1. Identification of novel oligonucleotides from mitochondrial DNA that spontaneously induce plasmacytoid dendritic cell activation
- Author
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Jörg Vollmer, Moritz Ries, Sabrina Thomann, Barbara Schmidt, Philipp Schuster, and Norbert Donhauser
- Subjects
Lipopolysaccharides ,CpG Oligodeoxynucleotide ,Immunology ,Enzyme-Linked Immunosorbent Assay ,Biology ,Lymphocyte Activation ,DNA, Mitochondrial ,Flow cytometry ,Cathelicidins ,medicine ,Immunology and Allergy ,Humans ,Fragmentation (cell biology) ,B cell ,Cells, Cultured ,Plasmacytoid dendritic cell activation ,B-Lymphocytes ,medicine.diagnostic_test ,TLR9 ,Interferon-alpha ,hemic and immune systems ,Cell Biology ,Transfection ,Dendritic Cells ,DNA Methylation ,Flow Cytometry ,Molecular biology ,medicine.anatomical_structure ,CpG site ,Oligodeoxyribonucleotides ,Leukocytes, Mononuclear ,CpG Islands ,Immunization ,Antimicrobial Cationic Peptides - Abstract
This study tested the hypothesis that mtDNA fragments carry immunostimulatory motifs that naturally induce immune activation by PDC. Genomic and mtDNA induced similar IFN-α production after transfection into PBMCs using the liposomal transfection reagent DOTAP. Shortening of mtDNA to CpG islands enhanced the immunostimulatory activity, based on the presence of unmethylated CpG DNA. Further fragmentation into mtODN, which exhibited similarities to published CpG ODN, resulted in a strong immunostimulatory activity in addition to PDC maturation and migration. The addition of the human cathelicidin LL-37 to CpG islands induced spontaneous PDC IFN-α production. Notably, one phosphodiester mtODN with a double-palindromic structure induced PDC IFN-α production in the absence of DOTAP. Flow cytometry, life-cell, and confocal imaging revealed attachment and spontaneous uptake into PDC, colocalizing, in part, with TLR9 in early endosomal vesicles. This process was accompanied by a moderate but significant PDC maturation in addition to B cell and NK cell activation (P
- Published
- 2013