scholarly journals Neisseria gonorrhoeaephagosomes delay fusion with primary granules to enhance bacterial survival inside human neutrophils

2013 ◽  
Vol 15 (8) ◽  
pp. 1323-1340 ◽  
Author(s):  
M. Brittany Johnson ◽  
Alison K. Criss
Keyword(s):  
Human Neutrophils ◽  
Bacterial Survival ◽  
Primary Granules

scholarly journals Activation of human neutrophils by mastoparan. Reorganization of the cytoskeleton, formation of phosphatidylinositol 3,4,5-trisphosphate, secretion up-regulation of complement receptor type 3 and superoxide anion production are stimulated by mastoparan

1992 ◽  
Vol 282 (2) ◽  
pp. 393-397 ◽  
Author(s):  
J Norgauer ◽  
M Eberle ◽  
H D Lemke ◽  
K Aktories
Keyword(s):  
Pertussis Toxin ◽  
Actin Polymerization ◽  
Cytochalasin B ◽  
Superoxide Radical ◽  
Human Neutrophils ◽  
Superoxide Anion Production ◽  
Radical Production ◽  
Rapid Formation ◽  
Primary Granules ◽  
Type 3

In human neutrophils, mastoparan induced rapid F-actin polymerization which was followed by a slow and sustained depolymerization to below the initial F-actin content. Incubation of neutrophils with pertussis toxin inhibited mastoparan-stimulated actin polymerization; however it did not prevent sustained depolymerization of F-actin. Analyses of phospholipids performed in parallel revealed that mastoparan stimulated rapid formation of phosphatidylinositol 3,4,5-trisphosphate (PIP3) and consumption of phosphatidylinositol 4,5-bisphosphate (PIP2). Pertussis toxin treatment blocked mastoparan-induced formation of PIP3. Furthermore, mastoparan stimulated the release of N-acetylglucosaminidase from primary granules. Cytochalasin B enhanced mastoparan-stimulated secretion. Mastoparan triggered superoxide radical production in a cytochalasin B-sensitive manner and induced complement type 3 receptor (CR3) up-regulation.

Morphometry of Equine Neutrophils Isolated at Different Temperatures

1982 ◽  
Vol 19 (5) ◽  
pp. 534-543 ◽  
Author(s):  
T. A. Bertram ◽  
F. L. Coignoul
Keyword(s):  
Morphometric Analysis ◽  
Peripheral Blood ◽  
Cell Swelling ◽  
Human Neutrophils ◽  
Density Gradients ◽  
Specific Granules ◽  
Neutrophil Degranulation ◽  
Different Temperatures ◽  
Primary Granules ◽  
In Cells

Equine neutrophils were evaluated ultrastructurally and by morphometric analysis. Homogeneous populations of neutrophils were isolated from peripheral blood at 4° and 22°C by centrifugation on two sequential Ficoll-Hypaque density gradients. Isolation procedures at both temperatures resulted in neutrophil degranulation but not cell swelling. Degranulation was more extensive in cells isolated at 22°C. Isolation temperature affected the neutrophil content of secondary granules more than primary granules. A granule similar to immature specific granules of human neutrophils was observed. Granules with a flocculent matrix were more frequent in cells processed at 22°C. These granules were considered to be involved in the degranulation process.

scholarly journals Roles of the Site 2 Protease Eep in Staphylococcus aureus

2020 ◽  
Vol 202 (15) ◽  
Author(s):  
Danhong Cheng ◽  
Huiying Lv ◽  
Yong Yao ◽  
Sen Cheng ◽  
Qian Huang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Drug Resistance ◽  
Sex Pheromone ◽  
Enterococcus Faecalis ◽  
Surface Proteins ◽  
Signal Peptidase ◽  
Future Research ◽  
Human Neutrophils ◽  
Bacterial Survival ◽  
Content Type

