title: Impact of nature and length of linker incorporated in agonists on toll-like receptor 9-mediated immune responses.
abstract: Oligodeoxynucleotides containing unmethylated CpG motifs act as ligands of Toll-like receptor 9 (TLR9). We previously reported a novel class of TLR9 agonists, referred to as immune-modulatory oligonucleotides (IMOs), in which two 11-mers of the same sequence are attached via their 3'-ends through a 1,2,3-propanetriol linker and contain a synthetic immune-stimulatory motif, Cp7-deaza-dG. In the present study, we have examined the impact of length, nature, and stereochemistry of the linker incorporated in agonists for TLR9 activation. The new linkers studied include (S)-(-)-1,2,4-butanetriol, 1,3,5-pentanetriol, cis,cis-1,3,5-cyclohexanetriol, cis,trans-1,3,5-cyclohexanetriol, 1,3,5-tris(2-hydroxyethyl)isocyanurate, tetraethyleneglycol, and hexaethyleneglycol in place of 1,2,3-propanetriol linker. Agonists with various linkers are studied for TLR9-mediated immune responses in HEK293 cells, human cell-based assays, and in vivo in mice. Results of these studies suggest that C3-C5 linkers, 1,2,3-propanetriol, (S)-(-)-1,2,4-butanetriol, or 1,3,5-pentanetriol, are optimal for stimulation of TLR9-mediated immune responses. Rigid C3 linkers with different stereochemistry have little effect on immune stimulation, while linkers longer than C5 reduced TLR9-mediated immune stimulation.
authors.affiliation: Idera Pharmaceuticals, Inc., 167 Sidney Street, Cambridge, Massachusetts 02139, USA.
authors.forename: Mallikarjuna Reddy
authors.initials: MR
authors.lastname: Putta
authors.forename: Dong
authors.initials: D
authors.lastname: Yu
authors.forename: Lakshmi
authors.initials: L
authors.lastname: Bhagat
authors.forename: Daqing
authors.initials: D
authors.lastname: Wang
authors.forename: Fu-Gang
authors.initials: FG
authors.lastname: Zhu
authors.forename: Ekambar R
authors.initials: ER
authors.lastname: Kandimalla
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D018899:CpG Islands; D003432:Cross-Linking Reagents / Q000737:chemistry*; D003848:Deoxyguanine Nucleotides; D006018:Glycols; D006801:Humans; D007155:Immunologic Factors / Q000737:chemistry*; D051379:Mice; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology*; D051217:Toll-Like Receptor 9 / Q000819:agonists*
chemical_list: D003432:Cross-Linking Reagents; D003848:Deoxyguanine Nucleotides; D006018:Glycols; D007155:Immunologic Factors; D009838:Oligodeoxyribonucleotides; D051217:Toll-Like Receptor 9