research

cell & gene therapy

summary

We are investigating possible ways of treating genetic disorders. One method involves gene therapy - introducing 'healthy' copies of genes into a patient's cells. This concept has proved harder to implement than previously thought. For example, the large size of most human genes has necessitated the use of 'stripped-down' versions of these genes. However, minimising the amount of genetic material used can exclude stretches of DNA that would normally control the gene's function.

Safer and more efficient ways of delivering these 'replacement' genes directly to their target cells need to be devised. Research is also required on how to keep the inserted DNA intact and retain its normal functions in the cell. We are very aware of the serious concerns about the safety and effectiveness of gene therapy, and are committed to addressing these issues.

We are also investigating treatments based on cell therapy, and the use of drugs to modify gene expression. In many genetic illnesses, it may even be possible to alter other genes pharmacologically so as to overcome the disease.

group leader(s)

AJA_6579 Dr Jim Vadolas
Cell & Gene Therapy
Murdoch Childrens Research Institute
Royal Children's Hospital
Flemington Road
Parkville Victoria 3052
Australia

T +61 3 8341 6232 (Office)
T +61 3 8341 6236 (Lab)
F +61 3 9348 1391
E jim.vadolas@mcri.edu.au

Group Leader Biography

Dr Jim Vadolas completed his PhD at the Departments of Microbiology and Immunology, University of Melbourne, and postdoctoral training at the Murdoch Childrens Research Institute with Panos Ioannou and Bob Williamson. In 2005, Jim became group leader of the Cell and Gene Therapy group at the MCRI.  He is primarily interested in the development of new therapeutic strategies for thalassaemia and related haemoglobinopathies. His work has led the establishment of several new model systems that can be used to identify and evaluate potential therapies. He is currently an Executive Committee member of the Australasian Gene Therapy Society. Jim is also an Executive Committee Member of Thalassaemia Australia.

current research projects

Project 1: Development of RNAi therapy for thalassaemia

β-Thalassaemia is an inherited disease caused by defective synthesis of the β-globin chain of haemoglobin, leading to imbalanced globin chains. Excess α-chains precipitate in erythroid progenitor cells resulting in cell death, ineffective erythropoiesis and severe anaemia. Decreased α-globin chain synthesis leads to milder symptoms, exemplified by individuals who co-inherit α-thalassaemia and β-thalassaemia. Therefore, a possible therapeutic strategy in the treatment of β-thalassaemia could include targeted reduction of α-globin chains to mimic co-inheritance of α/β-thalassaemia. One way of reducing α-chain synthesis is by using RNA interfering (RNAi). Numerous studies have shown promising results utilising RNAi in vitro and in vivo. This study will investigate the use of RNAi-mediated reduction of α-globin chains for the therapy for β-thalassaemia.

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Project 2: Novel cell and gene therapy approaches for genetic disorders

Effective therapy of genetic diseases still faces major obstacles in terms of long-term efficacy and safety. Our group is developing novel therapies using intact functional loci. One strategy involves the compaction of the therapeutic gene(s) and targeting their uptake into the nuclei of transfected cells. Fluorescence in situ hybridisation and reporter gene expression, are being used to determine the optimum conditions for delivering intact functional loci into haemopoietic, stem cells. Large genomic fragments may be maintained either as free episomes or as artificial minichromosomes, or may be integrated into specific chromosomal regions. The delivery of intact genetic loci into patient stem cells may eventually enable the combination of cell and gene therapy approaches for the effective therapy of various diseases.

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Project 3: Development and evaluation of novel fetal haemoglobin inducers for the therapy of β-thalassaemia and sickle cell anaemia

The most important haemoglobinopathies from the clinical point of view are the β-thalassaemias, sickle cell disease (SCD) and HbE disease and the interactions between them. These haemoglobinopathies are the result of mutations in the β-globin gene, causing β-globin chain synthesis that is abnormal, very low or absent leading to life-threatening severe anaemia, and blood transfusion-dependency for life. An alternative approach to the therapy of β-thalassemia is to reactivate fetal haemoglobin (HbF) synthesis. Our research group has launched a focused research effort to discover new approaches for screening of HbF inducers. We recently created an cellular assay that has allowed us for the first time to perform a side-by-side comparison of several previously described fetal haemoglobin inducers including existing pharmaceuticals used by patients unrelated to thalassaemia. This project will evaluate recently discovered novel inducers of fetal haemoglobin in our β-thalassemia mouse models and should provide early 'proof-of-concept' and enable the initiation of preclinical and clinical studies.

