Особенности воздействия иммиграции на рынок труда развитых стран

GNA2091 of Neisseria meningitidis is a lipoprotein of unknown function that is included in the novel 4CMenB vaccine. Here, we investigated the biological function and the subcellular localization of the protein. We demonstrate that GNA2091 functions in the assembly of outer membrane proteins (OMPs) because its absence resulted in the accumulation of misassembled OMPs. Cell fractionation and protease accessibility experiments showed that the protein is localized at the periplasmic side of the outer membrane. Pulldown experiments revealed that it is not stably associated with the -barrel assembly machinery, the previously identified complex for OMP assembly. Thus, GNA2091 constitutes a novel outer membrane-based lipoprotein required for OMP assembly. Furthermore, its location at the inner side of the outer membrane indicates that protective immunity elicited by this antigen cannot be due to bactericidal or opsonic activity of antibodies

Демократия «по-украински»

Сегодня наиболее развитые государства западного мира связывают все успехи в социально-экономическом и политическом развитии именно с демократическими формами управления обществом.Сьогодні найбільш розвинені держави західного світу зв'язують всі успіхи в соціально-економічному і політичному розвитку саме з демократичними формами управління суспільством.Отрывок из книги «Украинская национальная идея и украинский национализм»

Development of 16S rRNA-Based Probes for the Coriobacterium Group and the Atopobium Cluster and Their Application for Enumeration of Coriobacteriaceae in Human Feces from Volunteers of Different Age Groups

Two 16S rRNA-targeted probes were developed: one for the Coriobacterium group and the other for the Atopobium cluster (which comprises most of the Coriobacteriaceae species, including the Coriobacterium group). The new probes were based on sequences of three new Coriobacteriaceae strains isolated from human feces and clinical material and sequences from databases. Application of the probes to fecal samples showed that formula-fed infants had higher numbers of Coriobacterium group cells in their feces than breast-fed infants. In addition, based on the presented results, it is hypothesized that with the increasing age of a person, the diversity of Atopobium cluster species present in the feces increases

Production of Extracellular Polysaccharides by CAP Mutants of Cryptococcus neoformans▿

The human pathogen Cryptococcus neoformans causes meningoencephalitis. The polysaccharide capsule is one of the main virulence factors and consists of two distinct polysaccharides, glucuronoxylomannan (GXM) and galactoxylomannan (GalXM). How capsular polysaccharides are synthesized, transported, and assembled is largely unknown. Previously, it was shown that mutations in the CAP10, CAP59, CAP60, and CAP64 genes result in an acapsular phenotype. Here, it is shown that these acapsular mutants do secrete GalXM and GXM-like polymers. GXM and GalXM antibodies specifically reacted with whole cells and the growth medium of the wild type and CAP mutants, indicating that the capsule polysaccharides adhere to the cell wall and are shed into the environment. These polysaccharides were purified from the medium, either with or without anion-exchange chromatography. Monosaccharide analysis of polysaccharide fractions by gas-liquid chromatography/mass spectrometry showed that wild-type cells secrete both GalXM and GXM. The CAP mutants, on the other hand, were shown to secrete GalXM and GXM-like polymers. Notably, the GalXM polymers were shown to contain glucuronic acid. One-dimensional 1H nuclear magnetic resonance confirmed that the CAP mutants secrete GalXM and also showed the presence of O-acetylated polymers. This is the first time it is shown that CAP mutants secrete GXM-like polymers in addition to GalXM. The small amount of this GXM-like polymer, 1 to 5% of the total amount of secreted polysaccharides, may explain the acapsular phenotype

Septal Pore Cap Protein SPC18, Isolated from the Basidiomycetous Fungus Rhizoctonia solani, Also Resides in Pore Plugs▿

The hyphae of filamentous fungi are compartmentalized by septa that have a central pore. The fungal septa and septum-associated structures play an important role in maintaining cellular and intrahyphal homeostasis. The dolipore septa in the higher Basidiomycota (i.e., Agaricomycotina) are associated with septal pore caps. Although the ultrastructure of the septal pore caps has been studied extensively, neither the biochemical composition nor the function of these organelles is known. Here, we report the identification of the glycoprotein SPC18 that was found in the septal pore cap-enriched fraction of the basidiomycetous fungus Rhizoctonia solani. Based on its N-terminal sequence, the SPC18 gene was isolated. SPC18 encodes a protein of 158 amino acid residues, which contains a hydrophobic signal peptide for targeting to the endoplasmic reticulum and has an N-glycosylation motif. Immunolocalization showed that SPC18 is present in the septal pore caps. Surprisingly, we also observed SPC18 being localized in some plugs. The data reported here strongly support the hypothesis that septal pore caps are derived from endoplasmic reticulum and are involved in dolipore plugging and, thus, contribute to hyphal homeostasis in basidiomycetous fungi

