Search results for "Bacteria"
showing 10 items of 4919 documents
Tight Junctions as a Key for Pathogens Invasion in Intestinal Epithelial Cells
2021
Tight junctions play a major role in maintaining the integrity and impermeability of the intestinal barrier. As such, they act as an ideal target for pathogens to promote their translocation through the intestinal mucosa and invade their host. Different strategies are used by pathogens, aimed at directly destabilizing the junctional network or modulating the different signaling pathways involved in the modulation of these junctions. After a brief presentation of the organization and modulation of tight junctions, we provide the state of the art of the molecular mechanisms leading to permeability breakdown of the gut barrier as a consequence of tight junctions’ attack by pathogens, including…
Hetero-oligomerization of Bacillus thuringiensis Cry1A proteins enhance binding to the ABCC2 transporter of Spodoptera exigua
2021
The ATP binding cassette (ABC) transporters are membrane proteins that can act as putative receptors for Cry proteins from Bacillus thuringiensis (Bt) in the midgut of different insects. For the beet armyworm, Spodoptera exigua, ABCC2 and ABCC3 have been found to interact with Cry1A proteins, the main insecticidal proteins used in Bt crops, as well as Bt-based pesticides. The ABCC2 has shown to have specific binding towards Cry1Ac and is involved in the toxic process of Cry1A proteins, but the role of this transporter and how it relates with the Cry1A proteins is still unknown. Here, we have characterized the interactions between the SeABCC2 and the main proteins that bind to the receptor. …
Transcytosis of Bacillus subtilis extracellular vesicles through an in vitro intestinal epithelial cell model
2020
Bacterial EVs have been related to inter-kingdom communication between probiotic/pathogenic bacteria and their hosts. Our aim was to investigate the transcytosis process of B. subtilis EVs using an in vitro intestinal epithelial cell model. In this study, using Confocal Laser Scanning Microscopy, we report that uptake and internalization of CFSE-labeled B. subtilis EVs (115 nm ± 27 nm) by Caco-2 cells are time-dependent. To study the transcytosis process we used a transwell system and EVs were quantified in the lower chamber by Fluorescence and Nanoparticle Tracking Analysis measurements. Intact EVs are transported across a polarized cell monolayer at 60–120 min and increased after 240 min …
Carob leaf polyphenols trigger intrinsic apoptotic pathway and induce cell cycle arrest in colon cancer cells
2017
IF 3.973; International audience; Chemoprevention of Colorectal cancer (CRC) is the major concern for improving public health. We investigated the protective effects of carob, Ceratonia siliqua L, leaf polyphenols (CLP) against CRC. Phenolic content analysis showed that CLP is enriched with gallic acid and m-coumaric acid. We observed that CLP exerted a dose dependent cytotoxic effect through the induction of apoptosis on CRC cell lines, with an IC50 around 20 mu g/mL CLP induced intrinsic apoptotic pathway through the caspase-9 activation and PARP cleavage in HCT-116 and CT-26 cells. Moreover, CLP induced cell cycle arrest in the G1 phase through p53 activation. Gallic acid and m-coumaric …
Grey Matter Microstructural Integrity Alterations in Blepharospasm Are Partially Reversed by Botulinum Neurotoxin Therapy.
2016
OBJECTIVE Benign Essential Blepharospasm (BEB) and hemifacial spasm (HFS) are the most common hyperkinetic movement disorders of facial muscles. Although similar in clinical presentation different pathophysiological mechanisms are assumed. Botulinum Neurotoxin (BoNT) is a standard evidence-based treatment for both conditions. In this study we aimed to assess grey matter microstructural differences between these two groups of patients and compared them with healthy controls. In patients we furthermore tracked the longitudinal morphometric changes associated with BoNT therapy. We hypothesized microstructural differences between the groups at the time point of maximum symptoms representation a…
FLT3 Ligand as a Molecular Adjuvant for Naked RNA Vaccines
2016
Intranodal immunization with antigen-encoding naked mRNA has proven to be an efficacious and safe approach to induce antitumor immunity. Thanks to its unique characteristics, mRNA can act not only as a source for antigen but also as an adjuvant for activation of the immune system. The search for additional adjuvants that can be combined with mRNA to further improve the potency of the immunization revealed Fms-like tyrosine kinase 3 (FLT3) ligand as a potent candidate. Systemic administration of the dendritic cell-activating FLT3 ligand prior to or along with mRNA immunization-enhanced priming and expansion of antigen-specific CD8(+) T cells in lymphoid organs, T-cell homing into melanoma tu…
Whole-genome sequencing of Neisseria gonorrhoeae in a forensic transmission case.
2019
Abstract Molecular epidemiology and phylogenetic analyses are frequently used in the investigation of viral transmission cases in forensic contexts. Here, we present the methods and results of the analysis of a bacterial transmission episode in an alleged child abuse case using complete genome sequences obtained by high-throughput sequencing (HTS) methods. We obtained genomes of Neisseria gonorrhoeae from the victim, the suspect, and 29 unrelated controls. The analysis of the genomes revealed that the victim and suspect isolates had identical sequences in both the bacterial chromosome and the single plasmid present in them. One of the local controls was very similar (differing in only 2 SNP…
Reanalysis of Chinese Treponema pallidum samples: all Chinese samples cluster with SS14-like group of syphilis-causing treponemes
2018
[Objective]: Treponema pallidum subsp. pallidum (TPA) is the causative agent of syphilis. Genetic analyses of TPA reference strains and human clinical isolates have revealed two genetically distinct groups of syphilis-causing treponemes, called Nichols-like and SS14-like groups. So far, no genetic intermediates, i.e. strains containing a mixed pattern of Nichols-like and SS14-like genomic sequences, have been identifed. Recently, Sun et al. (Oncotarget 2016. https://doi. org/10.18632/oncotarget.10154) described a new “phylogenetic group” (called Lineage 2) among Chinese TPA strains. This lineage exhibited a “mosaic genomic structure” of Nichols-like and SS14-like lineages.
A New Niche for Anoxygenic Phototrophs as Endoliths
2018
ABSTRACT Anoxygenic phototrophic bacteria (APBs) occur in a wide range of aquatic habitats, from hot springs to freshwater lakes and intertidal microbial mats. Here, we report the discovery of a novel niche for APBs: endoliths within marine littoral carbonates. In a study of 40 locations around Isla de Mona, Puerto Rico, and Menorca, Spain, 16S rRNA high-throughput sequencing of endolithic community DNA revealed the presence of abundant phylotypes potentially belonging to well-known APB clades. An ad hoc phylogenetic classification of these sequences enabled us to refine the assignments more stringently. Even then, all locations contained such putative APBs, often reaching a significant pro…
Mg2+ homeostasis and transport in cyanobacteria – at the crossroads of bacterial and chloroplast Mg2+ import
2018
Abstract Magnesium cation (Mg2+) is the most abundant divalent cation in living cells, where it is required for various intracellular functions. In chloroplasts and cyanobacteria, established photosynthetic model systems, Mg2+ is the central ion in chlorophylls, and Mg2+ flux across the thylakoid membrane is required for counterbalancing the light-induced generation of a ΔpH across the thylakoid membrane. Yet, not much is known about Mg2+ homoeostasis, transport and distribution within cyanobacteria. However, Mg2+ transport across membranes has been studied in non-photosynthetic bacteria, and first observations and findings are reported for chloroplasts. Cyanobacterial cytoplasmic membranes…