Antiphospholipid Antibodies, Beta 2-Glycoprotein I And Control Of Coagulation.
Funder
National Health and Medical Research Council
Funding Amount
$471,000.00
Summary
Antiphospholipid antibodies are associated with an autoimmune condition characterised by the presence of clots and recurrent miscarriages. Although the name implies that the antibodies bind phospholipid the disorder is characterised by circulating antibodies which bind a protein in the blood known as Beta 2-Glycoprotein I. The exact role of Beta 2-GPI in the body has not been determined, although there are numerous studies looking at this protein. This protein has been thought to be important in ....Antiphospholipid antibodies are associated with an autoimmune condition characterised by the presence of clots and recurrent miscarriages. Although the name implies that the antibodies bind phospholipid the disorder is characterised by circulating antibodies which bind a protein in the blood known as Beta 2-Glycoprotein I. The exact role of Beta 2-GPI in the body has not been determined, although there are numerous studies looking at this protein. This protein has been thought to be important in controlling the clotting system in humans and other mammals. The evidence for this has been contradictory, however, we have recently made a major new finding on the function of this protein on the clotting system. We will be using sophisticated molecular biology techniques to further characterise the role that Beta 2-GPI has in controlling clotting factors in the body. We have been able to eliminate the gene for Beta 2-GPI in mice thus deriving mice that do not produce any Beta 2-GPI protein. These mice are called Beta 2-GPI knockout mice and will be an ideal animal model to examine the function of Beta 2-GPI and its new role in controlling the clotting cascade by targetting a specific part of this pathway. In addition, these findings may be able to provide new information on how Beta 2-GPI controls clotting factors and the effect of antiphospholipid antibodies on this system, which may lead to new treatments for antiphospholipid antibodies and more generally clotting disorders.Read moreRead less
Characterisation Of An In-vivo Thrombosis Animal Model Of The Antiphospholipid Syndrome Using Beta 2-GPI KO Mice
Funder
National Health and Medical Research Council
Funding Amount
$467,310.00
Summary
The antiphospholipid syndrome is an autoimmune condition characterised by the presence of thrombosis and recurrent miscarriage. The disorder is characterised by circulating antibodies which bind a protein in the blood known as Beta 2- Glycoprotein I. This protein has been thought to be important in controlling the clotting system in humans and other mammals. However, the experiments that have been designed to look at the function of this protein have looked at its function in the test tube. The ....The antiphospholipid syndrome is an autoimmune condition characterised by the presence of thrombosis and recurrent miscarriage. The disorder is characterised by circulating antibodies which bind a protein in the blood known as Beta 2- Glycoprotein I. This protein has been thought to be important in controlling the clotting system in humans and other mammals. However, the experiments that have been designed to look at the function of this protein have looked at its function in the test tube. The exact role of Beta 2-GPI in the body, has not been determined. A way of looking at the function of this protein in the body would be if you eliminated the protein from an animal such as a mouse. By sophisticated molecular biology techniques we have been able to eliminate the gene for Beta 2-GPI in mice thus deriving mice that do not produce any Beta 2-GPI protein. These mice are called Beta 2-GPI knockout mice and are an ideal animal model to examine the function of Beta 2-GPI. Experiments outlined in this proposal will examine the role of Beta 2-GPI in clotting, atherosclerosis and the effect of production of antibodies to Beta 2-GPI in these animals. In addition, since current treatment of patients that have these antibodies consists of long term, sometimes lifelong, treatment with drugs that thin the blood which have potential side effects, we are investigating a novel treatment approach which is directed at eliminating the antibodies that bind Beta 2-GPI. If one could eliminate the antibody production to Beta 2-GPI by these patients there would not be a need for lifelong treatment with drugs such as heparin which thins the blood and there would thus be a reduction in the problems with these medications. To do this we have obtained a specialised chemically modified portion of Beta 2-GPI that has already been shown to work in preliminary experiments.Read moreRead less
This study aims to determine the extent to which semen is important in initiating the maternal immune response to the fetus and placenta during pregnancy. We postulate that exposure to paternal proteins in sperm and other factors present in the semen may have a cumulative, beneficial effect in 'educating' the female immune system to respond in the correct way to the embryo when pregnancy occurs. To investigate this, the behaviour and movements of white blood cells responding to semen will be stu ....This study aims to determine the extent to which semen is important in initiating the maternal immune response to the fetus and placenta during pregnancy. We postulate that exposure to paternal proteins in sperm and other factors present in the semen may have a cumulative, beneficial effect in 'educating' the female immune system to respond in the correct way to the embryo when pregnancy occurs. To investigate this, the behaviour and movements of white blood cells responding to semen will be studied during the period after mating, in which the uterus prepares for and accommodates to pregnancy. In particular, the study will focus on the roles of a specific chemical messenger substance in semen, called transforming growth factor (TGF)-beta, which triggers the molecular changes leading to maternal immune tolerance. A deeper understanding of these events will have an important impact in human and veterinary medicine where implantation failure is a major cause of reproductive loss and inadequate placental growth poses a threat to the health of the conceptus both in utero and into adult life.Read moreRead less
Pathophysiological Mechanisms In The Antiphospholipid Syndrome: B2GPI Regulation Of FXI-FXIa
Funder
National Health and Medical Research Council
Funding Amount
$530,591.00
Summary
The major protein that the antibodies in the antiphospholipid syndrome (APS) bind is called Beta 2-GPI. Antibodies to Beta 2-GPI are associated with recurrent miscarriage, intrauterine growth retardation, clots and stroke. Treatment of patients with the APS are treated with medication that has significant side effects. The development of more targeted and effective therapies for the APS requires a greater understanding of how the antibodies cause their effects, which is addressed in this study.
