Neutralization of Neisseria meningitidis outer membrane vesicles.

Abstract

INTRODUCTION:

We aimed to determine the neutralization of Neisseria meningitidis outer membrane vesicles (blebs) by humoral and cellular elements of whole blood.

METHODS:

The interaction of FITC-labeled blebs with monocytes was studied by spectrofluorometry. Blebs are able to induce an oxidative burst in neutrophils, and we evaluated the inhibitory effect of plasma on this process.

RESULTS:

Human plasma reduced the priming activity of blebs containing 1-3 ng/ml lipopolysaccharide (LPS) by 50-60% and bactericidal permeability increasing protein (BPI) reduced priming to background levels. A complete neutralization of LPS and blebs by plasma and BPI was measured using the limulus amebocyte lysate (LAL) assay. Furthermore, only 3% of blebs were cell-associated, while the remainder were in the supernatant.

CONCLUSIONS:

Plasma and BPI are able to neutralize blebs, with phagocytosis playing only a minor role. As such, we conclude that blebs do not behave like particles but more like free LPS.

• Authors: András Vida, Annet Troelstra, Péter Antal-Szalmás, Toon J P van Bommel, André F M Verheul, Jan Verhoef, Kok P M van Kessel, Jos A G van Strijp
• Journal: Inflammation research : official journal of the European Histamine Research Society ... [et al.] (Inflamm Res) Vol. 60 Issue 9 Pg. 801-5 (Sep 2011) ISSN: 1420-908X [Electronic] Switzerland
• PMID: 21607761 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Bacterial Outer Membrane Proteins
• Lipopolysaccharides

Topics

• Bacterial Outer Membrane Proteins (metabolism)
• Humans
• Lipopolysaccharides (metabolism)
• Monocytes (cytology, metabolism, microbiology)
• Neisseria meningitidis (cytology, metabolism)
• Neutralization Tests
• Neutrophils (cytology, metabolism, microbiology)