Central Control Of Stress-induced Changes In Immune Function.
Funder
National Health and Medical Research Council
Funding Amount
$411,724.00
Summary
LONG-TERM STRESS CAN ALTER OUR BRAIN'S ATTEMPTS TO FIGHT INFECTION Long-term stress is often blamed for causing illness but precisely how this occurs is now only beginning to be realised. It is especially disturbing that long-term stress can increase one's susceptibility to infections. Stress can alter the way our brain can help deal with assaults by bacteria and viruses. Normally, at the start of an infection, we release a hormone called cortisol from our adrenal glands. A low level of cortisol ....LONG-TERM STRESS CAN ALTER OUR BRAIN'S ATTEMPTS TO FIGHT INFECTION Long-term stress is often blamed for causing illness but precisely how this occurs is now only beginning to be realised. It is especially disturbing that long-term stress can increase one's susceptibility to infections. Stress can alter the way our brain can help deal with assaults by bacteria and viruses. Normally, at the start of an infection, we release a hormone called cortisol from our adrenal glands. A low level of cortisol in our body is beneficial because it can prevent the infection from taking hold in our body and spreading. However if we are chronically stressed our brains tell the adrenal glands to secrete excessive amounts of cortisol over long periods of time and this imbalance can actually hinder the ability of one's immune system to fight an infection. The unfortunate consequence is that the infection is more likely to win the battle and spread to cause further havoc. The present study will identify which areas of the brain are important in driving the secretion of cortisol during infection and how long-term stress can influence those areas. Because we might be exposed to long-term psychological stress that is repeated regularly or irregularly we will determine which pattern of stress has the greatest effect. An investigation into how the brain operates during long-term stress and infection will help us develop ways to prevent stress from disrupting our immune systems.Read moreRead less
IMMUNE-MEDIATED INFLAMMATION IN DORSAL ROOT GANGLIA AFTER PERIPHERAL NERVE INJURY AND IN SENSORY NEUROPATHIES
Funder
National Health and Medical Research Council
Funding Amount
$378,300.00
Summary
Damage to the nervous system can occur because of accidental or iatrogenic trauma, toxins, infection, metabolic disorders, and even normal ageing. The consequences can outweigh the direct effects of the injury. Almost all injury to the nervous system results in loss of nerve cells and consequently modified sensation and movement. Nerve damage may also be followed by sensory disturbances, ranging from tingling, numbness and abnormal temperature sensations to spontaneous pain, allodynia (painful s ....Damage to the nervous system can occur because of accidental or iatrogenic trauma, toxins, infection, metabolic disorders, and even normal ageing. The consequences can outweigh the direct effects of the injury. Almost all injury to the nervous system results in loss of nerve cells and consequently modified sensation and movement. Nerve damage may also be followed by sensory disturbances, ranging from tingling, numbness and abnormal temperature sensations to spontaneous pain, allodynia (painful sensations from light touch) or hyperalgesia (increased sensitivity to a damaging stimulus). Some of these symptoms are encountered in older people as they lose sensory neurones. The problems are chronic and most are intractable to drugs. This project will clarify how immune-mediated inflammation of dorsal root (sensory) ganglia (DRGs) contributes to these sequelae. Even the simplest form of neural damage following peripheral nerve injury can produce changes in regions of the nervous system far from the parts directly involved in the injury. Our recent work has described for the first time the involvement of the immune system in triggering changes in DRGs following transection of a distant peripheral nerve in rats. T-cell activation leads to invasion of macrophages and production of proinflammatory cytokines. These substances can activate sensory neurones and may be responsible for progressive neuronal death. Thus we have established a simple system in which we can evaluate the influx of T-cells and macrophages of different kinds into DRGs after injury and other insults. We intend to use this to define the sequence of cellular events involved in recruitment of immune cells and compare it with other experimental interventions known to produce a neuroimmune response in this system. This will identify whether the DRG is a special site for neuroimmune interactions and so should be a target for therapy.Read moreRead less
Several members of the Flaviviridae family are major pathogens of humans including dengue (DEN), yellow fever (YF), tick-borne encephalitis (TBE), Murray valley encephalitis (MVE), Japanese encephalitis (JE), and hepatitis C virus (HCV). An Australian flavivirus Kunjin (KUN), however, appears to be naturally attenuated and does not cause an overt disease in humans. In contrast, genetically and antigenically closely related to KUN, New York strain of West Nile virus (NY WN) has already caused ~50 ....Several members of the Flaviviridae family are major pathogens of humans including dengue (DEN), yellow fever (YF), tick-borne encephalitis (TBE), Murray valley encephalitis (MVE), Japanese encephalitis (JE), and hepatitis C virus (HCV). An Australian flavivirus Kunjin (KUN), however, appears to be naturally attenuated and does not cause an overt disease in humans. In contrast, genetically and antigenically closely related to KUN, New York strain of West Nile virus (NY WN) has already caused ~500 deaths and over 20,000 registered infections since its emergence in North America in 1999, including 223 deaths and 9122 infections in 2003 alone. Recent studies with DEN indicated that flaviviruses may interfere with early steps of IFN-signalling pathway. The type I Interferon (IFN) response is the first line of defence against viral infections and many viruses have developed different strategies to counteract this response in order to ensure their survival in the infected host. In this grant we seek to exploit our extensive understanding of the molecular biology of KUN virus and the contrasting behaviour of KUN and NY WN viruses to gain an understanding of the role of flavivirus-mediated suppression of host anti-viral IFN response in virus-host relationships and its importance in determining virus virulence.Read moreRead less
SULT4A1 is not a sulfotransferase, but a sulfotransferase inhibitor. It forms high affinity heterodimers with other sulfotransferases via a conserved dimerisation site in its carboxyl terminus attenuating catalytic activity. Consequently, it is important for the metabolism of numerous important molecules including estrogens, thyroid hormones, neurotransmitters and many therapeutic agents.
Drugs are broken down in the body by the process of metabolism. Metabolism is important as both a detoxification and elimination mechanism, and determines dose rate for chronically administered drugs. Many drugs are metabolised by a reaction called glucuronidation. We will characterise the various components of the glucuronidation reaction in an integrated manner in order to understand and predict factors that influence an individual's capacity to metabolise drugs and other chemicals.
Dynamics And Mechanisms Of Immune Complex-mediated Skin Inflammation
Funder
National Health and Medical Research Council
Funding Amount
$526,467.00
Summary
Type III hypersensitivity underlies a number of common autoimmune diseases, including rheumatoid arthritis and lupus erythematosus. These diseases are caused by the deposition of immune complexes (IC) and the accumulation of neutrophils within small blood vessels. We will use real time imaging to dissect in space and time the recruitment of neutrophils and IC deposition during type III hypersensitivity reactions in order to better understand the pathogenesis of these conditions.