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Outer membrane vesicles from Neisseria meningitidis
Author(s) -
Mirlashari Mohammad Reza,
Høiby Ernst Arne,
Holst Johan,
Lyberg Torstein
Publication year - 2002
Publication title -
apmis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0903-4641
DOI - 10.1034/j.1600-0463.2002.100301.x
Subject(s) - lipopolysaccharide , cd14 , cd11c , integrin alpha m , bacterial outer membrane , chemistry , microbiology and biotechnology , superoxide , cell adhesion molecule , flow cytometry , biology , immunology , biochemistry , escherichia coli , enzyme , gene , phenotype
Flow cytometry was used to study the expression of leukocyte adhesion molecules CD11a, CD11b, CD11c, CD14, and CD62L (L‐selectin) and production of reactive oxygen species (ROS) in an ex vivo human whole‐blood system stimulated with lipopolysaccharide‐containing outer membrane vesicles (LPS‐OMV) from N. meningitidis. Results demonstrated a dose‐dependent increase in surface expression of CD11a, CD11b, CD11c and CD14 in granulocytes and monocytes (maximal at 30–120 min) upon OMV‐LPS challenge, whereas CD62L expression was heavily downregulated (maximal at 30–120 min). The OMV‐associated LPS was almost as potent (on a weight basis) as purified LPS from E. coli in inducing adhesion molecule modulation but the response was delayed. Upon stimulation with OMV‐LPS or E. coli ‐LPS, the production of intracellular ROS increased in both granulocytes and monocytes when dihydroethidium (DHE, mainly reflecting superoxide anion) was used as a probe, whereas peroxynitrite production monitored with dihydrorhodamine 123 (DHR) was not significantly changed. The OMV‐mediated modulation of leukocyte adhesion molecule expression and increased ROS production may certainly lead to increased entrapment of leukocytes in the microcirculation and contribute to untoward inflammatory reactions as seen in systemic meningococcal disease.