Several members of the Flaviviridae family are major pathogens of humans including dengue (DEN), yellow fever (YF), tick-borne encephalitis (TBE), Murray valley encephalitis (MVE), Japanese encephalitis (JE), and hepatitis C virus (HCV). An Australian flavivirus Kunjin (KUN), however, appears to be naturally attenuated and does not cause an overt disease in humans. In contrast, genetically and antigenically closely related to KUN, New York strain of West Nile virus (NY WN) has already caused ~50 ....Several members of the Flaviviridae family are major pathogens of humans including dengue (DEN), yellow fever (YF), tick-borne encephalitis (TBE), Murray valley encephalitis (MVE), Japanese encephalitis (JE), and hepatitis C virus (HCV). An Australian flavivirus Kunjin (KUN), however, appears to be naturally attenuated and does not cause an overt disease in humans. In contrast, genetically and antigenically closely related to KUN, New York strain of West Nile virus (NY WN) has already caused ~500 deaths and over 20,000 registered infections since its emergence in North America in 1999, including 223 deaths and 9122 infections in 2003 alone. Recent studies with DEN indicated that flaviviruses may interfere with early steps of IFN-signalling pathway. The type I Interferon (IFN) response is the first line of defence against viral infections and many viruses have developed different strategies to counteract this response in order to ensure their survival in the infected host. In this grant we seek to exploit our extensive understanding of the molecular biology of KUN virus and the contrasting behaviour of KUN and NY WN viruses to gain an understanding of the role of flavivirus-mediated suppression of host anti-viral IFN response in virus-host relationships and its importance in determining virus virulence.Read moreRead less
Functions Of Viral Chemokine Receptor Homologues Important For Cytomegalovirus Pathogenesis And Latency
Funder
National Health and Medical Research Council
Funding Amount
$461,597.00
Summary
Cytomegalovirus (CMV) causes life-threatening disease in babies, transplant recipients and HIV-AIDS patients. We will focus on a CMV gene that has been 'hijacked' from the host cell and enables the virus to switch on signalling molecules within infected cells. We will determine how these signals enable CMV to infect sites of the body that are critical for virus transmission and contribute to long-term virus persistence. Our results will provide new strategies for drugs against CMV.
Determination Of The Mechanisms Of Action Of A Cytomegalovirus Chemokine Receptor Homologue In Pathogenesis
Funder
National Health and Medical Research Council
Funding Amount
$251,341.00
Summary
A number of herpesviruses encode proteins that are similar to proteins of our immune system. These pirated proteins are exploited by the virus to enable it to replicate and persist in the infected individual, usually by evading or gaining advantage from the normal immune response. This project will investigate the role of one such protein found in both human and animal herpesviruses (specifically cytomegaloviruses (CMV)) that is conserved with cellular cell surface proteins (receptors) that bind ....A number of herpesviruses encode proteins that are similar to proteins of our immune system. These pirated proteins are exploited by the virus to enable it to replicate and persist in the infected individual, usually by evading or gaining advantage from the normal immune response. This project will investigate the role of one such protein found in both human and animal herpesviruses (specifically cytomegaloviruses (CMV)) that is conserved with cellular cell surface proteins (receptors) that bind immune signaling molecules (chemokines). Chemokines are important proteins in the early response to infection. Binding of chemokines to their receptors initiates a cascade of signals within the cell that has profound effects on cellular responses to environmental stimuli. Thus, it is believed that herpesviruses have acquired chemokine receptors to modify or react to the immune response, causing infected cells to behave abnormally either despite or in response to chemokine signals. This project will determine how this CMV specific protein affects the function of cells that CMV infects and how this may promote virus replication, dissemination and persistence in infected hosts. We will also engineer CMVs where the activity of the target protein can be inhibited by administration of prototype antiviral drugs. If inhibition of the activity of the protein is found to reduce virus replication, dissemination or persistence, then this will demonstrate that this type of protein would be a suitable target for the development of novel drugs active against CMV infections. CMV can cause serious (potentially life threatening) disease in newborn children (following infection in the uterus) and immunosuppressed people (eg. organ transplant recipients and people with HIV-AIDS). Our studies will improve our understanding of the contribution of a specific CMV protein to disease, thereby assisting efforts to reduce the impact of CMV infections.Read moreRead less
Viral Factors Contributing To Flavivirus-induced Cell Death And Pathogenicity
Funder
National Health and Medical Research Council
Funding Amount
$612,885.00
Summary
West Nile virus is a mosquito-transmitted pathogen that causes severe and fatal neurological disease in humans. There are currently no effective treatments or vaccines for this disease. In this project, we will investigate how West Nile virus and other viruses of the same group use a novel translational regulatory mechanism to modulate the host antiviral response and facilitate viral pathogenicity. This will provide valuable information for the development of effective treatments against this me ....West Nile virus is a mosquito-transmitted pathogen that causes severe and fatal neurological disease in humans. There are currently no effective treatments or vaccines for this disease. In this project, we will investigate how West Nile virus and other viruses of the same group use a novel translational regulatory mechanism to modulate the host antiviral response and facilitate viral pathogenicity. This will provide valuable information for the development of effective treatments against this medically important group of viral pathogens.Read moreRead less
Viral Factors Involved In Flavivirus Replication And Virus-host Interactions
Funder
National Health and Medical Research Council
Funding Amount
$743,696.00
Summary
