title: Prevention of Lethal Murine Hypophosphatasia by Neonatal Ex Vivo Gene Therapy Using Lentivirally Transduced Bone Marrow Cells.
abstract: Hypophosphatasia (HPP) is an inherited skeletal and dental disease caused by loss-of-function mutations in the gene that encodes tissue-nonspecific alkaline phosphatase (TNALP). The major symptoms of severe forms of the disease are bone defects, respiratory insufficiency, and epileptic seizures. In 2015, enzyme replacement therapy (ERT) using recombinant bone-targeted TNALP with deca-aspartate (D10) motif was approved to treat pediatric HPP patients in Japan, Canada, and Europe. However, the ERT requires repeated subcutaneous administration of the enzyme because of the short half-life in serum. In the present study, we evaluated the feasibility of neonatal ex vivo gene therapy in TNALP knockout (Akp2(-/-)) HPP mice using lentivirally transduced bone marrow cells (BMC) expressing bone-targeted TNALP in which a D10 sequence was linked to the C-terminus of soluble TNALP (TNALP-D10). The Akp2(-/-) mice usually die within 20 days because of growth failure, epileptic seizures, and hypomineralization. However, an intravenous transplantation of BMC expressing TNALP-D10 (ALP-BMC) into neonatal Akp2(-/-) mice prolonged survival of the mice with improved bone mineralization compared with untransduced BMC-transplanted Akp2(-/-) mice. The treated Akp2(-/-) mice were normal in appearance and experienced no seizures during the experimental period. The lentivirally transduced BMC were efficiently engrafted in the recipient mice and supplied TNALP-D10 continuously at a therapeutic level for at least 3 months. Moreover, TNALP-D10 overexpression did not affect multilineage reconstitution in the recipient mice. The plasma ALP activity was sustained at high levels in the treated mice, and tissue ALP activity was selectively detected on bone surfaces, not in the kidneys or other organs. No ectopic calcification was observed in the ALP-BMC-treated mice. These results indicate that lentivirally transduced BMC can serve as a reservoir for stem cell-based ERT to rescue the Akp2(-/-) phenotype. Neonatal ex vivo gene therapy thus appears to be a possible treatment option for treating severe HPP.
authors.affiliation: 1 Division of Gene Therapy, Department of Biochemistry and Molecular Biology, Research Center for Advanced Medical Technology, Nippon Medical School, Tokyo, Japan .
authors.forename: Osamu
authors.initials: O
authors.lastname: Iijima
authors.affiliation: 1 Division of Gene Therapy, Department of Biochemistry and Molecular Biology, Research Center for Advanced Medical Technology, Nippon Medical School, Tokyo, Japan .
authors.forename: Koichi
authors.initials: K
authors.lastname: Miyake
authors.affiliation: 1 Division of Gene Therapy, Department of Biochemistry and Molecular Biology, Research Center for Advanced Medical Technology, Nippon Medical School, Tokyo, Japan .|2 Division of Clinical Genetics, Nippon Medical School Hospital, Tokyo, Japan .
authors.forename: Atsushi
authors.initials: A
authors.lastname: Watanabe
authors.affiliation: 1 Division of Gene Therapy, Department of Biochemistry and Molecular Biology, Research Center for Advanced Medical Technology, Nippon Medical School, Tokyo, Japan .
authors.forename: Noriko
authors.initials: N
authors.lastname: Miyake
authors.affiliation: 1 Division of Gene Therapy, Department of Biochemistry and Molecular Biology, Research Center for Advanced Medical Technology, Nippon Medical School, Tokyo, Japan .|3 Department of Ophthalmology, Nippon Medical School Hospital, Tokyo, Japan .
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Igarashi
authors.affiliation: 1 Division of Gene Therapy, Department of Biochemistry and Molecular Biology, Research Center for Advanced Medical Technology, Nippon Medical School, Tokyo, Japan .
authors.forename: Chizu
authors.initials: C
authors.lastname: Kanokoda
authors.affiliation: 1 Division of Gene Therapy, Department of Biochemistry and Molecular Biology, Research Center for Advanced Medical Technology, Nippon Medical School, Tokyo, Japan .
authors.forename: Aki
authors.initials: A
authors.lastname: Nakamura-Takahashi
authors.affiliation: 4 Department of Dental Materials Science, Tokyo Dental College, Tokyo, Japan .
authors.forename: Hideaki
authors.initials: H
authors.lastname: Kinoshita
authors.affiliation: 5 Department of Anatomy, Tokyo Dental College, Tokyo, Japan .
authors.forename: Taku
authors.initials: T
authors.lastname: Noguchi
authors.affiliation: 5 Department of Anatomy, Tokyo Dental College, Tokyo, Japan .
authors.forename: Shinichi
authors.initials: S
authors.lastname: Abe
authors.affiliation: 6 Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute , La Jolla, California.
authors.forename: Sonoko
authors.initials: S
authors.lastname: Narisawa
authors.affiliation: 6 Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute , La Jolla, California.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Millán
authors.affiliation: 1 Division of Gene Therapy, Department of Biochemistry and Molecular Biology, Research Center for Advanced Medical Technology, Nippon Medical School, Tokyo, Japan .
authors.forename: Takashi
authors.initials: T
authors.lastname: Okada
authors.affiliation: 1 Division of Gene Therapy, Department of Biochemistry and Molecular Biology, Research Center for Advanced Medical Technology, Nippon Medical School, Tokyo, Japan .
authors.forename: Takashi
authors.initials: T
authors.lastname: Shimada
mesh_terms: D000469:Alkaline Phosphatase / Q000172:deficiency / Q000235:genetics*; D020816:Amino Acid Motifs; D000818:Animals; D000831:Animals, Newborn; D001854:Bone Marrow Cells / Q000166:cytology / Q000201:enzymology*; D016026:Bone Marrow Transplantation; D004195:Disease Models, Animal; D056947:Enzyme Replacement Therapy / Q000379:methods; D005260:Female; D015870:Gene Expression; D005804:Genes, Lethal; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D007014:Hypophosphatasia / Q000235:genetics / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D016086:Lentivirus / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D010641:Phenotype; D061251:Primary Cell Culture; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016019:Survival Analysis; D014161:Transduction, Genetic; D016896:Treatment Outcome
chemical_list: D011994:Recombinant Proteins; C510878:ALPL protein, mouse; D000469:Alkaline Phosphatase