title: Self-assembling CpG DNA nanoparticles for efficient antigen delivery and immunostimulation.
abstract: DNA containing unmethylated deoxycytidylyl-deoxyguanosine (CpG) dinucleotides (CpG DNA) is a potent stimulator of immune responses through triggering of Toll-like receptor 9 (TLR9). In the present study, we synthesized cholesterol-modified CpG oligodeoxynucleotide (Chol-CpG ODN) and investigated its ability to form nanoparticles by self-assembling, then examined their immunostimulatory activity and potency to deliver antigens to antigen presenting cells (APCs). Chol-CpG ODN spontaneously formed particles in aqueous solutions. Cholesterol modification increased the stability of ODN in serum. Chol-CpG ODN was efficiently taken up by mouse macrophage-like RAW264.7 cells and induced a large amount of tumor necrosis factor-α compared with unmodified CpG ODN. Then, ovalbumin (OVA), a model antigen, was incorporated into Chol-CpG ODN nanoparticles. Cholesterol-modified GpC ODN (Chol-GpC ODN) was used to assess the importance of CpG motif on the antigen-specific immune response. Vaccination of mice with OVA/Chol-CpG ODN induced high level interferon-γ production from splenocytes. Furthermore, a high serum level of OVA-specific immunoglobulin G2a was observed in mice receiving OVA/Chol-CpG ODN. Neither CpG ODN nor Chol-GpC ODN was effective at all. These results indicate that self-assembling nanoparticles of Chol-CpG ODN are effective for inducing antigen-specific immune responses because of the high immunostimulatory activity, ability to incorporate antigens and tropism to APCs.
authors: Department of Biopharmaceutics and Drug Metabolism, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
authors: Sakulrat
authors: S
authors: Rattanakiat
authors: Makiya
authors: M
authors: Nishikawa
authors: Yoshinobu
authors: Y
authors: Takakura
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage* / Q000737:chemistry; D000818:Animals; D000941:Antigens / Q000008:administration & dosage* / Q000276:immunology; D002460:Cell Line; D002784:Cholesterol / Q000008:administration & dosage* / Q000737:chemistry; D005260:Female; D007114:Immunization / Q000379:methods; D007074:Immunoglobulin G / Q000097:blood; D007371:Interferon-gamma / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D053758:Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry; D009838:Oligodeoxyribonucleotides / Q000008:administration & dosage* / Q000737:chemistry; D010047:Ovalbumin / Q000008:administration & dosage* / Q000276:immunology; D013154:Spleen / Q000187:drug effects / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000941:Antigens; C408982:CPG-oligonucleotide; D007074:Immunoglobulin G; D009838:Oligodeoxyribonucleotides; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D010047:Ovalbumin; D002784:Cholesterol