title: Anti-GAD antibody targeted non-viral gene delivery to islet beta cells.
abstract: An islet cell targeting polymeric gene carrier was synthesized by conjugating anti-GAD Fab' fragment to PEI via PEG linker (PEI-PEG-Fab'). The Fab' fragment was prepared from a murine monoclonal antibody against glutamic acid decarboxylase (GAD), which has been identified as one of the major auto-antigens expressed in islet cells, and used as a targeting moiety for islet cell targeting. The electrophoretic migration of plasmid DNA (pCMVLuc)/PEI-PEG-Fab' complexes in agarose gel was completely retarded above the N/P ratio of 2. The complexes demonstrated a size of 100-275 nm with an almost neutral surface charge. Confocal microscopy revealed that the PEI-PEG-Fab' complexes showed much higher cellular binding and uptake efficiency compared to PEI-PEG complexes. The PEI-PEG-Fab' showed about 10-fold higher transfection efficiency (relative luciferase activity) than PEI-PEG in GAD-expressing mouse insulinoma cells (MIN6), however the transfection efficiency of PEI-PEG-Fab' reduced to that of PEI-PEG in GAD negative cells (293) and in the presence of competitive free Fab'. Considering the neutral surface charge of its complexes with DNA, and selectivity toward the islet cells expressing a specific antigen, the PEI-PEG-Fab' conjugate could be thought as a potential candidate of the systemic gene therapy for the treatment of type I diabetes.
authors.affiliation: CCCD/Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT 84112, USA.
authors.forename: Ji Hoon
authors.initials: JH
authors.lastname: Jeong
authors.forename: Minhyung
authors.initials: M
authors.lastname: Lee
authors.forename: Won Jong
authors.initials: WJ
authors.lastname: Kim
authors.forename: James W
authors.initials: JW
authors.lastname: Yockman
authors.forename: Tae Gwan
authors.initials: TG
authors.lastname: Park
authors.forename: Yong Hee
authors.initials: YH
authors.lastname: Kim
authors.forename: Sung Wan
authors.initials: SW
authors.lastname: Kim
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage* / Q000276:immunology*; D002470:Cell Survival / Q000187:drug effects; D016503:Drug Delivery Systems; D004587:Electrophoresis, Agar Gel; D015316:Genetic Therapy / Q000379:methods*; D005968:Glutamate Decarboxylase / Q000276:immunology*; D007140:Immunoglobulin Fab Fragments / Q000235:genetics; D050417:Insulin-Secreting Cells / Q000187:drug effects* / Q000276:immunology*; D051379:Mice; D018613:Microscopy, Confocal; D011092:Polyethylene Glycols; D011094:Polyethyleneimine; D014162:Transfection
chemical_list: D000911:Antibodies, Monoclonal; D007140:Immunoglobulin Fab Fragments; D011092:Polyethylene Glycols; D011094:Polyethyleneimine; D005968:Glutamate Decarboxylase