• BMB Reports
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• v.36 no.6
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• pp.565-571
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• 2003

The locomotor responses of human peripheral blood neutrophils and lymphocytes were measured by the change from spherical to polarized shapes in the presence of endotoxins (lipopolysaccharide, LPS) of enteric pathogens: S. dysenteriae type 1, V. cholerae Inaba 569B, S. typhimurium, and K. pneumoniae. We reported earlier that these endotoxins are chemotactic factors for the neutrophils since they stimulated cell polarization within a few minutes of incubation. Endotoxins had an inhibitory effect upon neutrophil phagocytosis of opsonized yeast and the cells engulfed fewer yeasts. Interestingly, endotoxins increased neutrophil adhesion to clean glass surfaces, but stimulated the cells to exhibit increased random locomotion (chemokinesis) through cellulose nitrate filters and show an enhanced ability to reduce nitroblue tetrazolium (NBT) dye. Unlike neutrophils, lymphocytes direct from blood do not show polarized morphology towards chemotactic factors but the cells acquire locomotor capacity during 24-72 h culture with mitogens such as phytohemagglutinin (PHA), phorbol myristate acetate or concanavalin A. Stimulation of blood lymphocytes with endotoxins did not induce cell polarization in short-term but long-term culture resulted in an increase in the proportion of polarized cells that acquired locomotor morphologies. The majority of these cells were identified as esterase negative B-lymphocytes that migrated through filters. Despite the optimum time of incubation for each of these cell types being different, we found that lymphocytes respond to much lower concentrations of endotoxins than the neutrophils. These findings suggest that endotoxins of enteric pathogens modulate the functions of human blood neutrophils and lymphocytes.

• Journal of Veterinary Clinics
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• v.15 no.2
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• pp.352-357
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• 1998

Effects of chicken egg white derivatives (EWD and EF-203) on the changes of blood cells and the neutrophil phagocytic activity were examined in the rats. Rats were administered orally with either EWD (200 mg/kg) or EF-203 (200 mg/kg) for 3 days. Thereafter, the changes of blood cell values (RBC, WBC, platelets, PCV, differential count of neutrophils) and the phagocytic activity of neutrophils were evaluated for 7 days. The numbers of WBC and the differential count of neutrophils of rats administered with either EWD or EF-203 were significantly increased (p

• Parasites, Hosts and Diseases
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• v.49 no.3
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• pp.291-294
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• 2011

Trichomonas vaginalis is a flagellated lumen-dwelling extracellular protozoan parasite that causes human trichomoniasis via sexual intercourse. Human neutrophils play a crucial role in acute tissue inflammatory responses in T. vaginalis infection. In this study, we investigated the signaling mechanism of neutrophil responses when stimulated with T. vaginalis-derived secretory products (TvSP), which were collected from $1{\times}10^7$ live trichomonads. Incubation of human neutrophils isolated from peripheral blood with TvSP induced up-regulation of IL-8 protein secretion. In addition, stimulation with TvSP induced phosphorylation of NF-${\kappa}B$ and CREB in neutrophils. Moreover, TvSP-induced IL-8 production was also significantly inhibited by pretreatment of neutrophils with $i{\kappa}B$ inhibitor or CREB inhibitor. These results suggest that transcription factors NF-${\kappa}B$ and CREB are involved in IL-8 production in human neutrophils induced by stimulation with T. vaginalis infection.

• BMB Reports
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• v.55 no.10
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• pp.473-480
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• 2022

Neutrophils, the most abundant innate immune cells, play essential roles in the innate immune system. As key innate immune cells, neutrophils detect intrusion of pathogens and initiate immune cascades with their functions; swarming (arresting), cytokine production, degranulation, phagocytosis, and projection of neutrophil extracellular trap. Because of their short lifespan and consumption during immune response, neutrophils need to be generated consistently, and generation of newborn neutrophils (granulopoiesis) should fulfill the environmental/systemic demands for training in cases of infection. Accumulating evidence suggests that neutrophils also play important roles in the regulation of adaptive immunity. Neutrophil-mediated immune responses end with apoptosis of the cells, and proper phagocytosis of the apoptotic body (efferocytosis) is crucial for initial and post resolution by producing tolerogenic innate/adaptive immune cells. However, inflammatory cues can impair these cascades, resulting in systemic immune activation; necrotic/pyroptotic neutrophil bodies can aggravate the excessive inflammation, increasing inflammatory macrophage and dendritic cell activation and subsequent T_H1/T_H17 responses contributing to the regulation of the pathogenesis of autoimmune disease. In this review, we briefly introduce recent studies of neutrophil function as players of immune response.

