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Phagocytic activity of neutrophils

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https://www.readbyqxmd.com/read/28532685/nitroxide-4-hydroxy-2-2-6-6-tetramethylpiperidine-1-oxyl-tempol-inhibits-the-reductase-activity-of-protein-disulfide-isomerase-via-covalent-binding-to-the-cys400-residue-on-cxxc-redox-motif-at-the-a-active-site
#1
Gérsika Bitencourt Santos, Lucia Gonzalez-Perilli, Mauricio Mastrogiovanni, Adrián Aicardo, Cláudio Daniel Cerdeira, Andrés Trostchansky, Maísa Ribeiro Pereira Lima Brigagão
BACKGROUND AND AIM: Oxidative stress arising from inflammatory processes is a serious cause of cell and tissue damage. Tempol is an efficient antioxidant with superoxide dismutase-like activity. The purpose of this paper is to address the inhibition of protein disulfide isomerase (PDI), an essential redox chaperone whose active sites contain the Cys-Gly-His-Cys (CXXC) motif, by the nitroxide Tempol. RESULTS: In the presence of Tempol (5-120 μM), the reductase activity of PDI was reversibly affected both in vitro and in activated mice neutrophils, with an IC50 of 22...
May 19, 2017: Chemico-biological Interactions
https://www.readbyqxmd.com/read/28495931/neutrophil-extracellular-traps-drive-endothelial-to-mesenchymal-transition
#2
Elmar Pieterse, Nils Rother, Marjolein Garsen, Julia Hofstra, Simon Satchell, Markus Hoffmann, Markus Loeven, Hanneke Knaapen, Olivier van der Heijden, Jo Berden, Luuk Hilbrands, Johan van der Vlag
OBJECTIVE: An excessive release and impaired degradation of neutrophil extracellular traps (NETs) leads to the continuous exposure of NETs to the endothelium in a variety of hematologic and autoimmune disorders, including lupus nephritis. This study aims to unravel the mechanisms through which NETs jeopardize vascular integrity. APPROACH AND RESULTS: Microvascular and macrovascular endothelial cells were exposed to NETs, and subsequent effects on endothelial integrity and function were determined in vitro and in vivo...
May 11, 2017: Arteriosclerosis, Thrombosis, and Vascular Biology
https://www.readbyqxmd.com/read/28495524/granulomatosis-with-polyangiitis-wegener-granulomatosis-a-proteinase-3-driven-disease
#3
Véronique Witko-Sarsat, Nathalie Thieblemont
Granulomatosis with polyangiitis (GPA, Wegener granulomatosis) is a systemic autoimmune vasculitis that affects small arteries, arterioles, and capillaries, most notably in the kidneys and lungs. In this disease, proteinase 3 (PR3), produced by neutrophils, is targeted by antineutrophil cytoplasmic antibodies (ANCA). Recent work by our group has shown how PR3 impairs the resolution of inflammation and deregulates the immune system. Normally, the clearance of activated neutrophils triggers an anti-inflammatory, pro-resolution process...
May 8, 2017: Joint, Bone, Spine: Revue du Rhumatisme
https://www.readbyqxmd.com/read/28494242/pseudomonas-aeruginosa-effector-exos-inhibits-ros-production-in-human-neutrophils
#4
Chairut Vareechon, Stephanie Elizabeth Zmina, Mausita Karmakar, Eric Pearlman, Arne Rietsch
Neutrophils are the first line of defense against bacterial infections, and the generation of reactive oxygen species is a key part of their arsenal. Pathogens use detoxification systems to avoid the bactericidal effects of reactive oxygen species. Here we demonstrate that the Gram-negative pathogen Pseudomonas aeruginosa is susceptible to reactive oxygen species but actively blocks the reactive oxygen species burst using two type III secreted effector proteins, ExoS and ExoT. ExoS ADP-ribosylates Ras and prevents it from interacting with and activating phosphoinositol-3-kinase (PI3K), which is required to stimulate the phagocytic NADPH-oxidase that generates reactive oxygen species...
May 10, 2017: Cell Host & Microbe
https://www.readbyqxmd.com/read/28492700/coagulation-factor-xi-improves-host-defence-during-murine-pneumonia-derived-sepsis-independent-of-factor-xii-activation
#5
Ingrid Stroo, Sacha Zeerleder, Chao Ding, Brenda M Luken, Joris J T H Roelofs, Onno J de Boer, Joost C M Meijers, Francis J Castellino, Cornelis van 't Veer, Tom van der Poll
Bacterial pneumonia, the most common cause of sepsis, is associated with activation of coagulation. Factor XI (FXI), the key component of the intrinsic pathway, can be activated via factor XII (FXII), part of the contact system, or via thrombin. To determine whether intrinsic coagulation is involved in host defence during pneumonia and whether this is dependent on FXII activation, we infected in parallel wild-type (WT), FXI knockout (KO) and FXII KO mice with two different clinically relevant pathogens, the Gram-positive bacterium Streptococcus pneumoniae and the Gram-negative bacterium Klebsiella pneumoniae, via the airways...
