How Do Cross-reactive Memory B Cells Affect Influenza Vaccine Titers?
Funder
National Health and Medical Research Council
Funding Amount
$798,049.00
Summary
Influenza vaccines are updated frequently to protect against the highly variable influenza virus. Despite careful selection of vaccine viruses, most influenza vaccines provide only modest protection and protection is poor some years. In turn, the response to vaccination varies between individuals. This probably reflects complex and variable histories of influenza infection and vaccination. The project investigates how past influenza exposure influences vaccine responses and effectiveness.
Wrong Parasite, Wrong Host? How Plasmodium Falciparum Erythrocyte Membrane Protein 1 Expression And The Host’s Innate Immune Response Combine To Influence The Inflammatory Response To Malaria In Vitro And In Vivo. Implications For Severe Malaria
Funder
National Health and Medical Research Council
Funding Amount
$707,821.00
Summary
One factor that determines whether some children die of malaria is the type of protein that the parasite expresses on the red blood cell, to help it stick in blood vessels. Our new data suggests that some proteins stimulate excessive host immune response, possibly leading to severe malaria. People's immne response to malaria varies too, and we will discover whether severe malaria occurs when a dangerous parasite strain infects a susceptible host causing an excessive immune response, harming the ....One factor that determines whether some children die of malaria is the type of protein that the parasite expresses on the red blood cell, to help it stick in blood vessels. Our new data suggests that some proteins stimulate excessive host immune response, possibly leading to severe malaria. People's immne response to malaria varies too, and we will discover whether severe malaria occurs when a dangerous parasite strain infects a susceptible host causing an excessive immune response, harming the child.Read moreRead less
Structural Diversity And Evolution Of Variant-specific Surface Proteins In The Protozoan Parasite, Giardia
Funder
National Health and Medical Research Council
Funding Amount
$436,417.00
Summary
Giardia are well-known as a cause of travellers' diarrhoea, but our knowledge about these parasites remains rudimentary. Infections are common in Australia, especially in day-care centres and outback Aboriginal communities. The 1998 Sydney water crisis highlighted the necessity of monitoring reservoirs and reticulated water for contamination by faecal cysts of both human and animal origin. The aim of this project is to learn more about the 'coat' proteins which cover the organisms. These protect ....Giardia are well-known as a cause of travellers' diarrhoea, but our knowledge about these parasites remains rudimentary. Infections are common in Australia, especially in day-care centres and outback Aboriginal communities. The 1998 Sydney water crisis highlighted the necessity of monitoring reservoirs and reticulated water for contamination by faecal cysts of both human and animal origin. The aim of this project is to learn more about the 'coat' proteins which cover the organisms. These protect the parasites against digestion, enabling them to reside indefinitely within the intestine. However, the proteins are also the principal target of host immunity. Analysis of Giardia populations has shown that as many as 150-200 different coat proteins can be made. Although individual cells have coats comprised of only a single protein type, these can 'switch' spontaneously to production of another type - a phenomenon known as 'antigenic variation'. This process occurs slowly but continuously, giving rise to 'variants' which survive successive host responses (directed against each predominant coat type) and occupy the vacancies left by the destruction of their immediate forebears. It is important to gain information about the structural diversity of these variant-specific proteins (VSP), as any 'Giardia' vaccine is likely to require inclusion of each major type. It is also important to elucidate how the 'switching' process occurs, as this may provide clues as to how it might be interrupted. The project addresses both aspects.Read moreRead less
Epigenetic Control Of Antigenic Variation In Plasmodium Falciparum
Funder
National Health and Medical Research Council
Funding Amount
$505,563.00
Summary
Malaria is an enormous global health problem that kills millions of people each year. Humans develop only partial immunity to malaria only if they survive many years of repeated infection. Much of the difficulty in developing immunity to malaria lies in the ability of the causative agent, Plasmodium falciparum, to continually change the properties of its surface coat. The parasite achieves this immune evasion through a process called antigenic variation. Genetically identical parasites can expre ....Malaria is an enormous global health problem that kills millions of people each year. Humans develop only partial immunity to malaria only if they survive many years of repeated infection. Much of the difficulty in developing immunity to malaria lies in the ability of the causative agent, Plasmodium falciparum, to continually change the properties of its surface coat. The parasite achieves this immune evasion through a process called antigenic variation. Genetically identical parasites can express different surface coats, and the control of this process is superimposed above the level of genetic control. This system is referred to as epigenetic control. Epigenetic control includes regulatory mechanisms such as the way that genes are packed inside the parasite, and chemical modifications to the proteins (called histones) around which genes are wrapped. We wish to understand the epigenetic control system that the parasite uses to orchestrate the phenomenon of antigenic variation. We will use two methods to gain this understanding; the first is a genetic screen that will create mutations in the parasite using jumping DNA (called transposons) that will break down the control mechanism behind antigenic variation. Identifying the mutated genes will show us which genes organize antigenic variation in normal parasites. Our second approach is to genetically knockout parasite genes that are related to the genes that govern epigenetic mechanisms in other, better understood organisms like humans and yeast. We will test the effect of these targeted gene deletions to discover which of these genes are involved in regulating antigenic variation. The insights gained from these discoveries will improve our understanding of how the malaria parasite evades our immune system. A better understanding of this immune evasion may help us to understand how to build better vaccines against malaria.Read moreRead less