Regulation Of Viral Latency In Gamma-herpesvirus Infection
Funder
National Health and Medical Research Council
Funding Amount
$258,000.00
Summary
The cost to public health from herpesvirus infection is enormous. The gamma-herpesviruses chronically infect more than 95% of the world's population. This group of viruses induce a state of immunosuppression that cause down-regulation of immune responses. This allows the virus the opportunity to evade the immune system and thus survive within the host. The gamma-herpesviruses do not generally cause serious disease in normal individuals but reactivation of gamma-herpesviruses can cause severe dis ....The cost to public health from herpesvirus infection is enormous. The gamma-herpesviruses chronically infect more than 95% of the world's population. This group of viruses induce a state of immunosuppression that cause down-regulation of immune responses. This allows the virus the opportunity to evade the immune system and thus survive within the host. The gamma-herpesviruses do not generally cause serious disease in normal individuals but reactivation of gamma-herpesviruses can cause severe disease, even mortality, in individuals with an immature or a compromised immune system. Viral reactivation is a major complication of immunosuppressive diseases such as HIV (which currently affects more than 45 million people) and in transplant recipients. The virally-induced changes in the host cells can result in the development of secondary infections, post-transplantation lymphoproliferative disease and even the development of tumours. The central aim of the studies described in this proposal is to understand the cellular and viral mechanisms regulating how the virus is maintained in the host. These studies will improve our understanding of how antigen presenting cells and CD8+ T lymphocytes ensure an immune response is maintained and may identify critical targets to facilitate the rational design of antiviral drugs and vaccines.Read moreRead less
Systems Immunology Of Antigen Specific T Cells: From Single-cell To Immune Protection
Funder
National Health and Medical Research Council
Funding Amount
$470,144.00
Summary
T cells are key for establishment of immune protection and object of ongoing research in vaccines and more recently immunotherapy against infections and some cancers. Their dynamics are complex and many mechanisms remain unknown that could be exploited for modern therapies. Here, in a systems approach I will combined single cell technologies, immunology and computational biology to identify the factors that determine the establishment of long term memory cells utilising a unique set of samples.
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
Molecular Basis Of T Cell Receptor Bias In Viral Immunity
Funder
National Health and Medical Research Council
Funding Amount
$540,075.00
Summary
Viral infection results in the activation and proliferation of T cells that eradicate infected cells. Recognition of infected cells is meditated by presentation and recognition of viral protein fragments via specific cell surface receptors. This proposal plans to examine the factors that determine the diversity of the immune response and the consequences of such diversity on anti-viral immunity. This has implications for the development of vaccines.
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
Herpesviruses infect most Australians and cause recurrent ulcers, birth defects and cancer. Infection lasts lifelong, and spreads to close contacts without obvious clinical signs. Thus disease is hard to prevent. However we can learn much from related animal infections. We have shown that both mouse and human herpesviruses enter mice via cells in the nose. Thus human infections might follow the same route. We will define what body defences work here and whether vaccines can prevent infection.
Human ?-herpesviruses persist for life, cause cancers and emerge with particular virulence when the immune system is weak. Vaccination against them is therefore an important health priority. We have shown for a related ?-herpesvirus of mice that live vaccines protect. Antibody seems to play a major role. We will test whether safer, recombinant vaccines are also sufficient to elicit protective antibody. Thus we can establish a viable strategy for preventing virus-induced human cancers.
Escape And Reversion Of Critical Immune Responses: Insights Into Effective Immunity To HIV
Funder
National Health and Medical Research Council
Funding Amount
$372,446.00
Summary
The HIV pandemic is a global emergency. The overall goal of this grant proposal is to elucidate the requirements for protective immunity to HIV. Although immune responses have some effect on HIV replication, the virus mutates and evolves to escape immune pressure. However, each mutation away from wild-type virus likely results in at least some impairment in the ability of the virus to replicate. Where efficient immune responses target regions of the virus that are critical to virus replication, ....The HIV pandemic is a global emergency. The overall goal of this grant proposal is to elucidate the requirements for protective immunity to HIV. Although immune responses have some effect on HIV replication, the virus mutates and evolves to escape immune pressure. However, each mutation away from wild-type virus likely results in at least some impairment in the ability of the virus to replicate. Where efficient immune responses target regions of the virus that are critical to virus replication, escape mutations may result in viral variants incapable of causing disease. Resulting from an exciting collaboration between HIV and theoretical biologists, we have recently identified techniques to calculate the effectiveness of immunity and the cost of subsequent immune escape variants. We will use and expand these techniques to identify immune responses that result in the most effective control of viral replication. These studies will lead to ways to improve HIV vaccines and thereby prevent HIV.Read moreRead less
Viral infections of the gut are one of the most debilitating infections one can suffer from. Noroviruses are the most common causative agents of viral-associated gastroenteritis but unfortunately little is known regarding their biology and pathogenesis. Our study aims to investigate the replication and pathogenesis of a mouse norovirus to shed light on similar aspects relating to human norovirus infection. We aim to understand how virus infection in cells leads to disease symptoms.