May 11, 2017: Thrombosis and Haemostasis
https://www.readbyqxmd.com/read/28480538/glucuronides-of-phytoestrogen-flavonoid-enhance-macrophage-function-via-conversion-to-aglycones-by-%C3%AE-glucuronidase-in-macrophages
#6
Atsushi Kaneko, Takashi Matsumoto, Yosuke Matsubara, Kyoji Sekiguchi, Junichi Koseki, Ryo Yakabe, Katsuyuki Aoki, Setsuya Aiba, Kenshi Yamasaki
INTRODUCTION: Flavonoids are converted to inactive metabolites like glucuronides in the gut, and circulate mainly as glucuronides in blood stream, resulting in low concentrations of active aglycones in plasma. It is therefore unclear how oral flavonoids exert their effects in tissues. We recently reported the plasma pharmacokinetics of some flavonoids and suggested the possibility that the absorbed flavonoids modified macrophage functions leading to enhance bacterial clearance. We aimed to confirm their pharmacological profiles focusing on tissue macrophages...
May 8, 2017: Immunity, Inflammation and Disease
https://www.readbyqxmd.com/read/28480416/in-vitro-effects-of-a-commercial-herbal-medicine-used-as-african-traditional-medicine-on-human-neutrophils
#7
Mmamosheledi Elsie Mothibe, Christinah Kahler-Venter, Elżbieta Osuch
BACKGROUND: Commercial herbal medicines (CHMs) being marketed as immune boosters or tonics, have gained widespread popularity. The many herbal mixtures sold have not been tested for efficacy and safety, despite their modern packaging and presentations. It is imperative that these herbal mixtures be investigated for their effects on human neutrophils. METHODS: The selected herbal mixture (HM), Stametta™ Body healing liquid, is common in retail outlets in Pretoria, South Africa (SA) and is used as an immune booster or intended to strengthen the body...
2017: African Journal of Traditional, Complementary, and Alternative Medicines: AJTCAM
https://www.readbyqxmd.com/read/28467721/reactive-oxygen-species-regulate-both-priming-and-established-arthritis-but-with-different-mechanisms
#8
Outi Sareila, Cecilia Hagert, Tiina Kelkka, Marjo Linja, Bingze Xu, Jan Kihlberg, Rikard Holmdahl
AIMS: Neutrophil cytosolic factor 1 (NCF1) is a key regulatory component of the phagocytic NOX2 complex, which produces reactive oxygen species (ROS). Polymorphism of the Ncf1 gene is associated with increased arthritis severity. In this study, we generated targeted Ncf1 knock-in mice with inducible Ncf1 expression and determined the critical time window during which the NOX2-derived ROS protect the mice from arthritis. RESULTS: Targeted Ncf1 knock-in mice lacked NOX2-derived ROS, and in vivo allelic conversion of Ncf1 by the CreERT2 recombinase led to full protein expression and ROS production within ten days...
May 3, 2017: Antioxidants & Redox Signaling
https://www.readbyqxmd.com/read/28448042/imaging-the-neutrophil-phagosome-and-cytoplasm-using-a-ratiometric-ph-indicator
#9
Juliet R Foote, Adam P Levine, Philippe Behe, Michael R Duchen, Anthony W Segal
Neutrophils are crucial to host innate defense and, consequently, constitute an important area of medical research. The phagosome, the intracellular compartment where the killing and digestion of engulfed particles take place, is the main arena for neutrophil pathogen killing that requires tight regulation. Phagosomal pH is one aspect that is carefully controlled, in turn regulating antimicrobial protease activity. Many fluorescent pH-sensitive dyes have been used to visualize the phagosomal environment. S-1 has several advantages over other pH-sensitive dyes, including its dual emission spectra, its resistance to photo-bleaching, and its high pKa...
April 5, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28448018/live-imaging-of-antifungal-activity-by-human-primary-neutrophils-and-monocytes-in-response-to-a-fumigatus
#10
Shan F Brunel, Jude M Bain, Jill King, Lena J Heung, Shinji Kasahara, Tobias M Hohl, Adilia Warris
Aspergillus fumigatus is an opportunistic fungal pathogen causing invasive infections in immunocompromised hosts with a high case-fatality rate. Research investigating immunological responses against A. fumigatus has been limited by the lack of consistent and reliable assays for measuring the antifungal activity of specific immune cells in vitro. A new method is described to assess the antifungal activity of primary monocytes and neutrophils from human donors against A. fumigatus using FLuorescent Aspergillus REporter (FLARE) conidia...
