scholarly journals Effect of Lonomia obliqua Venom on Human Neutrophils

Toxins ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 908
Author(s):  
João Alfredo Moraes ◽  
Genilson Rodrigues ◽  
Daniel Guimarães-Bastos ◽  
Vany Nascimento-Silva ◽  
Erik Svensjö ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Polymorphonuclear Neutrophils ◽  
Matrix Proteins ◽  
Human Neutrophils ◽  
Oxygen Species ◽  
Antioxidant Treatment ◽  
Significant Incidence ◽  
Inflammatory Profile ◽  
Nuclear Factor Kb ◽  
Lonomia Obliqua

The significant incidence of deforestation in South America culminates in the contact of humans with typical forests species. Among these species, one may highlight Lonomia obliqua caterpillar, which, when touched by humans, can poison them through their bristles. Therefore, better acknowledging the mechanisms involved in envenomation caused by Lonomia obliqua caterpillar bristle extract (LOCBE) may contribute to further treatments. Recently, we demonstrated that LOCBE induces a pro-inflammatory profile in endothelial cells; thus, we decided to investigate the effects of LOCBE on human polymorphonuclear neutrophils (PMN), which are the first leukocytes that migrate to the inflammatory focus. Our results showed that treatment with LOCBE induced PMN chemotaxis together with alterations in actin cytoskeleton and focal adhesion kinase (FAK) activation, favoring migration. Concurrently, LOCBE induced PMN adhesion to matrix proteins, such as collagen IV, fibronectin, and fibrinogen. Moreover, we observed that LOCBE attenuated PMN apoptosis and increased reactive oxygen species (ROS) production together with nuclear factor kB (NF-κB) activation—a redox-sensitive transcription factor—as well as interleukin (IL)-1β and IL-8 release. We call attention to the ROS-dependent effect of LOCBE on increased cell migration once an antioxidant treatment reverted it. In summary, we report that LOCBE activates PMN, inducing pro-inflammatory responses modulated by ROS.

Mechanisms of Synergy Between Toll-Like Receptor 4 and Triggering Receptor Expressed on Myeloid Cells-1 in Human Neutrophils

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3547-3547
Author(s):  
Markus P Radsak ◽  
Hansjörg Schild ◽  
Philipp Haselmayer ◽  
Helmut R Salih
Keyword(s):  
Respiratory Burst ◽  
Transient Receptor Potential ◽  
Inflammatory Responses ◽  
Myeloid Cells ◽  
Receptor Potential ◽  
Transient Receptor Potential Channels ◽  
Polymorphonuclear Neutrophils ◽  
Human Neutrophils ◽  
Inflammatory Conditions ◽  
Potential Channels

Abstract The triggering receptor expressed on myeloid cells 1 (TREM-1) is an important player in the innate inflammatory response to microbial infections. Activation and expression of TREM-1 by polymorphonuclear neutrophils (PMN) occurs in concert with Toll-like receptors (TLR) such as TLR4 for bacterial lipopolysaccharide. However, it is currently unclear how this is mediated on a molecular level. Using pharmacologic inhibitors and western blot analysis we demonstrate that phosphatidyl inositide 3-kinase, phospholipase C and the mitogen activated kinase p38 are essential for the TREM-1 and TLR4 mediated respiratory burst of human PMN. The down stream phosphorylation of protein kinase B and extracellular signal related kinase show characteristic phosphorylation patterns upon single or co-ligation indicating individual activation pathways of both receptors. TREM-1, but not TLR4 mediated respiratory burst depended on calcium flow via store operated calcium entry channels, while transient receptor potential channels were important for TLR and TREM-1. Taken together, we provide new insights on the mechanisms how TREM-1 and TLR interact creating synergistic activation in PMN. These results shed a new light on our understanding how the innate inflammatory responses are regulated and might contribute to the development of future concepts for the treatment of severe inflammatory conditions such as sepsis.

scholarly journals Ultraviolet light A irradiation induces immunosuppression associated with the generation of reactive oxygen species in human neutrophils

2016 ◽  
Vol 09 (01) ◽  
pp. 1650001 ◽  
Author(s):  
Cunbo Li ◽  
Xuechen Shi ◽  
Mincai Chen ◽  
Guangxue Xu ◽  
Xinglei Su ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Ultraviolet Light ◽  
Inflammatory Responses ◽  
Reactive Oxygen ◽  
Human Neutrophils ◽  
Oxygen Species ◽  
Immune Functions ◽  
Uva Irradiation ◽  
Underlying Mechanisms

