A Functional Autoantibody In Human Narcolepsy: Direct Evidence For The Autoimmune Hypothesis
Funder
National Health and Medical Research Council
Funding Amount
$444,928.00
Summary
Narcolepsy is a chronic disabling sleep disorder causing irresistible sleepiness and, in most cases, brief attacks of weakness on emotional arousal (cataplexy). Other symptoms include a transient paralysis at the beginning or end of sleep and vivid hallucinations at the start of sleep. Symptoms usually appear during adolescence or early adulthood. It affects between one in 1,000 and one in 2,000 people, yet the diagnosis is often delayed for several years because of the lack of a simple diagnost ....Narcolepsy is a chronic disabling sleep disorder causing irresistible sleepiness and, in most cases, brief attacks of weakness on emotional arousal (cataplexy). Other symptoms include a transient paralysis at the beginning or end of sleep and vivid hallucinations at the start of sleep. Symptoms usually appear during adolescence or early adulthood. It affects between one in 1,000 and one in 2,000 people, yet the diagnosis is often delayed for several years because of the lack of a simple diagnostic marker. It has been suspected for some time that narcolepsy is caused by a malfunctioning immune system, but direct evidence for the so-called autoimmune hypothesis has been lacking. We have recently discovered the smoking gun in the form of an autoantibody that circulates in the bloodstream and produces some of the features of narcolepsy on transfer to experimental animals. The identification of the autoantibody, which we term a functional autoantibody because it directly alters the function of nerves thought to be involved in narcolepsy and cataplexy, opens a new chapter in narcolepsy research that has important diagnostic and therapeutic implications. Testing for the autoantibody in subjects recruited from national and international centres for sleep research will determine its value in the diagnosis of narcolepsy and may help distinguish narcolepsy from other sleep disorders. Preliminary findings are encouraging and suggest that the autoantibody is a sensitive and specific marker for human narcolepsy and might lead to a clinically useful diagnostic test. In another part of the project, experimental approaches willl be used to identify an antibody called an antiidiotype that can neutralise the narcolepsy autoantibody and therefore be developed as a therapeutic agent. Finally, experiments have been designed to examine the effect of the autoantibody on neurotransmitters in the brain that are believed to result in cataplexy.Read moreRead less
Neurological Manifestations Of Experimental Neuronal Voltage-gated Potassium Channel Autoimmunity.
Funder
National Health and Medical Research Council
Funding Amount
$65,148.00
Summary
Antibodies against neuronal voltage-gated potassium channels (VGKC) are seen in various neurological illnesses, most commonly epilepsy and memory loss. The role of VGKC antibodies in the development of brain disease will be studied by immunizing rabbits against VGKC and transferring these antibodies to mice.
The Bcl-2 Life/death Switch - Why Do Some Bcl-2 Proteins Kill Cells Whilst Others Promote Their Survival?
Funder
National Health and Medical Research Council
Funding Amount
$375,510.00
Summary
The cells of all animals possess the ability to commit suicide. When this natural process of cell death is dysfunctional, diseases such as cancer arise. Our aim is to understand the molecular mechanisms that underlie this process by providing atomic resolution snapshots of key components of the cell death machinery. By understanding the fine details of cell death regulation we can develop new drugs that target and kill rogue cells such as those found in tumours.