April 19, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28435198/association-between-udder-morphology-and-in-vitro-activity-of-milk-leukocytes-in-high-yielding-crossbred-cows
#11
Tripti Sharma, Pradip Kumar Das, Prabal Ranjan Ghosh, Dipak Banerjee, Joydip Mukherjee
AIM: The present investigation was conducted to study the association between udder morphology and in vitro activity of milk leukocytes in high yielding crossbred cows. MATERIALS AND METHODS: A total of 48 healthy high yielding crossbred cows were selected for the study. The udder configuration and teat/udder morphology were recorded before milking. Milk samples (100 ml/cow) were collected aseptically. Milk somatic cell counts (SCC) and milk differential leukocyte counts were performed microscopically...
March 2017: Veterinary World
https://www.readbyqxmd.com/read/28416609/cd36-regulates-malaria-induced-immune-responses-primarily-at-early-blood-stage-infection-contributing-to-parasitemia-control-and-resistance-to-mortality
#12
Ramesh P Thylur, Xianzhu Wu, Nagaraj M Gowda, Kishore Punnath, Shivayogeeshwara E Neelgund, Maria Febbraio, D Channe Gowda
In malaria, CD36 plays several roles including mediating parasite sequestration to host organs, phagocytic clearance of parasites and regulation of immunity. While the functions of CD36 in parasite sequestration and phagocytosis have been clearly defined, less is known about its role in malaria immunity. Here, to understand the function of CD36 in malaria immunity, we studied parasite growth, innate and adaptive immune responses, and host survival in WT and Cd36-/- mice infected with a nonlethal strain of Plasmodium yoelii...
April 17, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28407017/characterizing-the-anti-inflammatory-and-tissue-protective-actions-of-a-novel-annexin-a1-peptide
#13
Mauro Perretti, Clara Di Filippo, Michele D'Amico, Jesmond Dalli
Inflammation in now appreciated to be at the centre of may diseases that affect Western civilization. Current therapeutics for managing these conditions may interfere with the host response leading to immune suppression. We recently developed an annexin (Anx) A1-derived peptide, coined CR-AnxA12-50, which displays potent pro-resolving and tissue protective actions. Herein, we designed a novel peptide using CR-AnxA12-50 as a template that was significantly more resistant to neutrophil-mediated degradation. This peptide, termed CR-AnxA12-48, retained high affinity and specificity to the pro-resolving Lipoxin A4 receptor (ALX) with an IC50 of ~20nM...
2017: PloS One
https://www.readbyqxmd.com/read/28405616/the-impact-of-environmental-enrichment-on-the-murine-inflammatory-immune-response
#14
Samuel Brod, Thomas Gobbetti, Beatrice Gittens, Masahiro Ono, Mauro Perretti, Fulvio D'Acquisto
Living in a mentally and physically stimulating environment has been suggested to have a beneficial effect on the immune response. This study investigates these effects, utilizing a 2-week program of environmental enrichment (EE) and 2 models of acute inflammation: zymosan-induced peritonitis (ZIP) and the cecal ligation and puncture (CLP) model of sepsis. Our results revealed that following exposure to EE, mice possessed a significantly higher circulating neutrophil to lymphocyte ratio compared with control animals...
April 6, 2017: JCI Insight
https://www.readbyqxmd.com/read/28401804/human-umbilical-cord-mesenchymal-stromal-cells-improve-survival-and-bacterial-clearance-in-neonatal-sepsis-in-rats
#15
Yueniu Zhu, Liqun Xu, Jennifer J P Collins, Arul Vadivel, Chanèle Cyr-Depauw, Shumei Zhong, Lars Mense, Marius A Möbius, Bernard Thébaud
Sepsis is the main cause of morbidity and mortality in neonates. Mesenchymal stromal cells (MSCs) are potent immune-modulatory cells. Their effect in neonatal sepsis has never been explored. We hypothesized that human umbilical cord-derived MSCs (hUC-MSCs) improve survival in experimental neonatal sepsis. Sepsis was induced in 3-day-old rats by intravenous injection of Escherichia coli (5 × 10(5)/rat). One hour after infection, rats were treated intravenously with normal saline, hUC-MSCs, or with interferon-γ preconditioned hUC-MSCs (10(7) cells/kg)...