Itaconate promotes a wound resolving phenotype in pro-inflammatory macrophages

Pathological conditions associated with dysfunctional wound healing are characterized by impaired remodelling of extracellular matrix (ECM), increased macrophage infiltration, and chronic inflammation. Macrophages also play an important role in wound healing as they drive wound closure by secretion of molecules like transforming growth factor beta-1 (TGF-β). As the functions of macrophages are regulated by their metabolism, local administration of small molecules that alter this might be a novel approach for treatment of wound-healing disorders. Itaconate is a tricarboxylic acid (TCA) cycle-derived metabolite that has been associated with resolution of macrophage-mediated inflammation. However, its effects on macrophage wound healing functions are unknown. In this study, we investigated the effects of the membrane-permeable 4-octyl itaconate (4-OI) derivative on ECM scavenging by cultured human blood monocyte-derived macrophages (hMDM). We found that 4-OI reduced signalling of p38 mitogen-activated protein kinase (MAPK) induced by the canonical immune stimulus lipopolysaccharide (LPS). Likely as a consequence of this, the production of the inflammatory mediators like tumor necrosis factor (TNF)-α and cyclooxygenase (COX)-2 were also reduced. On the transcriptional level, 4-OI increased expression of the gene coding for TGF-β (TGFB1), whereas expression of the collagenase matrix metalloprotease-8 (MMP8) was reduced. Furthermore, surface levels of the anti-inflammatory marker CD36, but not CD206 and CD11c, were increased in these cells. To directly investigate the effect of 4-OI on scavenging of ECM by macrophages, we developed an assay to measure uptake of fibrous collagen. We observed that LPS promoted collagen uptake and that this was reversed by 4-OI-induced signaling of nuclear factor erythroid 2–related factor 2 (NRF2), a regulator of cellular resistance to oxidative stress and the reduced glycolytic capacity of the macrophage. These results indicate that 4-OI lowers macrophage inflammation, likely promoting a more wound-resolving phenotype

Species-Specificity of the BamA Component of the Bacterial Outer Membrane Protein-Assembly Machinery

<div><p>The BamA protein is the key component of the Bam complex, the assembly machinery for outer membrane proteins (OMP) in gram-negative bacteria. We previously demonstrated that BamA recognizes its OMP substrates in a species-specific manner <i>in vitro</i>. In this work, we further studied species specificity <i>in vivo</i> by testing the functioning of BamA homologs of the proteobacteria <i>Neisseria meningitidis</i>, <i>Neisseria gonorrhoeae</i>, <i>Bordetella pertussis</i>, <i>Burkholderia mallei</i>, and <i>Escherichia coli</i> in <i>E. coli</i> and in <i>N. meningitidis</i>. We found that no BamA functioned in another species than the authentic one, except for <i>N. gonorrhoeae</i> BamA, which fully complemented a <i>N. meningitidis bamA</i> mutant. <i>E. coli</i> BamA was not assembled into the <i>N. meningitidis</i> outer membrane. In contrast, the <i>N. meningitidis</i> BamA protein was assembled into the outer membrane of <i>E. coli</i> to a significant extent and also associated with BamD, an essential accessory lipoprotein of the Bam complex.Various chimeras comprising swapped N-terminal periplasmic and C-terminal membrane-embedded domains of <i>N. meningitidis</i> and <i>E. coli</i> BamA proteins were also not functional in either host, although some of them were inserted in the OM suggesting that the two domains of BamA need to be compatible in order to function. Furthermore, conformational analysis of chimeric proteins provided evidence for a 16-stranded β-barrel conformation of the membrane-embedded domain of BamA. </p> </div

