INVESTIGADORES
SERRADELL Maria De Los Angeles
congresos y reuniones científicas
Título:
Downregulation of intestinal epithelial innate response by probiotic yeast from kefir
Autor/es:
RUMBO, MARTÍN; ROMANIN, DAVID; SERRADELL, MARÍA; GONZALEZ MACIEL, DOLORES; GARROTE, GRACIELA
Lugar:
Rio de Janeiro, Brasil
Reunión:
Congreso; 13th International Congress of Immunology International Union of Immunological Societies; 2007
Institución organizadora:
International Union of Immunological Societies (IUIS)
Resumen:
There is evidence that commensal and probiotic
bacteria can modulate innate response on intestinal epithelial cells. Knowledge
on the activity of yeasts on intestinal epithelium is scarce. The aim of this
study was to select yeast strains with the capacity to downregulate innate
response in epithelial cell lines and determine the mechanisms responsible of
this activity.
Kefir grains are a complex symbiotic
association of yeasts and lactic acid bacteria and were used as source of
potentially probiotic yeasts. A panel of 30 yeast strains was screened using
Caco-2 cell line stably transfected with a luciferase reporter construction
under the control of CCL20 promotor. Several Saccharomyces and Kluyveromyces
strains were found to inhibit more than 90% the activation of the reporter
activity elicited by flagellin (1 ug/mL). The strain CIDCA 8154 of K marxianus that presented the highest
inhibitory activity was selected for further studies. This strain inhibited
completely the induction of CCL20, CXCL2 and IL-8 at the mRNA level upon
flagellin (1ug/mL), TNFa (50 ng/mL) or IL-1b (10 ng/mL) stimulation. This activity was completely dependent on yeast
viability and was not related to changes in pH of the culture medium along the
experiment. Pre-treatment of epithelial cells with the selected strain downregulate
NF-kB-dependent transcription in Caco-2 cells transiently transfected with a
NF-kB reporter construction.
This study shows that yeast strains from
different genus are able to inhibit the intestinal epithelial innate response
by downregulation of NF-kB activity, being putative candidates to be used for
modulation of intestinal inflammatory conditions.