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https://www.readbyqxmd.com/read/29166587/migrating-myeloid-cells-sense-temporal-dynamics-of-chemoattractant-concentrations
#1
Caren E Petrie Aronin, Yun M Zhao, Justine S Yoon, Nicole Y Morgan, Thorsten Prüstel, Ronald N Germain, Martin Meier-Schellersheim
Chemoattractant-mediated recruitment of hematopoietic cells to sites of pathogen growth or tissue damage is critical to host defense and organ homeostasis. Chemotaxis is typically considered to rely on spatial sensing, with cells following concentration gradients as long as these are present. Utilizing a microfluidic approach, we found that stable gradients of intermediate chemokines (CCL19 and CXCL12) failed to promote persistent directional migration of dendritic cells or neutrophils. Instead, rising chemokine concentrations were needed, implying that temporal sensing mechanisms controlled prolonged responses to these ligands...
November 21, 2017: Immunity
https://www.readbyqxmd.com/read/29164871/modeling-transport-of-chemotactic-bacteria-in-granular-media-containing-distributed-contaminant-sources
#2
Joanna S T Adadevoh, Sassan Ostvar, Brian D Wood, Roseanne Marie Ford
Chemotaxis has the potential to improve bioremediation strategies by enhancing the transport of pollutant-degrading bacteria to the source of contamination, leading to increased pollutant accessibility and biodegradation. This computational study extends work reported previously in the literature to include predictions of chemotactic bacterial migration in response to multiple localized contaminant sources within porous media. An advection-dispersion model, in which chemotaxis was represented explicitly as an additional advection-like term, was employed to simulate the transport of bacteria within a sand-packed column containing a distribution of chemoattractant sources...
November 22, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/29164822/a-transposon-mutant-library-of-bacillus-cereus-atcc-10987-reveals-novel-genes-required-for-biofilm-formation-and-implicates-motility-as-an-important-factor-for-pellicle-biofilm-formation
#3
Mira Okshevsky, Matilde Greve Louw, Elena Otero Lamela, Martin Nilsson, Tim Tolker-Nielsen, Rikke Louise Meyer
Bacillus cereus is one of the most common opportunistic pathogens causing foodborne illness, as well as a common source of contamination in the dairy industry. B. cereus can form robust biofilms on food processing surfaces, resulting in food contamination due to shedding of cells and spores. Despite the medical and industrial relevance of this species, the genetic basis of biofilm formation in B. cereus is not well studied. In order to identify genes required for biofilm formation in this bacterium, we created a library of 5000 +  transposon mutants of the biofilm-forming strain B...
November 22, 2017: MicrobiologyOpen
https://www.readbyqxmd.com/read/29164154/the-application-of-dextran-sedimentation-as-an-initial-step-in-neutrophil-purification-promotes-their-stimulation-due-to-the-presence-of-monocytes
#4
Alex Quach, Antonio Ferrante
The purification of human neutrophils for in vitro studies is challenging as they are easily activated through ex vivo manipulations. The technique of erythrocyte sedimentation combined with density gradient centrifugation remains widely practiced and was the subject of this study. Since in the sedimentation step the leukocytes are incubated with dextran, we have raised the likelihood that cellular activation would occur with mediator release leading to neutrophil activation. By comparing the activity of neutrophils purified from whole blood by the classical 2-step method of dextran sedimentation followed by low-density Ficoll-Hypaque (1...
