Hepatitis B Virus Drug Resistance: Impact On The Immunisation Program
Funder
National Health and Medical Research Council
Funding Amount
$113,322.00
Summary
ñAntiviral drug-associated vaccine escape mutantsî have the potential to jeopardize the hepatitis B immunization program. Which particular viral mutations or combination of mutations that can directly affect the clinical outcome of infection, especially in the context of vaccine induced immunity, are not known. In this study we will identify the clinical sequelae and public health consequences arising from the selection of these mutants.
Determining The Clinical Effectiveness Of Antiviral Drugs Against Oseltamivir- And Laninamivir-resistant Influenza Viruses In Animal Models
Funder
National Health and Medical Research Council
Funding Amount
$388,067.00
Summary
Currently, the neuraminidase inhibitors are the only drugs that are effective against seasonal influenza viruses. However, viruses can develop resistance to these drugs. Using viruses with varied levels of resistance, the project will determine the effectiveness of different drug treatments in animal models. This will lead to better treatment for those patients seriously ill with drug-resistant influenza viruses.
Combining Laboratory And Computational Approaches To Develop Reliable Low Cost HIV Prognostics
Funder
National Health and Medical Research Council
Funding Amount
$314,644.00
Summary
Certain anti-HIV drugs called "CCR5 antagonists" block HIV entry into immune cells. However, HIV drug-resistance can occur. Globally, patient access to CCR5 antagonists has been limited because the pre-treatment laboratory test required to determine HIV drug-resistant is expensive and time-consuming. My research will lead to development of computer programs that reliably, rapidly and cheaply determine HIV drug-resistance and thus greatly improve patient access to CCR5 antagonists worldwide.
Retroviral Recombination, RNA Dimers & Multiple Drug Resistant HIV-1
Funder
National Health and Medical Research Council
Funding Amount
$405,017.00
Summary
The emergence of multiple drug resistant strains of HIV-1 has threatened the continue success of current clinical treatment to suppress virus propagation. Retroviruses, such as HIV-1, can reshuffle its two copies of genetic materials during the viral replication process, which leads to the production of offspring viruses that contain a mixture of the parental genetic materials. This process of genetic information reshuffling is believed to be important for the generation of multiple drug resista ....The emergence of multiple drug resistant strains of HIV-1 has threatened the continue success of current clinical treatment to suppress virus propagation. Retroviruses, such as HIV-1, can reshuffle its two copies of genetic materials during the viral replication process, which leads to the production of offspring viruses that contain a mixture of the parental genetic materials. This process of genetic information reshuffling is believed to be important for the generation of multiple drug resistant strains of HIV-1. The objective of this proposal is to define the parameters that regulate the reshuffling of HIV-1 genetic materials and to design novel tools to inhibit the production of multiple drug resistant HIV-1.Read moreRead less
Drug Resistance Mutations In The Connection Subdomain Of The HIV-1 Reverse Transcriptase
Funder
National Health and Medical Research Council
Funding Amount
$376,710.00
Summary
Human immunodeficiency virus type 1 (HIV-1) infections can be controlled with antiretroviral drugs. In the majority of patients on antiretroviral therapy the virus mutates and is no longer inhibited by the drug. The emergence of drug-resistant HIV-1 is one of the major factors that lead to loss of drug efficacy in patients. Mutations that confer drug resistance have been defined and are specific for different drug classes. Genotype assays that are used to predict drug resistance are routinely us ....Human immunodeficiency virus type 1 (HIV-1) infections can be controlled with antiretroviral drugs. In the majority of patients on antiretroviral therapy the virus mutates and is no longer inhibited by the drug. The emergence of drug-resistant HIV-1 is one of the major factors that lead to loss of drug efficacy in patients. Mutations that confer drug resistance have been defined and are specific for different drug classes. Genotype assays that are used to predict drug resistance are routinely used to guide therapeutic decisions in the treatment of HIV-1 infected individuals. For drugs that target the HIV-1 reverse transcriptase (RT), commonly used genotype kits normally analyse mutations in the first 240 out of 560 amino acids of the reverse transcriptase. This ignores the impact of mutations in other regions of the enzyme, which are potentially important in drug resistance. Recently, mutations that inhibit ribonuclease H function of the HIV-1 RT have been shown to confer high-level resistance to zidovudine, providing the precendent that mutations beyond codon 240 can confer drug resistance. Our analysis of a different region to ribonuclease H called the connection subdomain has demonstrated the presence of mutations that are highly prevalent in drug-treated versus drug naive patients. In this study we will use in vitro assays to define the effect of these mutations on drug resistance and viral fitness . We will also determine the mechanism by which these mutations confer drug resistance. Finally, using our unique database consisting of over 20,000 genotyped samples , we will establish the role of these mutations in the patient. This study is anticipated to identify clinically significant mutations that are present in the RT connection subdomain. Additionally, this study will lead to the development of more accurate genotype assays which will improve the clinical management of HIV infected individuals.Read moreRead less
Silent Mutations In The HIV-1 Reverse Transcriptase Selected During Antiretroviral Therapy
Funder
National Health and Medical Research Council
Funding Amount
$555,325.00
Summary
This project seeks to determine the role of silent mutations in the HIV reverse transcriptase that are selected during drug therapy in HIV infected individuals on HIV fitness, reverse transcriptase function and the emergence of drug resistance. This study will increase our understanding of the mechanisms by which the virus evades the effects of antiretrovirals and will provide a rationale for deciding on the best drug combinations for use in patients infected with specific HIV strains (clades).
