title: A polysaccharide carrier to effectively deliver native phosphodiester CpG DNA to antigen-presenting cells.
abstract: Oligodeoxynucleotides containing unmethylated CpG sequences (CpG DNAs) activate the vertebrate innate immune system via toll-like receptor 9 (TLR-9). Although CpG DNA is a promising immunotherapeutic agent, its short circulation time in biological fluids due to nuclease is the major drawback. This paper proposes that a natural polysaccharide called schizophyllan (SPG) can be used as an effective CpG DNA carrier because SPG can complex with CpG DNA and the resultant complex shows the nuclease resistance of the bound DNA. In order to increase cellular uptake in vitro, we chemically attached spermine, cholesterol, arginine octamer, or RGD peptide to SPG. The complexes made of the chemically modified SPG and CpG DNA having a phosphorothioate (PS) or phosphodiester (PO) backbone led to increased secretion of cytokines of about 4- to 15-fold, compared with the uncomplexed dose. Furthermore, when PO CpG DNA was complexed with unmodified SPG, the IL-12 level increased by almost 3- to 11-fold compared with the naked dose. The PO CpG DNA/unmodified SPG complex data suggested that unmodified SPG might effectively deliver PO in vivo due to the electrically neutral nature of unmodified SPG. When the complexed CpG DNAs were injected intraperitoneally, a large amount of IL-12 production was observed compared with the uncomplexed material. Both in vivo and vitro assays indicated that the SPG complex may be of use for CpG DNA therapy.
authors.affiliation: Department of Chemical Processes & Environments, The University of Kitakyushu, 1-1, Hibikino, Wakamatu-ku, Kitakyushu, Fukuoka 808-0135, Japan.
authors.forename: Naohiko
authors.initials: N
authors.lastname: Shimada
authors.forename: Cevayir
authors.initials: C
authors.lastname: Coban
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Takeda
authors.forename: Masami
authors.initials: M
authors.lastname: Mizu
authors.forename: Jusaku
authors.initials: J
authors.lastname: Minari
authors.forename: Takahisa
authors.initials: T
authors.lastname: Anada
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Torii
authors.forename: Seiji
authors.initials: S
authors.lastname: Shinkai
authors.forename: Shizuo
authors.initials: S
authors.lastname: Akira
authors.forename: Ken J
authors.initials: KJ
authors.lastname: Ishii
authors.forename: Kazuo
authors.initials: K
authors.lastname: Sakurai
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000187:drug effects* / Q000276:immunology; D002478:Cells, Cultured; D018899:CpG Islands; D016207:Cytokines / Q000097:blood / Q000276:immunology; D004247:DNA / Q000008:administration & dosage* / Q000737:chemistry; D004337:Drug Carriers / Q000008:administration & dosage* / Q000737:chemistry; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010755:Organophosphates / Q000008:administration & dosage / Q000737:chemistry; D012566:Sizofiran / Q000008:administration & dosage* / Q000737:chemistry; D013154:Spleen / Q000166:cytology; D051217:Toll-Like Receptor 9 / Q000172:deficiency / Q000235:genetics / Q000276:immunology
chemical_list: D016207:Cytokines; D004337:Drug Carriers; D010755:Organophosphates; C495370:Tlr9 protein, mouse; D051217:Toll-Like Receptor 9; D012566:Sizofiran; D004247:DNA