scholarly journals Sulfate import in Salmonella Typhimurium impacts bacterial aggregation and the neutrophil respiratory burst

2020 ◽  
Author(s):  
TL Westerman ◽  
MK Sheats ◽  
JR Elfenbein
Keyword(s):  
Respiratory Burst ◽  
Protein A ◽  
Flagellar Motility ◽  
Rich Media ◽  
The Individual ◽  
Genomic Regions ◽  
System 1 ◽  
Type 3 ◽  
Neutrophil Respiratory Burst

AbstractDuring enteric salmonellosis, neutrophil generated reactive oxygen species alter the gut microenvironment favoring survival of Salmonella Typhimurium. While the type-3 secretion system-1 (T3SS-1) and flagellar motility are potent Salmonella Typhimurium agonists of the neutrophil respiratory burst in vitro, neither of these pathways alone are responsible for stimulation of a maximal respiratory burst. In order to identify Salmonella Typhimurium genes that impact the magnitude of the neutrophil respiratory burst, we performed a two-step screen of defined mutant libraries in co-culture with neutrophils. We first screened Salmonella Typhimurium mutants lacking defined genomic regions, followed by the individual mutants mapping to genomic regions under selection. Mutants in four genes, STM1696 (sapF), STM2201 (yeiE), STM2112 (wcaD), and STM2441 (cysA), induced an attenuated respiratory burst. We linked the altered respiratory burst to reduced T3SS-1 expression and/or altered flagellar motility for two mutants (ΔSTM1696 and ΔSTM2201). The ΔSTM2441 mutant, defective for sulfate transport, formed aggregates in minimal media and adhered to surfaces in rich media, suggesting a role for sulfur homeostasis in regulation of aggregation/adherence. We linked the aggregation/adherence phenotype of the ΔSTM2441 mutant to biofilm-associated protein A and flagellins and hypothesize that aggregation caused the observed reduction in the magnitude of the neutrophil respiratory burst. Our data demonstrate that Salmonella Typhimurium has numerous mechanisms to limit the magnitude of the neutrophil respiratory burst. These data further inform our understanding of how Salmonella may alter neutrophil antimicrobial defenses.

scholarly journals Sulfate import in Salmonella Typhimurium impacts bacterial aggregation and the respiratory burst in human neutrophils

2021 ◽  
Author(s):  
T. L. Westerman ◽  
M. K. Sheats ◽  
J. R. Elfenbein
Keyword(s):  
Respiratory Burst ◽  
Gene Deletion ◽  
Single Gene ◽  
Protein A ◽  
Human Neutrophils ◽  
Deletion Mutants ◽  
Flagellar Motility ◽  
Neutrophil Respiratory Burst ◽  
Single Gene Deletion

During enteric salmonellosis, neutrophil generated reactive oxygen species alter the gut microenvironment favoring survival of Salmonella Typhimurium. While the type-3 secretion system-1 (T3SS-1) and flagellar motility are potent Salmonella Typhimurium agonists of the neutrophil respiratory burst in vitro, neither of these pathways alone are responsible for stimulation of a maximal respiratory burst. In order to identify Salmonella Typhimurium genes that impact the magnitude of the neutrophil respiratory burst, we performed a two-step screen of defined mutant libraries in co-culture with human neutrophils. We first screened Salmonella Typhimurium mutants lacking defined genomic regions and then tested single gene deletion mutants representing particular regions under selection. A subset of single gene deletion mutants were selected for further investigation. Mutants in four genes, STM1696 (sapF), STM2201 (yeiE), STM2112 (wcaD), and STM2441 (cysA), induced an attenuated respiratory burst. We linked the altered respiratory burst to reduced T3SS-1 expression and/or altered flagellar motility for two mutants (ΔSTM1696 and ΔSTM2201). The ΔSTM2441 mutant, defective for sulfate transport, formed aggregates in minimal media and adhered to surfaces in rich media, suggesting a role for sulfur homeostasis in regulation of aggregation/adherence. We linked the aggregation/adherence phenotype of the ΔSTM2441 mutant to biofilm-associated protein A and flagellins and hypothesize that aggregation caused the observed reduction in the magnitude of the neutrophil respiratory burst. Our data demonstrate that Salmonella Typhimurium has numerous mechanisms to limit the magnitude of the neutrophil respiratory burst. These data further inform our understanding of how Salmonella may alter human neutrophil antimicrobial defenses.