Worldwide there are approximately 40 million people living with HIV-AIDS. An effective HIV vaccine does not exist at present. Therefore, current strategies to control the HIV pandemic include the use of life saving antiretroviral drugs. While the current drugs are successful in controlling infections, new and more effective agents are needed that inhibit HIV replication by distinct mechanisms due to the inevitable development of drug resistant strains of HIV. The HIV reverse transcriptase enzyme ....Worldwide there are approximately 40 million people living with HIV-AIDS. An effective HIV vaccine does not exist at present. Therefore, current strategies to control the HIV pandemic include the use of life saving antiretroviral drugs. While the current drugs are successful in controlling infections, new and more effective agents are needed that inhibit HIV replication by distinct mechanisms due to the inevitable development of drug resistant strains of HIV. The HIV reverse transcriptase enzyme is essential for HIV replication and has been a successful target for nucleoside reverse transcriptase inhibitors (NRTIs) and nonnucleoside reverse transcriptase inhibitors (NNRTIs). NNRTIs act in part by stabilizing the reverse transcriptase enzyme, thus blocking enzyme function. However, no drugs have been developed that can specifically prevent formation of the reverse transcriptase enzyme, which would result in the production of noninfectious viral particles. We propose that formation of the active reverse transcriptase enzyme, from a large polyprotein called Gag-Pol, proceeds through a homodimer intermediate, which represents an ideal target for blocking reverse transcriptase formation in HIV infected cells. This homodimer intermediate is an attractive target with greater potential for disruption with small molecule inhibitors compared to the mature reverse transcriptase enzyme as it is less stable than the reverse transcriptase found in viruses. This study will determine whether formation of the active RT enzyme is dependent on this intermediate. In addition, we will examine how the reverse transcriptase encoded on Gag-Pol regulates activation of the HIV protease, which is also critical for the formation of infectious virus particles. These studies will increase our understanding of how the virus produces infectious particles and will identify new approaches for targeting the HIV reverse transcriptase enzyme.Read moreRead less
Inhibitors Of West Nile Virus Protease As Antiviral Drugs
Funder
National Health and Medical Research Council
Funding Amount
$590,740.00
Summary
The West Nile Virus (WNV) was first isolated from a woman in the West Nile region of Uganda in 1937. It is one of ~70 known flaviviruses (e.g. Dengue fever, Yellow fever, West Nile, Kunjun, Japanese encephalitis, St. Louis encephalitis, tick-borne encephalitis, Australian encephalitis and the related hepatitis C virus) which annually infect hundreds of millions of people worldwide, particularly in tropical and sub-tropical areas, and cause major public health problems. WNV is endemic in people i ....The West Nile Virus (WNV) was first isolated from a woman in the West Nile region of Uganda in 1937. It is one of ~70 known flaviviruses (e.g. Dengue fever, Yellow fever, West Nile, Kunjun, Japanese encephalitis, St. Louis encephalitis, tick-borne encephalitis, Australian encephalitis and the related hepatitis C virus) which annually infect hundreds of millions of people worldwide, particularly in tropical and sub-tropical areas, and cause major public health problems. WNV is endemic in people in the Middle East, parts of Africa and Europe, but recent epidemics in Israel (1998), Romania (1996), United States (1999), and UK (2003), that have been traced to migratory birds, were characterized by severe symptoms , severe neurological pathology, and fatalities. In the USA alone there were 4,156 infections and 284 deaths in 2002, 9122 infections and 223 deaths in 2003, and this mosquito borne virus has quickly spread since 1999 through all USA states and into Canada and Mexico (http:--www.cdc.gov-ncidod-dvbid- westnile-index.htm). No treatments or vaccines are available. This project focuses on a viral enzyme, known as the West Nile Virus NS3 protease, that is essential for replication of the virus. By studying the enzyme in the laboratory we can design small molecules that block its function and these are potential leads for developing drug treatments for people infected, not only by this virus but potentially also other flaviviruses. A precedent is the success of inhibitors of HIV-1 protease that are the most effective treatment for humans with HIV-infections, and other viral proteases are now becoming recognized as viable antiviral targets for pharmaceutical development. The project involves experts on small molecule protease inhibitor design and development, proteases, and virology including West Nile virology. We expect to generate new information at the cutting edge of West Nile Virus and flavivirus research and promising new antiviral drug candidates.Read moreRead less
Novel Antivirals For The Treatment Of Hendravirus Infection.
Funder
National Health and Medical Research Council
Funding Amount
$199,227.00
Summary
Hendravirus outbreaks have become frequent and 7 human cases have been reported, this has resulted in 4 deaths. Currently we have no treatment options. Researchers at Griffith University and the CSIRO have developed a new treatment that attacks the virus by turning off the viral genes at the site of infection. The plan is to treat patients soon after infection to slow or stop the virus and allow patients to recover naturally from this highly lethal disease.
Targeting Novel Sites On Reverse Transcriptase For HIV Treatment And Prevention
Funder
National Health and Medical Research Council
Funding Amount
$978,994.00
Summary
HIV/AIDS remains a major global threat with 37 million individuals living with HIV in 2014. Antiretroviral drugs have transformed HIV from a death sentence into a chronic disease. Public health organisations recommend dramatic scale up of drugs for HIV treatment and prevention. However, a major threat is that drug options will be exhausted due to drug resistance and toxicity. The major aim of this study is to undertake fundamental studies to advance the development of a new HIV drug class.