期刊名称：Annals of Agricultural and Environmental Medicine
印刷版ISSN：1232-1966
电子版ISSN：1898-2263
出版年度：2008
卷号：15
期号：01
页码：153-153
出版社：Institute of Agricultural Medicine in Lublin
摘要：In the environment, Gram-negative bacteria are capable of producing large
amounts of endotoxin-containing microvesicles ¨C spherical structures measuring 30¨C5
nm in diameter, emerging by fragmentation of the outer membrane of the bacterial cell
wall. Microvesicles are suspected of inducing in? ammatory lung diseases, but possibly
also of stimulating anti-tumour defence mechanisms. The present study was aimed at
assessing the pro-in? ammatory and anti-tumour properties of microvesicles in vitro. Pe-
ripheral blood mononuclear cells of 5 healthy volunteers were cultured for 6 h, 24 h,
3 days, and 5 days with microvesicles (MV) of Pantoea agglomerans at concentrations
ranging from 0.48¨C1500g/ml. The following outcomes were measured: secretion of
IFN- and TNF- (by ELISA and ELISpot), intensity of cell proliferation (LPT), expres-
sion of surface markers CD8, CD14, CD16, CD25, CD69, CD80, CD83, HLA-DR, and
apoptosis markers (by ? ow cytometry). After 24 hours, a clear dose-dependent response
to microvesicles was seen for IFN- production, starting already at the lowest concentra-
tion of 0.48 g/ml (p=0.04). A 2-fold increase in TNF- production was seen after 3
days at the concentration of 1,500 g/ml (p=0.05). A clear and signi? cant dose-dependent
increase in cell proliferation in response to MV was detectable after 5 days (p=0.001).
A decrease in the percentage of CD14(+)CD83(+) monocytes was observed after 1 day
of culture. We conclude that IFN- and TNF- are triggered at different concentrations
of microvesicles: at lower concentrations only IFN- is upregulated, whereas at higher
concentrations both IFN- and TNF- are secreted.