ABSTRACT In Enterococcus faecalis, the site 2 protease Eep generates sex pheromones, including cAM373. Intriguingly, in Staphylococcus aureus, a peptide similar to cAM373, named cAM373_SA, is produced from the camS gene. Here, we report that the staphylococcal Eep homolog is not only responsible for the production of cAM373_SA but also critical for staphylococcal virulence. As with other Eep proteins, the staphylococcal Eep protein has four transmembrane (TM) domains, with the predicted zinc metalloprotease active site (HEXXH) in the first TM domain. eep deletion reduced the cAM373_SA activity in the culture supernatant to the level of the camS deletion mutant. It also markedly decreased the cAM373 peptide peak in a high-performance liquid chromatography (HPLC) analysis. Proteomics analysis showed that Eep affects the production and/or the release of diverse proteins, including the signal peptidase subunit SpsB and the surface proteins SpA, SasG, and FnbA. eep deletion decreased the adherence of S. aureus to host epithelial cells; however, the adherence of the eep mutant was increased by overexpression of the surface proteins SpA, SasG, and FnbA. eep deletion reduced staphylococcal resistance to killing by human neutrophils as well as survival in a murine model of blood infection. The overexpression of the surface protein SpA in the eep mutant increased bacterial survival in the liver. Our study illustrates that in S. aureus, Eep not only generates cAM373_SA but also contributes to the survival of the bacterial pathogen in the host. IMPORTANCE The emergence of multidrug-resistant Staphylococcus aureus makes the treatment of staphylococcal infections much more difficult. S. aureus can acquire a drug resistance gene from other bacteria, such as Enterococcus faecalis. Intriguingly, S. aureus produces a sex pheromone for the E. faecalis plasmid pAM373, raising the possibility that S. aureus actively promotes plasmid conjugation from E. faecalis. In this study, we found that the staphylococcal Eep protein is responsible for sex pheromone processing and contributes to the survival of the bacteria in the host. These results will enhance future research on the drug resistance acquisition of S. aureus and can lead to the development of novel antivirulence drugs.

scholarly journals Serine-Aspartate Repeat Protein D Increases Staphylococcus aureus Virulence and Survival in Blood

2016 ◽  
Vol 85 (1) ◽  
Author(s):  
Fatemeh Askarian ◽  
Satoshi Uchiyama ◽  
J. Andrés Valderrama ◽  
Clement Ajayi ◽  
Johanna U. E. Sollid ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Ex Vivo ◽  
Innate Immune ◽  
Human Neutrophils ◽  
Infection Model ◽  
Bacterial Survival ◽  
Bacterial Killing ◽  
Content Type ◽  
Repeat Protein

ABSTRACT Staphylococcus aureus expresses a panel of cell wall-anchored adhesins, including proteins belonging to the microbial surface components recognizing adhesive matrix molecule (MSCRAMM) family, exemplified by the serine-aspartate repeat protein D (SdrD), which serve key roles in colonization and infection. Deletion of sdrD from S. aureus subsp. aureus strain NCTC8325-4 attenuated bacterial survival in human whole blood ex vivo, which was associated with increased killing by human neutrophils. Remarkably, SdrD was able to inhibit innate immune-mediated bacterial killing independently of other S. aureus proteins, since addition of recombinant SdrD protein and heterologous expression of SdrD in Lactococcus lactis promoted bacterial survival in human blood. SdrD contributes to bacterial virulence in vivo, since fewer S. aureus subsp. aureus NCTC8325-4 ΔsdrD bacteria than bacteria of the parent strain were recovered from blood and several organs using a murine intravenous infection model. Collectively, our findings reveal a new property of SdrD as an important key contributor to S. aureus survival and the ability to escape the innate immune system in blood.

scholarly journals Bordetella parapertussis Survives the Innate Interaction with Human Neutrophils by Impairing Bactericidal Trafficking inside the Cell through a Lipid Raft-Dependent Mechanism Mediated by the Lipopolysaccharide O Antigen

2012 ◽  
Vol 80 (12) ◽  
pp. 4309-4316 ◽  
Author(s):  
Juan Gorgojo ◽  
Yanina Lamberti ◽  
Hugo Valdez ◽  
Eric T. Harvill ◽  
Maria Eugenia Rodríguez
Keyword(s):  
Whooping Cough ◽  
Human Neutrophils ◽  
Bacterial Survival ◽  
Bacterial Killing ◽  
Content Type ◽  
Bordetella Parapertussis ◽  
Bacterial Surface ◽  
O Antigen ◽  
Cell Recycling ◽  
Recycling Pathway

