Increasing numbers of clinical trials and animal experiments have shown that probiotic bacteria are promising tools for allergy prevention. Here, we analyzed the immunomodulatory properties of three selected lactobacillus strains and the impact of their mixture on allergic sensitization to Bet v 1 using a gnotobiotic mouse model. We showed that Lactobacillus (L.) rhamnosus LOCK0900, L. rhamnosus LOCK0908 and L. casei LOCK0919 are recognized via Toll-like receptor 2 (TLR2) and nucleotide-binding oligomerization domain-containing protein 2 (NOD2) receptors and stimulate bone marrow-derived dendritic cells to produce cytokines in species- and strain-dependent manners. Colonization of germ-free (GF) mice with a mixture of all three strains (Lmix) improved the intestinal barrier by strengthening the apical junctional complexes of enterocytes and restoring the structures of microfilaments extending into the terminal web. Mice colonized with Lmix and sensitized to the Bet v 1 allergen showed significantly lower levels of allergen-specific IgE, IgG1 and IgG2a and an elevated total IgA level in the sera and intestinal lavages as well as an increased transforming growth factor (TGF)-β level compared with the sensitized GF mice. Splenocytes and mesenteric lymph node cells from the Lmix-colonized mice showed the significant upregulation of TGF-β after in vitro stimulation with Bet v 1. Our results show that Lmix colonization improved the gut epithelial barrier and reduced allergic sensitization to Bet v 1. Furthermore, these findings were accompanied by the increased production of circulating and secretory IgA and the regulatory cytokine TGF-β. Thus, this mixture of three lactobacillus strains shows potential for use in the prevention of increased gut permeability and the onset of allergies in humans.

• MeSH
• alergie imunologie   prevence a kontrola   MeSH
• antigeny rostlinné toxicita   MeSH
• gnotobiologické modely imunologie   MeSH
• HEK293 buňky MeSH
• imunoglobulin A imunologie   MeSH
• imunoglobulin G imunologie   MeSH
• Lacticaseibacillus rhamnosus imunologie   MeSH
• Lactobacillus casei imunologie   MeSH
• lidé MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• signální adaptorový protein Nod2 imunologie   MeSH
• střevní sliznice imunologie   MeSH
• toll-like receptor 2 imunologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antigeny rostlinné MeSH
• Bet v 1 allergen, Betula MeSH Prohlížeč
• imunoglobulin A MeSH
• imunoglobulin G MeSH
• NOD2 protein, human MeSH Prohlížeč
• Nod2 protein, mouse MeSH Prohlížeč
• signální adaptorový protein Nod2 MeSH
• TLR2 protein, human MeSH Prohlížeč
• Tlr2 protein, mouse MeSH Prohlížeč
• toll-like receptor 2 MeSH

Here, we report the extensive bioinformatic and functional analyses of the unusual pLOCK 0919, a plasmid originating from the probiotic Lactobacillus casei LOCK 0919 strain. This plasmid is atypical because it harbors the spaCBA-srtC gene cluster encoding SpaCBA pili. We show that all other spaCBA-srtC sequences of the Lactobacillus genus that have been previously described and deposited in GenBank are present in the chromosomal DNA. Another important observation for pLOCK 0919 is that the spaCBA-srtC gene cluster and its surrounding genes are highly similar to the respective DNA region that is present in the most well-known and active SpaCBA pili producer, the probiotic Lactobacillus rhamnosus GG strain. Our results demonstrate that the spaCBA-srtC clusters of pLOCK 0919 and L. rhamnosus GG are genealogically similar, located in DNA regions that are rich in transposase genes and are poorly conserved among the publicly available sequences of Lactobacillus sp. In contrast to chromosomally localized pilus gene clusters from L. casei and Lactobacillus paracasei, the plasmidic spaC of L. casei LOCK 0919 is expressed and undergoes a slight glucose-induced repression. Moreover, results of series of in vitro tests demonstrate that L. casei LOCK 0919 has an adhesion potential, which is largely determined by the presence of the pLOCK 0919 plasmid. In particular, the plasmid occurrence positively influenced the hydrophobicity and aggregation abilities of L. casei LOCK 0919. Moreover, in vivo studies indicate that among the three Lactobacillus strains used to colonize the gastrointestinal tract of germ-free mice, already after 2 days of colonization, L. casei LOCK 0919 became the dominant strain and persisted there for at least 48 days.

