Kunjin Virus Replicon-based Vaccine Vectors: New Developments And Applications
Funder
National Health and Medical Research Council
Funding Amount
$227,036.00
Summary
The project is aimed towards further development of a unique gene expression and delivery system based on self-replicating RNA (replicon) of the nonvirulent Australian flavivirus Kunjin (KUN). A number of improvements in the design of KUN replicon vectors aimed to increase their efficiency and to optimize them for production of heterologous gene products with desired terminal sequences are proposed. Also proposed are improvements in the current KUN replicon packaging system and development of ne ....The project is aimed towards further development of a unique gene expression and delivery system based on self-replicating RNA (replicon) of the nonvirulent Australian flavivirus Kunjin (KUN). A number of improvements in the design of KUN replicon vectors aimed to increase their efficiency and to optimize them for production of heterologous gene products with desired terminal sequences are proposed. Also proposed are improvements in the current KUN replicon packaging system and development of new packaging systems for production of large amounts of virus-like particles (VLPs) containing KUN replicon RNA enclosed in KUN coat proteins for use as potential vaccines. The vaccine potentials of the curent and newly developed KUN vectors and VLPs will be evaluated in mice using respiratory syncytial virus as a model. An entirely new direction proposed in this application is generation of chimeric fowlpox virus-KUN replicon vectors which will combine the advantages of both systems and may result in the generation of an ultimate vaccine vector.Read moreRead less
Coordinated Cleavages In The Flavivirus Structural Polyprotein: Role In Virus Assembly And Host-pathogen Interaction
Funder
National Health and Medical Research Council
Funding Amount
$285,000.00
Summary
Flaviviruses are important human pathogens responsible for epidemics of hemorrhagic fever or encephalitis, world-wide. This project aims to investigate unique aspects in the biology of the flaviviruses with wider cell biological and immunological implications. First, we propose to test a mechanism important for the efficient assembly of virus particles. An understanding of this stage of the virus life-cycle will benefit research applying recombinant DNA technology in order to produce replication ....Flaviviruses are important human pathogens responsible for epidemics of hemorrhagic fever or encephalitis, world-wide. This project aims to investigate unique aspects in the biology of the flaviviruses with wider cell biological and immunological implications. First, we propose to test a mechanism important for the efficient assembly of virus particles. An understanding of this stage of the virus life-cycle will benefit research applying recombinant DNA technology in order to produce replication-incompetent viruses for use in vaccination and gene delivery. Second, we have recently discovered a mechanism for immune-modulation, so far unique to the flaviviruses, which interferes with the immune response important in the destruction of virus-infected cells. This project aims to identify the viral gene products responsible for this phenomenon.Read moreRead less
Chimeric Virus-like Particles (VLPs) Displaying H1, H3 And H5 Haemagglutinins - Construction And Immunogenicity
Funder
National Health and Medical Research Council
Funding Amount
$207,543.00
Summary
Virus-like particles (VLPs) provoke strong immune responses in the body. We have developed a novel VLP system that allows the production of VLPs containing foreign vaccine antigens of much larger size than previously possible, and have shown that these VLPs provoke strong immune responses in mice without the use of adjuvants. The capacity of these VLPs is large enough to accommodate the most important vaccine antigen of influenza, the haemagglutinin (HA) molecule. We will test whether VLPs can b ....Virus-like particles (VLPs) provoke strong immune responses in the body. We have developed a novel VLP system that allows the production of VLPs containing foreign vaccine antigens of much larger size than previously possible, and have shown that these VLPs provoke strong immune responses in mice without the use of adjuvants. The capacity of these VLPs is large enough to accommodate the most important vaccine antigen of influenza, the haemagglutinin (HA) molecule. We will test whether VLPs can be produced containing each of the three most important HA types _ H1 and H3 that are currently circulating in man, and H5 (avian) that is considered a pandemic threat. VLPs will be tested for their ability to induce neutralizing antibody and cellular immune responses in mice, and for their ability to protect ferrets from influenza infection. If successful, the HA-VLP system would provide a method for the rapid production of new influenza vaccines using large-scale fermentation technology as for hepatitis B and many other vaccines, rather than eggs or cell culture as used for current influenza vaccines.Read moreRead less
Humoral And Neutralising Antibody Responses To Self-adjuvanting Recombinant HCV Virus Like Particles
Funder
National Health and Medical Research Council
Funding Amount
$118,796.00
Summary
Hepatitis C virus (HCV) infects 3% of the world's population and causes an estimated 476,000 deaths per year as a result of HCV associated end-stage liver disease. HCV is one of the most common notifiable infectious diseases in Australia with 16,000 new cases reported annually and a vaccine will reduce the number of new infections. The aim of this project is to develop HCV virus like particles (VLP's) that have the potential for future development of preventative vaccine against HCV.