ABSTRACTWhooping cough is a reemerging disease caused by two closely related pathogens,Bordetella pertussisandBordetella parapertussis. The incidence ofB. parapertussisin whooping cough cases has been increasing since the introduction of acellular pertussis vaccines containing purified antigens that are common to both strains. Recently published results demonstrated that these vaccines do not protect againstB. parapertussisdue to the presence of the O antigen on the bacterial surface that impairs antibody access to shared antigens. We have investigated the effect of the lack of opsonization ofB. parapertussison the outcome of its interaction with human neutrophils (polymorphonuclear leukocytes [PMNs]). In the absence of opsonic antibodies, PMN interaction withB. parapertussisresulted in nonbactericidal trafficking upon phagocytosis. A high percentage of nonopsonizedB. parapertussiswas found in nonacidic lysosome marker (lysosome-associated membrane protein [LAMP])-negative phagosomes with access to the host cell-recycling pathway of external nutrients, allowing bacterial survival as determined by intracellular CFU counts. The lipopolysaccharide (LPS) O antigen was found to be involved in directingB. parapertussisto PMN lipid rafts, eventually determining the nonbactericidal fate inside the PMN. IgG opsonization ofB. parapertussisdrastically changed this interaction by not only inducing efficient PMN phagocytosis but also promoting PMN bacterial killing. These data provide new insights into the immune mechanisms of hosts againstB. parapertussisand document the crucial importance of opsonic antibodies in immunity to this pathogen.

scholarly journals Glycosaminoglycans in human neutrophils and leukemic myeloblasts: ultrastructural, cytochemical, immunologic, and biochemical characterization

Blood ◽  
1983 ◽  
Vol 61 (2) ◽  
pp. 257-266 ◽  
Author(s):  
RT Parmley ◽  
RE Hurst ◽  
M Takagi ◽  
SS Spicer ◽  
RL Austin
Keyword(s):  
Heparan Sulfate ◽  
Chondroitin Sulfate ◽  
Biochemical Characterization ◽  
Dermatan Sulfate ◽  
Myeloid Cells ◽  
Subcellular Location ◽  
Human Neutrophils ◽  
Normal Cells ◽  
Primary Granules ◽  
Primary Granule

Chondroitin sulfate is known to be present in normal and leukemic myeloid cells; however, its definitive subcellular location and association with other glycosaminoglycans (GAGs) has not been demonstrated. We have studied the type and distribution of GAGs in neutrophil granule subpopulations of normal and leukemic myeloid cells using ultrastructural, cytochemical, immunologic, and biochemical methods. At the ultrastructural level, high-iron diamine- thiocarbohydrazide-silver proteinate (HID-TCH-SP) stained sulfated glycoconjugates selectively in immature primary granules of normal promyelocytes and Auer rods and immature granules of leukemic myeloblasts. Staining was weak or absent in mature primary granules, whereas tertiary granules stained moderately. Primary granule staining with HID-TCH-SP was greatly diminished by prior treatment of the specimens with chondroitinase ABC and/or nitrous acid, indicating the presence of chondroitin sulfate and N-sulfated glycosaminoglycan. Immunostaining of myeloid cells with a rabbit antichondroitin 4-sulfate and ferritin-conjugated goat anti-rabbit IgG sequence resulted in staining of most primary granules. Biochemical analysis of GAGs from leukemic myeloblasts containing primary granules and Auer rods, but lacking secondary and tertiary granules, revealed 8 x 10(-17) mole of uronic acid/cell and electrophoretic and sulfaminohexose analysis showed 60%-70% chondroitin sulfate AC of heterogeneous molecular weight, 20%-30% of a GAG that most closely resembled heparan sulfate, and 10% dermatan sulfate. The lack of significant HID-TCH-SP staining of sulfate iin sites other than Auer rods and primary granules in leukemic myeloblasts indicates that these granules contain the chondroitin, dermatan, and heparan sulfate isolated from the same specimen. Similar GAGs are present in primary granules of normal cells as evidenced by their cytochemical and immunostaining properties. Thus, these studies demonstrate a heterogeneous population of GAGs not previously identified and localize these substances to the primary granule of leukemic and normal cells.

