Showing papers by "Patrizia Brigidi published in 2009"

Prevention of TNBS‐induced colitis by different Lactobacillus and Bifidobacterium strains is associated with an expansion of γδT and regulatory T cells of intestinal intraepithelial lymphocytes

Abstract: Background: Probiotics may protect against inflammatory bowel disease through regulation of lamina propria lymphocytes (LPLs) function Data are lacking on possible involvement of intraepithelial lymphocytes (IELs) The aim of this study was to investigate whether different probiotic mixtures prevented gut inflammatory disease and the role of both IELs and LPLs Methods: BALB/c mice received 2 probiotic mixtures orally for 3 weeks, as Mix1 (Lactobacillus acidophilus and Bifidobacterium longum), or Mix2 (Lactobacillus plantarum, Streptococcus thermophilus, and Bifidobacterium animalis subsp lactis) Colitis was induced by intrarectal administration of trinitrobenzene sulfonic acid (TNBS) Probiotics in stools were analyzed by real-time polymerase chain reaction (PCR) Colon subpopulations of IELs and LPLs were assayed by flow cytometry Serum cytokines were measured by cytometric bead array (CBA) Results: All probiotics colonized the intestine The 2 mixtures prevented the TNBS-induced intestinal damage, and Mix1 was the most effective The Mix1 protection was associated with a reduction in CD4+ cells of IELs and LPLs, an increase in γδT cells of IELs, and a decrease in γδT cells of LPLs An expansion of T regulatory (Treg) cells of IELs was induced by Mix1 and Mix2 Both probiotic mixtures inhibited tumor necrosis factor (TNF)-α and monocyte chemotactic protein (MCP)-1 production and upregulated interleukin (IL)-10 In addition, Mix1 prevented the TNBS-induced increase of IL-12 and interferon (IFN)-γ Conclusions: The 2 probiotic mixtures were able to prevent the TNBS-induced colitis; the L acidophilus and B longum mixture was the most effective Other than an involvement of LPLs, our results report a novel importance of the IELs population in probiotic protection Inflamm Bowel Dis 2009

Bifidobacterial enolase, a cell surface receptor for human plasminogen involved in the interaction with the host.

Abstract: The interaction with the host plasminogen/plasmin system represents a novel component in the molecular cross-talk between bifidobacteria and human host. Here, we demonstrated that the plasminogen-binding bifidobacterial species B. longum, B. bifidum, B. breve and B. lactis share the key glycolytic enzyme enolase as a surface receptor for human plasminogen. Enolase was visualized on the cell surface of the model strain B. lactis BI07. The His-tagged recombinant protein showed a high affinity for human plasminogen, with an equilibrium dissociation constant in the nanomolar range. By site-directed mutagenesis we demonstrated that the interaction between the B. lactis BI07 enolase and human plasminogen involves an internal plasminogen-binding site homologous to that of pneumococcal enolase. According to our data, the positively charged residues Lys-251 and Lys-255, as well as the negatively charged Glu-252, of the B. lactis BI07 enolase are crucial for plasminogen binding. Acting as a human plasminogen receptor, the bifidobacterial surface enolase is suggested to play an important role in the interaction process with the host.

Quantitative variations in the vaginal bacterial population associated with asymptomatic infections: a real-time polymerase chain reaction study

Abstract: The real-time polymerase chain reaction (PCR) quantification of several vaginal bacterial groups in healthy women and patients developing asymptomatic bacterial vaginosis (BV) and candidiasis (CA) was performed. Statistical analysis revealed that the BV condition is characterised by a great variability among subjects and that it is associated with a significant increase of Prevotella, Atopobium, Veillonella and Gardnerella vaginalis, and a drop in Lactobacillus. On the contrary, the vaginal microflora of healthy women and patients developing CA was found to be homogeneous and stable over time.