title: Expression in CHO cells and pharmacokinetics and brain uptake in the Rhesus monkey of an IgG-iduronate-2-sulfatase fusion protein.
abstract: Sulfatases are potential therapeutic biopharmaceuticals, as mutations in sulfatase genes leads to inherited disease. Mucopolysaccharidosis (MPS) Type II is caused by mutations in the lysosomal enzyme, iduronate-2-sulfatase (IDS). MPS-II affects the brain and enzyme replacement therapy is ineffective for the brain, because IDS does not cross the blood-brain barrier (BBB). To deliver IDS across the human BBB, the sulfatase has been re-engineered as an IgG-sulfatase fusion protein with a genetically engineered monoclonal antibody (MAb) against the human insulin receptor (HIR). The HIRMAb part of the HIRMAb-IDS fusion protein acts as a molecular Trojan horse to ferry the fused IDS across the BBB. Chinese hamster ovary (CHO) cells were stably transfected to produce the HIRMAb-IDS fusion protein. The fusion protein was triaged to the lysosomal compartment of MPS-II fibroblasts based on confocal microscopy, and 300 ng/mL medium concentrations normalized IDS enzyme activity in the cells. The HIRMAb-IDS fusion protein was tritiated and injected intravenously into the adult Rhesus monkey at a low dose of 0.1 mg/kg. The IDS enzyme activity in plasma was elevated 10-fold above the endogenous level, and therapeutic plasma concentrations were generated in vivo. The uptake of the HIRMAb-IDS fusion protein in the brain was sufficiently high to produce therapeutic concentrations of IDS in the brain following IV administration of the fusion protein.
authors.affiliation: ArmaGen Technologies, Inc, Santa Monica, California, USA.
authors.forename: Jeff Zhiqiang
authors.initials: JZ
authors.lastname: Lu
authors.forename: Ruben J
authors.initials: RJ
authors.lastname: Boado
authors.forename: Eric K-W
authors.initials: EK
authors.lastname: Hui
authors.forename: Qing-Hui
authors.initials: QH
authors.lastname: Zhou
authors.forename: William M
authors.initials: WM
authors.lastname: Pardridge
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification / Q000493:pharmacokinetics*; D001921:Brain / Q000378:metabolism*; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D005347:Fibroblasts / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D007066:Iduronate Sulfatase / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification / Q000493:pharmacokinetics*; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification; D007275:Injections, Intravenous; D008247:Lysosomes / Q000378:metabolism; D008253:Macaca mulatta; D011972:Receptor, Insulin / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification / Q000493:pharmacokinetics
chemical_list: D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G; D011993:Recombinant Fusion Proteins; D011972:Receptor, Insulin; D007066:Iduronate Sulfatase