May 17, 2017: Stem Cells and Development
https://www.readbyqxmd.com/read/28398824/15-deoxy-%C3%AE-12-14-prostaglandin-j2-exerts-proresolving-effects-through-nuclear-factor-e2-related-factor-2-induced-expression-of-cd36-and-heme-oxygenase-1
#16
Wonki Kim, Ha-Na Lee, Jeong-Hoon Jang, Seung Hyeon Kim, Yeon-Hwa Lee, Young-Il Hahn, Hoang-Kieu-Chi Ngo, Yeonseo Choi, Yeonsoo Joe, Hun Taeg Chung, Yingqing Chen, Young Nam Cha, Young-Joon Surh
AIMS: 15-Deoxy-Δ(12,14)-prostaglandin J2 (15d-PGJ2) has been shown to rescue cells from inflammatory insults and to participate in the resolution of acute inflammation. In this study, we investigated molecular mechanisms underlying proresolving effects of 15d-PGJ2. RESULTS: 15d-PGJ2 injected into the peritoneum of mice facilitated the resolution of zymosan A-induced peritonitis. 15d-PGJ2 administration reduced the number of total leukocytes and attenuated polymorphonuclear leukocyte infiltration...
May 12, 2017: Antioxidants & Redox Signaling
https://www.readbyqxmd.com/read/28396322/camp-elevating-capacity-of-the-adenylate-cyclase-toxin-hemolysin-is-sufficient-for-lung-infection-but-not-for-full-virulence-of-bordetella-pertussis
#17
Karolina Skopova, Barbora Tomalova, Ivan Kanchev, Pavel Rossmann, Martina Svedova, Irena Adkins, Ilona Bibova, Jakub Tomala, Jiri Masin, Nicole Guiso, Radim Osicka, Radislav Sedlacek, Marek Kovar, Peter Sebo
The adenylate cyclase toxin-hemolysin (CyaA, ACT or AC-Hly) of Bordetella pertussis targets phagocytic cells expressing the complement receptor 3 (CR3, Mac-1, αMβ2 integrin or CD11b/CD18). CyaA delivers into cells an N-terminal adenylyl cyclase (AC) enzyme domain that is activated by cytosolic calmodulin and catalyzes unregulated conversion of cellular ATP into cAMP, a key second messenger subverting bactericidal activities of phagocytes. In parallel, the hemolysin (Hly) moiety of CyaA forms cation-selective hemolytic pores that permeabilize target cell membranes...
April 10, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28377567/chronic-granulomatous-disease-presenting-as-aspergillus-fumigatus-pneumonia-in-a-previously-healthy-young-woman
#18
David Williams, Dipen Kadaria, Amik Sodhi, Roy Fox, Glenn Williams, Stephen Threlkeld
BACKGROUND Chronic Granulomatous Disease (CGD) is a rare immunodeficiency disease caused by a genetic defect in the NADPH (nicotinamide adenine dinucleotide phosphate) oxidase enzyme, resulting in increased susceptibility to bacterial and fungal infections. The inheritance can be X-linked or autosomal recessive. Patients usually present with repeated infections early in life. We present an unusual case of a 23-year-old patient diagnosed with CGD. CASE REPORT A 23-year-old white woman with no previous history of recurrent infections presented with complaints of fever, shortness of breath, and diffuse myalgia...
April 5, 2017: American Journal of Case Reports
https://www.readbyqxmd.com/read/28377108/immunological-response-to-mycobacterium-tuberculosis-infection-in-blood-from-type-2-diabetes-patients
#19
Sara Raposo-García, José Manuel Guerra-Laso, Silvia García-García, Javier Juan-García, Eduardo López-Fidalgo, Cristina Diez-Tascón, Teresa Nebreda-Mayoral, Ramiro López-Medrano, Octavio Miguel Rivero-Lezcano
The convergence of tuberculosis and diabetes represents a co-epidemic that threatens progress against tuberculosis. We have investigated type 2 diabetes as a risk factor for tuberculosis susceptibility, and have used as experimental model whole blood infected in vitro with Mycobacterium tuberculosis. Blood samples from diabetic patients were found to have a higher absolute neutrophil count that non-diabetic controls, but their immune functionality seemed impaired because they displayed a lower capacity to phagocytose M...
April 1, 2017: Immunology Letters
https://www.readbyqxmd.com/read/28373994/neutrophil-extracellular-traps-and-microcrystals
#20
REVIEW
Balázs Rada
Neutrophil extracellular traps represent a fascinating mechanism by which PMNs entrap extracellular microbes. The primary purpose of this innate immune mechanism is thought to localize the infection at an early stage. Interestingly, the ability of different microcrystals to induce NET formation has been recently described. Microcrystals are insoluble crystals with a size of 1-100 micrometers that have different composition and shape. Microcrystals have it in common that they irritate phagocytes including PMNs and typically trigger an inflammatory response...
2017: Journal of Immunology Research
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