Bacterial cell envelopes (ghosts) but not S-layers activate human endothelial cells (HUVECs) through sCD14 and LBP mechanism

Author(s)
S Fürst-Ladani, H Redl, A Haslberger, W Lubitz, P Messner, U B Sleytr, G Schlag
Abstract

Bacterial cell-envelopes (called ghosts) and surface layers (S-layers) are discussed to be used as vaccines and/or adjuvants, consequently it is necessary to find out which immunomodulatory mediators are induced in human cells. The present work focuses on the effects of ghosts (Escherichia coli O26:B6), S-layers (Bacillus stearothermophilus) in comparison with LPS and antibiotic-inactivated whole bacteria (E. coli O26:B6) on human umbilical vein endothelial cells (HUVEC) with regard to the release of interleukin 6 (IL-6) and the expression of surface E-selectin and the role of lipopolysaccharide binding protein (LBP), soluble CD14 (sCD14) and serum for this activation. Endothelial cells responded to ghosts, whole bacteria and LPS with IL-6 release up to 15000 pg/ml and surface E-selectin expression, while in contrast the response to S-layers with IL-6 release up to 500 pg/ml was very weak. Compared to LPS, 10-100-fold higher concentrations of bacterial ghosts and whole bacteria were required to induce the cytokine synthesis and E-selectin expression. IL-6 release and E-selectin expression of HUVECs were reduced in the absence of serum and equivalent to unstimulated samples. We have also studied the role of CD14 and LBP for the activation of endothelial cells using antiCD14 and antiLBP antibodies (Ab). AntiCD14 and antiLBP Ab both inhibited IL-6 release and E-selectin expression in a dose dependent manner after stimulation with ghosts, whole bacteria and LPS but had no effect on S-layers stimulated cells. AntiCD14 Ab inhibited more effectively than antiLBP Ab. These findings suggest that bacterial ghosts but not S-layers activate HUVECs through sCD14 and LBP dependent mechanisms.

Organisation(s)
Department of Geography and Regional Research, Department of Nutritional Sciences, Department of Biochemistry and Cell Biology
Journal
Vaccine
Volume
18
Pages
440-8
No. of pages
9
ISSN
0264-410X
Publication date
10-1999
Peer reviewed
Yes
Austrian Fields of Science 2012
302002 Allergology
Keywords
Sustainable Development Goals
SDG 3 - Good Health and Well-being
Portal url
https://ucrisportal.univie.ac.at/en/publications/bacterial-cell-envelopes-ghosts-but-not-slayers-activate-human-endothelial-cells-huvecs-through-scd14-and-lbp-mechanism(5863e6a5-6c91-4af3-9fc2-c005909b2025).html