With our increased understanding of virus-host interactions it has become apparent that small, non-structural proteins and small RNAs of most viruses are vital for numerous, often multiple, functions in the viral life cycle. In the proposed project, we seek to gain a detailed understanding of the functions of small nonstructural protein NS2A and small abundant viral RNAs of medicaly important encephalitic flaviviruses, which have remained so far elusive and are at the cutting-edge in the researc ....With our increased understanding of virus-host interactions it has become apparent that small, non-structural proteins and small RNAs of most viruses are vital for numerous, often multiple, functions in the viral life cycle. In the proposed project, we seek to gain a detailed understanding of the functions of small nonstructural protein NS2A and small abundant viral RNAs of medicaly important encephalitic flaviviruses, which have remained so far elusive and are at the cutting-edge in the research field. We anticipate that with a better understanding of the roles of these factors in flaviviral replication and pathogenesis, novel targets for antiviral therapies and-or molecular determinants for inclusion in candidate vaccines will be identified.Read moreRead less
SERPINB2 IS AN INDUCIBLE HOST FACTOR INVOLVED IN ENHANCING HIV-1 TRANSCRIPTION AND REPLICATION
Funder
National Health and Medical Research Council
Funding Amount
$496,446.00
Summary
SerpinB2 is one of the most abundant proteins made at sites of inflammation. We have shown that HIV-1 infection also induces SerpinB2 and that SerpinB2 then helps the virus to replicate. In this grant we seek to understand how the virus causes this protein to be made and how this protein then increases virus replication. In the human population there are different forms of SerpinB2 and this grant seeks to determine whether these different forms affect HIV-1 replications differently. It may for i ....SerpinB2 is one of the most abundant proteins made at sites of inflammation. We have shown that HIV-1 infection also induces SerpinB2 and that SerpinB2 then helps the virus to replicate. In this grant we seek to understand how the virus causes this protein to be made and how this protein then increases virus replication. In the human population there are different forms of SerpinB2 and this grant seeks to determine whether these different forms affect HIV-1 replications differently. It may for instance be possible that an individual who has a certain form of SerpinB2 may be less susceptable to AIDS following HIV-1 infection.Read moreRead less
The Role Of Actin-based Motility As A Virulence Mechanism And Potential As An Antiviral Target
Funder
National Health and Medical Research Council
Funding Amount
$325,798.00
Summary
Our repertoire of effective treatments for infectious diseases is fast becoming exhausted as resistance to antibiotics and antivirals evolves and rapidly spreads throughout our community. We have developed a new paradigm in treating viral diseases that we predict will not give rise to resistance, and this project will be the first to demonstrate the effectiveness of this novel therapy in an endemic disease model.
Influenza remains an important disease and exacts a high toll in both morbidity and mortality each year. This project will identify the carbohydrates that are utilised by influenza virus to initiate infection throughout the body and map how these carbohydrates interact with the key viral surface proteins. This research will provide new insight into the emergence of new influenza virus strains and cross-species pathogenicity.
The Balance Of Signals Received By NK Cells Is Modulated By Viruses As A Mean Of Immune Escape.
Funder
National Health and Medical Research Council
Funding Amount
$583,175.00
Summary
Cytomegalovirus (CMV) affects about 60% of the population in Australia. Infection is partially controlled by the immune system but CMV is never eliminated and people remain carriers for the rest of their life. Reactivation of CMV in healthy individuals is usually asymptomatic, but it causes severe diseases in people with immune deficiencies. We seek to discover the mechanisms used by CMV to escape immune surveillance, in order to gain insights into the development of improved antiviral therapies
Cellular Microenvironments Facilitating The Replication And Propagation Of Flaviviruses
Funder
National Health and Medical Research Council
Funding Amount
$505,279.00
Summary
Flaviviruses are the agents of many mosquito-transmitted infections and many deaths globally each year. The emerging virus West Nile virus (strain New York) is a member of this virus family and shares 99% amino acid homology with the endemic Australian virus Kunjin virus. During virus growth in cells, cellular membrane structures are induced or rearranged by these viruses for their own purpose. That being the production of more virus particles for reinfection of other cells. Using Kunjin virus a ....Flaviviruses are the agents of many mosquito-transmitted infections and many deaths globally each year. The emerging virus West Nile virus (strain New York) is a member of this virus family and shares 99% amino acid homology with the endemic Australian virus Kunjin virus. During virus growth in cells, cellular membrane structures are induced or rearranged by these viruses for their own purpose. That being the production of more virus particles for reinfection of other cells. Using Kunjin virus as a model, and advanced techniques in biochemistry and electron microscopy, we have identified for the first time these membrane structures as the apparent sites of replication of the viral RNA or genetic material, and of the viral proteins involved. We have also observed how new virus particles are able to get out of infected cells and shown how some drugs can prevent this occurring thus limiting their transmission. This research will focus on how the membrane structures are formed in infected cells. The research will determine what cellular components are required by the virus to help it propagate. In particular specific cellular proteins and membrane components that are captured by the virus and moved to different sites in the infected cells. These apparent requirements could possibly lead us to a greater understanding of the complex interactions that occur between the invading virus and the host cells. We aim to directly visualize the process of infection within living cells using new and innovative microscopic techniques. Another of our objectives is to determine the effects of infection on normal cells. The question being whether flavivirus infection disrupts normalcell fuctions like secretion etc. An understanding of these processes, and how the viral RNA is copied into new RNA for more virus particles, will assist in the development of antiviral drugs for treatment of this pathogenic group of viruses.Read moreRead less