Fc Alpha RI: Ligand Interaction And Membrane Organisation.
Funder
National Health and Medical Research Council
Funding Amount
$497,640.00
Summary
Antibodies tag invading viruses or bacteria thus marking them as foreign and targeting them for destruction by the immune system. In man the most prevelant antibody is IgA and this antibody provides protection from infecton in the blood and in the fluids at the surface of the lungs, gut and urinogenital tract. Once tagged by antibody the invading bacteria or antigen can be recogniseed white blood cells. These workhorses of the immune system use special molecules called Fc receptors on their surf ....Antibodies tag invading viruses or bacteria thus marking them as foreign and targeting them for destruction by the immune system. In man the most prevelant antibody is IgA and this antibody provides protection from infecton in the blood and in the fluids at the surface of the lungs, gut and urinogenital tract. Once tagged by antibody the invading bacteria or antigen can be recogniseed white blood cells. These workhorses of the immune system use special molecules called Fc receptors on their surface to recognise antibody tags. The receptor for IgA tags is called the Fc alpha receptor. This receptor is essential for the normal IgA-mediated protection against infection. However in a common kidney disease IgA tags accumulate in the glomerulus of the kidney stimulating white blood cells to attack and damage the kidney. This study will explain how the Fc alpha receptor recognises IgA antibody tags. It will investigate how the presentation of different forms of the receptor and different types of IgA antibody tags contributes to immunity to infection. For example one form of the receptor has a fat molecule joined to its end. We believe this may affect where the Fc alpha recptor goes to in the white blood cell membrane and whether it can activate the white blood cell to fight the invading microorganism.Read moreRead less
Oxidised Mannan As A Novel Adjuvant To Vaccinate Against Mucosal Infections
Funder
National Health and Medical Research Council
Funding Amount
$150,000.00
Summary
Most pathogens invade via the mucosal surfaces. However, current vaccines, which are delivered by injection, are poor at inducing mucosal immunity. An ideal vaccine would comprise a defined protein antigen combined with a suitable adjuvant which could be administered intranasally or orally. Protective antigens have been defined for a number of infections but suitable adjuvants have been elusive. We showed that mannan, a complex carbohydrate from yeast, oxidatively linked to protein antigens can ....Most pathogens invade via the mucosal surfaces. However, current vaccines, which are delivered by injection, are poor at inducing mucosal immunity. An ideal vaccine would comprise a defined protein antigen combined with a suitable adjuvant which could be administered intranasally or orally. Protective antigens have been defined for a number of infections but suitable adjuvants have been elusive. We showed that mannan, a complex carbohydrate from yeast, oxidatively linked to protein antigens can be used as an adjuvant for mucosal IgA and other classes of antibody. Given to mice intranasally, antigen coupled to mannan markedly enhanced production of IgA, IgG1 and IgG2a in serum, and IgA in lung, tears, vaginal secretions, saliva and gut. We have confirmed this for a number of known or putative protective antigens. In addition, both the Th1 and Th2 arms of the lymphocyte response were activated. We have demonstrated protection against P. gingivalis (cause of periodontitis and associated with premature birth and cardiovascular disease) in a mouse lesion model. However, before commercial interests will commit themselves, we need to demonstrate protection against viral infections and in other sites like lungs and gut. Three infection models where IgA has been shown to protect are already set up and can realistically produce results in 1 year. 1. Rotavirus is the major cause of severe infantile gastroenteritis in humans and animals world wide. The latest (live) vaccine was withdrawn because of side effects. We have established a model with Simian rotavirus causing an acute self-limiting disease in infant mice. Adult females will be immunised with mannan linked to killed virus preparations, mated and passive protection of their offspring will be assessed. Preliminary evidence links rotavirus infection with the onset of type 1 diabetes. If this is confirmed, there will be an opportunity to test the vaccine against diabetes. 2. Influenza: IN infection of mice with flu virus is a well established model. Mice will be immunised IN with mannan coupled to haemagglutinin-neuraminidase purified from egg-grown virus. They will be challenged IN with influenza virus and virus titrated in lung homogenates. Neutralising antibody in serum and lung washings will essayed. 3. Respiratory syncytial virus: RSV is the commonest cause of bronchiolitis and pneumonia in infants for which there have been unsuccessful attempts to produce a vaccine. F and G membrane glycoproteins have been shown to protect mice against IN infection, and they will be used coupled to mannan to vaccinate mice against intranasal challenge.Read moreRead less
Development Of A Vaccine For Genital Chlamydial Infection
Funder
National Health and Medical Research Council
Funding Amount
$207,551.00
Summary
Genital Chlamydia infections are the most common sexually transmitted infection in Australia with annual health costs of 90-160 million dollars. Infection rates in 15-29 olds are increasing at 15-20% per year. Antibiotics are currently the treatment of choice, however antibiotic resistance is increasing and most infections are asymptomatic and not treated in the absence of screening programs. This project aims to develop a genital Chlamydia vaccine using a combination of novel antigens.
