Postviral Wheezing In Childhood: Disregulation Of Airway Tone?
Funder
National Health and Medical Research Council
Funding Amount
$577,040.00
Summary
Asthma is a very common childhood condition that is becoming increasingly more common. Wheezing is common in infants and young children following viral infections and is often thought of as the first manifestation of asthma. However, many children and infants who wheeze with viral infections appear to grow out of asthma in their teenage years. Asthma that persists into adult life is usually associated with allergies to common environmental allergens, such as house dust mite and grass pollens. Ho ....Asthma is a very common childhood condition that is becoming increasingly more common. Wheezing is common in infants and young children following viral infections and is often thought of as the first manifestation of asthma. However, many children and infants who wheeze with viral infections appear to grow out of asthma in their teenage years. Asthma that persists into adult life is usually associated with allergies to common environmental allergens, such as house dust mite and grass pollens. However, many infants who wheeze with viral infections, especially in the first year of life, do not develop allergies in later life, raising the possibility that they did not have the same type of asthma as those whose symptoms persist. This project will study the effects of viral infections on lung function to determine whether particular types of virus can have detrimental effects of lung function lasting for years. We will also examine whether the age at which the infection occurs and the severity of the infection influence the long-term outcome. The project involves studying infants during the recovery phase of respiratory viral infections, older children years after documented infections and experimental animal models that have been infected under controlled conditions. By determining whether respiratory viral infections can have long-term effects on lung function that can mimic asthma, we will advance our understanding of how asthma develops. In addition, specific treatment and preventative strategies could then be developed to prevent these long-term abnormalities, instead of relying on asthma medication (especially inhaled corticosteroids) as is the current practice. Preventative strategies could include encouraging the development of specific vaccines.Read moreRead less
The Molecular Basis For Target Selection In The Central Nervous System By Sensory Axons
Funder
National Health and Medical Research Council
Funding Amount
$251,325.00
Summary
The normal function of the brain depends upon the specific connections that nerve cells make with each other. These connections are set up in the developing embryo when nerve cells send out long processes - axons - which grow towards their synaptic targets. How axons select their correct targets from amongst the millions of alternatives in the developing brain is unknown. A better understanding of this problem will help us develop therapies to assist regenerating axons re-establish correct conne ....The normal function of the brain depends upon the specific connections that nerve cells make with each other. These connections are set up in the developing embryo when nerve cells send out long processes - axons - which grow towards their synaptic targets. How axons select their correct targets from amongst the millions of alternatives in the developing brain is unknown. A better understanding of this problem will help us develop therapies to assist regenerating axons re-establish correct connections following injury to the brain or spinal cord. We propose to use a simple model system, the embryo of the fruitfly Drosophila, to find molecules that are involved in this process of neuron target recognition - ' axon targeting' molecules - and to study how they work. Drosophila can be genetically manipulated in ways not possible in higher animals. Furthermore the simplicity of its nervous system means that we can determine the connections of individual nerve cells with a high degree of precision. In the first part of our project, we will examine Drosophila embryos that carry mutations in genes suspected to code for targeting molecules. We will stain individual sensory nerve cells in these embryos with dyes to reveal the anatomy of their axons in the brain. If sensory axons terminate abnormally in the brain of a given mutant, the affected gene is likely to code for an axon targeting molecule. In the second part of the study, we will investigate the functions of candidate axon targeting molecules using two approaches. Firstly, we will seek to determine whether the molecule acts in the sensory axons or in their target cells. Secondly, we will use time-lapse microscopy to study how the homing behaviour of the sensory axons is affected in mutant embryos. The results of these studies will lead us closer to an answer to the question: How do axons recognise their specific target cells in the brain?Read moreRead less
Antigen Selection In The MHC-restricted Cellular Immune Response
Funder
National Health and Medical Research Council
Funding Amount
$175,570.00
Summary
The body's white cells eliminate microorganisms through the actions of immune lymphocytes and other cells which conspire to kill and neutralise these unwanted guests. When microorganisms hide inside the cells of the body they are still detected by a set of T lymphocytes which have specific receptors for scrutinising the surface of cells for any changes which might signal an intracellular infection. The immune system is ever vigilant in its search for signs of infection which are generally appare ....The body's white cells eliminate microorganisms through the actions of immune lymphocytes and other cells which conspire to kill and neutralise these unwanted guests. When microorganisms hide inside the cells of the body they are still detected by a set of T lymphocytes which have specific receptors for scrutinising the surface of cells for any changes which might signal an intracellular infection. The immune system is ever vigilant in its search for signs of infection which are generally apparent when molecules called antigens are released by microorganisms and captured by the body's cells. This activates lymphocytes resulting in an immune response capable of eliminating the microorganisms. Scrutiny of the body's cells by lymphocytes occurs continuously even when there is no infection present in the body. Following infection of a cell, microbial antigens reveal the infection by their appearance on the cell surface where they are detected by the immune system's lymphocytes. This occurs through a mechanism called antigen presentation. During antigen presentation the proteins inside the cell, including those of any invading microorganism, are first degraded into shorter molecules called peptides. This event is called antigen processing. A fraction of the peptides created by antigen processing are captured by specialised receptors present on all cells. These receptors are called HLA or histocompatibility molecules. This project examines the molecular events which mediate the capture of peptide antigens by HLA molecules. The main focus is on those peptide antigens which elicit killer T cell responses by the immune system. A knowledge of how these peptides are selected for presentation and how they are captured and carried to the cell surface is fundamental to understanding immune responses to microorganisms, tumours, allergens, transplants and self tissues as in autoimmunity. Therefore the study is of great general relevance.Read moreRead less