The different effects of probiotics treatment on Salmonella-induced interleukin-8 response in intestinal epithelia cells via PI3K/Akt and NOD2 expression.
Salmonella spp. remains a major public health problem for the whole world. Intestinal epithelial cells serve as an essential component of the innate mucosal immune system to defend against Salmonella infection. A substantial amount of evidence has accumulated that probiotics can regulate interleukin 8 (IL-8) involved in innate immunity. However, the exact effect of probiotics on epithelial IL-8 response to Salmonella infection is not well understood. Therefore, we investigated the action of probiotics on Salmonella-infected Caco-2 cells and its novel mechanisms. Two probiotic strains were examined for Salmonella-induced IL-8 responses and regulating proteins using Caco-2 cell cultures. We demonstrated probiotic, either Lactobacillus rhamnosus GG or Bifidobacterium animalis subsp. lactis DSM10140, administered before Salmonella infection conferred significantly suppressive effect on Salmonella-induced IL-8 responses in Caco-2 cells, either in secreted protein or mRNA, via the PI3K/Akt signal pathway while probiotic administered after infection enhanced Salmonella-induced IL-8 responses via nucleotide-binding oligomerisation domain-containing protein 2 expression in membrane. These findings suggest that the different regulation of probiotics on Salmonella-induced IL-8 responses in Caco-2 cells according to the administered timing supports a rationale for the therapeutic use of probiotics in the treatment of Salmonella colitis and inflammatory bowel disease. This can explain the reported controversial effect of probiotics on these diseases.
1 Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, 123, Ta-pei Road, Niao-Sung District, 833 Kaohsiung, Taiwan ROC.
F-C
FC
Huang
2 Department of Pathology, Kaohsiung Chang Gung Memorial Hospital, 123, Ta-pei Road, Niao-Sung District, 833 Kaohsiung, Taiwan ROC.
S-C
SC
Huang
D001644:Bifidobacterium; D018938:Caco-2 Cells; D004847:Epithelial Cells / Q000276:immunology; D006801:Humans; D007113:Immunity, Innate; D018928:Immunity, Mucosal; D007155:Immunologic Factors; D016209:Interleukin-8 / Q000378:metabolism; D007413:Intestinal Mucosa / Q000276:immunology; D007778:Lactobacillus; D053473:Nod2 Signaling Adaptor Protein / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D019936:Probiotics / Q000008:administration & dosage*; D012475:Salmonella / Q000276:immunology*; D012480:Salmonella Infections / Q000276:immunology* / Q000382:microbiology; D015398:Signal Transduction
C508606:CXCL8 protein, human; D007155:Immunologic Factors; D016209:Interleukin-8; C429018:NOD2 protein, human; D053473:Nod2 Signaling Adaptor Protein; D019869:Phosphatidylinositol 3-Kinases
beneficial microbes; host-microbe balance/interaction; infection; inflammation