title: Modulation of CpG oligodeoxynucleotide-mediated immune stimulation by locked nucleic acid (LNA).
abstract: Locked nucleic acid (LNA) is an RNA derivative that when introduced into oligodeoxynucleotides (ODN), mediates high efficacy and stability. CpG ODNs are potent immune stimulators and are recognized by toll-like receptor-9 (TLR9). Some phosphorothioate antisense ODNs bearing CpG dinucleotides have been shown to possess immune modulatory capacities. We investigated the effects of LNA substitutions on immune stimulation mediated by antisense ODN G3139 or CpG ODN 2006. LNA ODNs were tested for their ability to stimulate cytokine secretion from human immune cells or TLR9-dependent signaling. Phosphorothioate chimeric LNA/DNA antisense ODNs with phosphodiester-linked LNA nucleobases at both ends showed a marked decrease of immune modulation with an increasing number of 3' and 5' LNA bases. In addition, guanosine-LNA and cytosine-LNA or simply cytosine-LNA substitutions in the CpG dinucleotides of ODN 2006 led to strong decrease or near complete loss of immune modulation. TLR9-mediated signaling was similarly affected. These data indicate that increasing amounts of LNA residues in the flanks or substitutions of CpG nucleobases with LNA reduce or eliminate the immune stimulatory effects of CpG-containing phosphorothioate ODN.
authors.affiliation: Coley Pharmaceutical Group, D-40764 Langenfeld, Germany. jvollmer@coleypharma.com
authors.forename: Jörg
authors.initials: J
authors.lastname: Vollmer
authors.forename: Jan Stenvang
authors.initials: JS
authors.lastname: Jepsen
authors.forename: Eugen
authors.initials: E
authors.lastname: Uhlmann
authors.forename: Christian
authors.initials: C
authors.lastname: Schetter
authors.forename: Marion
authors.initials: M
authors.lastname: Jurk
authors.forename: Tanja
authors.initials: T
authors.lastname: Wader
authors.forename: Meike
authors.initials: M
authors.lastname: Wüllner
authors.forename: Arthur M
authors.initials: AM
authors.lastname: Krieg
mesh_terms: D002478:Cells, Cultured; D018899:CpG Islands / Q000187:drug effects* / Q000235:genetics / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D009838:Oligodeoxyribonucleotides / Q000494:pharmacology*
chemical_list: D016207:Cytokines; D009838:Oligodeoxyribonucleotides