N. Novak et al., Standardized extracts from Chinese herbs induce IL-10 production in human monocyte-derived dendritic cells and alter their differentiation in vitro, J ALLERG CL, 108(4), 2001, pp. 588-593
Background: The efficacy of traditional Chinese medicine (TCM) as a treatme
nt for atopic dermatitis has been evaluated in clinical trials. Until now,
the underlying mechanism of this treatment has remained completely elusive;
this is particularly true of its putative effects on dendritic cells (DCs)
, which might play a pivotal role in the disease.
Objective: We investigated the influence of a standardized extract from 10
Chinese herbs that was successfully used in clinical trials on the generati
on of monocyte-derived DCs from atopic donors.
Methods: Detailed phenotypic and functional exploration of DCs generated in
the presence of IL-4 and GM-CSF and treated with different concentrations
of TCM or a placebo control was performed.
Results: TCM profoundly affected the morphology and phenotype of the develo
ping DCs. They lost their typical dendritic morphology and decreased their
expression of CD1a as well as the low-affinity IgE receptor CD23. Most impo
rtantly, TCM-exposed DCs exhibited a diminished stimulatory activity toward
autologous antigen-specific and allogeneic T cells while secreting high am
ounts of IL-10.
Conclusion: TCM induces immunopharmacologic alterations on DCs from atopic
donors in vitro. These alterations might account, at least in part, for the
therapeutic effect of this treatment in AD in vivo.