title: Lactobacillus plantarum reduces Streptococcus pyogenes virulence by modulating the IL-17, IL-23 and Toll-like receptor 2/4 expressions in human epithelial cells.
abstract: Streptococcus pyogenes is a common colonizer of the mucosal layers in the mouth, nose, and pharynx but it is also a major Gram-positive human pathogen that causes infections ranging from pharyngitis to severe systemic diseases. The lactobacilli colonize the oral tracts and are known to protect against colonization by many pathogens. Epithelial cells participate in the innate host defense by expressing a variety of proinflammatory cytokines and TLRs in the interaction with microorganisms. The potentially probiotic strain Lactobacillus plantarum was investigated for its capacity to influence the innate immune response of HEp-2 and A549 epithelial cells to S. pyogenes infection. In both epithelial cell types, pre-treatment with L. plantarum showed inhibition of S. pyogenes growth and a greater decrease in IL-17 and IL-23 levels compared to the control. Pre-treatment with the anti-TLR2/4 antibody abolished the inhibitory effects of L. plantarum on IL-17 and IL-23 production following S. pyogenes infection, indicating that L. plantarum downregulates TLR2/4-dependent IL-17 and IL-23 production. Overall, our findings suggest that in epithelial cell cultures with S. pyogenes, cytokine responses are modulated by the presence of L. plantarum through the induction of TLR2/TLR4.
authors.affiliation: Department of Experimental Medicine, Second University of Naples, Naples, Italy. antonietta.rizzo@unina2.it
authors.forename: Antonietta
authors.initials: A
authors.lastname: Rizzo
authors.forename: Antonio
authors.initials: A
authors.lastname: Losacco
authors.forename: Caterina Romano
authors.initials: CR
authors.lastname: Carratelli
authors.forename: Marina Di
authors.initials: MD
authors.lastname: Domenico
authors.forename: Nazario
authors.initials: N
authors.lastname: Bevilacqua
mesh_terms: D002460:Cell Line; D004847:Epithelial Cells / Q000276:immunology* / Q000382:microbiology; D005786:Gene Expression Regulation; D054884:Host-Pathogen Interactions; D006801:Humans; D007113:Immunity, Innate; D020381:Interleukin-17 / Q000378:metabolism; D053759:Interleukin-23 / Q000378:metabolism; D048191:Lactiplantibacillus plantarum / Q000276:immunology*; D013297:Streptococcus pyogenes / Q000276:immunology* / Q000472:pathogenicity*; D051195:Toll-Like Receptor 2 / Q000235:genetics / Q000378:metabolism*; D051197:Toll-Like Receptor 4 / Q000235:genetics / Q000378:metabolism*; D014774:Virulence / Q000276:immunology
chemical_list: D020381:Interleukin-17; D053759:Interleukin-23; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4
keywords: 3-[4.5-dimethyl-2.5 thiazolyl]-2.5 diphenyl tetrazolium bromide; A549; ATCC; Abs; American Type Culture Collection; BH; CFU; ELISA; Epithelial cells; FI; GAS; HEp-2; IL; IL-17; IL-23; Lac; Lactobacillus plantarum; MOI; MTT; PBS; RT-PCR; Streptococcus pyogenes; TBE; TLR 2/4; TLRs; Toll-like receptors; Tris–borate–EDTA; antibodies; brain heart; cDNA; colony-forming units; complementary DNA; enzyme-linked immunosorbent assay; fluorescence intensity; group A Streptococci; human laryngeal carcinoma cell line; human lung alveolar epithelial cell line; interleukin; mRNA; messenger RNA; multiplicity of infection; phosphate-buffered saline; reverse transcriptase PCR