Antibodies to proteinase 3 prime human monocytic cells via protease-activated receptor-2 and NF-kappaB for Toll-like receptor- and NOD-dependent activation.
Anti-neutrophil cytoplasmic Abs against proteinase 3 (PR3) have been detected in relation to a wide range of inflammatory conditions, and the interaction of anti-PR3 Abs with leukocytes provokes cell activation, although how is not clear. Flow cytometric analysis revealed an increase in cell-surface CD14, Toll-like receptor (TLR)2, TLR4 and intracellular TLR3, TLR7, TLR8, TLR9, NOD1 and NOD2 expression during anti-PR3 priming in human monocytic THP-1 cells. Anti-RP3 Abs markedly promoted the release of IL-8 induced by chemically synthesized TLR and NOD ligands mimicking bacterial components: TLR2-agonistic lipopeptide (FSL-1), TLR3-agonistic poly I:C, TLR4-agonistic lipid A (LA-15-PP), TLR7/8-agonistic single stranded RNA (ssPolyU), TLR9-agonistic bacterial CpG DNA, NOD1-agonistic FK156/565 and NOD2-agonistic muramyldipeptide (MDP) in THP-1 cells and human peripheral blood mononuclear cells, although sole incubation with anti-PR3 Abs induced only a low level of IL-8. The priming response was evident after 2h of preincubation with anti-PR3 Abs and peaked after 6h. Priming was also observed for the production of TNF-alpha and monocyte chemoattractant protein-1. An RNA interference assay revealed that anti-PR3 Abs activated THP-1 cells in a PR3- and protease-activated receptor-2-dependent manner. Furthermore, the anti-PR3 Ab-mediated cell activation was significantly abolished by RNA interference targeted at PR3 mRNA and by inhibition of phospholipase C and NF-kappaB. These results suggest that anti-PR3 Abs prime human monocytic cells to produce cytokines upon stimulation with various bacterial components by up-regulating the TLR and NOD signaling pathway, and that these mechanisms may actively participate in the inflammatory process.
Uehara
Akiko
A
Department of Microbiology and Immunology, Tohoku University Graduate School of Dentistry, Sendai 980-8575, Japan. kyoro@mail.tains.tohoku.ac.jp <kyoro@mail.tains.tohoku.ac.jp>
Iwashiro
Atsushi
A
Sato
Tadasu
T
Yokota
Sou
S
Takada
Haruhiko
H
D000328:Adult; D000906:Antibodies / Q000494:pharmacology*; D053468:CARD Signaling Adaptor Proteins / Q000235:genetics / Q000276:immunology*; D002460:Cell Line; D016207:Cytokines / Q000378:metabolism; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D008024:Ligands; D018950:Lipopolysaccharide Receptors / Q000235:genetics; D009000:Monocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D053146:Myeloblastin / Q000276:immunology*; D016328:NF-kappa B / Q000276:immunology*; D053474:Nod1 Signaling Adaptor Protein / Q000235:genetics / Q000276:immunology; D053473:Nod2 Signaling Adaptor Protein / Q000235:genetics / Q000276:immunology; D044464:Receptor, PAR-2 / Q000276:immunology*; D013997:Time Factors; D051193:Toll-Like Receptors / Q000235:genetics / Q000276:immunology*; D010738:Type C Phospholipases / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects
D000906:Antibodies; D053468:CARD Signaling Adaptor Proteins; D016207:Cytokines; D018836:Inflammation Mediators; D008024:Ligands; D018950:Lipopolysaccharide Receptors; D016328:NF-kappa B; D053474:Nod1 Signaling Adaptor Protein; D053473:Nod2 Signaling Adaptor Protein; D044464:Receptor, PAR-2; D051193:Toll-Like Receptors; D010738:Type C Phospholipases; D053146:Myeloblastin