POSTER PRESENTATION ABSTRACTS
Please note: All posters will be displayed in
Salons 10-12.
FRIDAY, 5:45-6:30 PM
Rollwagen F, Kumaki F, Ives J*, and Jonas W.
Ultra low doses of lippopolysaccharide reduce cytokine
responses to subsequent lippopolysaccharide stimulation.
Samueli Institute jives@siib.org
*Presenting author
PURPOSE: To explore a model of endotoxin tolerance
mediated by ultra-low (homeopathic) concentrations of lippopolysaccharide
(LPS).
METHODS: A potent response of macrophages to
bacterial products is the initiation of the cytokine cascade. Cultured
macrophage cell lines secrete tumor necrosis factor (TNF), Interleukin
(IL)-1 and IL-6, among others, following co-culture with E coli LPS.
Pre-exposure of macrophages to low concentrations of LPS can reduce
or abort the subsequent response to stimulatory doses, a term known
as endotoxin tolerance. In a laboratory setting, cells from the
murine cell lines RAW 264.7 and MH-S were exposed to traditional endotoxin
tolerance testing to confirm that both cell lines could be suppressed
using traditional tolerance induction methods. In a separate ultra-low
LPS experiment, cells were exposed to a stimulatory dose of E Coli LPS
for a brief, prescribed period. After thorough washing, cells were re-exposed
to ultra-low (homeopathic) concentrations of E coli LPS (below measurable
levels, 10-60 µg/ml) six times at hourly intervals. After 12 hours,
cell cultures were evaluated for IL-6 and TNF production using an ELISA.
RESULTS: The data from this study show that
post-treatment of stimulated macrophages with ultra-low (homeopathic)
LPS significantly reduced the secretion of TNS and IL-6 in MH-S cells,
with no changes in ckytokine secretion in RAW 264.7 cells. In contrast,
both cell lines were rendered unresponsive in traditional endotoxin
models.
CONCLUSION: Homeopathy is a science in which
low concentrations (often below ponderable levels) of agents are used
to alleviate numerous diseases and conditions. The exact cellular mechanisms
involved in activation of the cytokine cascade by low and ultra-low
concentrations have not been elucidated. In this study, a novel model
of endotoxin tolerance is described in which the suppressive dose is
given after a stimulatory dose. These findings suggest that the mechanism(s)
of suppression between the two models is quite different, providing
a window for the detailed examination of macrophage tolerance and a
model system for elucidating homeopathic mechanisms.
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