Disruption of Lipid Rafts Modifies the Immunomodulatory Effect of Lactobacillus acidophilus in PBMC

JUAREZ G.; MECHOUD M.; FONT DE VALDÉZ G.; RODRIGUEZ A.V.

Carlos Paz, Córdoba, Argentina

Congreso; XLIV Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2008

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

DISRUPTION OF LIPID RAFTS MODIFIES THE IMMUNOMODULATORY EFFECT OF LACTOBACILLUS ACIDOPHILUS IN PBMC   Juarez GE, Mechoud MA, Font de Valdez G, Rodriguez AV. CERELA-CONICET. Chacabuco 145. CP: 4000. Tucumán, Argentina. E-mail: gjuarez@cerela.org.ar   Among the multiple health beneficial effects proposed to probiotics, is outlined their capacity to interact with the immune cells. However, up to date, the mechanisms of this effect remain unclear. We investigated whether disruption of lipid rafts could influence the effect of probiotic L. acidophilus CRL 1014 on cytokines production by human peripheral blood mononuclear blood cells (PBMC). To disrupt rafts, PBMC were treated with 10 mM methyl-β-cyclodextrin. Control (untreatedl) and disrupted-lipid rafts (d-lr) cells were co-incubated with: alive, heat-killed and UV-irradiated L. acidophilus and with bacterial cultures supernatant, at 37ºC and different incubation times. TNF-α and IL-10 were detected in co-cultures supernatant by ELISA. The results show that alive and UV-irradiated L. acidophilus stimulated TNF-α (3 times) production of control cells at 4h incubation. Similar effect was observed when PBMC were incubated with bacteria culture supernatant. This stimulatory effect was increased in d-lr cells with respect to control cells. In contrast, heat-killed bacteria produced no effect on TNF-α release by control and d-lr cells. Similar, but less pronounced effect, was observed in IL-10 release at 4 h incubation in both control and d-lr PBMC, and was significantly increased at 8 h incubation. Studies are currently in progress to further define the rafts role in this response.