Characterisation of EFV12 a bio-active small peptide produced by the human intestinal isolate Lactobacillus gasseri SF1109.

EFV12 is a small bioactive peptide produced by Lactobacillus gasseri SF1109, a human intestinal isolate with probiotic features. In this study, EFV12 antimicrobial and anti-inflammatory properties are characterised. In particular, we propose a possible mechanism of action for EFV12 involving bacterial membranes targeting. Moreover, we show that this small peptide is able to bind lipopolysaccharides (LPS) and to counteract its inflammatory insult preventing LPS action on Toll-like receptor 4, thus interfering with extracellular signal-regulated kinase, p38 and Jun N-terminal kinase, mitogen-activated protein kinases signalling pathways. Altogether these observations suggest that the bioactive peptide EFV12 is a good candidate to promote L. gasseri induced gut homeostasis and counteracting intestinal pathogens.

A new cryptic host defense peptide identified in human 11-hydroxysteroid dehydrogenase-1 ß-like: from in silico identification to experimental evidence.

BACKGROUND: Host defence peptides (HDPs) are evolutionarily conserved components of innate immunity. Human HDPs, produced by a variety of immune cells of hematopoietic and epithelial origin, are generally grouped into two families: beta structured defensins and variably-structured cathelicidins. We report the characterization of a very promising cryptic human HDP, here called GVF27, identified in 11-hydroxysteroid dehydrogenase-1 ß-like protein. METHODS: Conformational analysis of GVF27 and its propensity to bind endotoxins were performed by NMR, Circular Dichroism, Fluorescence and Dynamic Light Scattering experiments. Crystal violet and WST-1 assays, ATP leakage measurement and colony counting procedures were used to investigate antimicrobial, anti-biofilm, cytotoxicity and hemolytic activities. Anti-inflammatory properties were evaluated by ELISA. RESULTS: GVF27 possesses significant antibacterial properties on planktonic cells and sessile bacteria forming biofilm, as well as promising dose dependent abilities to inhibit attachment or eradicate existing mature biofilm. It is unstructured in aqueous buffer, whereas it tends to assume a helical conformation in mimic membrane environments as well as it is able to bind lipopolysaccharide (LPS) and lipoteichoic acid (LTA). Notably it is not toxic towards human and murine cell lines and triggers a significant innate immune response by attenuating expression levels of pro-inflammatory interleukins and release of nitric oxide in LPS induced macrophages. CONCLUSION: Human GVF27 may offer significant advantages as leads for the design of human-specific therapeutics. GENERAL SIGNIFICANCE: Human cryptic host defence peptides are naturally no immunogenic and for this they are a real alternative for solving the lack of effective antibiotics to control bacterial infections.

Identification of a new small bioactive peptide from Lactobacillus gasseri supernatant.

Ten lactic acid bacteria (LAB) strains, previously isolated from human ileal biopsy of healthy volunteers, were screened for production and secretion of molecules having anti-bacterial and anti-biofilm activities. Because many recent reports indicate that LAB secreted molecules may exert immune-modulatory action, we also tested the effect on human intestinal HCT116 cells challenged with bacterial lipopolysaccharides. One of the Lactobacillus gasseri strains, SF1109, strongly inhibited: (1) Pseudomonas aeruginosa growth; (2) Escherichia coli biofilm production; (3) LPS induction of P-ERK1/2 in HCT116 cells, and was selected for further characterisation of the secreted active molecule. Cell-free supernatant of the L. gasseri SF1109 was analysed and one 1.3 kDa peptide has been characterised. Eight out twelve amino acids of this peptide were identified allowing the synthesis of an octa-peptide which still presented the mentioned activities.

A retrospective analysis of the cost of hospitalizations for sickle cell disease with crisis in England, 2010/11.

BACKGROUND: Sickle cell disease (SCD) is an inherited blood disorder which may result in a broad range of complications including recurring and severe episodes of pain--sickle 'crises'--which require frequent hospitalizations. We assessed the cost of hospitalizations associated with SCD with crisis in England. METHODS: Hospital Episodes Statistics data for all hospital episodes in England between 2010 and 2011 recording Sickle Cell Anaemia with Crisis as primary diagnosis were used. The total cost of admissions and exceeded length of stay due to SCD were assessed using Healthcare Resource Groups tariffs. The impact of patients' characteristics on SCD admissions costs and the likelihood of incurring extra bed days were also examined. RESULTS: In 2010-11, England had 6077 admissions associated with SCD with crisis as primary diagnosis. The total cost for these admissions for commissioners was £18,798 255. The cost of admissions increases with age (children admissions costs 50% less than adults). Patients between 10 and 19 years old are more likely to stay longer in hospital compared with others. CONCLUSION: SCD represents a significant cost for commissioners and the NHS. Further work is required to assess how best to manage patients in the community, which could potentially lead to a reduction in hospital admissions and length of stay, and their associated costs.

Non Vascular Congenital Brain Malformations. An MR Study of 5000 Patients.

Central nervous system (CNS) malformations are frequently severe and often fatal. Diagnosis during pregnancy is of fundamental importance for a correct clinical evaluation and pharmacological management or, where possible, surgery. Modern imaging technology, pre and post-natal ultrasound scans, but above all magnetic resonance (MR) imaging have revolutionized the diagnostic study of cerebral malformations. In particular, MR provides images of the various brain sections by means of a multidisciplinary non invasive study that today is particularly rapid. MR allows an accurate assessment of cortical development, normal myelinization and the evolution of malformations. We report here our experience with MR carried out after birth on 5000 patients for the study of non vascular cortical anomalies. In only one case was the examination carried out during pregnancy, following ultrasound investigations that showed a developmental anomaly of the corpus callosum. We confirmed 112 malformations with an incidence of 2.24%, greater in males and affecting principally the anatomy of the supratentorial encephalic structures. These cases were selected and MR was carried out based on the clinical picture present at the time of the examination or a suspected diagnosis formulated following ultrasound. The ultrasound investigations were carried out principally in the obstetrics department; only a few were carried out in our unit, together with most of the postnatal ultrasound scans. The percentage of the various malformations was higher than those reported in the literature.

Monoclonal antibody detection of a major self peptide. MHC class II complex.

MHC class I and class II molecules transport foreign and self peptides to the cell surface and present them to T lymphocytes. Detection of these peptide:MHC complexes has thus far been limited to analysis of the response of a T cell. Previously, we showed that a mAb, Y-Ae, reacts with 10 to 15% of class II molecules on peripheral B lymphocytes and on cells in the thymus medulla but not thymus cortex in mice that express both I-Ab and I-Eb molecules. Elsewhere, we show that Y-Ae detects a self E alpha peptide bound to I-Ab molecules. Data presented here suggest that the antibody binds over the peptide binding groove of class II molecules, and, like a TCR, appears to recognize both the self peptide and polymorphic class II residues. In addition to B lymphocytes, the Y-Ae determinant is expressed at comparable levels on other APC, including macrophages and dendritic cells. Finally, the antibody does not react with invariant chain-associated class II complexes, thus providing direct evidence that invariant chain:class II complexes and peptide:class II complexes are mutually exclusive. These data provide further evidence that immunologic self is of limited complexity, and have important implications for T cell selection, self tolerance, and autoreactivity.