• The Korean Journal of Pharmacology
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• v.26 no.1
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• pp.55-66
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• 1990

In both resting and opsonized zymosan activated neutrophils, ATP stimulated superoxide generation, whereas adenosine inhibited it slightly. The superoxide generation in activated neutrophils to ATP was greater than that of resting neutrophils. In $Ca^{++}$ free medium, inhibitory effect of adenosine on superoxide generation was detectable, whereas ATP did not have any effect. The stimulatory effect of ATP on superoxide generation was inhibited by adenosine in a dose dependent manner. Neither ATP nor adenosine had any effect on NADPH oxidase acitivity. Effects of ATP or adenosine on superoxide generation were more prominent than that by other triphosphate nucleotides or nucleosides. ATP and ADP further stimulated $Ca^{++}$ uptake and increased cytosolic free $Ca^{++}$ level in neutrophils activated by opsonized zymosan, but adenosine inhibited a $Ca^{++}$ mobilization. Verapamil effectively and tetrodotoxin slightly inhibited an increase of cytosolic free $Ca^{++}$ level induced by ATP. Inhibitory effect of either verapamil or tetrodotoxin on superoxide generation in the ATP plus opsonized zymosan-activated neutrophils was greater than in the cells activated by opsonized zymosan alone. Tetraethylammonium chloride had no apparent effect on superoxide generation. CCCP, 2,4-dinitrophenol, diphenylhydantoin and procaine all inhibited superoxide generation in neutrophils activated by opsonized zymosan. Among these, CCCP only inhibited a stimulatory effect of ATP. ATP further stimulated a loss of sulfhydryl groups in activated neutrophils, whereas adenosine had no effect on it. These results suggest that functional responses of neutrophils may be regulated at least partly by purines. ATP and adenosine may further after functional responses of activated neutrophils through their effect on $Ca^{++}$ uptake, membrane phosphorylation and oxidation of soluble sulfhydryl groups.

• Journal of Pharmacopuncture
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• v.20 no.1
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• pp.52-56
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• 2017

Objectives: Neutrophils represent the front line of human defense against infections. Immediately after stimulation, neutrophilic enzymes are activated and produce toxic mediators such as pro-inflammatory cytokines, nitric oxide (NO) and myeloperoxidase (MPO). These mediators can be toxic not only to infectious agents but also to host tissues. Because flavonoids exhibit antioxidant and anti-inflammatory effects, they are subjects of interest for pharmacological modulation of inflammation. In the present study, the effects of rutin on stimulus-induced NO and tumor necrosis factor $(TNF)-{\alpha}$ productions and MPO activity in human neutrophils were investigated. Methods: Human peripheral blood neutrophils were isolated using Ficoll-Hypaque density gradient centrifugation coupled with dextran T500 sedimentation. The cell preparations containing > 98% granulocytes were determined by morphological examination through Giemsa staining. Neutrophils were cultured in complete Roswell Park Memorial Institute (RPMI) medium, pre-incubated with or without rutin ($25{\mu}M$) for 45 minutes, and stimulated with phorbol 12-myristate 13-acetate (PMA). Then, the $TNF-{\alpha}$, NO and MPO productions were analyzed using enzyme-linked immunosorbent assay (ELISA), Griess Reagent, and MPO assay kits, respectively. Also, the viability of human neutrophils was assessed using tetrazolium salt 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), and neutrophils were treated with various concentrations of rutin ($1-100{\mu}M$), after which MTT was appended and incubated at $37^{\circ}C$ for 4 hour. Results: Rutin at concentrations up to $100{\mu}M$ did not affect neutrophil viability during the 4-hour incubation period. Rutin significantly decreased the NO and $TNF-{\alpha}$ productions in human peripheral blood neutrophils compared to PMA-control cells (P < 0.001). Also, MPO activity was significantly reduced by rutin (P < 0.001). Conclusion: In this in vitro study, rutin had an anti-inflammatory effect due to its inhibiting NO and $TNF-{\alpha}$ productions, as well as MPO activity, in activated human neutrophils. Treatment with rutin may be considered as a therapeutic strategy for neutrophil-mediated inflammatory/autoimmune diseases.

• Parasites, Hosts and Diseases
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• v.42 no.4
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• pp.205-208
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• 2004

Neutrophils are important effector cells against protozoan extracellular parasite Entamoeba histolytica, which causes amoebic colitis and liver abscess in human beings. Apoptotic cell death of neutrophils is an important event in the resolution of inflammation and parasite's survival in vivo. This study was undertaken to investigate the ultrastructural aspects of apoptotic cells during neutrophil death triggered by Entamoeba histolytica. Isolated human neutrophils from the peripheral blood were incubated with or without live trophozoites of E. histolytica and examined by transmission electron microscopy (TEM). Neutrophils incubated with E. histolytica were observed to show apoptotic characteristics, such as compaction of the nuclear chromatin and swelling of the nuclear envelop. In contrast, neutrophils incubated in the absence of the amoeba had many protrusions of irregular cell surfaces and heterogenous nuclear chromatin. Therefore, it is suggested that Entamoeba-induced neutrophil apoptosis contribute to prevent unwanted tissue inflammation and damage in the amoeba-invaded lesions in vivo.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.1
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• pp.71-78
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• 1997

