title: Deoxyribonuclease II is a lysosomal barrier to transfection.
abstract: DNA delivered in nonviral vectors or as naked DNA must overcome a number of extracellular and intracellular barriers to transfection. Since many vectors deliver DNA into cells by the endocytic route, DNA degradation by lysosomal nucleases has been proposed as a significant barrier to transfection, despite the fact that this has not yet been formally demonstrated to occur. To test this hypothesis, we have investigated the role of deoxyribonuclease II (DNase II), the primary acidic endonuclease active in the lysosome, in transfection. Two genetic systems were engineered in which mammalian cells either overexpressed DNase II or were knocked out for the enzyme. In both models, higher levels of DNase II correlated with decreased transfection efficiency by nonviral DNA delivery vectors. These data provide direct evidence implicating lysosomal DNase II as a barrier to transfection.
authors.affiliation: Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: Dasein Pinto-González
authors.initials: DP
authors.lastname: Howell
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Krieser
authors.forename: Alan
authors.initials: A
authors.lastname: Eastman
authors.forename: Michael A
authors.initials: MA
authors.lastname: Barry
mesh_terms: D004247:DNA / Q000378:metabolism; D004706:Endodeoxyribonucleases / Q000235:genetics / Q000378:metabolism*; D017930:Genes, Reporter; D005822:Genetic Vectors / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008247:Lysosomes / Q000378:metabolism*; D014162:Transfection
chemical_list: D004247:DNA; D004706:Endodeoxyribonucleases; C019329:deoxyribonuclease II