CERELA   05438
CENTRO DE REFERENCIA PARA LACTOBACILOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Inhibition of TNF alpha by Lactobacillus reuteri in low cholesterol cells
Autor/es:
SORIA MA, FONT DE VALDÉZ G, RODRIGUEZ AV
Lugar:
Rosario, Santa Fé. Argentina
Reunión:
Congreso; XLII Reunión Anual Sociedad Argentina de Investigación Bioquímica y Biología Molecular; 2006
Institución organizadora:
Sociedad Argentina de Investigación Bioquímica y Biología Molecular.
Resumen:
INHIBITION OF TNF-α BY LACTOBACILLUS REUTERI IN LOW CHOLESTEROL CELLS Soria MA, Font de Valdéz G, Rodriguez AV CERELA-CONICET. Chacabuco 145. 4000 Tucumán, Argentina. E-mail: anavirr@cerela.org.ar     Several pathogen microorganisms and microbial-derived toxins interact with their target cells via cholesterol enriched plasma membrane microdomains or lipid rafts.  We investigated the role of lipid rafts in the action of a no pathogen microorganism, L. reuteri CRL 1098, on TNF-α production. To disrupt the lipid rafts of peripheral blood mononuclear cells (PBMC), cholesterol was depleted to 45% by extraction with 10 mM methyl-ß-cyclodextrin (MßCD). Control (no treatment) and low cholesterol PBMC were incubated with L. reuteri at different MOI and times of incubation at 37°C. TNF-α value detected by chemiluminiscence assay in the supernatant of 1x106 cells was 149 pg /ml. No modification was observed in TNF-α production when control and low cholesterol cells were incubated with L. reuteri at 10 MOI up to 4 h incubation. However, an inhibition of 27% and 51% of TNF-α produced was found in control and low cholesterol cells, respectively, incubated with L. reuteri at 20 MOI for 4 h, while no difference was detected in presence of heat-killed L. reuteri.  The inhibitory bacterial product was partially identified as a <10 kDa peptide. TNF-α production by control and low cholesterol PBMC was inhibited by this peptide by 41 and 63%, respectively. Studies are currently in progress to further define the role of lipid rafts in action of this peptide.