I am cellular immunologist determining the important host immune cell types and effector molecules that control tumour initiation, growth, and metastasis.
Chromatin Remodelling And Transcriptional Regulation Of CD8 T Cell Effector Gene Expression
Funder
National Health and Medical Research Council
Funding Amount
$531,696.00
Summary
A major role for cytotoxic, or killer, T cells is the recognition and removal of virus infected or tumor cells from a host. Upon recognition of a target host cell, killer T cells deliver a package of proteins, termed granzymes, that mediate the removal of these virus infected and tumor cells. Naive killer T cells need to be activated to start producing these effector molecules. This proposal plans to examine the factors that regulate both induction and maintanence of cell specific expression of ....A major role for cytotoxic, or killer, T cells is the recognition and removal of virus infected or tumor cells from a host. Upon recognition of a target host cell, killer T cells deliver a package of proteins, termed granzymes, that mediate the removal of these virus infected and tumor cells. Naive killer T cells need to be activated to start producing these effector molecules. This proposal plans to examine the factors that regulate both induction and maintanence of cell specific expression of these effector molecules. We plan to identify the molecular events that occur within a cells genome to turn on granzyme gene expression and how these factors influence subsequent killer T cell function. The conclusions from these studies will enable us to determine why some killer T cell responses are not effective and what can be done to improve killer T cell function. This has implications for the development of novel vaccine strategies designed to induce immunity against both viral and tumour challenges.Read moreRead less
Human cytomegalovirus (HCMV) is a classic example of a group of herpes viruses, which is found universally throughout all geographic locations and socioeconomic groups, and infects 50% of adults in developed countries. HCMV infection is important to certain high-risk groups. Major areas of concern are: (1) the risk of infection to unborn baby during pregnancy, (2) the risk of infection to people who work with children, and (3) the risk of infection to immunocompromised persons (e.g. organ transp ....Human cytomegalovirus (HCMV) is a classic example of a group of herpes viruses, which is found universally throughout all geographic locations and socioeconomic groups, and infects 50% of adults in developed countries. HCMV infection is important to certain high-risk groups. Major areas of concern are: (1) the risk of infection to unborn baby during pregnancy, (2) the risk of infection to people who work with children, and (3) the risk of infection to immunocompromised persons (e.g. organ transplant patients and HIV-infected individuals). Epidemiological studies have shown that 80%-90% of developing unborn babies who acquire congenital HCMV infection displays a variable pattern of pathological sequelae within the first few years of life that may include hearing loss, vision impairment and mental retardation. There is an increasing argument that a reduction in HCMV load will have a significant effect on the sequelae associated with congenital HCMV infection. Indeed, vaccination provides the most practical modality of achieving such a reduction in HCMV load. To develop such a vaccine, formulation based on viral antigens that activate both protective cellular and humoral responses needs to be tested to assess its immunogenicity. No such vaccine is presently available for HCMV. In this application we have sought to develop a prophylactic vaccine and to test its efficacy in a immunocompetent transgenic mouse model and as well under conditions of immunosuppression (CD4 T cell deficient). The overall strategy is to use this prophylactic vaccine to stimulate the cellular (CD8+ and CD4+ T cells) and humoral responses against multiple HCMV antigens. This vaccine will be based on the novel chimeric polyepitope technology and exploits a novel replication deficient adenovirus expression system which has recently been approved for human use.Read moreRead less
The immune system employs a variety of strategies to combat parasites including viruses. One of them is cytolytic lymphocytes, cells that can recognize and destroy virus-infected target cells. These cells use, besides other molecules, enzymes called granzymes to kill target cells by inducing suicide in them. We intend to investigate if those granzymes can protect cytolytic lymphocytes themselves from being infected by viruses and turned into viral factories. We are going to use a model of a natu ....The immune system employs a variety of strategies to combat parasites including viruses. One of them is cytolytic lymphocytes, cells that can recognize and destroy virus-infected target cells. These cells use, besides other molecules, enzymes called granzymes to kill target cells by inducing suicide in them. We intend to investigate if those granzymes can protect cytolytic lymphocytes themselves from being infected by viruses and turned into viral factories. We are going to use a model of a natural infection, ectromelia, mouse pox. Mouse pox is fatal in resistant strains of mice if the