A Preclinical Model Of Pig Islet Xenotransplantation As Treatment For Type 1 Diabetes
Funder
National Health and Medical Research Council
Funding Amount
$4,380,000.00
Summary
The object of this multi-disciplinary program grant is to develop a source of pig insulin secreting tissue that will be used to treat type 1 diabetic patients. At present the number of diabetic patients that would benefit from islet transplantation far outnumber any human source of this tissue. Pigs that have been genetically altered to avoid rejection and enhance survival could overcome this donor shortage problem.. It is our belief that with the appropriate genetic modification pig insulin-sec ....The object of this multi-disciplinary program grant is to develop a source of pig insulin secreting tissue that will be used to treat type 1 diabetic patients. At present the number of diabetic patients that would benefit from islet transplantation far outnumber any human source of this tissue. Pigs that have been genetically altered to avoid rejection and enhance survival could overcome this donor shortage problem.. It is our belief that with the appropriate genetic modification pig insulin-secreting tissue can avoid the aggressive rejection response that occurs with xenographs and provide normal blood glucose control without insulin. This project concentrates on the five main issues that need to be overcome before pig insulin-secreting tissue can be used in diabetics. These are: identifying the best source of insulin secreting tissue to use; adult islets, newborn or foetal islet cell clusters; overcoming the strong rejection response to pig tissue; identifying a safe and effective immunosuppressive regime; producing a new types of genetically modified pigs that will provide islets tissue that will work in humans; and demonstrating that pig islet transplantation will not pose undue infective risks for the patient or community. This truly collaborative program grant has brought together a large group of investigators with strong research records in diabetes, islet transplantation, xenotransplantation, pig transgenesis and pig genetics and includes scientists and clinicians who look after diabetic patients. Unique pig resources will be used including genetically manipulated pigs that have been shown to avoid some of the rejection mechanisms associated with transplanting pig tissue. There is a captive-bred baboon colony that provided a unique model of diabetes. A world class pig transgenesis facility has been enlisted to generate new lines of genetically altered pigs as new data is produced within the group. Finally because of the involvement of the National Pancreas Transplant Unit any proven therapeutic strategy can be brought quickly to clinical trials.Read moreRead less
This study will examine cellular immunity to the avian H5 influenza in people who have been previously infected with the currently circulating strains of H1 and H3 influenza, or in those who have been recently vaccinated with current influenza vaccines. This will give us an idea if there is any cross reactive immunity that may assist in developing immunity to pandemic strains of avian influenza, or may provide help in making antibody responses sooner to avian influenza vaccines once they are dev ....This study will examine cellular immunity to the avian H5 influenza in people who have been previously infected with the currently circulating strains of H1 and H3 influenza, or in those who have been recently vaccinated with current influenza vaccines. This will give us an idea if there is any cross reactive immunity that may assist in developing immunity to pandemic strains of avian influenza, or may provide help in making antibody responses sooner to avian influenza vaccines once they are developed. We will also establish assays to determine how immunogenic some new avian influenza vaccines are in mice.Read moreRead less
Gamma-ray Inactivated Influenza A Virus Vaccine For Cross-protective T Cell Immunity
Funder
National Health and Medical Research Council
Funding Amount
$239,963.00
Summary
Although there are new antiviral drugs that appear to be effective against influenza virus, the far more costeffective and efficient means to combat an influenza pandemic would be by vaccination. Current influenza vaccines employ virus preparations that are inactivated by chemical treatment. The inactivated vaccines, which function mostly by inducing antibody against the virus, have to be reformulated almost every year to take account of the changing virus because the antibodies recognize the vi ....Although there are new antiviral drugs that appear to be effective against influenza virus, the far more costeffective and efficient means to combat an influenza pandemic would be by vaccination. Current influenza vaccines employ virus preparations that are inactivated by chemical treatment. The inactivated vaccines, which function mostly by inducing antibody against the virus, have to be reformulated almost every year to take account of the changing virus because the antibodies recognize the viral surface which is prone to mutation. Accordingly, in terms of the threatening H5N1 avian influenza pandemic, it is not known if an inactivated vaccine based on the circulating H5N1 strain will be effective if the virus mutates to adapt to efficient growth and spread in the human population. In contrast to the antibody response against influenza virus, the cytotoxic T cell response is broadly crossreactive between heterologous influenza virus strains. Live virus infection efficiently induces cytotoxic T cell immunity which plays an important role in reducing disease severity and mortality following infection with a second, heterologous influenza virus, although infection per se is not prevented. Accordingly, vaccination strategies that elicit cytotoxic T cell memory should be given urgent consideration in the preparation against an influenza pandemic. We have found that the use of gamma-irradiation (in contrast to chemical treatment) for the preparation of inactivated experimental vaccines against influenza and other viruses does not destroy the ability of the vaccines to elicit cytotoxic T cell immunity. The gamma-ray inactivated vaccines conferred protection against lethal challenge with heterologous influenza virus strains in mice. This proposal is aimed at extending this novel finding to avian influenza viruses and to uncover the mechanisms involved in the cytotoxic T cell immunogenicity of gamma-ray inactivated vaccines.Read moreRead less