other animals. Marmosets are not an endangered species and are smaller, cheaper and easier to care for than other primates. Ultimately, experiments in other species would need repeating in primates before human trials could be done.Read moreRead less
Dental diseases affecting the gums (periodontal diseases) are extremely prevalent in our society. The effects of periodontal disease can be particularly severe as loss of support for the teeth leads to loose teeth and severely compromised chewing function. If left untreated, the associated loss of function may necessitate extraction of the teeth. We have recently identified cells residing in the periodontal ligament which may be adult stem cells. This project will further characterize these cell ....Dental diseases affecting the gums (periodontal diseases) are extremely prevalent in our society. The effects of periodontal disease can be particularly severe as loss of support for the teeth leads to loose teeth and severely compromised chewing function. If left untreated, the associated loss of function may necessitate extraction of the teeth. We have recently identified cells residing in the periodontal ligament which may be adult stem cells. This project will further characterize these cells and explore whether they can be used to restore periodontal tissues damaged by periodontal disease.Read moreRead less
Periodontal disease is an inflammatory disorder leading to tooth loosening and, if untreated, tooth loss. Once bone destruction has occurred around teeth the treatment outcomes are severely compromised and are mainly focussed towards slowing the process of destruction rather than repairing the damage. Over the last decade, treatment of advanced periodontal disease has focussed on ways in which the damaged tissues may be regenerated. We now have gained considerable insight into the molecular and ....Periodontal disease is an inflammatory disorder leading to tooth loosening and, if untreated, tooth loss. Once bone destruction has occurred around teeth the treatment outcomes are severely compromised and are mainly focussed towards slowing the process of destruction rather than repairing the damage. Over the last decade, treatment of advanced periodontal disease has focussed on ways in which the damaged tissues may be regenerated. We now have gained considerable insight into the molecular and cellular events associated with periodontal regeneration. Despite efforts to induce regeneration through the selective use of growth and differentiation factors it is becoming obvious that the most significant factor in successful clinical outcomes is the recruitment of special cells to the site of damage which have the potential to repair tissue damage. Thus, we intend to engineer different types of periodontal matrices in the laboratory and then transplant these newly formed tissues into sites affected by periodontal disease in an attempt to repair the damage caused by the disease process.Read moreRead less
The Role Of Perlecan In Tensional Connective Tissues
Funder
National Health and Medical Research Council
Funding Amount
$605,037.00
Summary
Musculoskeletal diseases affect tension and weight bearing connective tissues which have notoriously poor repair capabilities. These conditions are difficult to treat clinically and surgical repair in many cases does not provide a return to optimal joint function impinging on the quality of life of afflicted individuals and their carers. Our project aims to better understand the structure and function of these tissues in health and disease with a view to improving repair strategies.