scholarly journals The Salmonella type-3 secretion system-1 and flagellar motility influence the neutrophil respiratory burst

PLoS ONE ◽  
2018 ◽  
Vol 13 (9) ◽  
pp. e0203698 ◽  
Author(s):  
Trina L. Westerman ◽  
Lydia Bogomolnaya ◽  
Helene L. Andrews-Polymenis ◽  
M. Katherine Sheats ◽  
Johanna R. Elfenbein
Keyword(s):  
Respiratory Burst ◽  
Secretion System ◽  
Flagellar Motility ◽  
Type 3 Secretion System ◽  
System 1 ◽  
Type 3 ◽  
Neutrophil Respiratory Burst

scholarly journals Effect of spineless-cactus mucilage on the in vitro rumen fermentation of cellulose, starch, and protein

2017 ◽  
Vol 18 (4) ◽  
pp. 505-517 ◽  
Author(s):  
Ricardo Martins Araujo Pinho ◽  
Edson Mauro Santos ◽  
Juliana Silva de Oliveira ◽  
Alexandre Henrique Remigio Loureiro ◽  
Alberto Jefferson da Silva Macêdo ◽  
...  
Keyword(s):  
Protein A ◽  
Rumen Fermentation ◽  
Rumen Microorganisms ◽  
Randomized Experimental Design ◽  
The Media ◽  
Butyrate Fermentation ◽  
Cactus Mucilage ◽  
The Individual ◽  
In Vitro Rumen Fermentation

SUMMARY The aim of this study was to evaluate the effect of the levels of spineless-cactus mucilage on the in vitro rumen fermentation of cellulose, starch, and protein. A completely randomized experimental design was adopted with a 5 × 3 factorial arrangement consisting of five levels of spineless-cactus mucilage (0, 5, 10, 20, and 40%) and three substrates (carboxymethylcellulose, starch, and trypticase). Treatments were evaluated in a ruminal environment simulated by in vitro incubation at different times of assessment: 0, 3, 6, 12, 24, and 48 h. The incubation procedure was repeated three times, totaling three evaluations per incubation time for each treatment. There was an interaction (P<0.05) between the mucilage levels and substrate for all evaluated ruminal parameters, except for the concentration of microbial protein after 48 h of fermentation and for the proportions of acetate and butyrate fermentation at time 0 h. There was a quadratic increase (P<0.05) in the concentration of ammoniacal nitrogen after 48 h of incubation in the media containing carboxymethylcellulose and trypticase. pH values decreased quadratically (P<0.05) as a function of the mucilage levels in the media containing carboxymethylcellulose and trypticase. Overall, no expressive alterations were observed between the individual molar proportions of acetate, propionate, and butyrate with the addition of spineless-cactus mucilage levels to the different substrates. Spineless- cactus mucilage affects the pattern of fermentation of starch, cellulase, and protein performed by rumen microorganisms.

scholarly journals PneumococcalSurface Protein A Is Expressed In Vivo, and Antibodies to PspA AreEffective for Therapy in a Murine Model of PneumococcalSepsis

2003 ◽  
Vol 71 (12) ◽  
pp. 7149-7153 ◽  
Author(s):  
E. Swiatlo ◽  
J. King ◽  
G. S. Nabors ◽  
B. Mathews ◽  
D. E. Briles
Keyword(s):  
Northern Blot Analysis ◽  
Lethal Dose ◽  
Protein A ◽  
Surface Protein ◽  
Immune Serum ◽  
Invasive Infection ◽  
Pneumococcal Infections ◽  
Type 3

