Immunomodulatory Effect of Lactobacillus reuteri ( Limosilactobacillus reuteri ) and Its Exopolysaccharides Investigated on Epithelial Cell Line IPEC-J2 Challenged with Salmonella Typhimurium

• Published in: Life (Basel, Switzerland) Switzerland), 2022-11, Vol.12 (12), p.1955
• Main Authors: Kiššová, Zuzana, Tkáčiková, Ľudmila, Mudroňová, Dagmar, Bhide, Mangesh R
• Format: Article
• Language: English
• Subjects: Bacteria; Cell culture; Chemokines; Cytokines; Dilution; Epithelial cells; Epithelium; Exopolysaccharides; Experiments; Gastrointestinal system; Gastrointestinal tract; Gene expression; Immune system; Immunomodulation; Immunoregulation; Immunosuppressive agents; Infections; Inflammation; Inflammatory response; Interleukin 6; Interleukin 8; Intestine; IPEC-J2; Lactobacilli; Lactobacillus reuteri; Limosilactobacillus reuteri; Microorganisms; Pretreatment; Probiotics; Salmonella; Salmonella Typhimurium; TLR4 protein; TLR5 protein; Toll-like receptors; Tumor necrosis factor-α
• ISSN: 2075-1729; 2075-1729
• DOI: 10.3390/life12121955

The gastrointestinal tract is the largest and most complex component of the immune system. Each component influences the production and regulation of cytokines secreted by intestinal epithelial cells. The aim of this study was to see how the probiotic strain L26 and its exopolysaccharide (EPS) affect porcine intestinal-epithelial cells IPEC-J2 infected with Typhimurium. The results revealed that infection up-regulated all studied pro-inflammatory cytokines such as TNF-α, IL-8, IL-6 and TLR4, TLR5 signaling pathways, while decreasing the expression of TGF-β. An immunosuppressive activity was found in EPS-treated wells, since the transcriptional levels of the studied pro-inflammatory cytokines were not increased, and the pretreatment with EPS was even able to attenuate up-regulated pro-inflammatory genes induced by infection. However, there was a significant increase in the expression of mRNA levels of IL-8 and TNF-α in L26-treated cells, although this up-regulation was suppressed in the case of pretreatment. The immunoregulatory function of was also confirmed by the increased level of mRNA expression for TGF-β, a known immunosuppressive mediator. The most relevant finding of this ex vivo study was a case of immunity modulation, where the probiotic strain stimulated the innate immune-cell response which displayed both anti- and pro-inflammatory activities, and modulated the expression of TLRs in the IPEC-J2 cell line. Our findings also revealed that the pretreatment of cells with either EPS or live lactobacilli prior to infection has a suppressive effect on the inflammatory response induced by Typhimurium.