title: Induction of interferon synthesis and activation of interferon-stimulated genes by liposomal transfection reagents.
abstract: Liposome-mediated transfection is a widely used technique for the introduction of exogenous DNA into mammalian cells. We observed a significant induction of endogenous interferon (IFN)-stimulated genes (ISGs) in cells treated with the liposomal reagents, lipofectamine and DOSPER, in the absence of DNA. Liposome treatment induced expression of reporter constructs driven by IFN-responsive promoter elements, demonstrating a generalized effect on ISG expression. The kinetics of ISG induction were markedly delayed in response to liposome as compared with IFN or double-stranded RNA. ISG induction could be transferred to naive cells with conditioned medium from liposome-treated cells, suggesting that a secreted factor was responsible for this activity. A cell line defective in IFN signaling was refractory to liposome-induced ISG expression, indicating a role for IFN in this induction. Indeed, liposome treatment directly induced IFN-beta gene expression and, thus, represents a novel IFN inducer. IFN induction by liposomal reagents and its potential effects on transgene expression should be considered in the choice of transfection reagent. The ability of liposomal gene delivery reagents to induce IFN synthesis in the host may prove useful in gene therapy approaches to viral and neoplastic diseases.
authors.affiliation: Greenebaum Cancer Center and Department of Microbiology and Immunology, University of Maryland at Baltimore, 21201, USA.
authors.forename: X L
authors.initials: XL
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Boyanapalli
authors.forename: X
authors.initials: X
authors.lastname: Weihua
authors.forename: D V
authors.initials: DV
authors.lastname: Kalvakolanu
authors.forename: B A
authors.initials: BA
authors.lastname: Hassel
mesh_terms: D002411:Cation Exchange Resins / Q000494:pharmacology*; D002460:Cell Line; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D007202:Indicators and Reagents; D007369:Interferon Inducers / Q000494:pharmacology*; D016899:Interferon-beta / Q000096:biosynthesis; D008055:Lipids / Q000494:pharmacology*; D008081:Liposomes; D015398:Signal Transduction / Q000187:drug effects; D013268:Stimulation, Chemical; D014162:Transfection
chemical_list: D002411:Cation Exchange Resins; D007202:Indicators and Reagents; D007369:Interferon Inducers; D008055:Lipids; C086724:Lipofectamine; D008081:Liposomes; D016899:Interferon-beta