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
AIDS is caused by the human immunodeficiency virus type 1 (HIV-1). Long-term HIV infection leads to increased incidence of Kaposi's sarcoma, AIDS dementia complex, and immune dysfunctions. The HIV-1 Tat protein has been linked to disease progression. However, Tat is predominantly found in the cell nucleus while measurable levels in patient serum. This is not believed to be a passive event caused by dying cells. Here we will investigate how Tat is released by HIV-1 infected cells.
Study Of Papillomavirus DNA Encapsidation And Formation Of Infectious Virions
Funder
National Health and Medical Research Council
Funding Amount
$214,053.00
Summary
Papillomavirus (PV) is a sexually-transmitted virus that is a major cause of cervical cancer. Our study will determine how PV is able to form new virus particles inside infected cells. This is a critical part of the virus life-cycle, and a better understanding of this process may allow it to be trageted by anti-viral treatments. In addition, we will develop a method to create non-harmful virus particles which we will use to study human immune responses to the virus.
A NOVEL MOUSE MODEL TO INVESTIGATE THE MECHANISMS OF VIRUS-INDUCED ARTHRITIS
Funder
National Health and Medical Research Council
Funding Amount
$336,000.00
Summary
We have developed a novel animal model by which to study arthritic disease caused by insect-transmitted viruses known as arboviruses. The existence of this model and novel reagents provides an excellent opportunity to further explore the basic mechanisms of infectious disease in a complete functioning animal, rather than specific cultured cells. The study will use modern approaches in molecular and cellular biology to achieve this goal. The production by our immune systems of soluble mediators ( ....We have developed a novel animal model by which to study arthritic disease caused by insect-transmitted viruses known as arboviruses. The existence of this model and novel reagents provides an excellent opportunity to further explore the basic mechanisms of infectious disease in a complete functioning animal, rather than specific cultured cells. The study will use modern approaches in molecular and cellular biology to achieve this goal. The production by our immune systems of soluble mediators (cytokines-chemokines) and antibodies is an overwhelming positive aspect of our physiological response to infection by microbes. Protection from disease by these immune compounds can happen naturally, or the body's ability to produce these factors can be exploited to our benefit via the administration of vaccines. However, these factors can also be detrimental to the host contributing to severe disease. For instance, work performed almost 40 years ago showed for the first time that under particular conditions, antibodies against viruses can enhance infection, instead of inhibiting infection as normally seen. In the intervening years work by scientists all over the world has associated antibody-dependent enhancement (ADE) of infection to many types of viruses; ADE is even thought to be a risk factor to serious disease with dengue virus, and has been shown in vitro for the AIDS virus and Ebola virus. We have recently discovered a molecular mechanism which explains how antibody enhances viral infection in vitro. In studies on immune cells infected with Ross River Virus (RRV) we found that infection helped by antibody resulted in the specific disruption to the production of cellular chemicals which are toxic to viruses. Are these mechanisms of antibody-enhanced infection also found in animals? Will such mode of infection cause enhanced disease and tissue pathology (arthritis) in animals?Read moreRead less
The Role Of Subgenomic Non-coding Viral RNA In Flavivirus Pathogenicity
Funder
National Health and Medical Research Council
Funding Amount
$555,325.00
Summary
Flaviviruses are transmitted by insects and pose a serious health threat to the Australian population. They can cause fever syndromes, encephalitis and death. We aim at better understanding of how these viruses cause disease. We are particularly interested in elucidating the role of small non-coding nucleic acid produced by flaviviruses in the viral pathogenicity. Ultimately, this deeper understanding should lead to the development of effective vaccines and antiviral therapies.
Development Of Improved Vaccine Strategies For Measles Using Plant-derived Edible Vaccines
Funder
National Health and Medical Research Council
Funding Amount
$331,980.00
Summary
Measles is a highly contagious viral disease that is contracted via the respiratory tract. Severe infection may lead to complications such as otitis media, pneumonia, encephalitis. Despite our current vaccination strategy outbreaks still occur in Australia and measles is a major problem in developing countries. In developing nations the case fatality rate of measles is several hundred times that of developed nations. Over 800,000 children still die each year due to measles. Problems with the cur ....Measles is a highly contagious viral disease that is contracted via the respiratory tract. Severe infection may lead to complications such as otitis media, pneumonia, encephalitis. Despite our current vaccination strategy outbreaks still occur in Australia and measles is a major problem in developing countries. In developing nations the case fatality rate of measles is several hundred times that of developed nations. Over 800,000 children still die each year due to measles. Problems with the current vaccination strategy are: a) doesn't work in children less than 1 year of age, b) must be kept cold c) must be given by injection. We believe that a plant derived edible vaccine for measles will address the limitations of currently available vaccine i.e. we can give it children under the age of 1 year, it can be eaten and doesn't have to be kept cold.Read moreRead less
Though vaccination has had a major impact on the number of persons becoming infected, chronic infection with the hepatitis B virus (HBV) still remains a major worldwide problem, with 350 million people chronically infected. The existence of HBV vaccine escape mutants and the fact that 5% of vaccinees fail to respond implies that HBV will remain a significant public health problem for the foreseeable future. Current treatments for chronic HBV infection have a low success rate (~20%) and patients ....Though vaccination has had a major impact on the number of persons becoming infected, chronic infection with the hepatitis B virus (HBV) still remains a major worldwide problem, with 350 million people chronically infected. The existence of HBV vaccine escape mutants and the fact that 5% of vaccinees fail to respond implies that HBV will remain a significant public health problem for the foreseeable future. Current treatments for chronic HBV infection have a low success rate (~20%) and patients with chronic infection are expected to die prematurely due to chronic liver disease or primary liver cancer. Interestingly, exposure to HBV can lead to either acute resolving or chronic HBV infection. Like chronic infections, acute infections involve spread of virus to virtually every hepatocyte, followed by rapid clearance of the virus mediated by the host immune response. Our immediate aim is to study the resolution of acute HBV infections to determine how the stable intracellular viral genome, covalently closed circular DNA (cccDNA), is cleared from the nucleus of infected hepatocytes. Our broad long-term aim is to develop new and effective treatments for chronic HBV infection based on a better understanding of how acute HBV infections are resolved by the host. Based on our previous work we believe that clearance of cccDNA requires hepatocyte death, together with compensatory proliferation of other infected hepatocytes. We will perform detailed studies in duck hepatitis B virus (DHBV) infected ducks to determine if hepatocyte death and compensatory proliferation are essential to clear the infection, or if mechanisms exist for clearance that do not involve cell destruction.Read moreRead less