Role of toll-like receptor (TLR)-2 and TLR9 in the immunoregulatory effect of immunobiotic lactobacilli in porcine intestinal epithelial (PIE) cells and antigen presenting cells (APCs) from Peyer’s patches in response to poly(I:C). Monocultures of PIE cells or adherent cells from Peyer’s patches were stimulated with Lactobacillus rhamnosus CRL1505 (Lr1505) or L. rhamnosus CRL1506 (Lr1506) with or without the addition of anti-TLR2 or anti-TLR9 blocking antibodies. PIE and APCs were then challenged with poly(I:C). The mRNA expression of IFN-α, IFN-β, IL-6, MCP-1 and TNF-α in PIE and the mRNA expression of IFN-α, IFN-β, IL-1β, TNF-α, IFN-γ, IL-6, IL-2, IL-12, IL-10 and TGF-β in adherent cells was studied after 12 hours of poly(I:C) challenge (A). Cytokine mRNA levels were calibrated by the swine β-actin level and normalized by common logarithmic transformation. In addition, expression of MHC-II and CD80/86 molecules as well as intracellular levels of IL-1β, IL-10, IFN-γ and IL-10 (B) were studied in the three populations of APCs within adherent cells defined with CD172a and CD11R1 markers. 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.