12 research outputs found
Further studies on immunomodulatory effects of exopolysaccharide isolated from Lactobacillus rhamnosus KL37C
Pseudomonas aeruginosa biofilm is a potent inducer of phagocyte hyperinflammation
Objective Pseudomonas aeruginosa effectively facilitate resistance to phagocyte killing by biofilm formation. However,b the
cross talk between biofilm components and phagocytes is still unclear. We hypothesize that a biofilm provides a concentrated
extracellular source of LPS, DNA and exopolysaccharides (EPS), which polarize neighbouring phagocytes into an adverse
hyperinflammatory state of activation.
Methods We measured the release of a panel of mediators produced in vitro by murine neutrophils and macrophages exposed
to various biofilm components of P. aeruginosa cultures.
Results We found that conditioned media from a high biofilm-producing strain of P. aeruginosa, PAR5, accumulated high
concentrations of extracellular bacterial LPS, DNA and EPS by 72 h. These conditioned media induced phagocytes to release
a hyperinflammatory pattern of mediators, with enhanced levels of , IL-6, IL12p40,
and NO. Moreover, the
phagocytes also upregulated COX-2 and iNOS with no influence on the expression of arginase-1.
Conclusions Phagocytes exposed to biofilm microenvironment, called by us biofilm-associated neutrophils/macrophages
(BANs/BAMs), display secretory properties similar to that of N1/M1-type phagocytes. These results suggest that in vivo
high concentrations of LPS and DNA, trapped in biofilm by EPS, might convert infiltrating phagocytes into cells responsible
for tissue injury without direct contact with bacteria and phagocytosis
Immunosuppressive effect of systemic administration of Lactobacillus rhamnosus KL37C-derived exopolysaccharide on the OVA-specific humoral response
Identification and characterization of phage protein and its activity against two strains of multidrug-resistant Pseudomonas aeruginosa
Structural studies of the exopolysaccharide consisting of a nonasaccharide repeating unit isolated from "Lactobacillus rhamnosus" KL37B
Exopolysaccharide from Lactobacillus rhamnosus KL37 Inhibits T Cell.dependent Immune Response in Mice
Lactobacillus rhamnosus exopolysaccharide ameliorates arthritis induced by the systemic injection of collagen and lipopolysaccharide in DBA/1 mice
The structure and immunoreactivity of exopolysaccharide isolated from Lactobacillus johnsonii strain 151
Strain specific immunostimulatory potential of lactobacilli-derived exopolysaccharides
Lactobacilli, the most commonly used probiotics, show strain specific immunostimulatory effects. The strain specificity is related to the structure of cell-wall components such as lipoteichoic acids (LTAs), ligands for TLR2. In contrast, the role of exopolysaccharides (EPSs), the major components of lactobacilli biofilm, in the “cross-talk” between bacteria and the immune system is poorly documented. In this study, we have tested immunomodulating potential of lactobacilli derived EPSs, by their ability to modulate in vitro production of cytokines by murine peritoneal macrophages. We have examined EPSs of three lactobacilli strains (L. reuteri, L. johnsonii, L. animalis/murinus) isolated from colitic mice. The effect was compared with that of whole bacteria and LTA. All three nonviable Lactobacillus strains induced high amounts of cytokines with a strain specific profile. In contrast, the tested exopolysaccharides, exert low, albeit highly strain diversified stimulatory activities. The immunostimulatory potential of EPSs was correlated with the interaction strength between EPS and macrophage receptors as measured by atomic force spectroscopy