title: Self-Complementary AAV9 Gene Delivery Partially Corrects Pathology Associated with Juvenile Neuronal Ceroid Lipofuscinosis (CLN3).
abstract: Juvenile neuronal ceroid lipofuscinosis (JNCL) is a fatal lysosomal storage disease caused by autosomal-recessive mutations in CLN3 for which no treatment exists. Symptoms appear between 5 and 10 years of age, beginning with blindness and seizures, followed by progressive cognitive and motor decline and premature death (late teens to 20s). We explored a gene delivery approach for JNCL by generating two self-complementary adeno-associated virus 9 (scAAV9) constructs to address CLN3 dosage effects using the methyl-CpG-binding protein 2 (MeCP2) and β-actin promoters to drive low versus high transgene expression, respectively. This approach was based on the expectation that low CLN3 levels are required for cellular homeostasis due to minimal CLN3 expression postnatally, although this had not yet been demonstrated in vivo One-month-old Cln3(Δex7/8) mice received one systemic (intravenous) injection of scAAV9/MeCP2-hCLN3 or scAAV9/β-actin-hCLN3, with green fluorescent protein (GFP)-expressing viruses as controls. A promoter-dosage effect was observed in all brain regions examined, in which hCLN3 levels were elevated 3- to 8-fold in Cln3(Δex7/8) mice receiving scAAV9/β-actin-hCLN3 versus scAAV9/MeCP2-hCLN3. However, a disconnect occurred between CLN3 levels and disease improvement, because only the scAAV9 construct driving low CLN3 expression (scAAV9/MeCP2-hCLN3) corrected motor deficits and attenuated microglial and astrocyte activation and lysosomal pathology. This may have resulted from preferential promoter usage because transgene expression after intravenous scAAV9/MeCP2-GFP injection was primarily detected in NeuN(+) neurons, whereas scAAV9/β-actin-GFP drove transgene expression in GFAP(+) astrocytes. This is the first demonstration of a systemic delivery route to restore CLN3 in vivo using scAAV9 and highlights the importance of promoter selection for disease modification in juvenile animals.
  
  
  
  Juvenile neuronal ceroid lipofuscinosis (JNCL) is a fatal lysosomal storage disease caused by CLN3 mutations. We explored a gene delivery approach using two self-complementary adeno-associated virus 9 (scAAV9) constructs to address CLN3 dosage effects using the methyl-CpG-binding protein 2 (MeCP2) and β-actin promoters. hCLN3 levels were elevated 3- to 8-fold in Cln3(Δex7/8) mice receiving scAAV9/β-actin-hCLN3 versus scAAV9/MeCP2-hCLN3 after a single systemic injection. However, only scAAV9/MeCP2-hCLN3 corrected motor deficits and attenuated glial activation and lysosomal pathology. This may reflect preferential promoter usage because transgene expression with scAAV9/MeCP2-green fluorescent protein (GFP) was primarily in neurons, whereas scAAV9/β-actin-GFP drove transgene expression in astrocytes. This is the first demonstration of systemic delivery for CLN3 using scAAV9 and highlights the importance of promoter selection for disease modification in juvenile animals.
authors.affiliation: Department of Pharmacology and Experimental Neuroscience, and.
authors.forename: Megan E
authors.identifier: 0000-0003-1404-6870
authors.initials: ME
authors.lastname: Bosch
authors.affiliation: Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska 68198, and.
authors.forename: Amy
authors.initials: A
authors.lastname: Aldrich
authors.affiliation: Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska 68198, and.
authors.forename: Rachel
authors.initials: R
authors.lastname: Fallet
authors.affiliation: Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska 68198, and.
authors.forename: Jessica
authors.initials: J
authors.lastname: Odvody
authors.affiliation: Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska 68198, and.
authors.forename: Maria
authors.initials: M
authors.lastname: Burkovetskaya
authors.affiliation: Department of Pharmacology and Experimental Neuroscience, and.
authors.forename: Kaitlyn
authors.identifier: 0000-0001-8682-5588
authors.initials: K
authors.lastname: Schuberth
authors.affiliation: Department of Neuroscience, The Ohio State University, Columbus, Ohio 43210.
authors.forename: Julie A
authors.identifier: 0000-0002-7627-1689
authors.initials: JA
authors.lastname: Fitzgerald
authors.affiliation: Department of Neuroscience, The Ohio State University, Columbus, Ohio 43210.
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Foust
authors.affiliation: Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska 68198, and tkielian@unmc.edu.
authors.forename: Tammy
authors.identifier: 0000-0001-7624-670X
authors.initials: T
authors.lastname: Kielian
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism / Q000473:pathology; D000229:Dependovirus / Q000235:genetics*; D004195:Disease Models, Animal; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000627:therapeutic use*; D051783:Methyl-CpG-Binding Protein 2 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D018832:Molecular Chaperones / Q000235:genetics / Q000627:therapeutic use*; D009069:Movement Disorders / Q000209:etiology / Q000628:therapy; D009154:Mutation / Q000235:genetics; D009457:Neuroglia / Q000378:metabolism / Q000473:pathology; D009472:Neuronal Ceroid-Lipofuscinoses / Q000150:complications / Q000235:genetics* / Q000473:pathology / Q000628:therapy*; D009474:Neurons / Q000378:metabolism / Q000473:pathology
chemical_list: D000199:Actins; C105199:CLN3 protein, human; D008562:Membrane Glycoproteins; D051783:Methyl-CpG-Binding Protein 2; D018832:Molecular Chaperones
keywords: AAV9; Batten disease; CLN3; astrocyte; lysosomal storage disease; microglia