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Project 4: Understanding the molecular mechanisms leading to reactivation or derepression of γ-globin gene

Haemoglobin disorders, such as sickle cell disease and β-thalassaemia are the result of mutations in the adult β-globin gene. When these disorders are co-inherited with hereditary persistence of fetal haemoglobin (high levels of γ-globin gene expression in adult life), the clinical severity of disease is much reduced. Therefore, understanding the molecular events involved in γ-globin gene regulation through development has been the subject of intense investigation for many years. These studies have led to a greater understanding of the role of epigenetics in globin gene expression. As a result, considerable efforts have been focused on the pharmacological induction of fetal haemoglobin using epigenetic-specific agents capable of modifying DNA methylation and histone acetylation. This study will investigate the impact of epigenetics on γ-globin gene silencing. Positive outcomes of such studies may pave the way for the development of better treatment strategies for sickle cell anaemia and β-thalassaemia patients. 

team members

  • Orane Delagneau - Honours Student (UoM Path)
  • Betty Kao - PhD Student (UoM Paeds)
  • Tejal Kulkarni - PhD Student (UoM Paeds)
  • Bradley Mccoll - Research Officer
  • Thian Ng - Honours Student (UoM Micro&Immun)
  • Joe Sarsero - Research Fellow

publications

  • Holloway TP., Rowley SM., Delatycki MB., Sarsero JP. Detection of interruptions in the GAA trinucleotide repeat expansion in the FXN gene of Friedreich ataxia. BIOTECHNIQUES 50 (3) : 182 (2011) PubMed
  • Puspasari N., Rowley SM., Gordon L., Lockhart PJ., Ioannou PA., Delatycki MB., Sarsero JP. Long Range Regulation of Human FXN Gene Expression. PLOS ONE 6 (7) (2011) PubMed

competitive funding

 

  • 2007-2008 NHMRC Development Grant ID 436938 - Novel fetal hemoglobin inducers for the therapy of β-thalassaemia - Jim Vadolas - $280,375.
  • 2011-2012 NHMRC Project Grant ID 1009989 - Site-specific integration of functional genomic loci: Applications in gene therapy - Jim Vadolas & Richard Wade-Martins - $430,000.
  • 2012-2014 NHMRC Project Grant ID 1032871 - Development of RNAi therapy for β-thalassaemia - Jim Vadolas, Suthat Fucharoen & Saovaros Svasti - $588,000.
  • 2012-2013 NHMRC Development Grant ID1039474 - Development of new gene therapy vectors for β-thalassaemia - Jim Vadolas & Philippe Leboulch - $279,000.

collaborations & affiliations

  • Dr. Richard Wade-Martins, Department of Physiology, Anatomy and Genetics, University of Oxford, UK.
  • Prof. S. Fucharoen and Dr Saovaros Svasti. Institute of Molecular Biosciences, Thalassaemia Research Centre, Mahidol University, Thailand.
  • Prof Don Bowden, Medical Therapy Unit, Monash Medical Centre, Clayton, Melbourne, Australia.
  • Prof. Stuart Orkin and Dr Jian Xu, Harvard Medical School, Children's Hospital Boston, USA.
  • Prof Philippe Leboulch. INSERM, University of Paris, France.
  • Dr Marina Kleanthous and Dr Carsten Lederer, The Cyprus Institute of Neurology and Genetics, Department of Molecular Genetics of Thalassaemia Nicosia, Cyprus.
  • Dr Marnie Blewitt. Walter and Eliza Hall Institute, Melbourne, Australia.
  • Dr Odilia Wijburg, Department of Immunology and Microbiology, University of Melbourne, Australia.
  • Dr Chee Kai Chan and Dr Adam Hart, Latrobe University, Melbourne, Australia.