• Klíčová slova
• Lactobacillus, adhesion, in silico analyses, plasmid, probiotic properties, spaCBA pilus cluster,
• MeSH
• aminoacyltransferasy genetika   MeSH
• bakteriální fimbrie genetika   MeSH
• bakteriální proteiny genetika   MeSH
• cysteinové endopeptidasy genetika   MeSH
• genom bakteriální * MeSH
• Lactobacillus casei genetika   MeSH
• membránové proteiny genetika   MeSH
• molekulární sekvence - údaje MeSH
• multigenová rodina * MeSH
• plazmidy genetika   MeSH
• sekvence aminokyselin MeSH
• transposasy genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• aminoacyltransferasy MeSH
• bakteriální proteiny MeSH
• cysteinové endopeptidasy MeSH
• membránové proteiny MeSH
• sortase C MeSH Prohlížeč
• SpaC protein, bacteria MeSH Prohlížeč
• transposasy MeSH

The structures of polysaccharides (PS) isolated from Lactobacillus rhamnosus LOCK 0900 and results from stimulation of mouse bone marrow-derived dendritic cells (BM-DC) and human embryonal kidney (HEK293) cells stably transfected with Toll-like receptors (TLR) upon exposure to these antigens were studied. L. rhamnosus LOCK 0900 produces PS that differ greatly in their structure. The polymer L900/2, with a high average molecular mass of 830 kDa, is a branched heteropolysaccharide with a unique repeating unit consisting of seven sugar residues and pyruvic acid, whereas L900/3 has a low average molecular mass of 18 kDa and contains a pentasaccharide repeating unit and phosphorus. Furthermore, we found that both described PS neither induce cytokine production and maturation of mouse BM-DC nor induce signaling through TLR2/TLR4 receptors. However, they differ profoundly in their abilities to modulate the BM-DC immune response to the well-characterized human isolate Lactobacillus plantarum WCFS1. Exposure to L900/2 enhanced interleukin-10 (IL-10) production induced by L. plantarum WCFS1, while in contrast, L900/3 enhanced the production of IL-12p70. We conclude that PS, probably due to their chemical features, are able to modulate the immune responses to third-party antigens. The ability to induce regulatory IL-10 by L900/2 opens up the possibility to use this PS in therapy of inflammatory conditions, such as inflammatory bowel disease, whereas L900/3 might be useful in reverting the antigen-dependent Th2-skewed immune responses in allergies.

• MeSH
• bakteriální polysacharidy chemie   imunologie   farmakologie   MeSH
• buňky kostní dřeně cytologie   MeSH
• cytokiny metabolismus   MeSH
• dendritické buňky účinky léků   imunologie   metabolismus   MeSH
• HEK293 buňky účinky léků   imunologie   MeSH
• imunologické faktory imunologie   farmakologie   MeSH
• konformace sacharidů MeSH
• Lacticaseibacillus rhamnosus chemie   imunologie   MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie MeSH
• molekulová hmotnost MeSH
• monosacharidy analýza   MeSH
• myši inbrední BALB C MeSH
• probiotika MeSH
• toll-like receptor 2 metabolismus   MeSH
• toll-like receptor 4 metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bakteriální polysacharidy MeSH
• cytokiny MeSH
• imunologické faktory MeSH
• monosacharidy MeSH
• TLR2 protein, human MeSH Prohlížeč
• TLR4 protein, human MeSH Prohlížeč
• toll-like receptor 2 MeSH
• toll-like receptor 4 MeSH