Cell Migration And Granuloma Formation In The Expression Of Protective Immunity Against Tuberculosis In The Lung
Funder
National Health and Medical Research Council
Funding Amount
$212,036.00
Summary
Tuberculosis (TB) remains an enormous problem worldwide and a continuing health problem in Australia. Most TB is not due to disease at the time of infection, but is a reactivation of dormant infection in people who have never eradicated the organisms. This study will investigate, in mice, how TB is initially contained within the lungs and how reactivation occurs. All mice infected with TB control the infection initially. T lymphocytes are activated and T cells and macrophages are recruited to th ....Tuberculosis (TB) remains an enormous problem worldwide and a continuing health problem in Australia. Most TB is not due to disease at the time of infection, but is a reactivation of dormant infection in people who have never eradicated the organisms. This study will investigate, in mice, how TB is initially contained within the lungs and how reactivation occurs. All mice infected with TB control the infection initially. T lymphocytes are activated and T cells and macrophages are recruited to the lung, migrate into lung tissue and surround infected lung macrophages forming granulomas. We have identified mice that progress to TB disease early after infection (early progressor strains) and another strain that progresses later (late progressors). In the early progressors, lymphocytes are not as efficiently recruited to the lung and do not form the tight granulomas seen in late progressor strains. We plan to make a detailed comparison of these two strains looking at differences in cell-membrane molecules and the soluble messenger molecules (cytokines and chemokines) that provide the signals that attract cells to the lung and direct them to surround infected lung macrophages. By comparing events in early and late progressor strains we will find which molecules are required for initial and long-term containment, and which events lead to breakdown of granulomas and reactivation of disease. In addition, we recently showed that one cytokine, tumour necrosis factor (TNF), is essential for cell migration through the lung. By comparing normal mice with mice deficient in TNF we will study the downstream effects regulated by TNF, particularly the chemokine messengers that direct cell movement into granulomas. By identifying the molecules and cells required to control TB we plan to design improved vaccines to prevent TB infection and improved treatments to prevent disease reactivation.Read moreRead less
Cytokine And Macrophage Determinants Of Pulmonary Inflammation During Tuberculosis
Funder
National Health and Medical Research Council
Funding Amount
$455,899.00
Summary
Tuberculosis (TB) infects 33% of the world, causing over 2 million deaths per year. TB disease causes damaging lung pathology and new therapies to treat the infection and moderate inflammation are urgently required. TNF is essential for immunity to TB, acting to modulate inflammation. This grant will determine how soluble and membrane- bound TNF regulate the cellular and cytokine control of TB pathology and may lead to new therapies to limit inflammation in TB and other inflammatory diseases.
Human Cytomegalovirus Encoded Control Of The Latent Phase Of Infection
Funder
National Health and Medical Research Council
Funding Amount
$639,871.00
Summary
Human cytomegalovirus has the ability to hide in the body of a person throughout their life time without it making them ill but the virus can awaken (reactivate) from this latent state and produce new virus. In immunosuppressed people such as transplant patients this reactivation causes significant problems, even death, yet this latency remains poorly understood. This project will help us to understand how the virus can hide successfully from the immune system in a latent form in the human host.
Viral And Host Cell Gene Expression During The Establishment And Maintenance Phases Of Human Cytomegalovirus Latency
Funder
National Health and Medical Research Council
Funding Amount
$149,250.00
Summary
Human cytomegalovirus (CMV) is a herpesvirus which infects a majority of the population. HCMV is a significant cause of serious, life-threatening disease in neonates and in people who are immunosuppressed. Transplant recipients such as bone marrow, kidney and heart transplant patients are particularly at risk of developing CMV disease. Like other herpesviruses, after initial infection CMV can establish a life-long latent infection. During latency, the virus remains dormant in the human body and ....Human cytomegalovirus (CMV) is a herpesvirus which infects a majority of the population. HCMV is a significant cause of serious, life-threatening disease in neonates and in people who are immunosuppressed. Transplant recipients such as bone marrow, kidney and heart transplant patients are particularly at risk of developing CMV disease. Like other herpesviruses, after initial infection CMV can establish a life-long latent infection. During latency, the virus remains dormant in the human body and no infectious virus is made. However, when conditions are right the virus can awaken (ie reactivate) from its latent state, producing new infectious virus and disease. It is in immunosuppressed individuals such as transplant patients that viral latency and reactivation are of most medical concern, yet viral latency remains very poorly understood. The overall aim of these studies is to provide a much better understanding of how CMV latency is established and maintained, with the ultimate goal of making advances for the design of anti-viral therapies to disrupt these processes. This project has three major components: Firstly, we aim to identify and characterise viral gene expression during the establishment of latency and these findings will have profound implications to our understanding of latency. Secondly, we will examine how human cells are affected when they become latently infected. A new and exciting technology called DNA microarray now makes it possible to examine the expression of many thousands of genes in a single experiment. For the first time, we will be able to determine how the cell changes during the establishment and maintenance phases of latency. Thirdly, we will apply microarray technologies to determine how human cell genes are altered in response to the expression of individual viral genes that are active during the latent phase of infection.Read moreRead less
MECHANISMS AND MARKERS OF TUBERCULOSIS TRANSMISSION WITHIN AUSTRALIA
Funder
National Health and Medical Research Council
Funding Amount
$799,978.00
Summary
Tuberculosis (TB) kills nearly 2 million people each year. The emergence of drug resistant TB in the Asia-Pacific region poses a particular threat to Australia, due to frequent population mixing and ongoing TB transmission that may facilitate its spread within vulnerable communities. The proposed study will develop advanced tools to monitor and limit TB transmission within Australia. It will also provide novel insight into the evolution of the global TB epidemic and key factors that sustain it.