Development Of Chimeric Hepatitis B Virus Like Particles As A Vaccine Delivery Platform For Multiple HIV-1 Epitopes
Funder
National Health and Medical Research Council
Funding Amount
$139,500.00
Summary
The small envelope protein of hepatitis B virus (HBsAg) can self-assemble into highly organised viruslike particles with about 150 HBsAg-proteins forming a virus-like particle (VLP). VLPs induce an effective immune response, mainly against the exposed major antigenic site, the hydrophilic ‘a’- determinant region. To create a novel HBsAg-specific vaccine vector, foreign epitopes were inserted into the major antigenic site allowing surface orientation of the inserted sequence. Pilot studies involv ....The small envelope protein of hepatitis B virus (HBsAg) can self-assemble into highly organised viruslike particles with about 150 HBsAg-proteins forming a virus-like particle (VLP). VLPs induce an effective immune response, mainly against the exposed major antigenic site, the hydrophilic ‘a’- determinant region. To create a novel HBsAg-specific vaccine vector, foreign epitopes were inserted into the major antigenic site allowing surface orientation of the inserted sequence. Pilot studies involving the vaccination of mice with VLPs containing an epitope derived from the AIDS-virus (human immunodeficiency virus 1, HIV-1) or various hepatitis C virus-specific epitopes resulted in high titre antibody responses. This project aims for the development of a multi-component vaccine targeting a non-structural HIV-1 protein and therefore, avoiding the selective pressure directed against the structural proteins. The non-structural HIV-1 tat-protein is a multi-functional protein with an extracellular mode to sensitise uninfected cells for HIV-1 infection and to reactivate HIV-1 from quiescently infected cells. The use of eight tat-sequences is sufficient to provide coverage against 99% of HIV-1 sequences. We will develop hybrid particles that are composed of different sets of chimeric HBsAg proteins each containing a distinct tat-epitope. With this application, we aim to develop hybrid particles for the delivery of the complete set of tat-epitopes. The hybrid particles will be used for vaccination studies in mice, and the antibodies assessed by an in-vitro assay. This will lead to the development of a therapeutic and-or prophylactic HIV-1 vaccine, which could be used either for mass immunisation or in support of combination drug therapy and would have all the cost and production advantages of the widely used hepatitis B vaccine.Read moreRead less
Intrinsic Host Antiviral Activity Against Pathogenic Filoviruses
Funder
National Health and Medical Research Council
Funding Amount
$488,754.00
Summary
Bats are a major reservoir for deadly human viruses including Ebola and Marburg virus. In contrast to humans, bats can be infected with these viruses without showing clinical signs of disease. The reason why bats can co-exist with these viruses is unknown. This study will determine if a bat antiviral molecule contributes to limiting virus release compared to the human version that could reveal strategies to prevent and control these deadly viruses in humans.
Simplified Process Methods For Mass Vaccine Manufacture
Funder
National Health and Medical Research Council
Funding Amount
$158,393.00
Summary
The ideal way to protect against pandemic bird flu is to vaccinate all Australians as soon as possible after a dangerous strain starts to spread. Current manufacturing technology, which begins by making an infectious virus in chicken eggs, is unable to quickly deliver a mass vaccine to the entire Australian population. The existing process is slow, meaning that it will take several months before enough vaccine is available even to protect personnel working in essential services. The product from ....The ideal way to protect against pandemic bird flu is to vaccinate all Australians as soon as possible after a dangerous strain starts to spread. Current manufacturing technology, which begins by making an infectious virus in chicken eggs, is unable to quickly deliver a mass vaccine to the entire Australian population. The existing process is slow, meaning that it will take several months before enough vaccine is available even to protect personnel working in essential services. The product from chicken eggs is rendered safe after manufacture by breaking the virus structure. This make then break strategy reduces vaccine effectiveness meaning that even fewer individuals can be effectively protected per vaccine batch. Recent scientific progress has demonstrated that it is possible to make a non-infectious empty virus shell (a so-called virus-like particle) inside cells. This new product is able to provide full protection against a lethal influenza challenge, when administered nasally. However, these particles are very difficult to purify from contaminants that are packaged into the particles during manufacture in cells. These contaminants can cause an adverse reaction when the product is given to humans, meaning that although the product is effective it remains difficult to mass produce. A manufacturing problem remains. To overcome this manufacturing problem we will seek to assemble vaccine particles in vitro, building the particle from purified protein. Existing technology for manufacturing pure pharmaceutical protein is well-established and safe, and allows mass manufacture of contaminant-free product. This new make don't break manufacturing strategy is similar to that chosen by Merck to deliver a safe and effective vaccine, for cervical cancer, to mass market. Our key aim is to adapt this efficient manufacturing strategy to the manufacture of influenza vaccine. If successful, we will be able to immunize the Australian population using existing national biomanufacturing capability, within weeks of new strain identification, and without the requirement for high-level containment during manufacture.Read moreRead less
Construction And Immunogenic Evaluation Of Recombinant HBsAg-S Virus-like Particles Containing B And T Cell Epitopes Of
Funder
National Health and Medical Research Council
Funding Amount
$170,000.00
Summary
Helicobacter pylori is a significant human pathogen impacting on the health and well being of not only thousands of Australians, but also millions of people world-wide. However, the task of developing a vaccine against H. pylori remains important. Vaccination is the most effective mechanism to prevent disease associated with this infection, particularly gastric cancer, one of the most common causes of cancer death world-wide. However, current attempts to develop an effective vaccine for humans h ....Helicobacter pylori is a significant human pathogen impacting on the health and well being of not only thousands of Australians, but also millions of people world-wide. However, the task of developing a vaccine against H. pylori remains important. Vaccination is the most effective mechanism to prevent disease associated with this infection, particularly gastric cancer, one of the most common causes of cancer death world-wide. However, current attempts to develop an effective vaccine for humans has been limited by the non-availability of an effective and safe adjuvant. The aim is to construct a recombinant Virus-Like Particle which can be used as a safe and effective vaccine against Helicobacter pylori infections. We specifically aim to: · determine the most efficacious singular or combinatorial route-s of delivery of Virus-Like Particles (VLPs) which will induce the desired Th2 and B cell responses in mice · define the Th2 and B cell epitopes of H.pylori Kat A carboxyl terminus that can be used to construct chimeric HBsAg-S-Kat A VLPs · determine if the induction of desired immunological responses in mice are protective against wild type challengeRead moreRead less