title: Dual or triple activation of TLR7, TLR8, and/or TLR9 by single-stranded oligoribonucleotides.
abstract: The toll-like receptors (TLRs) 7, 8, and 9 stimulate innate immune responses upon recognizing pathogen nucleic acids. Certain GU- or AU-rich RNA sequences were described to differentiate between human TLR7- and TLR8-mediated immune effects. Those single-stranded RNA molecules require endosomal delivery for stabilization against ribonucleases. We have discovered RNA sequences that preferentially activate TLR7, form higher ordered structures, and do not require specific cellular delivery. In addition, a dual activation of TLR8 and TLR9 without affecting TLR7 can be achieved by chimeric molecules consisting of GU-rich RNA and Cytosin (C) phosphordiester or phosphorthioat (p) guanine (CpG) motif DNA sequences. Such chimeras stimulate TLR9-mediated type I interferon (IFN) and TLR8-depending proinflammatory cytokine and chemokine production upon primary human cell activation. However, an RNA-dependent TLR7 IFN-α cytokine release is suppressed by the phosphorothioate DNA sequence contained in the chimeric molecule. To convert the immune response of a single-stranded RNA from TLR7/8 to TLR9, a simple chemical modification at the 5' end proves to be sufficient. Such 8-oxo-2'-deoxy-guanosine or 8-bromo-2'-deoxy-guanosine modifications of the first guanosine in GU-rich single-stranded RNAs convert the immune response to include TLR9 activation and demonstrate strong additive effects for type I IFN immune responses in human primary cells.
authors.affiliation: Pfizer Oligonucleotides Therapeutics Unit, Coley Pharmaceutical GmbH, Düsseldorf, Germany. aforsbach@gmx.de
authors.forename: Alexandra
authors.initials: A
authors.lastname: Forsbach
authors.forename: Ulrike
authors.initials: U
authors.lastname: Samulowitz
authors.forename: Kirsten
authors.initials: K
authors.lastname: Völp
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Hofmann
authors.forename: Bernhard
authors.initials: B
authors.lastname: Noll
authors.forename: Sybille
authors.initials: S
authors.lastname: Tluk
authors.forename: Claudia
authors.initials: C
authors.lastname: Schmitz
authors.forename: Tanja
authors.initials: T
authors.lastname: Wader
authors.forename: Christian
authors.initials: C
authors.lastname: Müller
authors.forename: Anja
authors.initials: A
authors.lastname: Podszuweit
authors.forename: Angela
authors.initials: A
authors.lastname: Lohner
authors.forename: Rainer
authors.initials: R
authors.lastname: Curdt
authors.forename: Eugen
authors.initials: E
authors.lastname: Uhlmann
authors.forename: Jörg
authors.initials: J
authors.lastname: Vollmer
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D018925:Chemokines / Q000187:drug effects; D016207:Cytokines / Q000187:drug effects; D005260:Female; D057809:HEK293 Cells / Q000187:drug effects / Q000276:immunology; D006801:Humans; D007113:Immunity, Innate / Q000187:drug effects; D007370:Interferon Type I / Q000187:drug effects; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000276:immunology; D008297:Male; D051379:Mice; D009843:Oligoribonucleotides / Q000008:administration & dosage* / Q000737:chemistry*; D054735:Phosphorothioate Oligonucleotides / Q000008:administration & dosage / Q000737:chemistry; D051199:Toll-Like Receptor 7 / Q000187:drug effects* / Q000276:immunology; D051200:Toll-Like Receptor 8 / Q000187:drug effects* / Q000276:immunology; D051217:Toll-Like Receptor 9 / Q000187:drug effects* / Q000276:immunology
chemical_list: D018925:Chemokines; D016207:Cytokines; D007370:Interferon Type I; D009843:Oligoribonucleotides; D054735:Phosphorothioate Oligonucleotides; C495348:TLR7 protein, human; C495349:TLR8 protein, human; C495371:TLR9 protein, human; D051199:Toll-Like Receptor 7; D051200:Toll-Like Receptor 8; D051217:Toll-Like Receptor 9