Adaptation Of Hepatitis C To Host HLA-Restricted Immune Responses In Australian Populations
Funder
National Health and Medical Research Council
Funding Amount
$480,750.00
Summary
Over 200,000 Australians are infected with the Hepatitis C Virus (HCV) and about 11,000 new infections are diagnosed each year. Around 25% of people infected with HCV will clear the virus while for individuals with chronic infection 10 to 20% will develop cirrhosis of the liver within the next 20-40 years. Differences in host genetic factors and viral variants will, in large part, explain the observed heterogeneity in the clinical outcome and course of HCV infection. The basic theory underpinnin ....Over 200,000 Australians are infected with the Hepatitis C Virus (HCV) and about 11,000 new infections are diagnosed each year. Around 25% of people infected with HCV will clear the virus while for individuals with chronic infection 10 to 20% will develop cirrhosis of the liver within the next 20-40 years. Differences in host genetic factors and viral variants will, in large part, explain the observed heterogeneity in the clinical outcome and course of HCV infection. The basic theory underpinning this research is that the evolution of viruses such as HCV and HIV are influenced by the HLA type of the individual (hots), in combination with the ability of the virus to mutate (rid itself of deleterious mutations) to avoid the host's immune challenge (analogous to drug resistance) even at the lesser cost of impairing viral fitness or replication. We have shown that this is dependent on the immune environment that the virus encounters in relation to which HLA alleles are present in the host, therefore the escape is context specific. After transmission to a new host who lacks the same HLA type, the virus eliminates the previously advantageous mutations which could potentially impair viral fitness. The current study will carry out HCV sequencing and HLA typing on approximately 500 people with HCV from multiple Centres in Australia in order to characterise the interaction between the viral and host genetic factors. A customised software programme, Epipop, has been designed to perform sophisticated statistical analyses on the generated data, and has been successfully applied to HIV vaccine design. The results of this study could help explain why some infected individuals can spontaneously clear their infection while others go on to severe liver disease and allow clinicians to anticipate the course of infection in individuals and plan their management accordingly. Furthermore, the results may facilitate the search for optimal therapeutic and vaccination strategies.Read moreRead less
Characterization Of Neutralizing Antibody Responses In HCV Infected Individuals.
Funder
National Health and Medical Research Council
Funding Amount
$478,076.00
Summary
Hepatitis C virus is a major human pathogen infecting 200 million people world-wide. Currently, there is no vaccine to prevent infection and treatment regimes are only partially effective. IInitial HCV infection is frequently asymptomatic and 30% of people spontaneously clear the virus. The remaining 70% of people develop a life-long chronic infection that causes progressive liver disease, cirrhosis and in some cases liver cancer. The reason why some people are able to clear virus has been attri ....Hepatitis C virus is a major human pathogen infecting 200 million people world-wide. Currently, there is no vaccine to prevent infection and treatment regimes are only partially effective. IInitial HCV infection is frequently asymptomatic and 30% of people spontaneously clear the virus. The remaining 70% of people develop a life-long chronic infection that causes progressive liver disease, cirrhosis and in some cases liver cancer. The reason why some people are able to clear virus has been attributed to the development of a strong cellular immune response and antibody is belived to play a monir role in achieving viral clearance. However, measurememnt of antibody responses in HCV infected pateints is routinely performed using conventional diagnostic tests that do not measure antibody that can help neutralize and clear virus. We have developed an assay that accurately measures the level of NAb in patient sera. We have found that chronically infected patients have broadly reactive neutralizing antibodies but that patients who clear virus, naturally or through treatment do not have broadly reactive neutralizing antibodies. Possibly explaining this phenomenon is that early during infection, antibody is frequently specific only to the infecting virus therefore to detect neutralizing antibodies, homologous viral sequences must be examined. In addition, we have found evidence that HCV can evade neutralzing antibodies through masking of sites to which antibodies bind. We propose to explore whether acutely infected patients develop NAb to autologous viral sequences, and how do these viral sequences and the antibody titre change throughout the course of infection and treatment. We also plan to determine the mechanism of neutralization resistance through the use of mutagenesis of resistant HCV glycoproteins. These studies are aimed at gaining a thorough understanding of the true role of antibody in HCV infection and its influence on viral evolution.Read moreRead less
The Role Of Reduced Phagocytosis In The Pathogenesis Of Age-related Macular Degeneration
Funder
National Health and Medical Research Council
Funding Amount
$786,742.00
Summary
Understanding the underlying mechanisms which lead to age-related macular degeneration (AMD) is critical if we are to ultimately develop novel treatments. We hypothesise that there is a defective ability to remove debris that accumulates in the retina as we age and this is a crucial step in the development of AMD. We will investigate this hypothesis in an AMD cohort and in a pre-clinical model where we will test the efficacy of an intervention that improves the ability to clear debris.