Ultraviolet blood irradiation has been used as a physical therapy to treat many nonspecific diseases in clinics; however, the underlying mechanisms remain largely unclear. Neutrophils, the first line of host defense, play a crucial role in a variety of inflammatory responses. In the present work, we investigated the effects of ultraviolet light A (UVA) on the immune functions of human neutrophils at the single-cell level by using an inverted fluorescence microscope. N-Formyl-methionyl-leucyl-phenylalanine (FMLP), a classic physiological chemotactic peptide, was used to induce a series of immune responses in neutrophils in vitro. FMLP-induced calcium mobilization, migration, and phagocytosis in human neutrophils was significantly blocked after treatment with 365[Formula: see text]nm UVA irradiation, demonstrating the immunosuppressive effects of UVA irradiation on neutrophils. Similar responses were also observed when the cells were pretreated with H2O2, a type of reactive oxygen species (ROS). Furthermore, UVA irradiation resulted in an increase in NAD(P)H, a member of host oxidative stress in cells. Taken together, our data indicate that UVA irradiation results in immunosuppression associated with the production of ROS in human neutrophils.

scholarly journals Interleukin-6 Production by Human Neutrophils After Fc-Receptor Cross-Linking or Exposure to Granulocyte Colony-Stimulating Factor

Blood ◽  
1998 ◽  
Vol 91 (6) ◽  
pp. 2099-2107
Author(s):  
Solveig G. Ericson ◽  
Yue Zhao ◽  
Huilan Gao ◽  
Kathryn L. Miller ◽  
Laura F. Gibson ◽  
...  
Keyword(s):  
Interleukin 6 ◽  
Inflammatory Responses ◽  
Polymorphonuclear Neutrophils ◽  
Human Neutrophils ◽  
Cross Linking ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
Stimulating Factor

Polymorphonuclear neutrophils (PMNs) are essential effector cells in host defense and tissue inflammatory responses. These responses may be initiated after cross-linking of cell surface Fc receptors that bind the constant portion of IgG (FcγR). We evaluated the effect of cross-linking FcγRI or FcγRII on interleukin-6 (IL-6) production by purified PMNs from normal donors or from patients being treated with recombinant human granulocyte colony-stimulating factor (rhG-CSF). In PMNs from normal donors, IL-6 mRNA was detected by reverse transcriptase-polymerase chain reaction only after FcγRI or FcγRII cross-linking. We also found that IL-6 mRNA could be detected in PMNs after either in vitro or in vivo rhG-CSF treatment in the absence of FcγR cross-linking. IL-6 protein was found to be produced intracellularly and secreted by PMNs after cross-linking FcγRI or FcγRII or after rhG-CSF stimulation. Cross-linking FcγRI or FcγRII on PMNs from patients treated with rhG-CSF resulted in a synergistic increase in IL-6 secretion. Upregulation of IL-6 production by PMNs after rhG-CSF treatment may contribute to a clinical engraftment syndrome that occurs during periods of rapid increase in PMN numbers in patients receiving rhG-CSF.

scholarly journals Interleukin-6 Production by Human Neutrophils After Fc-Receptor Cross-Linking or Exposure to Granulocyte Colony-Stimulating Factor

Blood ◽  
1998 ◽  
Vol 91 (6) ◽  
pp. 2099-2107 ◽  
Author(s):  
Solveig G. Ericson ◽  
Yue Zhao ◽  
Huilan Gao ◽  
Kathryn L. Miller ◽  
Laura F. Gibson ◽  
...  
Keyword(s):  
Interleukin 6 ◽  
Inflammatory Responses ◽  
Polymorphonuclear Neutrophils ◽  
Human Neutrophils ◽  
Cross Linking ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
Stimulating Factor

Abstract Polymorphonuclear neutrophils (PMNs) are essential effector cells in host defense and tissue inflammatory responses. These responses may be initiated after cross-linking of cell surface Fc receptors that bind the constant portion of IgG (FcγR). We evaluated the effect of cross-linking FcγRI or FcγRII on interleukin-6 (IL-6) production by purified PMNs from normal donors or from patients being treated with recombinant human granulocyte colony-stimulating factor (rhG-CSF). In PMNs from normal donors, IL-6 mRNA was detected by reverse transcriptase-polymerase chain reaction only after FcγRI or FcγRII cross-linking. We also found that IL-6 mRNA could be detected in PMNs after either in vitro or in vivo rhG-CSF treatment in the absence of FcγR cross-linking. IL-6 protein was found to be produced intracellularly and secreted by PMNs after cross-linking FcγRI or FcγRII or after rhG-CSF stimulation. Cross-linking FcγRI or FcγRII on PMNs from patients treated with rhG-CSF resulted in a synergistic increase in IL-6 secretion. Upregulation of IL-6 production by PMNs after rhG-CSF treatment may contribute to a clinical engraftment syndrome that occurs during periods of rapid increase in PMN numbers in patients receiving rhG-CSF.

