Project description:Sortases are transpeptidase enzymes that couple surface proteins to the peptidoglycan of Gram-positive bacteria. Several sortase-dependent proteins (SDPs) have been identified that are crucial for bacterial pathogenesis and, although less frequently, for the physiology of non-pathogenic bacteria. We found that an isogenic sortase A (srtA) deletion derivative (NZ7104) of Lactobacillus plantarum WCFS1 did not express any residual SrtA activity, i.e. failed to cleave the LPQTDE SrtA recognition motif. Trypsination of intact bacterial cells, followed by mass spectrometry based peptide identification, revealed a significant decrease, but not complete loss of SDPs on the NZ7104 cell surface as compared to the wildtype. Using LiCl, we further found that several SDPs could be extracted from the cell surface of NZ7104 but not from the wildtype, demonstrating that SrtA is involved in the covalent coupling of these SDPs. Neither the gastrointestinal persistence of L. plantarum in mice, nor the cytokine secretion patterns induced in monocyte derived immature dendritic cells (iDCs) was significantly affected by the srtA deletion. However, contrary to the wild-type cells, LiCl washed NZ7104 cells induced drastically increased proinflammatory cytokine production in iDCs, indicating a role of the SDPs in attenuation of immune system stimulation.
Project description:Sortases are transpeptidase enzymes that couple surface proteins to the peptidoglycan of Gram-positive bacteria. Several sortase-dependent proteins (SDPs) have been identified that are crucial for bacterial pathogenesis and, although less frequently, for the physiology of non-pathogenic bacteria. We found that an isogenic sortase A (srtA) deletion derivative (NZ7104) of Lactobacillus plantarum WCFS1 did not express any residual SrtA activity, i.e. failed to cleave the LPQTDE SrtA recognition motif. Trypsination of intact bacterial cells, followed by mass spectrometry based peptide identification, revealed a significant decrease, but not complete loss of SDPs on the NZ7104 cell surface as compared to the wildtype. Using LiCl, we further found that several SDPs could be extracted from the cell surface of NZ7104 but not from the wildtype, demonstrating that SrtA is involved in the covalent coupling of these SDPs. Neither the gastrointestinal persistence of L. plantarum in mice, nor the cytokine secretion patterns induced in monocyte derived immature dendritic cells (iDCs) was significantly affected by the srtA deletion. However, contrary to the wild-type cells, LiCl washed NZ7104 cells induced drastically increased proinflammatory cytokine production in iDCs, indicating a role of the SDPs in attenuation of immune system stimulation. array were constructed in two subdesigns: one comparing all samples from logarithmic phase (WT vs mutant) and one comparing the stationary phase samples (WT vs mutant)
Project description:Mannose-specific interactions of Lactobacillus plantarum 299v with jejunal epithelium were investigated using an in situ pig small intestinal segment perfusion (SISP) model. L. plantarum 299v wildtype strain was compared to two isogenic mutant strains either lacking the gene encoding for the mannose-specific adhesin (msa) or sortase (srtA; responsible for anchoring of cell surface proteins like Msa to the cell wall). Salmonella typhimurium served as a positive control for gene expression analysis. Scrapings from jejunal segments were collected after perfusion with bacterial suspensions or PBS (control) for 4 or 8 hours, and host gene expression was assessed using a home-made cDNA porcine microarray. Keywords: host-microbe interaction, Lactobacillus plantarum, mannose-specific adhesion
Project description:Mannose-specific interactions of Lactobacillus plantarum 299v with jejunal epithelium were investigated using an in situ pig small intestinal segment perfusion (SISP) model. L. plantarum 299v wildtype strain was compared to two isogenic mutant strains either lacking the gene encoding for the mannose-specific adhesin (msa) or sortase (srtA; responsible for anchoring of cell surface proteins like Msa to the cell wall). Salmonella typhimurium served as a positive control for gene expression analysis. Scrapings from jejunal segments were collected after perfusion with bacterial suspensions or PBS (control) for 4 or 8 hours, and host gene expression was assessed using a home-made cDNA porcine microarray. Keywords: host-microbe interaction, Lactobacillus plantarum, mannose-specific adhesion A Small Intestinal Segment Perfusion (SISP) test was performed using 4 pigs. 10 segments were prepared in the jejunum of each pig and perfused with Lactobacillus plantarum 299v wildtype, Lactobacillus plantarum 299v msa mutant strain, Lactobacillus plantarum 299v srtA mutant strain, Salmonella typhimurium or PBS (control) for 4 or 8 hours. Pooled samples from each treatment at each timepoint were used for microarray analysis. 8 comparisons were done: L. plantarum wildtype vs control (4 hours), L. plantarum wildtype vs control (8 hours), L. plantarum msa mutant vs control (4 hours), L. plantarum msa mutant vs control (8 hours), L. plantarum srt mutant vs control (4 hours), L. plantarum srt mutant vs control (8 hours), S. typhimurium vs control (8 hours), samples taken at the beginning of the experiment vs control (8 hours). Dye-swaps were performed for each comparison.
Project description:The study evaluates the effect of Lactiplantibacillus plantarum IMC 510® supplementation on anthropometric and biochemical parameters, GM composition and gastrointestinal and general symptoms of overweight/obese subjects.
