title: Effect of adeno-associated virus-specific immunoglobulin G in human amniotic fluid on gene transfer.
abstract: Intra-amniotic administration of adeno-associated virus (AAV) vector may be an effective way to deliver gene therapy for treatment of congenital pulmonary and intestinal disorders. In an effort to understand potential barriers to intra-amniotic gene therapy better, we determined whether human amniotic fluid (AF) could act as an inhibitor of AAV2-mediated gene transfer. AF samples were obtained from 21 different human pregnancies during routine amniocentesis at 16-20 weeks of gestation. An immortalized fetal human tracheal epithelial cell line (FHTE) was infected with AAV2 containing a luciferase reporter gene driven by the SV40 promoter in the presence and absence of each AF sample. Inhibition of transgene expression was observed in 8 (38%) of the AF samples (inhibitory AF) and resulted in luciferase levels of only 1.4% +/- 0.6% of those obtained with infection in normal media. Infections in 13 samples (62%) resulted in transgene expression comparable or in excess of infection in media alone (noninhibitory AF). Removal of immunoglobulin G (IgG) from inhibitory AF samples with Protein A returned luciferase expression to control levels (119% +/- 37% of control), suggesting the possible presence of inhibiting antibody. Eleven of the AF samples were evaluated by enzyme-linked immunosorbent assay (ELISA) for specific anti-AAV antibodies. All noninhibitory AF samples were negative (titers of < 1:20; n = 3), and 6 of the 8 inhibitory samples contained specific anti-AAV antibodies at titers ranging from 1:40 to 1:160. These studies demonstrate that AF from some individuals contains AAV-specific IgG that can inhibit gene transfer.
authors.affiliation: Department of Medicine, The Johns Hopkins University School of Medicine, Jefferson B1-170, 600 North Wolfe Street, Baltimore, MD 21287-8922, USA. mboyle@jhmi.edu
authors.forename: Michael P
authors.initials: MP
authors.lastname: Boyle
authors.forename: Raymond A
authors.initials: RA
authors.lastname: Enke
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Mogayzel
authors.forename: William B
authors.initials: WB
authors.lastname: Guggino
authors.forename: Dana B
authors.initials: DB
authors.lastname: Martin
authors.forename: Shikha
authors.initials: S
authors.lastname: Agarwal
authors.forename: Pamela L
authors.initials: PL
authors.lastname: Zeitlin
mesh_terms: D000653:Amniotic Fluid / Q000276:immunology*; D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology*; D002461:Cell Line, Transformed; D002470:Cell Survival; D000229:Dependovirus / Q000235:genetics* / Q000276:immunology; D005260:Female; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000008:administration & dosage; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D007150:Immunohistochemistry; D008156:Luciferases / Q000032:analysis / Q000235:genetics; D011247:Pregnancy; D011489:Protein Denaturation; D011506:Proteins / Q000032:analysis
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D011506:Proteins; D008156:Luciferases