A New Model For The Pathogenesis Of Rheumatic Fever: Superantigen Priming Of The Immune Response To Group A Streptococci
Funder
National Health and Medical Research Council
Funding Amount
$248,820.00
Summary
Acute rheumatic fever (ARF) is now rare in developed countries. However, it remains a major problem in Aboriginal Australians in the NT where the rate of ARF is the highest in the world. This leads to high rates of rheumatic heart disease (up to 3% of individuals in some communities) and a premature mortality of over four times that for developing countries. Immunisation and improved living conditions offer a long-term solution but these remain a distant prospect. In the short and medium term, c ....Acute rheumatic fever (ARF) is now rare in developed countries. However, it remains a major problem in Aboriginal Australians in the NT where the rate of ARF is the highest in the world. This leads to high rates of rheumatic heart disease (up to 3% of individuals in some communities) and a premature mortality of over four times that for developing countries. Immunisation and improved living conditions offer a long-term solution but these remain a distant prospect. In the short and medium term, control of this ARF will partly depend on new and better treatment and prevention strategies. To achieve these goals a deeper understanding of the immune mechanisms underlying this disease is urgently needed. It is known that ARF is caused by an abnormal immune response following streptococcal infection. This leads to the production of cells called T cells that attack the body s own tissues rather than the bacteria itself. This autoimmune disease is responsible for the heart damage that underlies ARF. It is believed that this proces only occurs when susceptible individuals are infected with specific rheumatogenic strains of streptococci. However there are a number of deficiencies in this model and it is proposed that there is an additional factor responsible for the abnormal immune response in ARF. This project will explore the possibility that bacterial toxins called superantigens are the critical missing factor , by studying the immune response in ARF. Superantigens are produced by certain streptococci and staphylococci, and are potent in minute quantities causing widespread activation of the immune system. They have been found to play an important role in a number of autoimmune diseases and the type of immune response found in ARF fits well with that expected if superantigens were involved. If superantigens play an important role in causing the abnormal immune response in ARF then a number of new avenues would open for the treatment and prevention of this disease.Read moreRead less
Molecular Epidemiology Of Melioidosis In Australia
Funder
National Health and Medical Research Council
Funding Amount
$357,875.00
Summary
Melioidosis is an important infection in northern Australia. It is a common cause of fatal pneumonia and blood infection in the region. Two outbreaks of melioidosis with fatalities occurring in remote Aboriginal communities have been linked to contamination of the community water supply with the melioidosis bacteria, Burkholderia pseudomallei. In addition, a rare form of melioidosis affecting the brain and spinal cord has resulted in a number of deaths in healthy Aboriginal people and also a num ....Melioidosis is an important infection in northern Australia. It is a common cause of fatal pneumonia and blood infection in the region. Two outbreaks of melioidosis with fatalities occurring in remote Aboriginal communities have been linked to contamination of the community water supply with the melioidosis bacteria, Burkholderia pseudomallei. In addition, a rare form of melioidosis affecting the brain and spinal cord has resulted in a number of deaths in healthy Aboriginal people and also a number left living in remote communities with severe disabilities such as complete paralysis of both legs. Melioidosis has also been identified in two outbreaks occurring over many years in separate locations in southern Australia. It is thought that it may have been introduced to these regions by imported animals, eg via cattle drives, and human fatalities have occurred after local flooding in these temperate locations. This project is built on the ongoing melioidosis collaboration between researchers in Western Australia, the Northern Territory and Queensland. The aim is to use new DNA fingerprinting methods developed specifically for the melioidosis bacteria to understand better why melioidosis can be such a severe disease and how it spreads from the environment to humans and animals and also how it has possibly spread within Australia and overseas. Better recognition and treatment of melioidosis has resulted in a halving of the death rate from this disease in northern Australia (mortality decreased from 40%-18%). This study aims to give us a better understanding of how this soil and water bacteria interacts with humans to cause such severe disease and will hopefully result in new primary preventative measures to complement the improved diagnosis and treatment.Read moreRead less