title: Lipid-derived nanoparticles for immunostimulatory RNA adjuvant delivery.
abstract: The specific activation of Toll-like receptors (TLRs) has potential utility for a variety of therapeutic indications including antiviral immunotherapy and as vaccine adjuvants. TLR7 and TLR 8 may be activated by their native ligands, single-stranded RNA, or by small molecules of the imidazoquinoline family. However the use of TLR7/8 agonists for in vivo therapy is limited by instability, in the case of RNA, or systemic biodistribution and toxicity in the case of small molecule agonists. We hypothesized that unique lipid-like materials, termed "lipidoids," could be designed to efficiently deliver immunostimulatory RNA (isRNA) to TLR-expressing cells to drive innate and adaptive immune responses. A library of lipidoids was synthesized and screened for the ability to induce type I IFN activation in human peripheral blood mononuclear cells when combined with isRNA oligonucleotides. Effective lipidoid-isRNA nanoparticles, when tested in mice, stimulated strong IFN-α responses following subcutaneous injection, had robust antiviral activity that suppressed influenza virus replication, and enhanced antiovalbumin humoral and cell-mediated responses when used as a vaccine adjuvant. Further, we demonstrate that whereas all immunological activity was MyD88-dependent, certain materials were found to engage both TLR7-dependent and TLR7-independent activity in the mouse suggestive of cell-specific delivery. These lipidoid formulations, which are materials designed specifically for delivery of isRNA to Toll-like receptors, were superior to the commonly used N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethylammonium methylsulfate-RNA delivery system and may provide new tools for the manipulation of TLR responses in vitro and in vivo.
authors.affiliation: Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
authors.forename: David N
authors.initials: DN
authors.lastname: Nguyen
authors.forename: Kerry P
authors.initials: KP
authors.lastname: Mahon
authors.forename: Ghania
authors.initials: G
authors.lastname: Chikh
authors.forename: Phillip
authors.initials: P
authors.lastname: Kim
authors.forename: Hattie
authors.initials: H
authors.lastname: Chung
authors.forename: Alain P
authors.initials: AP
authors.lastname: Vicari
authors.forename: Kevin T
authors.initials: KT
authors.lastname: Love
authors.forename: Michael
authors.initials: M
authors.lastname: Goldberg
authors.forename: Steve
authors.initials: S
authors.lastname: Chen
authors.forename: Arthur M
authors.initials: AM
authors.lastname: Krieg
authors.forename: Jianzhu
authors.initials: J
authors.lastname: Chen
authors.forename: Robert
authors.initials: R
authors.lastname: Langer
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Anderson
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000818:Animals; D007370:Interferon Type I / Q000378:metabolism; D008055:Lipids / Q000737:chemistry*; D008562:Membrane Glycoproteins / Q000502:physiology; D051379:Mice; D053594:Myeloid Differentiation Factor 88 / Q000235:genetics / Q000502:physiology; D053758:Nanoparticles; D012313:RNA / Q000008:administration & dosage*; D034741:RNA, Small Interfering / Q000235:genetics; D051199:Toll-Like Receptor 7 / Q000502:physiology
chemical_list: D000276:Adjuvants, Immunologic; D007370:Interferon Type I; D008055:Lipids; D008562:Membrane Glycoproteins; C507780:Myd88 protein, mouse; D053594:Myeloid Differentiation Factor 88; D034741:RNA, Small Interfering; C477038:Tlr7 protein, mouse; D051199:Toll-Like Receptor 7; D012313:RNA