Impact of sarA Mutation on Immune System Evasion and Stress Response in Staphylococcus aureus

2020 ◽  
Vol 29 (3) ◽  
pp. 105-112
Author(s):  
Yomna A. Hagag ◽  
Abdelaziz Elgaml ◽  
Ramadan Hassan ◽  
Hany I. Kenawy
Keyword(s):  
Staphylococcus Aureus ◽  
Immune System ◽  
Biofilm Formation ◽  
Type Strain ◽  
Wild Type Strain ◽  
Human Neutrophils ◽  
Bacterial Survival ◽  
Wild Type ◽  
The Impact

Background: Staphylococcus aureus is a major human pathogen responsible for a large number of infections. In S. aureus, SarA is an important global locus responsible for the regulation of virulence factors, as well as biofilm formation. Objectives: The aim of this work is to clarify the impact of SarA on biofilm formation, immune system evasion, as well as the survival of S. aureus under stress conditions. Methodology: A comparative study between S. aureus wild type strain, sarA mutant and complemented strains was established addressing the biofilm formation, opsonization, phagocytosis, as well as ability of the bacterium to survive in stressful environments including acidic pH, hyperosmotic and oxidative stress. The in vitro experiments were confirmed by challenging of mice via intraperitoneal injection with the wild type strain, sarA mutant and complemented strains. Results: Mutation of sarA diminished significantly biofilm formation. Moreover, this mutation resulted in a slight decrease in the deposition of the most important opsonin in complement-mediated immunity, named C3 on S. aureus cells. However, this mutation was associated with a significant enhancement of bacterial phagocytosis and killing by human neutrophils. Furthermore, this mutation altered bacterial survival in stressful conditions. It is also noteworthy that sarA mutation resulted in a significant higher survival rates during the challenging of mice. Conclusion: SarA plays a role as a key regulator of biofilm formation, which in turn has a great impact on immune system evasion through affecting opsonization and phagocytosis. In addition, SarA improves the ability of S. aureus to survive in stressful conditions.

scholarly journals Enhanced Pseudomonas aeruginosa Biofilm Development Mediated by Human Neutrophils

2005 ◽  
Vol 73 (6) ◽  
pp. 3693-3701 ◽  
Author(s):  
Travis S. Walker ◽  
Kerry L. Tomlin ◽  
G. Scott Worthen ◽  
Katie R. Poch ◽  
Jonathan G. Lieber ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Human Neutrophils ◽  
Bacterial Survival ◽  
Phenotypic Characteristic ◽  
Neutrophil Accumulation ◽  
Innate Response ◽  
Biofilm Development ◽  
A Site ◽  
Cellular Components

ABSTRACT Cystic fibrosis (CF) lung disease features persistent neutrophil accumulation to the airways from the time of infancy. CF children are frequently exposed to Pseudomonas aeruginosa, and by adulthood, 80% of CF patients are chronically infected. The formation of biofilms is a particularly important phenotypic characteristic of P. aeruginosa that allows for bacterial survival despite aggressive antibiotic therapy and an exuberant immune response. Here, we show that the presence of neutrophils enhances initial P. aeruginosa biofilm development over a period of 72 h through the formation of polymers comprised of actin and DNA. F-actin was found to be a site of attachment for P. aeruginosa. These actin and DNA polymers are present in CF sputum, and disruption of the polymers dispersed the associated P. aeruginosa cells and reduced biofilm development. These findings demonstrate a potential maladaptation of the primary innate response. When the host fails to eradicate the infection, cellular components from necrotic neutrophils can serve as a biological matrix to facilitate P. aeruginosa biofilm formation.

Adhesion-Dependent Release of Elastase From Human Neutrophils in a Novel, Flow-Based Model: Specificity of Different Chemotactic Agents

Blood ◽  
1998 ◽  
Vol 92 (12) ◽  
pp. 4819-4827 ◽  
Author(s):  
G. Ed Rainger ◽  
Andrew F. Rowley ◽  
Gerard B. Nash
Keyword(s):  
Current Knowledge ◽  
Platelet Activating Factor ◽  
Cytotoxic Agents ◽  
Human Neutrophils ◽  
Protective Function ◽  
Activated Neutrophils ◽  
Primary Granules ◽  
Differential Ability ◽  
Endogenous Synthesis

