Here, we compared the abilities of polysaccharides L900/2 and L900/3, which were previously isolated from Lactobacillus rhamnosus LOCK 0900, to modulate the immune response to bystander antigens in a mouse model of ovalbumin (OVA) sensitization. In vivo, both polysaccharides reduced the levels of OVA-specific IgE, IgE-dependent basophil degranulation and IgG2a antibodies, but had no effect on the levels of OVA-specific IgA or IgG1. Interestingly, both polysaccharides triggered recall cellular responses with distinct properties. L900/3 significantly suppressed the OVA-induced upregulations of IL-4, IL-5, IL-10 and IL-13 in re-stimulated spleen cells and mesenteric lymph nodes. Our findings support and expand on our previous in vitro studies by demonstrating that polymer L900/3 might modulate the Th1/Th2 balance and could be a promising candidate molecule for preventing allergic sensitization.

• MeSH
• alergeny imunologie   MeSH
• bakteriální polysacharidy aplikace a dávkování   izolace a purifikace   MeSH
• bazofily imunologie   MeSH
• cytokiny biosyntéza   MeSH
• degranulace buněk MeSH
• imunizace * MeSH
• imunoglobulin E krev   MeSH
• imunoglobulin G krev   MeSH
• imunologické faktory aplikace a dávkování   izolace a purifikace   MeSH
• Lacticaseibacillus rhamnosus chemie   MeSH
• myši MeSH
• serpiny imunologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: The genus Lactobacillus belongs to a large heterogeneous group of low G + C Gram-positive anaerobic bacteria, which are frequently used as probiotics. The health-beneficial effects, in particular the immunomodulation effect, of probiotics depend on the strain and dose used. Strain variations may be related to diversity of the cell surface architecture of bacteria and the ability to express specific antigens or secrete compounds. The use of Lactobacillus as probiotic requires a comprehensive understanding of its effect on host immune system. To evaluate the potential immunoreactive properties of proteins isolated from four Lactobacillus strains: L. johnsonii 142 and L. johnsonii 151, L. rhamnosus LOCK 0900 and L. casei LOCK 0919, the polyclonal sera obtained from mouse and human have been tested as well as with sera from rabbits immunized with whole lactobacilli cells. RESULTS: The reactivity of isolated proteins detected by SDS-PAGE and Western blotting was heterogeneous and varied between different serum samples. The proteins with the highest immunoreactivity were isolated, purified and sequenced, in particular the fractions were identified as phosphoglycerate kinase (L. johnsonii 142), glyceraldehyde 3-phosphate dehydrogenase (L. johnosnii 142, L. rhamnosus LOCK 0900), hypothetic protein JDM1_1307 (L. johnsonii 151) and fructose/tagatose-bisphosphate-aldolase (L. casei LOCK 0919). CONCLUSION: The different prevalence of reactions against tested antigens in rabbit, mouse and human sera may indicate significant differences in immune system and commensal cross-talk in these groups. The identification of immunoreactive lactobacilli proteins opens the possibility to use them as an antigens for development of vaccines.

• MeSH
• antisérum analýza   imunologie   MeSH
• bakteriální proteiny analýza   imunologie   MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• králíci MeSH
• Lactobacillus chemie   klasifikace   imunologie   MeSH
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie 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

The Lactobacillus casei strain, LOCK 0919, is intended for the dietary management of food allergies and atopic dermatitis (LATOPIC®BIOMED). The use of a probiotic to modulate immune responses is an interesting strategy for solving imbalance problems of gut microflora that may lead to various disorders. However, the exact bacterial signaling mechanisms underlying such modulations are still far from being understood. Here, we investigated variations in the chemical compositions and immunomodulatory properties of the polysaccharides (PS), L919/A and L919/B, which are produced by L. casei LOCK 0919. By virtue of their chemical features, such PS can modulate the immune responses to third-party antigens. Our results revealed that L919/A and L919/B could both modulate the immune response to Lactobacillus planatarum WCFS1, but only L919/B could alter the response of THP-1 cells (in terms of tumor necrosis factor alpha production) to L. planatarum WCFS1 and Escherichia coli Nissle 1917. The comprehensive immunochemical characterization is crucial for the understanding of the biological function as well as of the bacteria-host and bacteria-bacteria cross-talk.

• MeSH
• buněčná imunita účinky léků   MeSH
• Escherichia coli imunologie   MeSH
• imunologické faktory chemie   imunologie   terapeutické užití   MeSH
• Lactobacillus casei chemie   imunologie   MeSH
• lidé MeSH
• polysacharidy chemie   imunologie   MeSH
• probiotika terapeutické užití   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH