Immune Regulation During Uncomplicated And Severe P. Falciparum And P. Vivax Malaria
Funder
National Health and Medical Research Council
Funding Amount
$292,639.00
Summary
Malaria is a major global disease that kills over 1 million people every year. Immune responses induced during infection help fight the infection but can also cause tissue damage and thereby worsen disease. This study will determine differences in cellular immune responses during uncomplicated and severe malaria. Better understanding of the role of immune cells in response to infection and disease progression will assist the development of novel treatment interventions and vaccine development.
NOD-like Receptors And Severe Malaria: Do Inflammasomes Mediate Immunopathogenesis?
Funder
National Health and Medical Research Council
Funding Amount
$263,001.00
Summary
Our immune system is very effective in preventing disease. But sometimes our immune cells overreact and actually make us sick. Recently, a new component of the immune system, the inflammasome, was discovered. Overreaction of the inflammasome can result in fever, inflammation, and even death. This project will investigate whether inflammasome overreaction exacerbates diseases as diverse as malaria and cancer, and whether drugs that inhibit the inflammasome can help cure these and other diseases.
I am an cellular immunologist determining the mechanisms by which immunity to foreign organisms is generated, how tolerance to self tissues is maintained, and how the immune system iscriminates between foreign organisms and self.
Defining The Role Of Lymphotoxin Alpha In Experimental Cerebral Malaria
Funder
National Health and Medical Research Council
Funding Amount
$158,250.00
Summary
Malaria kills millions of children every year. A major cause of death is cerebral malaria (CM) resulting from Plasmodium falciparum infection. At present, there is no effective vaccine available and drug-resistant parasites are widespread. CM is a serious neurological condition characterised by the sequestration of infected red blood cells (iRBC) in cerebral blood vessels. This event is thought to initiate a cascade of inflammatory reactions that ultimately lead to cerebral damage and often deat ....Malaria kills millions of children every year. A major cause of death is cerebral malaria (CM) resulting from Plasmodium falciparum infection. At present, there is no effective vaccine available and drug-resistant parasites are widespread. CM is a serious neurological condition characterised by the sequestration of infected red blood cells (iRBC) in cerebral blood vessels. This event is thought to initiate a cascade of inflammatory reactions that ultimately lead to cerebral damage and often death. The factors that cause the sequestration of iRBC in the brain are poorly understood. In this project, we will use an experimental model to define the changes that occur in the cerebral vessels during malaria. The identity of the cells and molecules that mediate the binding of iRBC to the blood vessels of the brain will be identified. It is anticipated that results from this work will increase our understanding of the development of pathology in the brain, as well as identify potential targets for modulation to prevent disease.Read moreRead less
Pathophysiological Significance Of Reverse Signaling Through Membrane TNF
Funder
National Health and Medical Research Council
Funding Amount
$453,055.00
Summary
Cytokines are molecules produced by cells that take part in immune and inflammatory responses. They coordinate the activities of leukocytes and therefore are important in the host response against infections. However, overproduction of some cytokines, particularly tumour necrosis factor, seems to cause the deleterious consequences. Tumour necrosis factor is made by cells, particularly macrophages, T lymphocytes and natural killer cells, in two stages: first, the cytokine is exposed on the surfac ....Cytokines are molecules produced by cells that take part in immune and inflammatory responses. They coordinate the activities of leukocytes and therefore are important in the host response against infections. However, overproduction of some cytokines, particularly tumour necrosis factor, seems to cause the deleterious consequences. Tumour necrosis factor is made by cells, particularly macrophages, T lymphocytes and natural killer cells, in two stages: first, the cytokine is exposed on the surface of the cell and then it is 'clipped off' and released as a smaller, soluble form. In either form it can interact with specific receptors on other cells and, in this way, change the cells' activities. We believe that binding of tumour necrosis factor receptors to the cytokine while it is in its membrane form can also send a message backwards, into the cell bearing the tumour necrosis factor. This process, known as reverse signalling, then changes the activity of this cell. In this project we will investigate this phenomenon in detail. The results will be extremely relevant to new methods of treatment of diseases, that rely either on 'masking' tumour necrosis factor by administering soluble forms of its receptor or on blocking the release of the soluble form of the molecule from the surface of the cell. Our work will enable us to understand the consequences of these approaches more fully. We will also be looking at the role of the membrane form of tumour necrosis factor in a model of infectious disease. Influenza virus is responsible for a great deal of morbidity and mortality around the world. We, and others, have shown, in a mouse model, that some cells in the lungs make tumour necrosis factor during the course of viral pneumonia. Here we will determine whether the membrane form of this cytokine plays a role in clearing virus or causing some of the complications of this disease. This also may have relevance to other inflammatory and infectious disease.Read moreRead less
Tropical Infectious Diseases - Pathogenisis And Vaccine Research
Funder
National Health and Medical Research Council
Funding Amount
$7,311,989.00
Summary
