I am a Clinical Immunologist, Immunopathologist, clinical researcher and laboratory scientist exploring the interactions between T cell and viral infections. My area of particular interest is the mechanisms by which HIV infection subverts effective T cel
Determining The Role Of DOCK8 In CD4+ T And B Cell Differentiation And Its Implications On Autosomal Recessive Hyper IgE Syndrome (AR-HIES)
Funder
National Health and Medical Research Council
Funding Amount
$512,600.00
Summary
Autosomal recessive hyper IgE (AR-HIES) syndrome due to mutations in DOCK8 is a rare primary immunodeficiency whereby patients present with susceptibility to severe and recurrent viral infections as well as an increased risk of developing cancer, severe food and environmental allergies, and atopic disease characterised by hyper IgE and extreme eosinophilia. This grant will investigate how abnormal DOCK8 function in CD4+ T cells and B cells contributes to disease pathogenesis in AR-HIES patients.
Effector And Memory CD8+ T Cell Responses To Engineered Influenza A Escape Mutants
Funder
National Health and Medical Research Council
Funding Amount
$465,210.00
Summary
T cells are a critical component of the immune system after infection with viruses. In particular, virus-specific CD8+ T cells can clear viral infections by killing virally-infected cells and the release of immunomodulators. These are called effector T cells. After the viral infection is cleared, a small proportion of T cells (around 5 to 10%) survives for many years and constitute a memory pool of virus-specific T cells. Memory T cells provide a rapid and effective protection in case of a repea ....T cells are a critical component of the immune system after infection with viruses. In particular, virus-specific CD8+ T cells can clear viral infections by killing virally-infected cells and the release of immunomodulators. These are called effector T cells. After the viral infection is cleared, a small proportion of T cells (around 5 to 10%) survives for many years and constitute a memory pool of virus-specific T cells. Memory T cells provide a rapid and effective protection in case of a repeated infection with the same virus, and hence result in a less severe disease. However, viruses often mutate their genes to escape such efficient T cell responses. In this study, we will investigate T cell responses after infection with mutated strains of influenza viruses. We will engineer a panel of mutant influenza viruses, which alter the nature and characteristics of T cells. We will analyse how efficient are these T cells and whether they can protect against a normal strain of influenza A. Subsequently, we will characterise quantitative and qualitative aspects of memory T cell pools after infection with mutant influenza viruses. Since a number of viruses such as influenza, HIV and HCV rapidly mutate their genes, our study will not only address the question of T cell responses to mutated influenza viruses, but also will provide an excellent model for investigating protective T cell responses to other viral infections.Read moreRead less
Antigen Dose And TCR Repertoire In CD8+ T Cell Immunodominance Hierarchies
Funder
National Health and Medical Research Council
Funding Amount
$558,920.00
Summary
The CD8+, or killer , T lymphocytes (white blood cells) are the hit men of immunity, recirculating continually around the body to eliminate other cells that are dangerous because they are cancerous or infected with a virus. A major difficulty is that killer T cells also exert selective pressures that cause viruses and tumours to mutate and thus avoid immune control. This is a particularly serious problem for RNA viruses that readily mutate as they divide. These include the human immunodeficiency ....The CD8+, or killer , T lymphocytes (white blood cells) are the hit men of immunity, recirculating continually around the body to eliminate other cells that are dangerous because they are cancerous or infected with a virus. A major difficulty is that killer T cells also exert selective pressures that cause viruses and tumours to mutate and thus avoid immune control. This is a particularly serious problem for RNA viruses that readily mutate as they divide. These include the human immunodeficiency virus (HIV) that causes AIDS and, while the mutations that are most important with influenza viruses are those that modify viral surface proteins recognized by antibodies, such T cell escape mutants can also be a problem with influenza. The other reason why there is particular interest in promoting CD8+ T cell-mediated immunity to influenza is that the killer T cells are very cross-reactive. We have shown that vaccination approaches that prime mouse CD8+ T cells to resist influenza A viruses circulating currently in humans will also protect against the highly lethal, and dangerous H5N1 bird 'flu. The present flu vaccines only stimulate antibodies, so there is interest in the possibility of a major re-design. The CD8+ T cells recognize tiny elements (peptides) of the virus or tumour bound in the tip of our own transplantation, or class I major histocompatibility complex (MHCI) molecules. These pMHCI complexes are called epitopes. The focus here is on the use of novel genetic engineering strategies to find out how, when the virus mutates to disrupt the major epitopes seen by killer T cells, other minor epitopes can be abnormally emphasized in a way that promotes effective immune control. As we work on this with the relatively simple and safe influenza model we will concurrently develop strategies that may be of value in HIV and tumour immunity. Solving this problem could prove to be a substantial advance in the design of vaccines and immunotherapy approaches.Read moreRead less
Utilising Human Primary Immunodeficiencies To Study Lymphocyte Differentiation
Funder
National Health and Medical Research Council
Funding Amount
$429,346.00
Summary
Human immunodeficiencies are diseases arising from naturally occurring mutations. In this instance, the specific genes mutated in the immunodeficiencies we study have been identified. However, it is unclear how defects in these genes make an individual manifest as an immune deficient state, rendering them vulnerable to disease. By studying immune cells from these individuals we hope to uncover the normal function of these genes and subsequently provide for new therapies for these conditions.
Identifying T Cell Correlates Of Protective Immunity To Malaria In Childhood
Funder
National Health and Medical Research Council
Funding Amount
$396,026.00
Summary
Malaria claims nearly one million lives each year, mostly children. Although those living in endemic regions can acquire natural immunity, it develops slowly and isn`t completely protective. This project studies the impact of different levels of malaria exposure and age on the development of a protective immune response in children. By understanding the effect of high malaria exposure in the development of immunity it is hoped that new avenues for drug development may be identified.
Understanding And Modulating The Human Immune System
Funder
National Health and Medical Research Council
Funding Amount
$470,144.00
Summary
T cells are the sentinels of our immune system continually scanning our tissue for abnormalities and eliminating threats in many forms. They are our second and last line of defence against microorganisms and cancer. Unfortunately, T cells can also cause harm through accidental crossreactvity or overzealous function. My work is directed at understanding how T cells work and how they can be controlled using drugs and gene therapy. If we can ‘tune’ the power of this master immune lineage we can unl