Effect of live Lactobacillus plantarum L2 on TNF-α-induced MCP-1 production in Caco-2 cells

Lactobacillus plantarum is a commensal bacterium that is known to ameliorate intestinal injury and inflammation caused by a wide variety of enteric pathogens. We hypothesized that L plantarum may exert its probiotic effects by attenuation of pro-inflammatory signaling induced by TNF-alpha. Caco-2 cells were stimulated with TNF-alpha in the presence of L plan forum L2 and Lactobacillus acidophilus LA. The protein and mRNA levels of the pro-inflammatory cytokine, MCP-1, were measured by ELISA and RT-PCR, respectively. The effect of Lactobacillus bacteria on I kappa B alpha degradation was further studied by western blotting. L. plantarum L2 and L acidophilus LA had no effect on mRNA expression and production of MCP-1 in Caco-2 cells. A significant elevation in MCP-1 mRNA and protein expression in Caco-2 cells was detected after a 4 h exposure to TNF-alpha. Pre-incubation of Caco-2 cells with L plantarum 12 for 2 h resulted in an attenuation of both MCP-1 protein production and mRNA expression in TNF-alpha-stimulated cells. L plantarum 12 also prevented I kappa B alpha degradation in TNF-alpha-stimulated Caco-2 cells. L plantarum 12 inhibited MCP-1 secretion and mRNA expression via a NF-kappa B dependent pathway by interfering with I kappa B alpha degradation in TNF-alpha-stimulated Caco-2 cells. (C) 2010 Elsevier B.V. All rights reserved.