Cholera Toxin Co-receptor Interaction In The Prevention Of Inflammatory Autoimmune Disorders
Funder
National Health and Medical Research Council
Funding Amount
$359,577.00
Summary
Vaccination is undoubtedly one of mankind's greatest achievements. While infections continue to be the major cause of morbidity and mortality in the developing world, heart disease, cancer, chronic allergies and autoimmune disorders are taking their toll in advanced societies. Our expanding knowledge of these 'modern diseases' shows that the immune system plays a central role and hence it is important to learn if new immunologically-based therapies can be developed for such chronic human disorde ....Vaccination is undoubtedly one of mankind's greatest achievements. While infections continue to be the major cause of morbidity and mortality in the developing world, heart disease, cancer, chronic allergies and autoimmune disorders are taking their toll in advanced societies. Our expanding knowledge of these 'modern diseases' shows that the immune system plays a central role and hence it is important to learn if new immunologically-based therapies can be developed for such chronic human disorders. This project takes advantage of our recent discoveries on the immunological properties of a hitherto feared molecule - cholera toxin. We have shown that one portion of the toxin, the B-subunit, responsible for binding to cell membranes, possesses remarkable immunomodulatory properties that prevent the development of inflammatory autoimmune disorders such as rheumatoid arthritis in animal models. The B-subunit, in contrast to the whole cholera toxin, is non-toxic and has no adverse effects in humans. This has sparked considerable interest in the development of such molecules as novel anti-inflammatory agents and highlighted the necessity to better understand the B-subunit's mode of action. Current theory specifies that the B-subunit mediates its immunomodulatory effects by binding and cross-linking a ubiquitous plasma membrane glycosphingolipid, GM1 ganglioside. The essential role of GM1-interaction was recently challenged by our discovery that a mutant B-subunit (H57A) was unable to modulate the immune system even though it still bound to GM1; suggesting that the B-subunits interact with another receptor (or co-receptor), and that it is this second interaction that directs the immune system to prevent development of autoimmune disease. The primary aims are to characterize the nature of B-subunit interaction with the cell membrane and to identify the co-receptor. This work has the potential to provide a new target for drug discovery and development of immunotherapeutics.Read moreRead less
The Generation And Function Of Tissue-specific Regulatory T Cells
Funder
National Health and Medical Research Council
Funding Amount
$488,577.00
Summary
The immune system normally protects against invasion by pathogens such as harmful viruses and bacteria. In autoimmune diseases the same mechanisms that are used to protect us are erroneously targeted to our own tissues. We will discover how regulatory lymphocytes, are able to protect against autoimmune disease. Such regulatory lymphocytes are attractive therapeutic agents to prevent a variety of immune-mediated diseases, including autoimmune diseases, allergy and transplantation rejection.
An Autoantibody In Type 1 Diabetes That Mediates Autonomic Complications
Funder
National Health and Medical Research Council
Funding Amount
$254,591.00
Summary
Type 1 diabetes is a chronic autoimmune disease characterised by destruction of insulin producing cells in the pancreas. One of the most common and serious complications of type 1 diabetes is disruption of the autoimmune nervous system, and once symptoms appear the 5-year mortalityrate is approximately 50%. Symptoms of autonomic dysfunction can be extensive, and involve the stomach, intestine, bladder, heart and reproductive organs. Currently, the management of autonomic dysfunction remains prim ....Type 1 diabetes is a chronic autoimmune disease characterised by destruction of insulin producing cells in the pancreas. One of the most common and serious complications of type 1 diabetes is disruption of the autoimmune nervous system, and once symptoms appear the 5-year mortalityrate is approximately 50%. Symptoms of autonomic dysfunction can be extensive, and involve the stomach, intestine, bladder, heart and reproductive organs. Currently, the management of autonomic dysfunction remains primative due to our poor understanding of the mechanisms underlaying the disease. Recent work from our group has identified an excitatory autoantibody (an antibody against the self) to calcium channels in patients with type 1 diabetes. The anti-calcium channel autoantibody profoundly disrupts gut and bladder function by interfering with autonomic regulation of smooth muscle within these organs. The anti-calcium channel autoantibody is the first functional autoantibody to be detected in type 1 diabetes, and represents a conceptual advance in our understanding of immune mechanisms in this disease. Using animal models and a panel of novel, functional assays of colon, stomach and bladder we will investigate how the anti-calcium channel autoantibodies contribute to autonomic dysfunction in type 1 diabetes. Understanding the mechanisms by which this autoantibody effects autonomic regulation of organ function will enable the development of new therapeutic strategies for better management of patients.Read moreRead less
