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Principal Investigator: Matthew Shtrahman
Organization: UNIVERSITY OF CALIFORNIA, SAN DIEGO
Fiscal Year: 2024
Award: $416,198
Funding agency: National Institute of Neurological Disorders and Stroke
PROJECT SUMMARY
Medicine is currently undergoing a revolution, where viable gene therapies are being developed for
multiple disorders, including diseases of the central nervous system (CNS). One of the obstacles that limits the
use of gene therapy is the availability of safe and effective vectors for widespread delivery of genes. Due to its
stable transgene expression, broad tropism, and modest immunogenicity, recombinant adeno-associated virus
(rAAV) is the most widely used viral vector for human gene therapy. Almost 200 rAAV therapies have been
completed or are currently in clinical trials, including two FDA-approved therapies for genetic diseases of the
CNS. However, evidence is mounting that rAAV-based gene therapies are not without toxicity or significant risk,
with several rAAV-related deaths and numerous adverse outcomes reported during the past three years alone.
In a recent trial for Sanfilippo syndrome, 1 patient died and others demonstrated concerning MRI changes at
rAAV injection sites within the brain, halting the study. Other rAAV trials have reported serious adverse effects
ranging from thrombocytopenia to acute kidney failure to cardio-pulmonary insufficiency. While some of these
adverse effects are thought to be caused by immune reactions to the AAV capsid or transgene, increasing
evidence indicates that the rAAV genome, which contains two 145-base pair DNA segments named inverted
terminal repeats (ITRs), is a major source of rAAV toxicity.
While conducting fundamental experiments on learning and memory, we discovered that rAAV was toxic
to dividing neural progenitor cells (NPCs) and immature neurons, completely ablating adult neurogenesis in the
mouse hippocampus. Consistent with previous work, these experiments indicate that the AAV ITRs appear to
be sufficient and necessary for this toxicity. Embarking on a new research direction, we will utilize our
complimentary expertise in neuroscience, stem cell biology, and engineering to develop new methods for rAAV
production and create the first rAAVs with engineered ITRs that are safer for human gene therapy. These new
therapies will be particularly important in the treatment of neurodevelopmental and other diseases in children
who have active proliferation of stem/progenitor cells, which are exquisitely sensitive to rAAV toxicity. In the
current proposal we aim to:
Aim 1. Determine which components of the ITR DNA sequence are required for toxicity in NPCs in vivo.
Aim 2. Develop a cell-free synthetic rAAVs capable of packaging genomes with mutant ITRs.
Aim 3. Engineer an rAAV that will rescue loss of function in a murine model of Rett syndrome while
demonstrating less toxicity than conventional rAAVs.
Terms: <0-11 years old><Ablation><Acute Kidney Failure><Acute Kidney Insufficiency><Acute Renal Failure><Acute Renal Insufficiency><Adeno-Associated Viruses><Adverse effects><Ammon Horn><Attenuated><Base Pairing><Brain><Brain Nervous System><C9ALS/FTD><CNS Diseases><CNS disorder><Capsid><Cardiopulmonary><Cell Body><Cell Death><Cells><Central Nervous System Diseases><Central Nervous System Disorders><Cerebroatrophic Hyperammonemia><Cessation of life><Child><Child Youth><Children (0-21)><Clinical Trials><Cornu Ammonis><DNA><DNA Damage><DNA Injury><DNA Sequence><DNA Therapy><Death><Deoxyribonucleic Acid><Dependoparvovirus><Dependovirus><Disease><Disorder><Dysfunction><Electroporation><Embryo><Embryonic><Encephalon><Engineering><FDA approved><Flanking Repeat Sequences><Functional disorder><Gene Delivery><Gene Transfer Clinical><Genes><Genetic Alteration><Genetic Change><Genetic Diseases><Genetic Intervention><Genetic defect><Genome><HS-mucopolysaccharidosis><Hippocampus><Histology><Human><Immune reaction><Injections><Inverted Terminal Repeat><Learning><Learning Disabilities><Learning disability><MPS III><MR Imaging><MR Tomography><MRI><MRIs><Magnetic Resonance Imaging><MeCP-2 protein><MeCP2><MeCP2 protein><Mediating><Medical Imaging, Magnetic Resonance / Nuclear Magnetic Resonance><Medicine><Memory><Methods><Methyl CpG Binding Protein 2><Methyl CpG binding protein MeCP2><Methyl-CpG binding protein 2><Methyl-CpG-Binding Protein 2><Methyl-DNA binding protein MECP2><Mice><Mice Mammals><MoMuSV 124 variant R7><Modern Man><Mucopolysaccharidosis 3><Mucopolysaccharidosis III><Murine><Mus><Mutation><NMR Imaging><NMR Tomography><Names><Nerve Cells><Nerve Unit><Neural Cell><Neural Stem Cell><Neurocyte><Neurons><Neurosciences><Non-Polyadenylated RNA><Nuclear Magnetic Resonance Imaging><Nucleotides><Pathologic><Patients><Physiopathology><Polydystrophic Oligophrenia><Production><Proteins><Publishing><R7 Virus><RNA><RNA Gene Products><Recombinant 7><Recombinant adeno-associated virus><Recombinant adeno-associated virus (rAAV)><Recombinants><Reporting><Research><Rett Disorder><Rett Syndrome><Ribonucleic Acid><Risk><San Filippo's Syndrome><Sanfilippo syndrome (A, B, C, D)><Sanfilippo's Syndrome><Sanfilippos Syndrome><Single-Stranded DNA><Site><Source><Structure><Symptoms><Terminal Repeat><Terminal Repeat Sequences><Testing><Therapeutic><Thrombocytopenia><Thrombopenia><Toxic effect><Toxicities><Transgenes><Tropism><Viral><Viral Genome><Viral Vector><Virus><Work><Zeugmatography><adeno associated virus group><adult neurogenesis><adverse consequence><adverse outcome><attenuate><attenuates><c9FTD/ALS><c9als/frontotemporal dementia><c9ftd/amyotrophic lateral sclerosis><digital><electroporative delivery><experiment><experimental research><experimental study><experiments><gene electrotransfer><gene product><gene repair therapy><gene therapy><gene-based therapy><genetic condition><genetic disorder><genetic therapy><genome mutation><genomic therapy><heparitinuria><hippocampal><immunogenicity><immunoreaction><in utero><in vivo><kids><loss of function><mouse model><mucopolysaccharide storage disease III><mucopolysaccharidosis (MPS) III (A, B, C, D)><mucopolysaccharidosis type III><murine model><mutant><name><named><naming><necrocytosis><nerve stem cell><neural precursor><neural precursor cell><neural progenitor><neural progenitor cells><neuron progenitors><neuronal><neuronal progenitor><neuronal progenitor cells><neuronal stem cells><neuroprogenitor><new drug treatments><new drugs><new pharmacological therapeutic><new therapeutics><new therapy><next generation therapeutics><novel drug treatments><novel drugs><novel pharmaco-therapeutic><novel pharmacological therapeutic><novel therapeutics><novel therapy><pathophysiology><progenitor biology><progenitor cell biology><progenitor cell proliferation><progenitor proliferation><rAAV><recombinant AAV><response><ssDNA><stem and progenitor biology><stem and progenitor cell proliferation><stem cell biology><stem cell proliferation><transgene><transgene expression><vector><virus genome><youngster>