Modifying Epigenetics As A Novel Treatment In COPD
Funder
National Health and Medical Research Council
Funding Amount
$1,122,854.00
Summary
Smoking leads to inflammation that causes emphysema, which is a major health problem. Once induced there is a progressive decline in health, which continues even after stopping smoking. There are no treatments that halt this decline. Recently smoking-induced changes in genes have been discovered that control inflammation. We may be able to reverse these changes and stop the induction and progression of emphysema. This project may lead to a completely new way of preventing and treating emphysema.
Age-and Species-related Regulation Of Host Inflammatory Responses In Falciparum And Vivax Malaria
Funder
National Health and Medical Research Council
Funding Amount
$323,640.00
Summary
Malaria kills 1 million people every year, mostly children. The cause of death from malaria differs between children and adults, yet the reason for these differences is unknown. We have shown that in adults regulatory immune cells contribute to malaria disease complications. We want to test if these cells also worsen malaria disease in children. Understanding age-related differences in immune cell regulation will help to improve malaria treatment and aid development of effective malaria vaccines ....Malaria kills 1 million people every year, mostly children. The cause of death from malaria differs between children and adults, yet the reason for these differences is unknown. We have shown that in adults regulatory immune cells contribute to malaria disease complications. We want to test if these cells also worsen malaria disease in children. Understanding age-related differences in immune cell regulation will help to improve malaria treatment and aid development of effective malaria vaccines for adults and children.Read moreRead less
Induction Of Reactive Oxygen Species By Hepatitis C Virus And Its Role In Liver Pathogenesis.
Funder
National Health and Medical Research Council
Funding Amount
$376,320.00
Summary
The majority of individuals infected with hepatitis C virus (HCV) show a slow progression of liver disease over a period of 20-30 years. There is increased scaring of the liver which can result in liver failure and in some individuals liver cancer. Due to the lack of suitable model systems to study HCV infection and disease progression there is no currently available vaccine and treatment options are limited. While the host defense mechanisms to HCV are relatively well studied the role that vira ....The majority of individuals infected with hepatitis C virus (HCV) show a slow progression of liver disease over a period of 20-30 years. There is increased scaring of the liver which can result in liver failure and in some individuals liver cancer. Due to the lack of suitable model systems to study HCV infection and disease progression there is no currently available vaccine and treatment options are limited. While the host defense mechanisms to HCV are relatively well studied the role that viral proteins and viral replication play in the development of liver disease are not well characterized. Previous experiments in the laboratory have shown that one of the hepatitis C virus proteins results in the formation of toxic oxygen molecules known as a reactive oxygen species. This toxic oxygen molecules can have an effect on liver cells that may enhance the progression of the liver disease process in hepatitis C virus infected individuals. The role that these molecules play in liver cells is unknown but experiments are planned in laboratory model systems and in specimens obtained from hepatitis C virus infected individuals to further examine potential mechanisms. This will hopefully lead to the identification of new treatments for hepatitis C virus liver disease. Some patients with hepatitis C will develop liver cancer, however, all the reasons are not known. Using new technology known as microarray, a consequence of the human genome project, we have been able to look at the expression levels of thousands of genes in liver cancer. Experiments are planned to determine if these genes are important in liver cancer and if they can be used as targets for therapy or to more easily diagnose liver cancer.Read moreRead less
Identification Of Interferon Stimulated Genes That Limit HCV Replication And Predict Therapeutic Outcome
Funder
National Health and Medical Research Council
Funding Amount
$389,224.00
Summary
The only treatment for hepatitis C is Interferon-ribavirin combination therapy. Interferon works by stimulating the liver cells to produce antiviral proteins that can control hepatitis C virus replication, however we do not know which proteins are responsible. The aim of this proposal is to identify those proteins that can limit HCV replication using both a laboratory based and clinical approach and to identify markers that will predict treatment outcome.