2017: Journal of Immunology Research
https://www.readbyqxmd.com/read/29163376/complete-genome-sequence-analysis-of-enterobacter-sp-sa187-a-plant-multi-stress-tolerance-promoting-endophytic-bacterium
#5
Cristina Andrés-Barrao, Feras F Lafi, Intikhab Alam, Axel de Zélicourt, Abdul A Eida, Ameerah Bokhari, Hanin Alzubaidy, Vladimir B Bajic, Heribert Hirt, Maged M Saad
Enterobacter sp. SA187 is an endophytic bacterium that has been isolated from root nodules of the indigenous desert plant Indigofera argentea. SA187 could survive in the rhizosphere as well as in association with different plant species, and was able to provide abiotic stress tolerance to Arabidopsis thaliana. The genome sequence of SA187 was obtained by using Pacific BioScience (PacBio) single-molecule sequencing technology, with average coverage of 275X. The genome of SA187 consists of one single 4,429,597 bp chromosome, with an average 56% GC content and 4,347 predicted protein coding DNA sequences (CDS), 153 ncRNA, 7 rRNA, and 84 tRNA...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/29163375/isolation-and-characterization-of-pseudomonas-spp-strains-that-efficiently-decompose-sodium-dodecyl-sulfate
#6
Ewa M Furmanczyk, Michal A Kaminski, Grzegorz Spolnik, Maciej Sojka, Witold Danikiewicz, Andrzej Dziembowski, Leszek Lipinski, Adam Sobczak
Due to their particular properties, detergents are widely used in household cleaning products, cosmetics, pharmaceuticals, and in agriculture as adjuvants tailoring the features of pesticides or other crop protection agents. The continuously growing use of these various products means that water soluble detergents have become one of the most problematic groups of pollutants for the aquatic and terrestrial environments. Thus it is important to identify bacteria having the ability to survive in the presence of large quantities of detergent and efficiently decompose it to non-surface active compounds...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/29163156/role-of-translocator-18-kda-ligands-in-the-activation-of-leukotriene-b4-activated-g-protein-coupled-receptor-and-toll-like-receptor-4-pathways-in-neutrophils
#7
Léonard de Vinci Kanda Kupa, Carine C Drewes, Eric D Barioni, Camila L Neves, Sandra Coccuzzo Sampaio, Sandra H P Farsky
TSPO (Translocator 18 KDa; tryptophan-rich sensory protein oxygen sensor) is a constitutive outer mitochondrial membrane protein overexpressed in inflammatory cells during local or systemic processes. Despite its expression is characterized, role of TSPO in inflammation remains elusive. For this study, we investigated the role of TSPO ligands on neutrophil functions elicited by two different inflammatory pathways. Peritoneal neutrophils were isolated from male Balb-C mice, treated with TSPO ligand diazepam, Ro5-4864 or PK11195 (1,100 or 1000 nM; 2 h) and further stimulated with lipopolysaccharide from Escherichia coli (LPS), a binding for Toll-Like Receptor-4 (TLR4), or leukotriene B4 (LTB4), a G-protein coupled receptor (GPCR) ligand...
2017: Frontiers in Pharmacology
https://www.readbyqxmd.com/read/29155792/assessment-of-dictyostelium-discoideum-response-to-acute-mechanical-stimulation
#8
Yulia Artemenko, Peter N Devreotes
Chemotaxis, or migration up a gradient of a chemoattractant, is the best understood mode of directed migration. Studies using social amoeba Dictyostelium discoideum revealed that a complex signal transduction network of parallel pathways amplifies the response to chemoattractants, and leads to biased actin polymerization and protrusion of a pseudopod in the direction of a gradient. In contrast, molecular mechanisms driving other types of directed migration, for example, due to exposure to shear flow or electric fields, are not known...
November 9, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/29155713/quantifying-human-monocyte-chemotaxis-in-vitro-and-murine-lymphocyte-trafficking-in-vivo
#9
Eliza Prangley, Terrence Kumar, Manish P Ponda
Chemotaxis is migration along a specific chemical gradient(1). Chemokines are chemotactic cytokines that promote cellular trafficking with anatomic and temporal specificity(2). Chemotaxis is a critical function of lymphocytes and other immune cells that can be quantitatively assessed in vitro. This manuscript describes methods that permit the evaluation of chemotaxis, both in vitro and in vivo, for diverse cell types including cell lines and native cells. The in vitro, plate-based format permits the comparison of several conditions simultaneously in real-time, and can be completed within 1-4 h...
October 30, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/29154408/chemokine-c-c-motif-ligand-25-expressed-by-trophoblast-cells-and-leukocytes-bearing-its-receptor-ccr9-an-alliance-during-embryo-implantation
#10
Rodrigo Barbano Weingrill, Mara S Hoshida, Ciro Dresch Martinhago, Simone Correa-Silva, Elaine Cardoso, Patrícia Palmeira, Claudio Romero Farias Marinho, Estela Bevilacqua
PROBLEM: We hypothesized that trophoblast expression of Ccl25 attracts a specific leukocyte cell population to the implantation site for local regulation. METHOD OF STUDY: Mice blastocysts, ectoplacental cones, and decidua at gestational days 3.5-7.5 were evaluated for Ccl25 and Ccr9 expressions. Peripheral availability and characterization of Ccr9+ leukocytes were determined by flow cytometry. Leukocyte chemotaxis was assessed in the presence of Ccl25 recombinant protein and embryos using antisense oligomers (ODNs) to Ccl25 and Ccr9 neutralizing antibody...
