Autoimmune diseases are those caused by the body's immune system attacking the body's own tissues. One group of autoimmune diseases, termed the thyrogastric cluster appear to share genetic risk factors, because they tend to occur together - either in the same patient, or else in families. Some of the diseases within the thyrogastric cluster are known to be very complex genetically, while others appear to be much less complex. Furthermore, some animal models of autoimmune diease are genetically s ....Autoimmune diseases are those caused by the body's immune system attacking the body's own tissues. One group of autoimmune diseases, termed the thyrogastric cluster appear to share genetic risk factors, because they tend to occur together - either in the same patient, or else in families. Some of the diseases within the thyrogastric cluster are known to be very complex genetically, while others appear to be much less complex. Furthermore, some animal models of autoimmune diease are genetically simpler still. We have chosen to study the genetics of gastritis in mice that have had their thymuses removed on the third day of life, because this model has relatively few genes involved; we have found that only 4 genes affect the risk of disease. This means that it will give us the optimum chance of identfiying at least one of these genes. The methods used involve both selective breeding techniques and generating special gene transfer mice in which individuals from one strain will carry the inserted genes from another. In this way, we can identify exactly which genes affect the risk of disease. Once identified, the gene sequences will help us determine if the same gene plays a role in human disease, and if so, to develop new diagnostic tests and therapies.Read moreRead less
A Functional Genomic Approach To The Genetics Of Autoimmune (type A) Gastritis
Funder
National Health and Medical Research Council
Funding Amount
$467,640.00
Summary
The thymus produces white blood cells which defend the body from infections and cancer. Unfortunately, these white blood cells can also cause disease if they target the body's own tissues. These disesaes are called autoimmune diseases, and an example of such a disease is autoimmune (type A) gastritis, in which the white cells target the acid-producing cells of the stomach. The resulting damage can lead to the development of pernicious anaemia (vitamin B12 deficiency) and cancer of the stomach. T ....The thymus produces white blood cells which defend the body from infections and cancer. Unfortunately, these white blood cells can also cause disease if they target the body's own tissues. These disesaes are called autoimmune diseases, and an example of such a disease is autoimmune (type A) gastritis, in which the white cells target the acid-producing cells of the stomach. The resulting damage can lead to the development of pernicious anaemia (vitamin B12 deficiency) and cancer of the stomach. This project studies a mouse model of autoimmune gastritis with the aim of identifying the genes that encode susceptibility to the disease in this model. Ultimately, this information should help us to devise therapies that can be applied to the clinical situation. We have previously identified the locations of the genes which are responsible for causing gastritis in these mice. Two of them are very close together on one chromosome and appear to be very important because they have the strongest effects. Furthermore, there is some evidence that these genes may also be involved in determining susceptibility to diabetes and lupus. This project aims to further characterise these genes by locating them more exactly and by examining their effect on mice not normally prone to gastritis.Read moreRead less
Role Of NK Receptors In Susceptibility And Resistance To Human Malaria
Funder
National Health and Medical Research Council
Funding Amount
$546,588.00
Summary
Malaria kills 2 million children every year. However, many eventually become resistant to the disease. What causes some kids to die, and how others become resistant, is unknown. We believe that genes for Natural Killer molecules in the immune system can protect people against malaria, but can also over-react in the wrong way and make things worse. We plan to investigate the role of Natural Killer genes in causing disease and also protecting in young children in Papua New Guinea against malaria.
In Vivo And In Vitro Studies Of The Human -308 TNF Promoter Polymorphism.
Funder
National Health and Medical Research Council
Funding Amount
$232,131.00
Summary
The identification of genetic variation in region of the DNA that controls expression of the inflammatory cytokine Tumour Necrosis Factor (TNF) and its association with a number of autoimmune and inflammatory diseases, has led to speculation that this genetic difference may play a role in predisposing some people to these diseases. We have isolated an activity, TPF1, that may regulate expression through interaction with this DNA control region. During the tenure of this grant we intend to clarif ....The identification of genetic variation in region of the DNA that controls expression of the inflammatory cytokine Tumour Necrosis Factor (TNF) and its association with a number of autoimmune and inflammatory diseases, has led to speculation that this genetic difference may play a role in predisposing some people to these diseases. We have isolated an activity, TPF1, that may regulate expression through interaction with this DNA control region. During the tenure of this grant we intend to clarify some of these questions, we will generate genetically modified mice that have either of the two genetic forms of the human TNF promoter. These mice will be compared in two models of associated disease, murine Lupus and cerebral malaria. We will also characterise the interactions of TPF1 with other components of the TNF control region. An understanding of the role of TPF1 in controlling TNF expression and an appreciation of the cell types that are able to express the phenotype, will allow the development of more subtle, cell specific strategies to modulate the activity of TNF without completely abolishing expression and may lead to better preventative and therapeutic strategies.Read moreRead less
Genetic And Phyisological Regulation Of KIR2DL4 Expression
Funder
National Health and Medical Research Council
Funding Amount
$224,250.00
Summary
Genetic mutations occur frequently but most are deleterious and are lost from the population. Advantageous mutations are selected for and eventually replace the original gene. However, some mutations are advantageous under one set of circumstances and disadvantageous under others. These mutations often reach a high frequency in the population and are maintained along with the original gene. An example of this situation is the mutation in the haemoglobin gene that causes sickle cell anaemia. A si ....Genetic mutations occur frequently but most are deleterious and are lost from the population. Advantageous mutations are selected for and eventually replace the original gene. However, some mutations are advantageous under one set of circumstances and disadvantageous under others. These mutations often reach a high frequency in the population and are maintained along with the original gene. An example of this situation is the mutation in the haemoglobin gene that causes sickle cell anaemia. A single copy of the mutant gene protects against malaria (advantageous) but a double dose of the gene results in sickle cell anaemia, which is fatal. Both the mutant and original gene are maintained in the population as the number of people dying from sickle cell anaemia is less than the number who would die from malaria if the mutant gene did not exist. This phenomenon is known as balancing selection. There are many examples of balancing selection and for each example there is usually a medical condition associated with a double dose of the mutant gene. We have discovered a new example of balancing selection in one of the genes used by the immune system. Very little is known about the function of this gene. In fact the literature abounds with contradictory findings concerning this gene. Our discovery that a mutant gene is present at very high frequency in the population helps explain these contradictory findings and places us in a very strong position to achieve a much better understanding of the function of this gene. We propose to investigate the basic biology of this gene and how it used in the immune system in order to obtain clues as to which medical condition this mutation may be relevant to.Read moreRead less