Role Of PLZF In Regulating The Interferon Response
Funder
National Health and Medical Research Council
Funding Amount
$531,696.00
Summary
The Interferon (IFN) pathway is essential for immune defense against pathogens in vertebrates. IFNs both protect and alert cells about viral, bacterial, and other immune assaults and promote a cellular antiviral state, reduce proliferation, or induce apoptosis depending on the cell type and environment. Based on these properties, IFNs have been used clinically against a variety of diseases including viral infections, immunomodulatory disorders and hematologic and solid tumors including renal cel ....The Interferon (IFN) pathway is essential for immune defense against pathogens in vertebrates. IFNs both protect and alert cells about viral, bacterial, and other immune assaults and promote a cellular antiviral state, reduce proliferation, or induce apoptosis depending on the cell type and environment. Based on these properties, IFNs have been used clinically against a variety of diseases including viral infections, immunomodulatory disorders and hematologic and solid tumors including renal cell carcinoma. However, the factors determining outcome of IFN treatment, remain to be determined. We have identified a subset of interferon stimulated genes whose sustained expression was found to correlate with heightened antiviral sensitivity of renal cell carcinoma cell lines to IFN. Many of these genes were found to have binding sites for the transcriptional repressor promyleocytic zinc finger protein (PLZF). PLZF was first identified in a subset of Acute Promyelocytic Leukemia patients and is involved in maintenance of erythroid lineage stem cells and spermatogonial stem cells in male mice. PLZF has not previously been implicated in the IFN response. Accordingly, we investigated the expression of interferon stimulated genes and showed that increased expression of immune related genes depends on PLZF expression. PLZF was also found to directly associate with binding sites in promoters of interferon stimulated genes and that this requires histone deacetylation. Thus, we uncovered a novel function for PLZF in enhancement of IFN associated gene expression. We propose to test the hypothesis that PLZF is an essential component of the IFN response. As a corollary, we will also test whether PLZF expression can be linked to IFN responsiveness in renal cell carcinoma. These studies will establish the role of PLZF in the IFN response and define its utility in predicting IFN responsiveness in therapeutic applications.Read moreRead less
Dissecting In Vivo Cellular Responses To Interferons In Pathogen-infected Hosts
Funder
National Health and Medical Research Council
Funding Amount
$479,694.00
Summary
Tuberculosis (TB) is caused by virulent bacterium Mycobacterium tuberculosis and is a leading cause of death worldwide. Mechanisms underlying host resistance to the pathogen are poorly understood. Using a novel reporter mouse, the function of interferons in Mtb infection will be defined in vivo by tracking the cytokine-responsive cells. This will increase our understanding of the effects of these important cytokines in vivo, and could provide new candidate biomarkers for TB diagnosis.
Cellular Activation And Apoptosis In Response To Foreign Cytoplasmic DNA
Funder
National Health and Medical Research Council
Funding Amount
$496,446.00
Summary
Viruses are simple organisms. They grow within cells, needing host cell proteins for their replication. Viruses have only a few proteins of their own, and evolve rapidly to change these. It is therefore challenging for the immune system to identify viral infections. Recently it has been recognised that the genetic material of viruses (DNA or RNA) is detected by the immune system. A novel pathway for recognition of viral double stranded DNA is emerging. The genetic material of mammalian cells (DN ....Viruses are simple organisms. They grow within cells, needing host cell proteins for their replication. Viruses have only a few proteins of their own, and evolve rapidly to change these. It is therefore challenging for the immune system to identify viral infections. Recently it has been recognised that the genetic material of viruses (DNA or RNA) is detected by the immune system. A novel pathway for recognition of viral double stranded DNA is emerging. The genetic material of mammalian cells (DNA) is found within the membrane-bound nucleus of the cell. The presence of DNA outside the nucleus in the cytoplasm is abnormal, and is detected as an indication of viral infection. This causes either death of the cell, or activation to produce anti-viral molecules. We have identified a protein from the cytoplasm of cells which binds specifically to DNA. This protein, X is found in association with foreign DNA within 5 minutes of it being introduced into the cell. In this project we propose to confirm that X recognises foreign DNA and initiates cellular activation or death. Other molecules to which X binds during this process will be identified. This project is relevant to a number of problems in health and disease as well as biotechnology. In both gene therapy and biotechnology, DNA is introduced into cells in order to allow those cells to make specific proteins. The cell sees the introduced DNA as a potential viral infection, and it responds in ways which limit the production of the desired proteins. Lupus is an autoimmune disease with high levels of DNA in circulation. X is proposed as a protein involved lupus in mouse models. We suggest that DNA taken up by cells is recognised by X and this contributes to the disease. Understanding the means by which DNA is recognised in the cytoplasm may allow the development of much more efficient processes for gene therapy and protein production in biotechnology, and more effective lupus and antiviral therapies.Read moreRead less
Investigating Type I Interferon-mediated Immune-suppression During Plasmodium Infection
Funder
National Health and Medical Research Council
Funding Amount
$561,617.00
Summary
Some infections tend to afflict us only once in our lifetimes, for example chickenpox. This is because our bodies develop immunity to these infections relatively easily. The same is not true for malaria. It is thought that our immune systems are somehow suppressed during this disease. This project aims to understand how the immune system is suppressed during malaria infection, in order that we can block this process, and help our bodies fight this disease more effectively.