Identifying The Underlying Mechanisms Responsible For The Generation Of Pathogenic B Cells In Type 1 Diabetes
Funder
National Health and Medical Research Council
Funding Amount
$163,755.00
Summary
Type 1 diabetes (T1D) occurs when the body's own immune system mistakenly attacks and destroys all the beta cells of the pancreas which produce insulin, a hormone essential for regulating sugar levels in the blood. The non-obese diabetic (NOD) mouse develops a form of T1D closely resembling the human disease, and as a model, has led to numerous important insights into its cause. Based on studies in NOD mice, it is now well accepted that a class of cell in the immune system, termed T cells, are r ....Type 1 diabetes (T1D) occurs when the body's own immune system mistakenly attacks and destroys all the beta cells of the pancreas which produce insulin, a hormone essential for regulating sugar levels in the blood. The non-obese diabetic (NOD) mouse develops a form of T1D closely resembling the human disease, and as a model, has led to numerous important insights into its cause. Based on studies in NOD mice, it is now well accepted that a class of cell in the immune system, termed T cells, are responsible for most of the damage to the beta cells in T1D. Recent work in this model, however, has demonstrated that another class of immune cell, termed B cells, also play an important role in T1D as NOD mice made deficient in these cells no longer develop disease. In addition to producing antibodies, B cells are one of the few cell types which are able to take up and present protein fragments in a form recognizable to T cells. Normally, this only leads to the activation of T cells recognising foreign insults, like viruses or bacteria, resulting in their destruction. We have shown that a dangerous population of B cells can arise in NOD mice that can specifically take up beta cell proteins and present them to the T cells, which subsequently become armed to recognise and destroy the beta cells. Just like T cells, B cells that recognize the body's own proteins are normally eliminated in healthy mice and human individuals. This research proposal aims to determine the faulty immune mechanisms that give rise to the beta cell specific B cells in NOD mice. We have also set out to identify the diabetes susceptibility genes which control the generation of this dangerous population of B cells in this model. By understanding how these dangerous B cells are generated in NOD mice, we hope to form the basis for new therapies aimed at inhibiting these cells from forming in T1D susceptible humans, thus preventing the disease at an early stage.Read moreRead less
Organ-specific Autoimmunity: The Role Of The Thymus And Periphery In Shaping The Gastric-specific T Cell Repertoire
Funder
National Health and Medical Research Council
Funding Amount
$579,763.00
Summary
The immune system normally protects against invasion by pathogens such as harmful viruses and bacteria. In autoimmune diseases the same mechanisms that are used to protect us are erroneously targeted to our own tissues. White blood cells, called T lymphocytes are responsible for attacking our own tissues in autoimmune diseases. Our studies will employ a range of molecular, genetic and imaging technologies to track the rare and potential harmful white blood cells. Our studies should reveal the me ....The immune system normally protects against invasion by pathogens such as harmful viruses and bacteria. In autoimmune diseases the same mechanisms that are used to protect us are erroneously targeted to our own tissues. White blood cells, called T lymphocytes are responsible for attacking our own tissues in autoimmune diseases. Our studies will employ a range of molecular, genetic and imaging technologies to track the rare and potential harmful white blood cells. Our studies should reveal the mechanisms by which these self destructive T lymphocytes are silenced in healthy individuals on the one hand, and on the other hand escape to cause destruction in individuals with autoimmune diseases. This fundamental information will allow the development of therapeutic strategies to selectively turn-off these destructive T lymphoctyes in individuals with autoimmune disease and thereby remove the damaging immune response and cure the disease.Read moreRead less
Immunopathogenesis Of Organ-specific Autoimmune Disease
Funder
National Health and Medical Research Council
Funding Amount
$284,638.00
Summary
The immune system normally protects against invasion by pathogens such as harmful viruses and bacteria. In autoimmune diseases the same mechanisms that are used to protect us are erroneously targeted to our own tissues. Our studies will employ state-of-the art technologies to further our knowledge of this class of diseases and to uncover the normal mechanisms that allow the immune system to differentiate foreign and self components.
The Role Of NKT Cell Subsets In The Regulation Of EAE
Funder
National Health and Medical Research Council
Funding Amount
$455,899.00
Summary
Multiple sclerosis (MS) is the most cause of paralysis amongst young adults. Experimental autoimmune encephalomyelitis (EAE) is an animal model of MS that recapitulates many features of the human disease. NKT cells are a group of T cells, whose actiavtion protects against EAE, in an as yet unidentified manner. These studies will provide critical information on the way in which NKT cells regulate immunity and will enhance development of therapies for MS.