Neutrophils must adhere to the vessel wall, migrate, and degranulate in an ordered manner to perform their protective function. Disruption of these processes may be pathogenic. Current knowledge of the degranulation process is derived almost exclusively from studies on neutrophils in suspension, in which priming with the nonphysiological agent cytochalasin B is necessary to obtain elastase release in response to activating agents. To avoid this, we have adopted a different approach. Using a novel flow-based adhesion system, we have been able to quantify the release of elastase from the primary granules of activated neutrophils adherent to immobilized platelets or purified receptors without priming. Comparing stimuli, formyl tripeptide (fMLP), interleukin-8 (IL-8), activated complement fragment C5a, and platelet-activating factor (PAF) all induced rapid conversion to CD11b/CD18 (MAC-1) -mediated stationary adhesion when perfused over neutrophils already rolling on platelet monolayers or purified P-selectin. However, fMLP, C5a, and IL-8, but not PAF, induced release of elastase from the adherent cells in minutes. Neutrophils stimulated in suspension showed little degranulation. Treatment of neutrophils with an inhibitor of 5-lipoxygenase–activating protein (MK886) and thus synthesis of leukotrienes (LTs) or with an antagonist of the LTB4 receptor (LY223982) blocked the release of elastase. This indicated that endogenous synthesis of 5-lipoxygenase products such as LTs and autocrine activation of neutrophils was required for fMLP-driven elastase release. We hypothesize that the differential ability of PAF and fMLP to induce elastase release from surface-adherent neutrophils could arise from differential ability to generate leukotrienes, such as LTB4, and would be an appropriate mechanism for the control of elastase release during inflammation in vivo, where it is important that cytotoxic agents are not released until activated neutrophils have migrated into the extravascular tissues.

Adhesion-Dependent Release of Elastase From Human Neutrophils in a Novel, Flow-Based Model: Specificity of Different Chemotactic Agents

Blood ◽  
1998 ◽  
Vol 92 (12) ◽  
pp. 4819-4827 ◽  
Author(s):  
G. Ed Rainger ◽  
Andrew F. Rowley ◽  
Gerard B. Nash
Keyword(s):  
Current Knowledge ◽  
Platelet Activating Factor ◽  
Cytotoxic Agents ◽  
Human Neutrophils ◽  
Protective Function ◽  
Activated Neutrophils ◽  
Primary Granules ◽  
Differential Ability ◽  
Endogenous Synthesis

Abstract Neutrophils must adhere to the vessel wall, migrate, and degranulate in an ordered manner to perform their protective function. Disruption of these processes may be pathogenic. Current knowledge of the degranulation process is derived almost exclusively from studies on neutrophils in suspension, in which priming with the nonphysiological agent cytochalasin B is necessary to obtain elastase release in response to activating agents. To avoid this, we have adopted a different approach. Using a novel flow-based adhesion system, we have been able to quantify the release of elastase from the primary granules of activated neutrophils adherent to immobilized platelets or purified receptors without priming. Comparing stimuli, formyl tripeptide (fMLP), interleukin-8 (IL-8), activated complement fragment C5a, and platelet-activating factor (PAF) all induced rapid conversion to CD11b/CD18 (MAC-1) -mediated stationary adhesion when perfused over neutrophils already rolling on platelet monolayers or purified P-selectin. However, fMLP, C5a, and IL-8, but not PAF, induced release of elastase from the adherent cells in minutes. Neutrophils stimulated in suspension showed little degranulation. Treatment of neutrophils with an inhibitor of 5-lipoxygenase–activating protein (MK886) and thus synthesis of leukotrienes (LTs) or with an antagonist of the LTB4 receptor (LY223982) blocked the release of elastase. This indicated that endogenous synthesis of 5-lipoxygenase products such as LTs and autocrine activation of neutrophils was required for fMLP-driven elastase release. We hypothesize that the differential ability of PAF and fMLP to induce elastase release from surface-adherent neutrophils could arise from differential ability to generate leukotrienes, such as LTB4, and would be an appropriate mechanism for the control of elastase release during inflammation in vivo, where it is important that cytotoxic agents are not released until activated neutrophils have migrated into the extravascular tissues.

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