Itaconate promotes a wound resolving phenotype in pro-inflammatory macrophages

Pathological conditions associated with dysfunctional wound healing are characterized by impaired remodelling of extracellular matrix (ECM), increased macrophage infiltration, and chronic inflammation. Macrophages also play an important role in wound healing as they drive wound closure by secretion of molecules like transforming growth factor beta-1 (TGF-β). As the functions of macrophages are regulated by their metabolism, local administration of small molecules that alter this might be a novel approach for treatment of wound-healing disorders. Itaconate is a tricarboxylic acid (TCA) cycle-derived metabolite that has been associated with resolution of macrophage-mediated inflammation. However, its effects on macrophage wound healing functions are unknown. In this study, we investigated the effects of the membrane-permeable 4-octyl itaconate (4-OI) derivative on ECM scavenging by cultured human blood monocyte-derived macrophages (hMDM). We found that 4-OI reduced signalling of p38 mitogen-activated protein kinase (MAPK) induced by the canonical immune stimulus lipopolysaccharide (LPS). Likely as a consequence of this, the production of the inflammatory mediators like tumor necrosis factor (TNF)-α and cyclooxygenase (COX)-2 were also reduced. On the transcriptional level, 4-OI increased expression of the gene coding for TGF-β (TGFB1), whereas expression of the collagenase matrix metalloprotease-8 (MMP8) was reduced. Furthermore, surface levels of the anti-inflammatory marker CD36, but not CD206 and CD11c, were increased in these cells. To directly investigate the effect of 4-OI on scavenging of ECM by macrophages, we developed an assay to measure uptake of fibrous collagen. We observed that LPS promoted collagen uptake and that this was reversed by 4-OI-induced signaling of nuclear factor erythroid 2–related factor 2 (NRF2), a regulator of cellular resistance to oxidative stress and the reduced glycolytic capacity of the macrophage. These results indicate that 4-OI lowers macrophage inflammation, likely promoting a more wound-resolving phenotype

Zinc Piracy as a Mechanism of <i>Neisseria meningitidis</i> for Evasion of Nutritional Immunity

<div><p>The outer membrane of Gram-negative bacteria functions as a permeability barrier that protects these bacteria against harmful compounds in the environment. Most nutrients pass the outer membrane by passive diffusion via pore-forming proteins known as porins. However, diffusion can only satisfy the growth requirements if the extracellular concentration of the nutrients is high. In the vertebrate host, the sequestration of essential nutrient metals is an important defense mechanism that limits the growth of invading pathogens, a process known as “nutritional immunity.” The acquisition of scarce nutrients from the environment is mediated by receptors in the outer membrane in an energy-requiring process. Most characterized receptors are involved in the acquisition of iron. In this study, we characterized a hitherto unknown receptor from <i>Neisseria meningitidis</i>, a causative agent of sepsis and meningitis. Expression of this receptor, designated CbpA, is induced when the bacteria are grown under zinc limitation. We demonstrate that CbpA functions as a receptor for calprotectin, a protein that is massively produced by neutrophils and other cells and that has been shown to limit bacterial growth by chelating Zn²⁺ and Mn²⁺ ions. Expression of CbpA enables <i>N. meningitidis</i> to survive and propagate in the presence of calprotectin and to use calprotectin as a zinc source. Besides CbpA, also the TonB protein, which couples energy of the proton gradient across the inner membrane to receptor-mediated transport across the outer membrane, is required for the process. CbpA was found to be expressed in all <i>N. meningitidis</i> strains examined, consistent with a vital role for the protein when the bacteria reside in the host. Together, our results demonstrate that <i>N. meningitidis</i> is able to subvert an important defense mechanism of the human host and to utilize calprotectin to promote its growth.</p></div

Expression and assembly of <i>N. meningitidis</i> BamA in <i>E. coli</i>.

<p>A: Expression of Nm<i>bamA</i> in <i>E. coli</i>. <i>E. coli</i> strain UTP_BAD::<i>bamA</i> containing pFP10-Nm<i>bamA</i> was grown in LB containing 0.02% arabinose in the absence or presence of IPTG. Cell envelopes were isolated and analyzed by immunoblotting with Mab α-POTRA1_Nm. B: Assembly of <i>Nm</i>BamA in the <i>E. coli</i> OM. Cell envelopes from <i>E. coli</i> strain UTP_BAD::<i>bamA</i> containing pFP10-Nm<i>bamA</i>grown in LB containing 0.02% arabinose and IPTG were extracted with urea (Ec). As a control, cell envelopes of strain HB-1 were extracted with urea (Nm). Input (i), urea-insoluble (p) and -soluble (s) fractions were analyzed by SDS-PAGE and immunoblot analysis with Mab α-POTRA1_Nm. C: Co-purification of Bam-complex components with His-tagged <i>Nm</i>BamA in <i>E. coli</i>. Cell envelopes of <i>E. coli</i> DH5α cells containing pRV-His-Nm<i>bamA</i> either induced (lanes 2) or not (lanes 1) with IPTG were extracted with Elugent and subjected to Ni²⁺-NTA purification. Shown are elution fractions analyzed by denaturing SDS-PAGE and silver staining (left panel) or immunoblotting (right panels) using antisera against the indicated proteins. As a positive control for BamB detection, cell envelopes derived from strain DH5α were also analyzed on blot (lane c). The arrow indicates the position of BamB.</p