The Role Of Apoptosis In Pathogenesis And Immunology Of Salmonella Infections
Funder
National Health and Medical Research Council
Funding Amount
$276,988.00
Summary
Salmonellae are important human pathogens in developed and developing countries. The most severe salmonella disease, typhoid fever, is becoming more difficult to treat because of increasing antibiotic resistance. In addition, current vaccines only provide short-term protection. The studies in this proposal are designed to answer important questions about immunity against typhoid fever, including how this immunity is provoked, and the direct and indirect causes of pathology in the disease. The fo ....Salmonellae are important human pathogens in developed and developing countries. The most severe salmonella disease, typhoid fever, is becoming more difficult to treat because of increasing antibiotic resistance. In addition, current vaccines only provide short-term protection. The studies in this proposal are designed to answer important questions about immunity against typhoid fever, including how this immunity is provoked, and the direct and indirect causes of pathology in the disease. The focus of this project is the induction of host cell apoptosis, an important virulence mechanism shared by many bacteria and viruses. The research will have direct application to human typhoid and may lead to novel therapies and improved vaccines for typhoid fever.Read moreRead less
Structural Investigations Of Bacterial Evasion Of IgA Mucosal And Systemic Immunity
Funder
National Health and Medical Research Council
Funding Amount
$488,812.00
Summary
Nose, throat and skin infections are often caused by streptococcal and staphylococcal bacteria, known as Strep Throat and Golden Staph. Infections can be life-threatening in newborns, the elderly or individuals with weak immune systems. These bacteria make proteins bind and inactivate immune proteins. Our research examines the structural basis for bacterial interactions with a key immune system protein (an antibody called IgA) and may lead to new prevention and treatment strategies.
Towards A Chlamydia Vaccine For Males: The Key Role Of Mucosal IgA
Funder
National Health and Medical Research Council
Funding Amount
$418,978.00
Summary
Genital Chlamydia infections are the most common sexually transmitted infection in Australia with annual health costs of 90-160 million dollars. Infection rates in 15-29 olds are increasing at 15-20% per year in both females and males. Antibiotics are currently the treatment of choice, however antibiotic resistance is increasing and most infections are asymptomatic and not treated in the absence of screening programs. This project aims to develop a Chlamydia vaccine tailored to protect males .
The Role Of Novel G-Protein Coupled Receptors In Immunity And Inflammatory Diseases
Funder
National Health and Medical Research Council
Funding Amount
$69,684.00
Summary
Recent advances in molecular biology techniques have resulted in the identification of many novel GPCRs. Novel GPCRs expressed selectively on immune cells display a potential target for novel therapies for inflammatory diseases such as Asthma and Rheumatoid arthritis. This project aims to define the activity and significance of a novel group of GPCRs, the GPR40 family. Outcomes of this project will be further understanding of immune cell development and inflammatory disease development.
The Effect Of Innate Immune Responses On The Induction Of Protective Immunity In Murine Typhoid Fever
Funder
National Health and Medical Research Council
Funding Amount
$136,500.00
Summary
Salmonella are important pathogens of humans causing diseases ranging from gastroenteritis, typhoid fever to arthritis. Like most if not all infections, the early interaction between the host and the bacterium is characterised by very non-specific symptoms. These non-specific symptoms arise because the so-called innate immune system is activated by the infection. The purpose of this grant is to establish whether these non-specific symptoms, caused by the release of immunological homrones called ....Salmonella are important pathogens of humans causing diseases ranging from gastroenteritis, typhoid fever to arthritis. Like most if not all infections, the early interaction between the host and the bacterium is characterised by very non-specific symptoms. These non-specific symptoms arise because the so-called innate immune system is activated by the infection. The purpose of this grant is to establish whether these non-specific symptoms, caused by the release of immunological homrones called cytokines, are essential to the development of an effective immune response which can protect against subsequent re-infection. This study has important implications for vaccines, of our understanding of how bacteria cause disease, and the role-capacity of the innate immune system in the development of immunity.Read moreRead less
Defining The Mechanisms That Regulate Effective Long-term Anti-viral Immunity
Funder
National Health and Medical Research Council
Funding Amount
$547,315.00
Summary
Human cytomegalovirus (HCMV) is a common human pathogen which normally causes a mild or even asymptomatic infection. However, in immunocompromised individuals, HCMV causes severe disease whose manifestations include chorioretinitis, interstitial pneumonia and hepatitis. Similarly, in neonates lacking a fully mature immune system, HCMV causes severe morbidity. Vaccines that protect against HCMV induced cytomegalic inclusion disease have been designated Level I (most favourable) due to the predict ....Human cytomegalovirus (HCMV) is a common human pathogen which normally causes a mild or even asymptomatic infection. However, in immunocompromised individuals, HCMV causes severe disease whose manifestations include chorioretinitis, interstitial pneumonia and hepatitis. Similarly, in neonates lacking a fully mature immune system, HCMV causes severe morbidity. Vaccines that protect against HCMV induced cytomegalic inclusion disease have been designated Level I (most favourable) due to the prediction that they could save lives and prevent life-long disability. Similarly, therapies that prevent and-or reduce HCMV reactivation will significantly improve the prognosis of transplant and AIDS patients. The murine CMV (MCMV) infection model has provided important insights as to how the immune system controls infection, and the mechanisms utilized by the virus to circumvent these processes. The design of effective therapies and vaccines requires a thorough understanding of the mechanisms required to generate and maintain long-lasting anti-viral responses. The studies outlined in this proposal aim to define the impact of specific components of the immune system n the generation, maintenance and effectiveness of anti-viral immunity. The well characterized MCMV model will be used to address these issues.Read moreRead less
The Role Of Fractalkine In Leukocyte Recruitment In The Periphery
Funder
National Health and Medical Research Council
Funding Amount
$215,196.00
Summary
This research will determine whether a new type of gene plays an important role in inflammation in tissues in the periphery. If it does, we will design strategies to inhibit its function, thereby controlling its effects in inflammation. Such treatment may be useful for diseases such as rheumatoid arthritis, diabetes as well as allergies.