ABSTRACT Pneumococcal surface protein A (PspA) is an immunogenic protein expressed on the surface of all strains of Streptococcus pneumoniae (pneumococcus) and induces antibodies which protect against invasive infection in mice. Pneumococci used for infectious challenge in protection studies are typically collected from cultures grown in semisynthetic medium in vitro. The purpose of these studies is to confirm that PspA is expressed by pneumococci during growth in vivo at a level sufficient for antibodies to PspA to be protective. Mice were actively immunized with purified PspA or by passive transfer of monoclonal antibody (MAb) and challenged with a capsular type 3 strain in diluted whole blood from bacteremic mice. All were protected against challenge with 10 times the 50% lethal dose (LD50), and mice challenged with 1,000 times the LD50 had increased survival compared with controls. Additionally, nonimmune mice treated with MAbs to PspA or PspA immune serum at 6 and 12 h after infection with 10 times the LD50 also showed increased survival. Northern blot analysis of RNA from pneumococci grown either in vitro or in vivo showed similar levels of PspA mRNA. These results demonstrate that PspA is expressed in vivo in a mouse model and that immunization with PspA induces antibodies to an antigen which is expressed during the course of invasive infection. Immunotherapy with antibodies to PspA may have some utility in treating pneumococcal infections in humans.

Surfactant protein A modulates release of reactive oxygen species from alveolar macrophages

1994 ◽  
Vol 267 (6) ◽  
pp. L660-L666 ◽  
Author(s):  
S. Weissbach ◽  
A. Neuendank ◽  
M. Pettersson ◽  
T. Schaberg ◽  
U. Pison
Keyword(s):  
Reactive Oxygen Species ◽  
Respiratory Burst ◽  
Protein A ◽  
Reactive Oxygen ◽  
Surfactant Protein ◽  
Oxygen Radical ◽  
Surfactant Protein A ◽  
Oxygen Species ◽  
Coated Surfaces

The production and release of reactive oxygen species (the respiratory burst) is a common metabolic pathway linked to several macrophage-related reactions. The most abundant surfactant protein A (SP-A) binds to alveolar macrophages (AM) through a specific surface receptor with high affinity. Because such binding might initiate or modulate the respiratory burst, we wanted to know whether and how SP-A affects the oxygen radical release from AM. To answer these questions, we measured the release of reactive oxygen species from rat AM under various in vitro conditions using enhanced chemiluminescence systems. We prepared SP-A from pulmonary surfactant isolated either from silica-treated rats or adult dogs. Resident AM were harvested from pathogen-free Wistar rats by lung lavage. Adhered and nonadhered AM were assessed on protein-free or protein-coated surfaces of 96-well microtiter plates. On protein-free surfaces, the sole addition of SP-A failed to induce measurable oxygen radical release from 2 x 10(5) adhered or nonadhered AM, while zymosan opsonized with SP-A induced a marked increase over control. On protein-coated surfaces, AM respond differently depending on the coated protein: on SP-A-coated surfaces, a dose-dependent enhancement of oxygen radical release with a mean effective concentration of approximately 1.15 micrograms/ml was found. No such enhancement was seen on plates coated with similar amounts of either human fibronectin or collagen, and the enhancement with serum albumin was not dose related. Our data demonstrate that SP-A only enhances oxygen radical release from AM if SP-A is fixed to zymosan or the surface of the reaction vial in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Comparison of the in vitro effects of amoxicillin and ampicillin on the polymorphonuclear neutrophil respiratory burst

2009 ◽  
Vol 63 (3) ◽  
pp. 458-461 ◽  
Author(s):  
M.-L. Reynaert ◽  
A.-C. Hochart-Behra ◽  
J. Behra-Miellet ◽  
B. Gressier ◽  
L. Mine ◽  
...  
Keyword(s):  
Respiratory Burst ◽  
Polymorphonuclear Neutrophil ◽  
In Vitro Effects ◽  
Neutrophil Respiratory Burst