genes for the two dominant granzymes are deleted. This indicates that granzymes are essential for fighting this viral disease. We will explore in which cells of the immune system granzymes are expressed and whether virus entry into a cell can actually trigger their expression. Furthermore, we will investigate how the granzymes inhibit virus infection within the infected cell to determine whether the mechanisms involved resemble those used by cytolytic lymphocytes in killing of target cells (i.e. degradation of DNA and mitochondrial damage), or whether they represent entirely new facets of granzyme function. Finally, using viruses from a number of different families, we will establish whether these functions of granzymes also contribute to protection from other viral infections. An understanding of the role of these granzymes in the innate immune response, i.e. before antigen specific T cell and antibody responses are fully activated, is of great significance as it may allow us to manipulate this particular anti-viral response and thus enhance survival and reduce morbidity in viral infections.Read moreRead less
A T Cell-Specific GR Promoter Determines Responsiveness To Glucocorticoids In Different Immune Compartments
Funder
National Health and Medical Research Council
Funding Amount
$417,500.00
Summary
Synthetic glucocorticoids, such as dexamethasone and prednisolone, are commonly used as potent anti-inflammatory steroid drug during the treatment of major human trauma and cancer. A side-effect of these very high steroid doses is a major down-regulation of the immune system, particularly massive death of important immune cells called T-cells, which can have a major impact on patient recovery and potential mortality. These T cells are particularly sensitive to glucocorticoid-induced cell death a ....Synthetic glucocorticoids, such as dexamethasone and prednisolone, are commonly used as potent anti-inflammatory steroid drug during the treatment of major human trauma and cancer. A side-effect of these very high steroid doses is a major down-regulation of the immune system, particularly massive death of important immune cells called T-cells, which can have a major impact on patient recovery and potential mortality. These T cells are particularly sensitive to glucocorticoid-induced cell death and have very high levels of receptors for these steroids called glucocorticoid receptors (GRs). We have discovered a unique GR gene promoter (designated 1A) that is active in T cells. Very little is known about how this gene promoter is regulated. This promoter may be a useful therapeutic target to block T cell death (caused by steroids) during recovery from injury, infection and cancer. Separation of anti-inflammatory and side-effects such as high T-cell death or blockade of these effects on T cells would have a major impact on patient immune status and recovery, and reduce the incidence of debilitating side-effects. Therapeutic down-regulation of this T cell-specific GR gene promoter could lead to targeted blockade of steroid-induced T cell death and help maintain a strong immune system. This application brings together a unique team of investigators (CIs) that have a strong history of collaboration in this area with recent publications in very high ranking international journals. The CIs bring a multi-disciplined approach combining endocrinology, molecular biology and cellular immunology to determine the underlying mechanisms of steroid actions and their effects on immune function. Both Dr Cole (CIA) and Dr Godfrey (CIB) have excellent track records in this area.Read moreRead less
Structural Basis Of Influenza A Virus-specific CD8+ T Cell Receptor Diversity
Funder
National Health and Medical Research Council
Funding Amount
$469,500.00
Summary
Viral infection results in the activation and proliferation of virus-specific T cells that mediate clearance of virally infected cells. Recognition of virally infected cells is meditated by presentation of peptide fragments complexed to Major histocompatibility complex (MHC) class I glycoproteins. Virus-specific T cells recognise these viral protein fragments via a specific receptor expressed at the T cell surface. This proposal plans to examine the structural factors that determine influenza-sp ....Viral infection results in the activation and proliferation of virus-specific T cells that mediate clearance of virally infected cells. Recognition of virally infected cells is meditated by presentation of peptide fragments complexed to Major histocompatibility complex (MHC) class I glycoproteins. Virus-specific T cells recognise these viral protein fragments via a specific receptor expressed at the T cell surface. This proposal plans to examine the structural factors that determine influenza-specific T cell receptor recognition. From these studies, we plan to determine how these structural factors can influence the diversity of virus-specific T cells that are generated after viral infection. The conclusions from these studies will enable us to determine why some virus-specific T cell responses are not diverse and what are the consequences for virus-specific T cell immunity. This has implications for the development of novel vaccine strategies designed to induce immunity against both viral and tumour challenge.Read moreRead less