The diseases on which three themes of the work proposed centre, malaria, streptococcal diseases and scabies are infectious diseases largely affecting indigenous people in various parts of the world on a massive scale, for which there are no vaccines. The aim of the work is to develop vaccines or other biological prevention measures against each of these diseases and the problems that need to be solved are similar. The team includes senior experts on thebiology of infectious diseases with long hi ....The diseases on which three themes of the work proposed centre, malaria, streptococcal diseases and scabies are infectious diseases largely affecting indigenous people in various parts of the world on a massive scale, for which there are no vaccines. The aim of the work is to develop vaccines or other biological prevention measures against each of these diseases and the problems that need to be solved are similar. The team includes senior experts on thebiology of infectious diseases with long histories of collaboration as well as younger members with impressive credentials that are new to the collaboration. The fourth theme of the work proposed is concerned with inventive new ways of making such vaccines by novelchemical methods. It has already been the subject of published collaborative work onstreptococcal disease and is equally applicable to the other themes.Read moreRead less
Contribution Of Dendritic Cell Paralysis To The Immunosuppression Associated With Systemic Infections
Funder
National Health and Medical Research Council
Funding Amount
$490,051.00
Summary
The immune system fights viruses and other infections mobilising antibody-producing B cells and killer T cells. The B cells and killer T cells are recruited by specialysed cell of the immune system called Dendritic Cells (DC). The DC are distributed all over the body, where they play an immunosurveillance role: they constantly monitor their sorroundings for the presence of pathogens. When DC detect these pathogens they become activated . They capture the pathogen, break it into small pieces call ....The immune system fights viruses and other infections mobilising antibody-producing B cells and killer T cells. The B cells and killer T cells are recruited by specialysed cell of the immune system called Dendritic Cells (DC). The DC are distributed all over the body, where they play an immunosurveillance role: they constantly monitor their sorroundings for the presence of pathogens. When DC detect these pathogens they become activated . They capture the pathogen, break it into small pieces called antigens, and display these antigens on their surface, where they can be seen by helper T cells, which in turn mobilise the B cells, and by killer T cells. This chain of reactions initiates an immune response. The DC undergo profound changes after they detect pathogens. They stop monitoring their sorroundings, and concentrate on displaying to T cells the antigens that belonged to the pathogen that triggered their initial activation. Indeed, they do not respond to new pathogen encounters. In normal conditions few DC are activated by each pathogen encounter, so there are always enough DC ready to respond to new infections. However, there are situation that activate nearly all the DC at the same time. This can happen during sepsis (bacterial infection of the blood) and malaria. It has been recognised for a long time that these two conditions can be immunosuppressive they shut-down the immune system. Our previous work has demonstrated that this is in part due to the excessive number of DC that sepsis or malaria activate, leaving no more DC capable of responding to subsequent infections. This work has focused on the immediate effects of sepsis or malaria -within the first 24 hours or so; now we want to investigate the efffect of these conditions on the reconstitution of the DC network. We think this will help us to find treatments to restore immunocompetence a functional immune system- in sepsis or malaria patients.Read moreRead less
I study basic mechanisms of the interaction of pathogens and particles with the immune system, to gain insight into mechanisms of adjuvanticity, immune evasion and generally immuno-modulation. With this specific insight I further pursue the development of
Investigation Of Dendritic Cell Activation And Function In A Murine Model Of Plasmodium And Schistosoma Co-infection
Funder
National Health and Medical Research Council
Funding Amount
$358,938.00
Summary
Malaria is responsible for over 2 million deaths annually, mainly in sub-Saharan Africa. Importantly, around 1 billion people in malaria endemic areas are infected with parasitic worms, thus malaria and worm co-infections frequently occur. This project will investigate how malaria and worm parasites interact to influence the immune response and clinical outcomes of each other in a mouse infection model. This will provide new strategies for the design of effective treatments in co-endemic areas.
Malaria is characterised by defective T cell responses, particularly suppressed T cell growth. T cells are critical to malaria protection and defective immune responses are likely to benefit the parasite. We want to find out how immune-responses are turned off in malaria, so that then we can do something about this, and help fight off the parasite. Malaria kills over 2 million children each year and there is no effective vaccine. We have two important clues as what may be happenning to cause sup ....Malaria is characterised by defective T cell responses, particularly suppressed T cell growth. T cells are critical to malaria protection and defective immune responses are likely to benefit the parasite. We want to find out how immune-responses are turned off in malaria, so that then we can do something about this, and help fight off the parasite. Malaria kills over 2 million children each year and there is no effective vaccine. We have two important clues as what may be happenning to cause suppressed T cell growth during malaria infection. Firstly, we found a massive increase in T cells expressing a surface molecule called CD38 duirng infection. Increases in these cells correlated with decreases in the ability of the T cells from the animals to grow. Indeed, other researchers had observed that in mice CD38 T cells can suppress immunity. Secondly, we hypothesized that they may be responsible for the impaired T cell reactivity observed during acute malaria, and the general poor state of immune responses in humans living in areas where they are being constantly infected by the parasite. Indeed, when we removed cells expressing CD38 from blood cells from such individuals, these 'recovered' and were able to grow much better in our assays. Therefore we propose that CD38 T cells are importnat mediators of malaria immuno-suppression. We now want to understand how the parasite induces these CD38 T cells, and how their ability to suppress T cell responses can benefit the parasite. Knowing this we aim to develop vaccines which can avoid being turned off by malaria. T cells expressing CD38 are also increased in cancer and acute viral disease, such as late stage HIV. Understanding their role in malaria will also give us new clues to fight such diseases.Read moreRead less