2007 Research Grants The National MPS Society has awarded $508,000 in new grants for 2007. Drs. Biffi, Haskins and Simonaro were awarded the general research grants of $100,000 total. Dr. Fuller was awarded the $90,000 MPS II grant, and Dr. Mellon was awarded the MPS III grant for $80,000. Each grant is for two years, and the researchers will receive half of the total each year. This year we collaborated with two foundations to offer partnership grants. In May, in partnership with the Ryan Foundation, we awarded $19,000 to Drs. Katherine Ponder and Mark Haskins for their work in "Retroviral vector-mediated gene therapy for MPS I". The second partnership grant of $19,000 will be offered in conjunction with ISMRD (International Society for Mannosidosis and Related Diseases). We will report the details of that grant in our next newsletter. Drs. Katherine Ponder and Mark Haskins Partnership Grant with the Ryan Foundation "Retroviral vector-mediated gene therapy for MPS I" Washington University School of Medicine (Dr. Ponder) St. Louis. MO University of Pennsylvania, School of Veterinary Medicine (Dr. Haskins) Philadelphia, PA Mucopolysaccharidosis I (MPS I) is a lysosomal storage disease caused by deficient α-L-iduronidase (IDUA) activity, which results in the accumulation of the glycosaminoglycans heparan and dermatan sulfate. The severe form, known as Hurler syndrome, causes bone and joint abnormalities, pulmonary and cardiac disease, hearing and visual deficiencies, mental retardation, and death around age 5 if untreated. Hematopoietic stem cell transplantation can reduce some manifestations, but has a 15% mortality rate, costs $130,000, and requires a compatible donor. Enzyme replacement therapy can also reduce some symptoms, but costs over $500,000 per year for an adult, requires a weekly infusion, and is not available to all patients. The development of an effective and safe gene therapy for MPS I could have a dramatic positive impact on the lives of patients and the families that care for them. We previously demonstrated that neonatal intravenous injection of a gamma retroviral vector (γ-RV) with an intact long-terminal repeat (LTR) expressing canine IDUA had a truly remarkable effect in both mice and dogs with MPS I, with elimination or reduction in all major clinical manifestations. This was due at least in part to efficient transduction of liver cells, which secreted mannose 6-phosphate (M6P)-modified IDUA into blood, which diffused to other organs and was taken up via the M6P receptor. There was also some transduction of blood cells and an undefined cell type in brain, which may have contributed to the therapeutic response. Although no tumors developed in mice or dogs with this approach, the risk of insertional mutagenesis with an LTR-intact vector is a concern. Another problem is that administration of this vector to adult MPS I mice or newborn MPS I cats resulted in a potent cytotoxic T lymphocyte (CTL) response that destroyed transduced cells. The aims of this project are to: 1) reduce the risk of insertional mutagenesis by developing a self-inactivating γ-RV with a deletion in the enhancer of the 3' LTR; 2) attempt to prevent an immune response by avoiding expression in antigen-presenting cells; and 3) analyze the duration of efficacy and evaluate for toxicity in a long-lived large animal model (dog). If successful, this study may hasten the development of a simple and effective treatment for newborn patients that will reduce or prevent the devastating clinical manifestations of MPS I. Dr. Alessandra Biffi "Novel efficacious and safe gene therapy approaches for the treatment of MPS I" San Raffaele Telethon Institute for Gene Therapy (HSR-TIGET) Milano, Italy Type I Mucopolysaccharidoses (MPSI) is a lysosomal storage disorder (LSD) due to the inherited deficiency of a-L-iduronidase (IDUA) and the resulting accumulation of its toxic substrates in many organs. Among MPSI clinical variants, the Hurler syndrome is fatal in childhood, and represents the form with the higher need for the development of new efficacious therapies, capable of alleviating all disease-related symptoms. Indeed, despite several experimental therapies have been tested both in MPSI animal models and in patients, no efficacious treatment is currently available for the cure of Hurler syndrome. This lack of efficacy is likely due to the difficulty of providing sufficient amount of the functional IDUA to all disease sites, including the brain, in the absence of toxicity. Therefore, the main goal of the project is the identification of a novel gene therapy strategy capable of efficiently deliver therapeutic levels of functional IDUA enzyme to all disease sites of MPS I mice, and of correcting disease manifestations, in the absence of toxicity. To this goal, based on our expertise in other LSD models, we will compare two gene therapy protocols based on advanced generation viral vectors, which might over-come the major limitations of currently available therapies. This work will allow us to identify and further develop towards clinical application the most promising and efficacious gene therapy strategy for the treatment of MPSI. Dr. Mark Haskins "Lentiviral Vector Therapy for Canine MPS VII" University of Pennsylvania, School of Veterinary Medicine Philadelphia, PA Based upon experiments in mice, a clinical trial has been approved for our collaborator, Mark Sands, PhD, to use a lentiviral vector containing the human gene for the enzyme that is deficient in mucopolysaccharidosis VII to treat bone marrow cells in