November 20, 2017: American Journal of Reproductive Immunology: AJRI
https://www.readbyqxmd.com/read/29150517/multi-omics-reveal-the-lifestyle-of-the-acidophilic-mineral-oxidizing-model-species-leptospirillum-ferriphilum-t
#11
Stephan Christel, Malte Herold, Sören Bellenberg, Mohamed El Hajjami, Antoine Buetti-Dinh, Igor V Pivkin, Wolfgang Sand, Paul Wilmes, Ansgar Poetsch, Mark Dopson
Leptospirillum ferriphilum plays a major role in acidic, metal rich environments where it represents one of the most prevalent iron oxidizers. These milieus include acid rock and mine drainage as well as biomining operations. Despite its perceived importance, no complete genome sequence of this model species' type strain is available, limiting the possibilities to investigate the strategies and adaptations Leptospirillum ferriphilum(T) applies to survive and compete in its niche. This study presents a complete, circular genome of Leptospirillum ferriphilum(T) DSM 14647 obtained by PacBio SMRT long read sequencing for use as a high quality reference...
November 17, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/29150498/identification-of-a-chez-like-gene-in-azorhizobium-caulinodans-a-key-gene-in-the-control-of-chemotaxis-and-colonization-of-the-host-plant
#12
Xiaolin Liu, Wei Liu, Yu Sun, Chunlei Xia, Claudine Elmerich, Zhihong Xie
Chemotaxis can provide bacteria with competitive advantages for survival in complex environments. The CheZ chemotaxis protein is a phosphatase, affecting the flagellar motor in Escherichia coli, by dephosphorylating the response regulator CheY-P protein responsible for clockwise rotation. A cheZ gene has been found in Azorhizobium caulinodans ORS571, in contrast to other rhizobial species studied so far. The CheZ protein in ORS571 has a conserved motif similar to that corresponding to the phosphatase active site in E...
November 17, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/29146598/structural-analyses-unravel-the-molecular-mechanism-of-cyclic-di-gmp-regulation-of-bacterial-chemotaxis-via-a-pilz-adaptor-protein
#13
Xin-Fu Yan, Lingyi Xin, Jackie Tan Yen, Yukai Zeng, Shengyang Jin, Qing Wei Cheang, Rachel Andrea Chea Yuen Fong, Keng-Hwee Chiam, Zhao-Xun Liang, Yong-Gui Gao
The bacterial second messenger cyclic di-GMP (c-di-GMP) has emerged as a prominent mediator of bacterial physiology, motility and pathogenicity. Cdi-GMP often regulates the function of its protein targets through a unique mechanism that involves a discrete PilZ adaptor protein. However, the molecular mechanism in c-di-GMP-mediated protein regulation is unclear. Here, we present the structure of the PilZ adaptor protein MapZ co-crystallized in complex with c-di-GMP and its protein target CheR1, a chemotaxis-regulating methyltransferase in Pseudomonas aeruginosa This co-crystal structure, together with the structure of free CheR1, revealed that the binding of c-di-GMP induces dramatic structural changes in MapZ that are crucial for CheR1 binding...
November 16, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/29142191/immune-neuroendocrine-interactions-evolution-ecology-and-susceptibility-to-illness
#14
Johanna M C Blom, Enzo Ottaviani
The integration between immune and neuroendocrine systems is crucial for maintaining homeostasis from invertebrates to humans. In the first, the phagocytic cell, i.e., the immunocyte, is the main actor, while in the latter, the principle player is the lymphocyte. Immunocytes are characterized by the presence of pro-opiomelanocortin (POMC) peptides, CRH, and other molecules that display a significant similarity to their mammalian counterparts regarding their functions, as both are mainly involved in fundamental functions such as immune (chemotaxis, phagocytosis, cytotoxicity, etc...
November 16, 2017: Medical Science Monitor Basic Research
https://www.readbyqxmd.com/read/29142050/collectin-11-promotes-the-development-of-renal-tubulointerstitial-fibrosis
#15
Weiju Wu, Chengfei Liu, Conrad A Farrar, Liang Ma, Xia Dong, Steven H Sacks, Ke Li, Wuding Zhou
Collectin-11 is a recently described soluble C-type lectin, a pattern recognition molecule of the innate immune system that has distinct roles in host defense, embryonic development, and acute inflammation. However, little is known regarding the role of collectin-11 in tissue fibrosis. Here, we investigated collectin-11 in the context of renal ischemia-reperfusion injury. Compared with wild-type littermate controls, Collec11 deficient (CL-11(-/-) ) mice had significantly reduced renal functional impairment, tubular injury, renal leukocyte infiltration, renal tissue inflammation/fibrogenesis, and collagen deposition in the kidneys after renal ischemia-reperfusion injury...
