Background: Sugar moiety of macromolecules is today very well known for its
implications in many biological recognition mechanisms including cell-cell,
extracellular matrix-cell and/or bacteria-cell interactions. In this context
lectins, which are carbohydrate-binding proteins displaying a high affinity for
sugar groups of other molecules, are of a great importance, notably in immune response
involving bacteria, viruses and fungi. As protein-carbohydrate interactions are
often mediated by ions such as calcium, zinc or magnesium, we were prompted to
study the effect of a thermal spring water (which contains this type of
component) on interactions existing between: 1) osidic receptors of human
normal keratinocytes and 2) two lectins greatly implicated in the immune
response mechanisms (i.e. the
dectin-1 and the langerin), and their ligands. Materials and Methods: In
a first series of experiments, we studied the effect of increasing
concentrations of a thermal spring water on interactions existing between glycosylated molecules and the osidic receptors
expressed at the normal human keratinocytes surface. In a second step, and in
order to better understand the putative effect of our thermal spring water on
the immune response, we analyzed its effect on the interactions existing
between the dectin-1 (implicated in the recognition of bacteria, viruses and
fungi) and the langerin (expressed by Langerhans cells, the immune cells of the
cutaneous tissue), and their ligands in a model using recombinant human lectins
and appropriate binding molecules. Results: We showed here that our
thermal spring water was able to reinforce interactions between keratinocytes
osidic receptors and some of their ligands,
in a dose-related manner: From 8% to 55% of increase with 10% to 30% (v/v) of
thermal spring water. In the second part of our studies, we also showed that
our thermal spring water was able to modulate interactions between dectin-1 and
langerin and their ligands through a biphasic effect: Interactions were
enhanced by more than 40% and 20% respectively with 10% of thermal spring water,
and return to their basal level or lower for higher concentrations. Conclusion: The tested thermal spring water, probably due to its ionic composition, could
significantly affect interactions of osidic receptors with their ligands. This
property could be of a great interest to help immune system to maintain an
appropriate “vigilance state” by using the thermal water at up to a
concentration of 10%, and by avoiding any runaway reaction in case of
aggression, by using concentrations higher than 10%.