culture and then return them to the children with MPS VII. Currently, the clinical trial is on hold while Dr. Sands collects more safety data for the FDA. We have a well-characterized dog model of MPS VII and believe it is essential to test the safety and efficacy of this therapy in MPS VII dogs prior to its use in children. We also have successfully treated MPS VII dogs intravenously with a retrovirus vector at three days of age dramatically improving the skeletal, ocular, and cardiac lesions. Five treated dogs are currently more than 6 years post-treatment and are being maintained to evaluate possible long-term side effects of therapy, together with four dogs treated by intravenous, neonatal adeno-associated virus vector gene therapy. Dr. Calogera Simonaro "Pathogenesis and Treatment of the Mucopolysaccharidoses" Mount Sinai School of Medicine New York, NY The past decade has witnessed remarkable advances in the understanding and treatment of the MPS. However, despite these advances, major challenges remain. For example, although enzyme replacement therapy (ERT) has recently become available for several of these disorders, it is extremely expensive and requires life-long infusions of recombinant enzyme. ERT also has very limited effects on the bones and joints, major sites of disease in MPS patients. Our laboratory has been using MPS VI animal models to study the mechanism of disease in bones and joints, as well as to evaluate new approaches to treatment. This research has led to a better understanding of the specific changes that occur in these tissues, facilitating the future design of more effective therapies. In the current proposal we will extend these findings and pursue three aims. In the first we will continue to investigate the mechanism by which GAG storage leads to bone and cartilage destruction using cells from MPS VI rats. In the second we will obtain fluid from the joints of MPS VI cats, and measure the levels of several proteins to see if they are abnormally expressed. We will determine the level of these proteins as a function of age, and evaluate whether they can be used to predict the severity of disease and/or the outcome of treatment in the bones and joints (i.e., biomarkers). In the last aim we will use MPS VI rats to evaluate the effects of two clinically available "anti-inflammatory" medications on the progression of disease, as well as one experimental medication that targets a pathway we have found abnormal in MPS VI cells. If we obtain evidence in the rats that such therapies are effective, in the future these approaches could be evaluated in MPS patients, alone or as adjuncts to ERT. Dr. Maria Fuller "Membrane microdomains and improved clinical management for the mucopolysaccharidosis" Children, Youth and Women’s Health Service North Adelaide, SA, Australia The mucopolysaccharidoses (MPS) are chronic progressive genetic diseases that generally affect young children. Symptoms are debilitating and progressive, and include heart and breathing difficulties, skeletal deformity and brain degeneration. The MPS result from the progressive storage of waste in a component of each cell known as the lysosome. In affected children, the accumulation of this waste interferes with each cell’s normal functioning and leads to the deterioration and death of cells, organs and tissues. There are no cures for MPS and current treatment options are not without their limitations. Although the underlying genetic defects have been determined for many MPS, the disease process remains poorly understood. The diverse array of clinical symptoms in MPS suggests that many cellular processes are altered. A major one is likely to be the fat composition and distribution in cells. Fats have been shown to be altered in the MPS and this project proposes to examine the types of fats that are altered and their location in the cell. Once we understand the changes in fats, we will attempt to correct these changes using conventional drugs and fatty acid manipulation. Successful studies performed in cells in this project will pave the way for further studies in animal models to see if the pathology in MPS can be treated with diet and drugs. Dr. Synthia Mellon "Neurosteroid treatment of MPS IIIA" University of California, San Francisco Department of Obstetrics, Gynecology & Reproductive Sciences San Francisco, CA We have identified a potential treatment for a lysosomal storage disorder that involves a class of biological compounds called neurosteroids. These compounds are synthesized in the brain in a developmentally programmed fashion. Among their many effects, they have effects on development of new neurons, survival of neurons, protection against toxicity to neurons. We showed that treatment of a mouse model of the lysosomal storage disorder Niemann Pick Type C (NP-C) with the neurosteroid allopregnanolone doubles lifespan, delays loss of motor function, and rescues neurons that die in NP-C. We now have preliminary data in MPS IIIA mice that a similar treatment with allopregnanolone will enhance lifespan, delay loss of motor function, increase muscle strength, and reduce aggressive behavior. We now propose to expand these studies to include more mice to assess the effect of allopregnanolone treatment on MPS IIIA 1. longevity 2. locomotor function 3. neuronal survival 4. neuronal storage and 5. begin to assess peripheral markers of disease progression and effective allopregnanolone treatment. Successful completion of these aims should provide preliminary data for submission of a larger grant to the NIH.