Mucopolysaccharidosis type IIIA (MPS IIIA) is caused by mutations in the N-sulphoglucosamine sulphohydrolase (SGSH) gene, leading to cellular accumulation of heparan sulphate and progressive neurodegeneration in patients. One of the proposed treatment methods is haematopoietic stem cell (HSC) gene therapy, which should result in an excess of SGSH produced in the peripheral organs and brain. The pre-clinical feasibility of this approach was demonstrated by our group in a mouse model of MPS IIIA. However, the overall efficiency of this method was limited and a number of approaches to solving these issues were addressed in this project in order to bring this therapy closer to clinical application. Our first aim was to optimise transduction of HSCs using cytokines, bovine serum albumin (BSA), and chemicals, such as MG132, genistein and valproic acid. Addition of BSA with cytokines improved cell viability, addition of MG132/ BSA/ cytokines improved transduction, but also caused cellular toxicity, while addition of genistein was inefficient. Addition of valproic acid with cytokines resulted in increased number of colony forming units. Next, we generated clinically applicable third generation pCCL lentiviral vector backbones with the eGFP reporter gene driven by one of ubiquitous hPGK or myeloid specific hCD11b and hCD18 internal human promoters, and optimised production of lentiviral vectors to increase titre and reduce production cost. These lentiviral vectors were used to transduce lineage depleted HSCs and transplanted into WT mice. Full chimerism and over 80% transduction were achieved with an average of 5 vector copy numbers/ cell. The hCD11b promoter resulted in the highest eGFP expression in monocytes and B cells in blood, but was weaker than the hPGK in T cells. The hCD18 promoter was more monocyte-specific but weak. Significant numbers of GFP-positive microglial cells were present in the brain from all groups, with an average of 25% transduced CD11b-positive cells in perfused mice. We subsequently codon-optimised (CO) the SGSH gene significantly improving enzyme activity, and transduced lineage depleted WT cells with one of hCD18.SGSH-CO, hCD11b.SGSH-CO, or hPGK.SGSH-CO lentiviral vectors, or MPS IIIA cells with either hCD11b.SGSH-CO or hPGK.SGSH-CO lentiviral vectors. These transduced cells were transplanted into MPS IIIA mice and outcomes were measured 6 months later. Only treatment with the hCD11b.SGSH-CO-LV transduced WT or MPS IIIA HSCs corrected abnormal behaviour of MPS IIIA mice. However, all treatments resulted in complete GAG storage clearance in the periphery and brain, and significantly elevated enzyme activity in the brain, liver and spleen to 7-11%, 60-75%, and 170-250% of WT enzyme activity respectively. A fine threshold of over 8.6% brain enzyme activity appeared to be required for behavioural correction in MPS IIIA mice. Further assessment of treated mice for the amount of secondary storage, HS sulphation patterning, neuroinflammation and longevity are still required for complete therapeutic assessment. However, it appears that neurological correction of the MPS IIIA mouse using MPS IIIA cells is feasible using a clinically-relevant pCCL vector with the hCD11b promoter and the codon-optimised SGSH gene.

Addenda page on inside back cover. Bibliography: leaves 153-176. Mucopolysaccharideosis type IIIA (MPS IIIA, Sanfilippo A syndrome) is an autosomal recessive lysosomal storage disease, with a prevalence in Australia of 1 in 114,000. MPS IIIA is caused by a deficiency of the lysosomal enzyme sulphamidase which is needed together with other exohydrolases and a N-acetyltransferase to break down the glycosaminoglycan heparan sulphate to sulphate and monosaccharides. Patients are characterised by severe central nervous systems degeneration together with mild somatic involvement; this disproportionate correlation is unique amongst the mucopolysaccharidoses. Features include severe behavioural disturbances, such as hyperactivity and aggressiveness, coarse hair and mild hepatosplenomegaly. Death is usually in the mid- to late-teenage years. Enzyme replacement therapy by intravenous administration of recombinant human NS (rhNS) has been proposed as a potential therapy for MPS IIIA. This thesis suggests that rhNS, entering the brain in the first few weeks of life, is able to retard the behaviour and learning difficulties in MPS IIIA mice.

Addenda page on inside back cover. / Bibliography: leaves 153-176. / xiii, 176 leaves ; ill. (some col.) ; 30 cm / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Mucopolysaccharideosis type IIIA (MPS IIIA, Sanfilippo A syndrome) is an autosomal recessive lysosomal storage disease, with a prevalence in Australia of 1 in 114,000. MPS IIIA is caused by a deficiency of the lysosomal enzyme sulphamidase which is needed together with other exohydrolases and a N-acetyltransferase to break down the glycosaminoglycan heparan sulphate to sulphate and monosaccharides. Patients are characterised by severe central nervous systems degeneration together with mild somatic involvement; this disproportionate correlation is unique amongst the mucopolysaccharidoses. Features include severe behavioural disturbances, such as hyperactivity and aggressiveness, coarse hair and mild hepatosplenomegaly. Death is usually in the mid- to late-teenage years. Enzyme replacement therapy by intravenous administration of recombinant human NS (rhNS) has been proposed as a potential therapy for MPS IIIA. This thesis suggests that rhNS, entering the brain in the first few weeks of life, is able to retard the behaviour and learning difficulties in MPS IIIA mice. / Thesis (Ph.D.)--University of Adelaide, Dept. of Paediatrics, 2003

