title: Immunostimulatory properties of CpG-oligonucleotides are enhanced by the use of protamine nanoparticles.
abstract: The aim of this paper was to investigate if the immunostimulatory effects of CpG-oligonucleotides (CpG-ODN) can be enhanced by the use of biodegradable protamine nanoparticles (proticles). We analyzed size, surface charge, and morphology of protamine nanoparticles containing CpG-ODN with photon correlation spectroscopy and transmission electron microscopy. Immunostimulatory effects of these nanoparticles on B cells, plasmacytoid dendritic cells (PDC), peripheral blood mononuclear cells, and whole blood were studied. Cytokine production, activation of the cells in terms of upregulation of surface molecules and uptake of nanoparticles were examined. We found that the use of protamine nanoparticles significantly increased (20-fold) CpG-ODN mediated interferon (IFN)-alpha production of PDC. ODN uptake in PDC was only marginally enhanced. CpG-ODN mediated IP-10 production in whole blood was strongly enhanced by the use of nanoparticles. Apart from a slight increase in CpG-ODN-induced interleukin (IL)-6 production in B cells, other parameters like the CpG-mediated activation of B cells and PDC as well as tumor necrosis factor (TNF)-alpha production of PDC remained largely unchanged. The use of control ODN indicated that the protamine nanoparticles themselves have no immunostimulatory properties. These results strongly support the use of particulate delivery systems like biodegradable protamine nanoparticles for the development of CpG-ODN-based therapeutics.
authors.affiliation: Department of Clinical Pharmacology, Division of Internal Medicine, Ludwig Maximilians University of Munich, Munich, Germany.
authors.forename: Miren
authors.initials: M
authors.lastname: Kerkmann
authors.forename: Dirk
authors.initials: D
authors.lastname: Lochmann
authors.forename: Jörg
authors.initials: J
authors.lastname: Weyermann
authors.forename: Anja
authors.initials: A
authors.lastname: Marschner
authors.forename: Hendrik
authors.initials: H
authors.lastname: Poeck
authors.forename: Moritz
authors.initials: M
authors.lastname: Wagner
authors.forename: Julia
authors.initials: J
authors.lastname: Battiany
authors.forename: Andreas
authors.initials: A
authors.lastname: Zimmer
authors.forename: Stefan
authors.initials: S
authors.lastname: Endres
authors.forename: Gunther
authors.initials: G
authors.lastname: Hartmann
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000293:Adolescent; D000328:Adult; D000368:Aged; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology; D001672:Biocompatible Materials / Q000008:administration & dosage; D016207:Cytokines / Q000096:biosynthesis; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology; D016503:Drug Delivery Systems; D004357:Drug Synergism; D006801:Humans; D066298:In Vitro Techniques; D016898:Interferon-alpha / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects; D008854:Microscopy, Electron; D008875:Middle Aged; D053758:Nanoparticles; D009838:Oligodeoxyribonucleotides / Q000008:administration & dosage*; D010316:Particle Size; D011479:Protamines / Q000008:administration & dosage*; D013499:Surface Properties
chemical_list: D000276:Adjuvants, Immunologic; D001672:Biocompatible Materials; C408982:CPG-oligonucleotide; D016207:Cytokines; C508600:IL6 protein, human; D016898:Interferon-alpha; D015850:Interleukin-6; D009838:Oligodeoxyribonucleotides; D011479:Protamines