[The influence of the LPS from Bacteroides fragilis on the secretion of IL-2 and IL-4 from the peripheral blood mononuclear cells of normal volunteers].
OBJECTIVE
To investigate the influence of the LPS of Bacteroides fragilis on the secretion of IL-2 and IL-4 from the peripheral blood mononuclear cells of normal individuals, so as to elucidate the mechanism of the infection by Bacteroides fragilis.


METHODS
LPS was obtained from both the strains isolated from patients and from standard NCTC9343. Peripheral blood mononuclear cells (PBMCs) were treated with different concentrations of LPS thus obtained. The supernatants from the cell culture of the PBMCs were harvested at 24 PBHs and were subjected to the determination of the IL-2 and IL-4 contents by ELISA method. RESULTS The IL-2 secretion from the PBMCs of normal volunteers was obviously inhibited by the LPS from Bacteroides fragilis (P < 0.01), and the inhibitory effect was dose-dependent. Nevertheless, the IL-4 secretion from the PBMCs of normal volunteers was significantly stimulated by the LPS from Bacteroides Fragilis (P < 0.05), and it was not concentration dependent. There was no difference between the effects of the LPSs from patients and standard strains (P < 0.05).


CONCLUSIONS
The LPS from Bacteroides fragilis was inhibitory to the secretion of IL-2 from PBMCs and was stimulative to that of IL-4 from PBMCs of normal human persons.
Zhou
Jie
J
Department of Burns and Plastic Surgery, Xiangya Hospital, Central South University Changsha, 410008, Hunan Province, P.R. China.
Huang
Xiao-Yuan
XY
Ren
Li-Cheng
LC
Tang
Yin
Y
D001441:Bacteroides fragilis / Q000378:metabolism*; D002478:Cells, Cultured; D006801:Humans; D007376:Interleukin-2 / Q000276:immunology / Q000378:metabolism*; D015847:Interleukin-4 / Q000276:immunology / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D009000:Monocytes / Q000187:drug effects* / Q000276:immunology
D007376:Interleukin-2; D008070:Lipopolysaccharides; D015847:Interleukin-4