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.
Host-virus Interactions That Define The Outcome Of Anti-viral T Cell Responses: Relevance To Viral Persistence
Funder
National Health and Medical Research Council
Funding Amount
$487,500.00
Summary
Infection with human cytomegalovirus (hCMV) is normally resolved without symptomatic evidence of infection. However, severe hCMV disease can occur in immunocompromised patients in which the manifestations of disease include chorioretinitis, interstitial pneumonia and hepatitis. In immunologically immature children, congenital infection results in cytomegalic inclusion disease (CID). CID in infants causes severe neurological sequelae resulting in mental retardation, deafness and blindness. Vaccin ....Infection with human cytomegalovirus (hCMV) is normally resolved without symptomatic evidence of infection. However, severe hCMV disease can occur in immunocompromised patients in which the manifestations of disease include chorioretinitis, interstitial pneumonia and hepatitis. In immunologically immature children, congenital infection results in cytomegalic inclusion disease (CID). CID in infants causes severe neurological sequelae resulting in mental retardation, deafness and blindness. Vaccination against hCMV induced cytomegalic inclusion disease has been designated Level I (most favourable) due to the prediction that it could save lives and prevent life-long disability. Given the essential nature of CD8 T cells in CMV control and the high prevalence of CMV in society, it will be crucial to develop a vaccine capable of eliciting an efficacious T cell response which develops lasting memory. We hypothesise that mCMV has evolved mechanisms for generating an appropriate T cell response involved in viral control and the establishment of a persistent infection. The central aim of the work in the current proposal is to investigate the cellular and viral mechanisms involved in the generation of cytomegalovirus specific T cells. The proposed studies will improve our understanding of the generation of anti-viral T cell responses and hence will be relevent to further our understanding of the role of T cells in human infection. More importantly the results will provide critical insights into the rational design of suitable antiviral drugs and vaccines.Read moreRead less
Inhibition Of Interferon-alpah-beta By Chikungunya Virus And The Induction Of Arthritis
Funder
National Health and Medical Research Council
Funding Amount
$709,193.00
Summary
Chikungunya virus is a mosquito borne virus which has caused epidemics of arthritis around the world (recently 260,000 people Reunion Island, France and 1.6 million people in India). The virus is ordinarily very sensitive to the main mammalian anti-viral defence system (interferon alpha-beta). This grant seeks to understand how, despite the activation of this system during infection, the virus manages to persist and cause 3-6 months of debilitating arthritis.
In recent years it has become clear that certain white blood cells called CD8+ T lymphocytes or killer T cells are required to protect people against HIV. Unfortunately, current vaccines that produce or anti-HIV CD8 T cells only produce effective T cells for a short period. In this project we intend to test a novel vaccine vector called a Kunjin replicon, which promises to persistently produce or maintain effective T cells because the vaccine itself persists and continually immunises for extende ....In recent years it has become clear that certain white blood cells called CD8+ T lymphocytes or killer T cells are required to protect people against HIV. Unfortunately, current vaccines that produce or anti-HIV CD8 T cells only produce effective T cells for a short period. In this project we intend to test a novel vaccine vector called a Kunjin replicon, which promises to persistently produce or maintain effective T cells because the vaccine itself persists and continually immunises for extended periods. We intend to test the ability of this vaccine to persist and persistently produce effective CD8 T cells not only systemically in the blood system but also at mucosal surfaces, where HIV usually gains entry during sexual intercourse.Read moreRead less
Current combination antiviral therapy can't cure an HIV infection because long-lived T-cells carrying latent HIV DNA can rekindle the infection when drugs are removed. We will study elements in HIV genetic code that control expression of HIV proteins from latent HIV. A detailed molecular understanding of the structure and function of these HIV RNA elements and the viral and host cell factors that interact with them will expose new targets for therapy of latent HIV.
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
Multiple Cytomegalovirus Infections: Biological And Evolutionary Significance.
Funder
National Health and Medical Research Council
Funding Amount
$555,776.00
Summary
This project involves the study of cytomegalovirus (CMV) a common viral infection of humans which normally cause little disease. However in individuals whose immune system is suppressed (such as AIDS patients or transplant recipients), or in infection of pregnant women, CMV can cause serious or life-threatening disease in the patient or foetus. An interesting feature of CMV diseases in such patients is that enhanced viral growth and more severe disease is frequently associated with the presence ....This project involves the study of cytomegalovirus (CMV) a common viral infection of humans which normally cause little disease. However in individuals whose immune system is suppressed (such as AIDS patients or transplant recipients), or in infection of pregnant women, CMV can cause serious or life-threatening disease in the patient or foetus. An interesting feature of CMV diseases in such patients is that enhanced viral growth and more severe disease is frequently associated with the presence of multiple strains of CMV in the patient. We suggest that mixed CMV infections provide a survival advantage to the virus, with different strains within the mixed infection assisting the growth of other strains. This would result in increased virus growth overall, and enhanced disease. To study the mechanisms by which multiple infections with different CMV strains may affect both the virus and the host, experiments will be performed using an animal model of CMV, murine cytomegalovirus (MCMV). We will examine the effect of the presence of multiple strains of virus on virus growth and distribution within the infected host. We will also determine if functional MCMV strains are capable of assisting non-functional strains to survive within the host. These studies are relevant to the design of a CMV vaccine, and will be valuable in revealing the ways in which viruses can co-operate within an infection.Read moreRead less
Behavioural, Virological And Immunological Factors Influencing Hepatitis C Virus Infection In Injecting Drug Users
Funder
National Health and Medical Research Council
Funding Amount
$963,437.00
Summary
The hepatitis C virus (HCV) is a major public health problem affecting over 170 million people worldwide. In Australia an estimated 157,000 people have HCV and are at risk of serious disease, and 16,000 new infections occur each year. Treating HCV-related disease is expensive, and this healthcare burden is projected to grow significantly in coming years. Almost all new HCV infections in Australia occur among injecting drug users (IDUs), and despite our world-leading prevention programs, the viru ....The hepatitis C virus (HCV) is a major public health problem affecting over 170 million people worldwide. In Australia an estimated 157,000 people have HCV and are at risk of serious disease, and 16,000 new infections occur each year. Treating HCV-related disease is expensive, and this healthcare burden is projected to grow significantly in coming years. Almost all new HCV infections in Australia occur among injecting drug users (IDUs), and despite our world-leading prevention programs, the virus is spreading. Consensus is emerging that the best hope for control of HCV and related disease lies in a vaccine; our research will lay much of the groundwork for its development. The applicants' research to date shows that IDUs are being infected with HCV more frequently than previously assumed, that many carry multiple strains, and that dominant strains vary rapidly in individuals over time. These results reinforce the view that our prevention methods will not reduce infection rates and that current anti-viral treatments are not the solution. Nevertheless, we also found that some IDUs remain free of HCV infection despite risky behaviour with infected associates; intensive study of the immune functioning of these persistently non-infected individuals holds promise for vaccine development. In our proposed research, a collaboration of leading Australian epidemiologists, virologists and immunologists, we will recruit 210 young IDUs and follow them regularly for two years. Recruits will describe their social networks and nominate IDUs with whom they inject, provide blood samples and be interviewed about their behaviour at 3-month intervals. Individuals with recent and resolved HCV infection, change of dominant strain and lack of infection despite risky behaviour will be identified and their blood analysed for genetic factors that may be linked to immune protection. The outcomes will be crucial to the development and trialling of a vaccine against HCV.Read moreRead less
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