November 15, 2017: Journal of the American Society of Nephrology: JASN
https://www.readbyqxmd.com/read/29139565/leukocyte-adhesion-defect-i-rare-primary-immune-deficiency
#16
Nitesh Tewari, Vijay Prakash Mathur, Vikender Singh Yadav, Prabhat Chaudhari
Leukocyte adhesion defect I is a rare disorder (1:1,000,000) caused by diminished expression of CD-18 β2 integrins on leukocytes leading to abnormal adhesion, migration, and chemotaxis. Clinical manifestations include delayed separation of umbilical cord, omphalitis, recurrent severe infections, impaired wound healing, persistent oral ulcers, and severe periodontitis in primary and permanent dentition. A 5-year-old girl, second-born child to parents with consanguinity, presented with pain and mobility of lower teeth...
November 15, 2017: Special Care in Dentistry
https://www.readbyqxmd.com/read/29137139/deduction-of-novel-genes-potentially-involved-in-osteoblasts-of-rheumatoid-arthritis-using-next-generation-sequencing-and-bioinformatic-approaches
#17
Yi-Jen Chen, Wei-An Chang, Ya-Ling Hsu, Chia-Hsin Chen, Po-Lin Kuo
The role of osteoblasts in peri-articular bone loss and bone erosion in rheumatoid arthritis (RA) has gained much attention, and microRNAs are hypothesized to play critical roles in the regulation of osteoblast function in RA. The aim of this study is to explore novel microRNAs differentially expressed in RA osteoblasts and to identify genes potentially involved in the dysregulated bone homeostasis in RA. RNAs were extracted from cultured normal and RA osteoblasts for sequencing. Using the next generation sequencing and bioinformatics approaches, we identified 35 differentially expressed microRNAs and 13 differentially expressed genes with potential microRNA-mRNA interactions in RA osteoblasts...
November 11, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/29134930/involvement-of-many-chemotaxis-sensors-in-negative-chemotaxis-to-ethanol-in-ralstonia-pseudosolanacearum-ps29
#18
Shota Oku, Akiko Hida, Tunchai Mattana, Takahisa Tajima, Yutaka Nakashimada, Junichi Kato
Ralstonia pseudosolanacearum Ps29 showed repellent responses to alcohols including methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1,3-propanediol and prenol. R. pseudosolanacearum Ps29 possesses 22 putative chemoreceptors known as methyl-accepting chemotaxis proteins (MCPs). To identify a MCP involved in negative chemotaxis to ethanol, we measured ethanol chemotaxis of a complete collection of single mcp gene deletion mutants of R. pseudosolanacearum Ps29. However, all the mutants showed repellent responses to ethanol comparable to that of the wild-type strain...
November 14, 2017: Microbiology
https://www.readbyqxmd.com/read/29134714/identification-of-perivascular-and-stromal-mesenchymal-stem-progenitor-cells-in-porcine-endometrium
#19
J Wiater, M Niedziela, A Posmysz, K Wartalski, B Gajda, Z Smorąg, Z Rajfur, J Karasiński
Mammalian uterus contains a population of mesenchymal stem/progenitor cells that likely contribute to endometrial regeneration during each reproductive cycle. In human and mouse, they reside in perivascular, epithelial and stromal compartments of the endometrial functionalis and basalis. Here, we aimed to identify tissue resident cells expressing mesenchymal stem cell markers CD29, CD44, CD90, CD105, CD140b and CD146 in the porcine endometrium. We used single immunofluorescence and Western blotting. Each of these markers was detected in small cells surrounding endometrial blood vessels...
November 14, 2017: Reproduction in Domestic Animals, Zuchthygiene
https://www.readbyqxmd.com/read/29133402/assigning-chemoreceptors-to-chemosensory-pathways-in-pseudomonas-aeruginosa
#20
Davi R Ortega, Aaron D Fleetwood, Tino Krell, Caroline S Harwood, Grant J Jensen, Igor B Zhulin
In contrast to Escherichia coli, a model organism for chemotaxis that has 5 chemoreceptors and a single chemosensory pathway, Pseudomonas aeruginosa PAO1 has a much more complex chemosensory network, which consists of 26 chemoreceptors feeding into four chemosensory pathways. While several chemoreceptors were rigorously linked to specific pathways in a series of experimental studies, for most of them this information is not available. Thus, we addressed the problem computationally. Protein-protein interaction network prediction, coexpression data mining, and phylogenetic profiling all produced incomplete and uncertain assignments of chemoreceptors to pathways...
November 13, 2017: Proceedings of the National Academy of Sciences of the United States of America
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