title: Rapid induction of mitogen-activated protein kinases by immune stimulatory CpG DNA.
abstract: Unmethylated CpG motifs in bacterial DNA or synthetic oligodeoxynucleotides (CpG DNA) rapidly activate B cells and monocyte-derived cells; however, the intracellular signaling pathways involved in this process are unclear. Here, we demonstrate that CpG DNA induces the activation of c-Jun NH2-terminal kinase and p38 but does not activate the extracellular receptor kinase in murine B and monocyte-like cell lines. CpG DNA also induces the phosphorylation of activating transcription factor-2, c-Jun, and mitogen-activated protein kinase (MAPK)-activated protein kinase 2 as well as the activation of activator protein-1 (AP-1) DNA binding. Inhibition of p38 led to the suppression of CpG DNA-induced AP-1 DNA-binding activity and cytokine production, indicating that the p38 pathway is required for mediating these immune stimulatory effects of CpG DNA. Chloroquine, an endosomal acidification inhibitor, selectively abolished CpG DNA-mediated MAPK activation. Our results indicate that CpG DNA activates the p38 and c-Jun NH2-terminal kinase MAPK and leads to the activation of AP-1 via a pathway which is sensitive to chloroquine.
authors.affiliation: Department of Internal Medicine, University of Iowa College of Medicine, Iowa City 52242, USA.
authors.forename: A K
authors.initials: AK
authors.lastname: Yi
authors.forename: A M
authors.initials: AM
authors.lastname: Krieg
mesh_terms: D051698:Activating Transcription Factor 2; D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000096:biosynthesis* / Q000235:genetics; D002478:Cells, Cultured; D002738:Chloroquine / Q000494:pharmacology; D018899:CpG Islands; D017362:Cyclic AMP Response Element-Binding Protein / Q000096:biosynthesis* / Q000235:genetics; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics; D004247:DNA / Q000378:metabolism; D019175:DNA Methylation; D004268:DNA-Binding Proteins / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D004790:Enzyme Induction / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D018398:Homeodomain Proteins; D007093:Imidazoles / Q000494:pharmacology; D048031:JNK Mitogen-Activated Protein Kinases; D016393:Lymphoma, B-Cell / Q000473:pathology; D048370:MAP Kinase Kinase 2; D051379:Mice; D015778:Minor Histocompatibility Antigens; D020929:Mitogen-Activated Protein Kinase Kinases; D020928:Mitogen-Activated Protein Kinases; D009841:Oligonucleotides / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D011499:Protein Processing, Post-Translational / Q000187:drug effects*; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis* / Q000235:genetics; D011505:Protein-Tyrosine Kinases / Q000096:biosynthesis* / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2; D011725:Pyridines / Q000494:pharmacology; D051818:Replication Protein C; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D015398:Signal Transduction / Q000187:drug effects*; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics; D014407:Tumor Cells, Cultured; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D051698:Activating Transcription Factor 2; D000276:Adjuvants, Immunologic; C497106:Atf2 protein, mouse; C096816:BCL2-related protein A1; D017362:Cyclic AMP Response Element-Binding Protein; D016207:Cytokines; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D005419:Flavonoids; D018398:Homeodomain Proteins; D007093:Imidazoles; C096063:MATA1 protein, S cerevisiae; D015778:Minor Histocompatibility Antigens; D009841:Oligonucleotides; D019253:Proto-Oncogene Proteins c-bcl-2; D011725:Pyridines; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D002738:Chloroquine; D004247:DNA; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D048370:MAP Kinase Kinase 2; D020929:Mitogen-Activated Protein Kinase Kinases; D051818:Replication Protein C; C090942:4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)imidazole; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one