Regulation From The Outside: Control Of Transport And Assembly Of Major Cell Wall Components In Mycobacteria
Funder
National Health and Medical Research Council
Funding Amount
$652,019.00
Summary
Tuberculosis (TB) kills nearly two million people each year while the causative bacterial species, Mycobacterium tuberculosis, infects one-third of the entire human population. An alarmingly high rate of TB exists in Australia's indigenous population. This proposal aims to identify and characterise essential processes that regulate synthesis of the outer coat of the bacterium, which are potential targets for new drugs for the treatment of this devastating disease.
Membrane TNF And Lymphotoxin Control Of Chemokine Induction And Inflammation In Tuberculosis
Funder
National Health and Medical Research Council
Funding Amount
$457,500.00
Summary
Tuberculosis (TB) remains an enormous problem worldwide. Most TB is not due to disease at the time of infection, but is a reactivation of dormant disease in people who have never completely eradicated the organisms. Macrophages containing dormant TB organisms are located in lesions called granulomas. Granulomas consist of TB-infected macrophages surrounded by T lymphocytes that actively contain the infection. T lymphocytes prevent the growth of TB organisms in the macrophages and so prevent wide ....Tuberculosis (TB) remains an enormous problem worldwide. Most TB is not due to disease at the time of infection, but is a reactivation of dormant disease in people who have never completely eradicated the organisms. Macrophages containing dormant TB organisms are located in lesions called granulomas. Granulomas consist of TB-infected macrophages surrounded by T lymphocytes that actively contain the infection. T lymphocytes prevent the growth of TB organisms in the macrophages and so prevent widespread infection that would cause illness in the host. Activated T lymphocytes that recognise TB-infected macrophages circulate in blood, are recruited from blood capillaries into the lung, migrate through the tissue and co-localise with infected macrophages. Soluble molecules (cytokines and chemokines) are known to provide the signals that direct cell migration and activation events. This study will investigate in detail cytokines and chemokines that are involved, the cells that produce then and where these cells are located in the lung. We recently showed that tumour necrosis factor (TNF), and the related cytokine lymphotoxin (LT), are essential for lymphocyte migration through the lung. These belong to a family of related molecules that signal through the same panel of receptors and regulate chemokine expression and inflammation. In this study we will use genetically manipulated mice that lack TNF. LT or other family members or that express only membrane-bound TNF to study how each affects production of different chemokines, chemokine receptors and other molecules. Since there are at least 50 known chemokines and 17 chemokine receptors we will use microarray technology to simultaneously screen changes in expression of several thousand genes and laser microdissection to study cells from different location in infected lungs. Understanding signals necessary to direct T cells into granulomas may facilitate new treatments to prevent TB reactivation disease.Read moreRead less
Investigating The Mechanisms Of Regulation Of Mycobacterial Cell Wall Biosynthesis
Funder
National Health and Medical Research Council
Funding Amount
$597,349.00
Summary
Tuberculosis (TB) kills around two million people each year while the causative bacterial species, Mycobacterium tuberculosis, infects one-third of the entire human population. An alarmingly high rate of TB exists in Australia's indigenous population. This proposal aims to identify and characterise essential processes involved in synthesis of the outer coat of the bacterium which are potential targets for new drugs for the treatment of this devastating disease.