Shared Team Approach Between Nurses And Doctors For Improved Risk Factor Management (STAND FIRM)
Funder
National Health and Medical Research Council
Funding Amount
$1,945,676.00
Summary
There are many proven treatments for preventing people with stroke from having a recurrent event, e.g. maintaining blood pressure at acceptable levels. However, uptake of therapies is poor. We will assess whether patients receiving individualised management plans, prepared and administered by both doctors and nurses will have risk factors controlled better than those receiving usual care. The plan includes education of patients to help them have more control over their own care.
The outcomes to be assessed are recurrent ischaemic stroke, intracranial haemorrhage, myocardial infarction, parenchymal embolism and vascular death. Should these outcomes be significantly reduced, the public health and economic issues which will be addressed in this study are considerable. Approximately 40,000 new and recurrent cases of stroke occur in Australia each year, and about 80% of these are ischaemic. There is an average prevalence of about 20% of large or complex aortic plaque among p ....The outcomes to be assessed are recurrent ischaemic stroke, intracranial haemorrhage, myocardial infarction, parenchymal embolism and vascular death. Should these outcomes be significantly reduced, the public health and economic issues which will be addressed in this study are considerable. Approximately 40,000 new and recurrent cases of stroke occur in Australia each year, and about 80% of these are ischaemic. There is an average prevalence of about 20% of large or complex aortic plaque among patients with ischaemic stroke. About the same proportion of cases of ischaemic stroke yearly are associated with the presence of complex aortic plaque alone, and as many again with simple plaque (40% in total). Using the NHMRC estimated cost of $40,000 per stroke (and assuming that recurrent stroke costs are similar to initial stroke costs) and the estimated recurrent stroke rates of 11.9-100 person-years for plaque > 4 mm, the national cost of recurrent ischaemic stroke attributable to complex aortic plaque alone is about $3 million in the first year. This estimate does not include patients with incident TIA and atherosclerotic plaque or the resources spent on evaluating recurrent stroke and TIA attributable to aortic plaque, the cost of lost wages, or the negative impact on the quality of life of the victims. The economic and public health burden to our society could be greatly reduced by successful efforts at secondary stroke prevention in individuals with aortic plaque and TIA or ischaemic stroke. If just 25% of recurrent ischaemic strokes associated with aortic arch debris could be prevented by treatment interventions, the annual savings to society for recurrent ischaemic stroke alone would be considerable.Read moreRead less
Immunobiology Of Early Pregnancy - A Model Of Virus-induced Abortion
Funder
National Health and Medical Research Council
Funding Amount
$454,500.00
Summary
The lack of 'self' molecule expression on the trophoblast cells of the placenta which interface directly with the mother's circulation, as well as the local suppression of the mother's immune response at this interface, may be important factors in the successful implantation of the embryo. This immunological 'silence' allows the embryo, whose paternal genetic contribution makes it immunologically foreign to the mother, to escape the rejection reaction normally associated with foreign graft trans ....The lack of 'self' molecule expression on the trophoblast cells of the placenta which interface directly with the mother's circulation, as well as the local suppression of the mother's immune response at this interface, may be important factors in the successful implantation of the embryo. This immunological 'silence' allows the embryo, whose paternal genetic contribution makes it immunologically foreign to the mother, to escape the rejection reaction normally associated with foreign graft transplantation. Infection with flaviviruses increases the concentrations of cell surface self and adhesion molecules in vertebrate cells, including the trophoblast cells of the placenta. As a result, these molecules can then be recognised by the maternal immune system and the embryo targeted for destruction. We hypothesise that the induction of these molecules by this and other viruses may break the immunological silence of the early embryo and reverse the local suppression of the maternal immune response. This would result in maternal immune rejection of the embryo and abortion. This initial sensitisation of the mother by the virus might be one of the reasons that some women suffer recurrent abortions. We will use a novel viral mouse model where we implant virus-infected embryos into receptive animals to enable us to dissect out the unusual requirements for induction of maternal anti-viral immunity during pregnancy. This model was developed in our laboratory to directly test our hypotheses. It does not cause systemic illness in the mother which itself can lead to non-specific abortion. This model therefore can for the first time elucidate the specific mechanisms associated with the delicate balance between eradicating virus and maintaining pregnancy. Results from this project will inform rational design of treatment of recurrent abortions in the community.Read moreRead less