This thesis investigated behaviour and behavioural phenotypes in the Mucopolysaccharide (MPS) disorders. The MPS disorders are a group of rare lysosomal storage disorders which are characterised by a period of normal development followed by gradual cognitive and/or physical decline.Paper 1 describes a systematic review of the extant literature on cognitive, motor, social, linguistic and behavioural presentation in all of the MPS disorders. 25 papers were reviewed and the methodology they employed was assessed. Sleep disturbance was found to be part of the behavioural phenotype of MPS III. In MPS I and II fearfulness and sleep problems occurred in most cases. In MPS II participants with the mild form were found to have relatively normal development and few or no behavioural problems, while those with the severe form had behavioural problems, delayed speech, delayed development and limited motor function. High rates of challenging behaviour, most commonly associated with aggression, hyperactivity, orality, unusual affect and temper tantrums were consistently observed in children with MPS III.Paper 2 describes an empirical study investigating the behavioural phenotype of MPS III, Sanfilippo syndrome. Parents of 20 children with MPS III, 5 adults with MPS III and 25 children with Intellectual Disability (ID) completed questionnaires relating to their son/daughter’s behaviour and adaptive skills. The frequency of challenging behaviours displayed by children aged 2-9 years with MPS III and ID were high but not significantly different. Behaviours associated with hyperactivity, orality, body movements and inattention were seen significantly more frequently in 2-9 year olds with MPS III than ID. The frequency of challenging behaviours displayed by children with MPS III and their adaptive skills was found to decrease with age. Children age 10-15 years with MPS III displayed significantly fewer problem behaviours than children of the same age with ID. It is recommended that parents with a child with MPS III aged 2-9 years are offered clinical services to support them with managing challenging behaviour while those with a child of 10 years or over are offered support with managing health concerns and end of life care.The third Paper, provides an evaluation of the strengths and limitations of the literature review and the empirical study. The findings and clinical implications from both studies are discussed. The process of conducting research into rare, life limiting, genetic syndromes is reflected upon and recommendations for replication and further research are made.

Mucopolysaccharidosis IIIB (MPS IIIB) is an autosomal recessive disorder of glycosaminoglycan (GAG) metabolism. Disruption of the gene encoding a-N-acetylglucosaminidase (Naglu) results in the inability to degrade the GAG heparan sulfate (HS). Consequently. undegraded HS builds up and results in the secondary accumulation of gangliosides and substantial changes in the expression of genes related to neural cell growth and function. Clinically, affected individuals display hyperactivity. insomnia and severe and progressive mental retardation. Currently. no treatment or cure is available for this devastating disorder which is ultimately fatal. Enzyme replacement therapy is one method being examined as an avenue for treatment of MPS IIIB. but it has yet to overcome difficult obstacles, such as production and targeted delivery. This thesis examines the use of the methylotrophic yeast Pichia pastoris as a host for the production of recombinant Naglu. A protein transduction domain (PTD) derived from the HIV-l Tat protein was fused to Naglu to circumvent the current problems faced in delivering this therapeutic enzyme. Expression of this fusion protein was tested in four different strains of Pichia. each with unique attributes. Though the Naglu produced was in an active recombinant form. it was not abundant and this has precluded further characterization. It is likely that inefficiency at the transcriptional/post-transcriptional level hindered higher expression levels. Optimization of these factors may well facilitate Naglu expression in Pichia pastoris. and ultimately allow for substantial enzyme production for use in replacement therapy.

Bibliography: leaves 269-297. / xvii, 297, [10] leaves, [31] leaves of plates : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Evaluates the efficacy of enzyme replacement therapy (ERT) with artifically produced recombinant human 4S (rh4S) in feline mucopolysaccharidosis Type VI (MPS VI) and tests the hypothesis that this form of therapy would reverse or alter the disease course, particularly the bone dysplasia and connective tissue pathologics. / Thesis (Ph.D.)--University of Adelaide, Dept. of Paediatrics, 1998

Thesis (Ph.D.)--University of Adelaide, Dept. of Paediatrics, 1998. / Bibliography: leaves 269-297.

Thesis (Ph.D.) -- University of Adelaide, Dept. of Paediatrics, 1998. / Errata pasted onto back end paper. Bibliography: p. 187-204.

Thesis (Ph.D.)--University of Adelaide, Dept. of Paediatrics, 2001. / Addenda slip inserted in back. Includes bibliographical references (leaves 178-231).

Thesis (Ph.D.)--University of Adelaide, Dept. of Paediatrics, 2003. / Addenda page on inside back cover. Bibliography: leaves 153-176.