In an attempt to investigate the role of phospholipase $A_2$($PLA_2$) in interleukin-l (IL-l) induced acute lung injury, mepacrine was tried to inhibit $PLA_2$ in IL-l induced ARDS rats. For confirmation of acute lung injury by IL-l, and to know the role of neutrophils in this injury, lung leak index, lung myeloperoxidase(MPO), number of neutrophils and protein content in the bronchoalveolar lavage (BAL) and wet lung weight were measured. At the same time lung $PLA_2$ was measured to know the effect of IL-l on $PLA_2$ activity. Pulmonary surfactant was also measured for an investigation of type II alveolar cell function. Neutrophil adhesion assay was performed to know the effect of $PLA_2$ inhibition in vitro with human umbilical vein endothelial cells (HUVEC). For precise location of injury by IL-l, morpholgical study was performed by electron microscopy. Five hours after instillation of IL-l (50 ng/rat), lung leak index, protein content, number of neutrophils, lung MPO and wet lung weight were increased significantly. Five hours after IL-l instillation lung $PLA_2$ activity was increased significantly, and increased surfactant release was observed in IL-l induced ARDS rats' BAL. In contrast, in rats given mepacrine and IL-l, there was decrease of acute lung injury i.e. decrease of lung leak index, wet lung weight, protein content, number of neutrophils in BAL and decreased lung MPO activity. Mepacrine decreased surfactant release also. Interestingly, inhibition of $PLA_2$ decreased adhesion of human neutrophils to HUVEC in vitro. Morphologically, IL-l caused diffuse necrosis of endothelial cells, type I and II epithelial cells and increased the infiltration of neutrophils in the interstitium of the lung but after mepacrine treatment these pathological findings were lessened. On the basis of these experimental results it is suggested that $PLA_2$ has a major role in the pathogenesis of acute lung injury mediated by neutrophil dependent manner in IL-l induced acute lung injury.

• International Journal of Oral Biology
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• v.37 no.2
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• pp.69-75
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• 2012

Although neutrophils function in both defense and tissue destruction, their defensive roles have rarely been studied in association with periodontitis. We hypothesized that peripheral neutrophils are pre-activated in vivo in periodontitis and that hyperactive neutrophils would show enhanced phagocytic ability as well as an increased production of reactive oxygen species (ROS). Peripheral blood neutrophils from patients with aggressive periodontitis and age/gender-matched healthy subjects (10 pairs) were isolated. The levels of CD11b and CD64 expression on the neutrophils and the level of plasma endotoxin were determined by flow cytometry and a limulus amebocyte lysate test, respectively. In addition, neutrophils were subjected to a flow cytometric phagocytosis assay and luminol-enhanced chemiluminescence for non-opsonized Fusobacterium nucleatum in parallel. The neutrophilsfrom most patients expressed increased levels of both CD11b and CD64. In addition, the plasma from these patients tended to contain a higher level of endotoxin than the healthy controls. In contrast, no differences were found between the two groups with regard to phagocytosis or ROS generation by F. nucleatum. The ability to phagocytose F. nucleatum was found to positively correlate with the ability to produce ROS. In conclusion, peripheral neutrophils from patients with aggressive periodontitis are hyperactive but not hyperreactive to F. nucleatum.

• International Journal of Oral Biology
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• v.43 no.3
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• pp.141-146
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• 2018

Periodontitis is generally a chronic disorder characterized by breakdown of tooth-supporting tissues, producing dentition loss. Porphyromonas gingivalis (P. gingivalis), a Gramnegative anaerobic rod, is one of the major pathogens associated with periodontitis. Neutrophils are first line defense cells in the oral cavity that play a significant role in inflammatory response. Xylitol is a known anti-caries agent and has anti-inflammatory effects. In this study, we conducted experiments to evaluate anti-inflammatory effects of xylitol on P. gingivalis infected neutrophils for possible usage in prevention and treatment of periodontal infections. P. gingivalis was intraperitoneally injected and peritoneal lavage was collected for cytokine determination. For in vitro study, neutrophils were collected from mouse peritoneal cells after zymosan injection or bone marrow cells. Neutrophils were stimulated with live P. gingivalis and ELISA was used to determine the effect of xylitol on P. gingivalis induced cytokine production. $IL-1{\beta}$, IL-6, $TNF-{\alpha}$ concentration and neutrophil population in the peritoneal lavage was increased in P. gingivalis-infected mouse. Peritoneal cells infected with live P. gingivalis revealed significantly increased production of $IL-1{\beta}$, IL-6 and $TNF-{\alpha}$ at multiplicity of infection of 10. Neutrophils from bone marrow and peritoneal lavage revealed increased production of $IL-1{\beta}$, IL-6 and $TNF-{\alpha}$. Xylitol significantly mitigated P. gingivalis induced cytokine production in neutrophils. Findings indicate that xylitol is an anti-inflammatory agent in neutrophils infected with live P. gingivalis, that suggests its use in periodontitis management.