Immunomodulatory effects of Lactobacillus rhamnosus CRL1505 cellular fractions on human dendritic cells and intestinal epitelial cells.

SALVA SUSANA; TISCORNIA INÉS; ALVAREZ SUSANA; ISLA MARIA INES; BOLLATI-FOGOLÍN MARIELA

Tucumán

Simposio; IV International Symposium on Lactic Acid Bacteria - Food, Health and Applications; 2013

Centro de Referencia para Lactobacilos. CERELA-CONICET

The use of non-viable lactic acid bacteria and their cellular fractions are excellent alternatives to stimulate immunity in immunocompromised hosts, in which the use of viable microorganisms could involve a risk for health. Previously we demonstrated by in vivo studies that viable Lactobacillus rhamnosus CRL1505 (Lr1505) is able to improve systemic and mucosal immunity in immunocompetent and immunocompromised hosts. The aim of this work was to evaluate the immunoenhancing properties of non-viable Lr1505 and their cellular fractions in order find suitable immunomodulatory products for their application in the recovery of immunocompromised hosts. Viable and ultraviolet (UV)-killed Lr1505 were used in experiments. In addition, intact cell wall (CW), cell wall peptidoglycan (Pg) and intracellular contents (IC) were obtained from Lr1505. NF-kB activation assays were performed in human intestinal epithelial cells (HT-29) stably transfected with plasmid pNF-kB-hrGFP. Transfectants in exponential growth phase were cultured 24 h in the absence or presence of TNF-α and with or without the addition of Lr1505 or its cellular fractions. We demonstrated that 90% of HT29-NF-kB hrGFP cells remained viable after the treatments with Lr1505 or the cellular fractions. Viable and non-viable Lr1505 as well as the cellular fraction were not able to induce activation of NF-kB determined as increased expression of GFP. However Lr1505 and Pg (50 and 100 ug/mL) significantly modulated the NF-kB activation induced by TNF-a (p