FIG 1.

Schematic representation of the design of studies on the interactions between P. gingivalis outer membrane vesicles (OMVs) and human neutrophils. Human neutrophils were challenged with OMVs of P. gingivalis. Subsequently, the viability of the neutrophils was assessed by measuring reduction of 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT), the interaction of neutrophils and OMVs was assessed by microscopy, and the turnover of myeloperoxidase (MPO) and the antimicrobial peptide LL-37 in neutrophil supernatants was measured by enzyme-linked immunosorbent assays (ELISAs). In addition, the bactericidal activity of purified MPO was assayed using LIVE/DEAD staining, possibly citrullination by mass spectrometry (MS), and turnover by Western blotting. PPAD, Porphyromonas peptidyl-arginine deiminase.