Effect of immunobiotic lactobacilli in the response of porcine intestinal epithelial (PIE) cells to poly(I:C) challenge. Monocultures of PIE cells were stimulated with Lactobacillus rhamnosus CRL1505 (Lr1505) or L. rhamnosus CRL1506 (Lr1506) for 48 hours and then challenged with poly(I:C). The mRNA expression of IFN-α, IFN-β, IL-6, MCP-1 and TNF-α was studied in PIE cells at different time points after challenge. Cytokine mRNA levels were calibrated by the swine β-actin level and normalized by common logarithmic transformation. Values represent means and error bars indicate the standard deviations. The results are means of 3 measures repeated 4 times with independent experiments. The mean differences among different superscripts letters were significant at the 5% level.