P.38 Omega-3 parenteral lipid solution inhibits neutrophil respiratory burst in vitro

1997 ◽  
Vol 16 ◽  
pp. 33
Author(s):  
J. Heine ◽  
M. André ◽  
D. Scheinichen ◽  
K. Jaeger ◽  
M. Leuwer ◽  
...  
Keyword(s):  
Respiratory Burst ◽  
Omega 3 ◽  
Neutrophil Respiratory Burst

In vivo and in vitro evidences that carotenoids could modulate the neutrophil respiratory burst during dietary manipulation

2004 ◽  
Vol 44 (2) ◽  
pp. 114-120 ◽  
Author(s):  
S. Walrand ◽  
M.-C. Farges ◽  
O. Dehaese ◽  
N. Cardinault ◽  
R. Minet-Quinard ◽  
...  
Keyword(s):  
Respiratory Burst ◽  
Dietary Manipulation ◽  
Neutrophil Respiratory Burst

scholarly journals Generation of signals activating neutrophil functions by leukocyte integrins: LFA-1 and gp150/95, but not CR3, are able to stimulate the respiratory burst of human neutrophils.

1992 ◽  
Vol 116 (4) ◽  
pp. 1007-1017 ◽  
Author(s):  
G Berton ◽  
C Laudanna ◽  
C Sorio ◽  
F Rossi
Keyword(s):  
Respiratory Burst ◽  
Protein A ◽  
Human Neutrophils ◽  
Necrosis Factor Alpha ◽  
Tissue Culture Polystyrene ◽  
Leukocyte Integrins ◽  
Camp Analogue ◽  
Factor Alpha ◽  
Beta 2 Microglobulin ◽  
Neutrophil Respiratory Burst

To address the question whether leukocyte integrins are able to generate signals activating neutrophil functions, we investigated the capability of mAbs against the common beta chain (CD18), or the distinct alpha chains of CR3, LFA-1, or gp150/95, to activate neutrophil respiratory burst. These investigations were performed with mAbs bound to protein A immobilized to tissue culture polystyrene. Neutrophils plated in wells coated with the anti-CD18 mAbs IB4 and 60.3 released H2O2; H2O2 release did not occur when neutrophils were plated in wells coated with an irrelevant, isotype-matched mAb (OKDR), or with mAbs against other molecules (CD16, beta 2-microglobulin) expressed on the neutrophil surface at the same density of CD18. Four different mAbs, OKM1, OKM9, OKM10, 60.1, which recognize distinct epitopes of CR3 were unable to trigger H2O2 or O2- release from neutrophils. However, mAbs against LFA-1 or gp150/95 triggered both H2O2 and O2- release from neutrophils. Stimulation of neutrophils respiratory burst by both anti-CD18, and anti-LFA-1 or gp150/95 mAbs was totally inhibited by the microfilaments disrupting agent, cytochalasin B, and by a permeable cAMP analogue. While the capability to activate neutrophil respiratory burst was restricted to anti-LFA-1 and gp150/95 mAbs, we observed that mAbs against all members of leukocyte integrins, including CR3, were able to trigger neutrophil spreading. These findings indicate that, in neutrophils, all three leukocyte integrins can generate signals activating spreading, but only LFA-1 and gp150/95 can generate signals involved in activation of the respiratory burst. This observation can be relevant to understand the mechanisms responsible for the activation of neutrophil respiratory burst by tumor necrosis factor-alpha, which has been shown to be strictly dependent on expression of leukocyte integrins (Nathan, C., S. Srimal, C. Farber, E. Sanchez, L. Kabbash, A. Asch, J. Gailit, and S. Wright. 1989. J. Cell Biol. 109:13411349.

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