Glomerulonephritis Research
What is the role of anti-neutrophil cytoplasmic antibody in the development of crescent glomerulonephritis?
Supervisor: Professor Stephen Holdsworth
Anti-neutrophil cytoplasmic antibody (ANCA) associated crescentic glomerulonephritis (GN) is the most common form of severe crescentic GN occurring in man. The association of ANCA with this disease suggests a pathogenetic role for this antibody in the induction of injury. Measurement of ANCA is the standard way of diagnosing and monitoring this disease. Most research into new treatments are focussed on ANCA. However, this form of GN is characterised by the absence of antibody in glomeruli raising doubts about the role of ANCA as the inducer of injury. We have recently shown that T cells and macrophages (effectors of DTH) as invariably present in glomeruli of patients with ANCA associated GN. This suggests that DTH effectors not ANCA may induce the disease. The recent development of an animal model of crescentic ANCA associated GN allows these issues to be resolved. In this project, the experimental ANCA model will be induced in m chain gene knockout mice (lacking B cells) to show that the disease can be induced without the development of ANCA. CD4 positive T cell depletion will be induced (using protocols that do not effect antibody levels) assessing whether abrogation of DTH in the presence of ANCA can prevent disease. These experiments will experimentally address the issue of whether ANCA and/or DTH induces this important form of GN.
The pathogenesis of glomerulonephritis
Supervisors: Professor Stephen Holdsworth, Associate Professor Peter Tipping or Associate Professor Richard Kitching
Glomerulonephritis is the commonest cause of end-stage renal failure, and crescentic glomerulonephritis is the most aggressive form of crescentic glomerulonephritis. Using a murine model of crescentic glomerulonephritis, we have been working on how and why the immune response is directed against the glomerulus, and how this response can be modified to improve treatments for people with glomerulonephritis. We can offer a number of projects in studying why some cytokines (immune proteins, including interleukins, interferons and colony stimulating factors) are damaging, while other cytokines are protective; how T cells are activated to direct immune glomerular injury; and how the coagulation system participates in inflammation in the glomerulus. Projects will involve working with gene knock out and transgenic mice, tests of immune function and coagulation, ELISAs, immunohistology and molecular biology.
The role of humoral and cell mediated immune responses in organ specific autoimmune crescentic glomerulonephritis
Supervisor: Associate Professor Richard Kitching
Human Goodpasture’s disease is an autoimmune renal disease directed against a fragment of type IV collagen that results in severe crescentic glomerulonephritis and renal failure. It has long been considered to be primarily antibody driven, although evidence exists to support a critical role for cell mediated effectors of injury. This project will examine the role of humoral and cell mediated mechanisms of injury in a murine model of Goodpasture’s that is induced by the same antigen as the human disease. To test the hypothesis that cell mediated effector responses are required for Goodpasture’s syndrome, the immune system of T and B cell deficient RAG-1 -/- mice will be reconstituted with CD4+ cells transferred from mice with autoimmune disease. The absolute requirement for antibodies to the glomerular basement membrane will be tested by inducing autoimmune crescentic glomerulonephritis in immunoglobulin m chain deficient mice that lack secreted antibody. Techniques involved in this project include whole animal models, cell culture, FACS analysis and sorting, ELISAs, histology, immunohistochemistry and RT-PCR (for genotyping of mice and the presence of mRNA for proinflammatory mediators of injury in diseased mice).
The role of interleukin-18 (IL-18) in glomerulonephritis
Supervisor: Associate Professor Richard Kitching
Crescentic glomerulonephritis is a rapidly progressive form of renal inflammation that has a poor prognosis. Recent evidence suggests that this lesion is the result of a T helper 1 (Th1) immune response involving the kidney. Interleukin-18 is a recently described cytokine that is emerging as an important co-factor in the generation of Th1 responses. This project will test the hypothesis that IL-18 plays a damaging role in a murine model of crescentic glomerulonephritis by studying disease in mice genetically deficient in IL-18 and antibodies directed against the IL-18 receptor. The relationship between IL-12, considered the cytokine that induces Th1 responses and IL-18 will be studied by generating combined IL-12 and IL-18 deficient mice and studying the development of glomerulonephritis in combined IL-12/IL-18 deficient mice and mice with deficiencies of either IL-12 or IL-18. Techniques involved in this project include whole animal models of disease, cell culture, FACS analysis, ELISAs, histology, immunohistochemistry and RT-PCR (for genotyping of mice and the presence of mRNA for proinflammatory mediators of injury in diseased mice).
The contribution of fibrinolytic proteins to renal interstitial fibrosis
Supervisor: Associate Professor Richard Kitching
Interstitial fibrosis in the kidney is the final common pathway to end stage kidney failure. It has been thought that plasminogen and plasminogen activators (PAs) are important in the development of this fibrosis, but no direct evidence exists that this is the case. Using a model of interstitial fibrosis in the mouse, this project will determine the role of the fibrinolytic system by studying disease in mice lacking plasmingen, tPA, uPA, plasminogen activator inhibitor-1 (PAI-1) and in mice that overproduce PAI-1. This project will involve working with gene knock out and transgenic mice, immunohistology, biochemical measurements, ELISAs, and molecular biology.
Roles for coagulation molecules as cellular activation receptors
Supervisor: Associate Professor Peter Tipping
Tissue factor is the primary initiator of coagulation in vivo. Tissue factor is a transmembrane molecule expressed on activated macrophages and has the potential to have a dual role in activation of coagulation and amplification of inflammation. In this project, the potential role of tissue factor as a cellular activator in inflammatory diseases will be explored. This project will have a strong emphasis on molecular biology, including include molecular mutation and transfection of tissue factor and studies in genetically mutated mice expressing mutated tissue factor. There will also be an opportunity to develop skills in immuno-histochemistry, ELISA and animal models of disease. These studies will provide insights into mechanisms of inflammatory injury in diseases including atherosclerosis and glomerulonephritis.
Is atherosclerosis an immunologically mediated disease?
Supervisor: Associate Professor Peter Tipping
Historically, atherosclerosis has been viewed as a disease of dysregulated lipoprotein metabolism. Recently, the participation of macrophages, T lymphocytes and cytokines has been recognised demonstrating the involvement of inflammatory processes and the potential contribution of cognate immunity. The precise contribution of immune initiated injury is difficult to elucidate in human studies. Mice genetically deficient in apolipoprotein E (apoE GKO) provide an excellent animal model of human atherosclerosis. These mice allow the contribution of T cells and immuno-regulatory cytokines to be studied using a molecular biological approach and have demonstrated a role for immuno-competent T cells in the development of atherosclerosis. This project will address the hypothesis that cell mediated immunity directed by Th1 cells plays an important role in the initiation and progression of atherosclerosis. ApoE GKO mice with deficiencies in Th1 and Th2 subset development have been generated and will allow the contribution of polarised T cell subset responses to the development of atherosclerosis to be studied.
The role of Protease Activated Receptors (PAR's) in inflammation and renal disease
Supervisor: Associate Professor Peter Tipping
PAR's are a family of seven transmembrane, G protein couple receptors, which are activated by proteolytic cleavage of their extra-cellular N terminal. PAR-1 is a member of this family that is cleaved by thrombin, a key molecule in activation of coagulation. PAR-1 activation by thrombin may play an important role in systemic an local inflammatory diseases. The contribution of PAR-1 to inflammation in will be studied in PAR-1 deficient mice using models of systemic inflammation and organ specific cognate and innate immunity.
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