The Signaling Pathways in Nitric Oxide Production by Neutrophils Exposed to N-nitrosodimethylamine

2018 ◽  
Vol 16 (2) ◽  
pp. 194-199
Author(s):  
Wioletta Ratajczak-Wrona ◽  
Ewa Jablonska
Keyword(s):  
Nitric Oxide ◽  
Signaling Pathways ◽  
Molecular Mechanisms ◽  
Polymorphonuclear Neutrophils ◽  
Microbial Pathogens ◽  
Human Neutrophils ◽  
No Production ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

Background: Polymorphonuclear neutrophils (PMNs) play a crucial role in the innate immune system’s response to microbial pathogens through the release of reactive nitrogen species, including Nitric Oxide (NO). </P><P> Methods: In neutrophils, NO is produced by the inducible Nitric Oxide Synthase (iNOS), which is regulated by various signaling pathways and transcription factors. N-nitrosodimethylamine (NDMA), a potential human carcinogen, affects immune cells. NDMA plays a major part in the growing incidence of cancers. Thanks to the increasing knowledge on the toxicological role of NDMA, the environmental factors that condition the exposure to this compound, especially its precursors- nitrates arouse wide concern. Results: In this article, we present a detailed summary of the molecular mechanisms of NDMA’s effect on the iNOS-dependent NO production in human neutrophils. Conclusion: This research contributes to a more complete understanding of the mechanisms that explain the changes that occur during nonspecific cellular responses to NDMA toxicity.

scholarly journals A sand fly salivary protein acts as a neutrophil chemoattractant

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anderson B. Guimaraes-Costa ◽  
John P. Shannon ◽  
Ingrid Waclawiak ◽  
Jullyanna Oliveira ◽  
Claudio Meneses ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Calcium Influx ◽  
Parasite Burden ◽  
Salivary Protein ◽  
Sand Fly ◽  
Human Neutrophils ◽  
Chemotactic Protein ◽  
The Impact

AbstractApart from bacterial formyl peptides or viral chemokine mimicry, a non-vertebrate or insect protein that directly attracts mammalian innate cells such as neutrophils has not been molecularly characterized. Here, we show that members of sand fly yellow salivary proteins induce in vitro chemotaxis of mouse, canine and human neutrophils in transwell migration or EZ-TAXIScan assays. We demonstrate murine neutrophil recruitment in vivo using flow cytometry and two-photon intravital microscopy in Lysozyme-M-eGFP transgenic mice. We establish that the structure of this ~ 45 kDa neutrophil chemotactic protein does not resemble that of known chemokines. This chemoattractant acts through a G-protein-coupled receptor and is dependent on calcium influx. Of significance, this chemoattractant protein enhances lesion pathology (P < 0.0001) and increases parasite burden (P < 0.001) in mice upon co-injection with Leishmania parasites, underlining the impact of the sand fly salivary yellow proteins on disease outcome. These findings show that some arthropod vector-derived factors, such as this chemotactic salivary protein, activate rather than inhibit the host innate immune response, and that pathogens take advantage of these inflammatory responses to establish in the host.

scholarly journals In Vitro Anti-Inflammatory and Immunomodulatory Activities of an Extract from the Roots of Bupleurum rotundifolium

Medicines ◽  
2019 ◽  
Vol 6 (4) ◽  
pp. 101 ◽  
Author(s):  
Cholet ◽  
Decombat ◽  
Vareille-Delarbre ◽  
Gainche ◽  
Berry ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Polymorphonuclear Neutrophils ◽  
Ros Production ◽  
Peripheral Blood Mononuclear ◽  
Aerial Parts ◽  
Bupleurum Scorzonerifolium Willd ◽  
Anti Inflammatory ◽  
Inflammatory Profile ◽  
Bupleurum Scorzonerifolium

Background: Some Bupleurum species, such as the Bupleurum chinense DC. or the Bupleurum scorzonerifolium Willd have been extensively studied (especially their roots) for the treatment of inflammation. In contrast, only compounds extracted from the aerial parts of Bupleurum rotundifolium have been studied and showed anti-inflammatory or antiproliferative activities. This study was conducted to investigate the antioxidant, anti-inflammatory, and immunomodulatory effects of Bupleurum rotundifolium roots. Methods: To tackle the various aspects of inflammation, we studied in vitro a methanolic extract from the roots of Bupleurum rotundifolium on peripheral blood mononuclear cells (PBMCs), polymorphonuclear neutrophils (PMNs), and the monocytic cells THP-1. Its antioxidant capacities and iron-chelating activity were assessed. The extract was tested on THP-1 differentiation, reactive oxygen species (ROS) production by leukocytes, neutrophils chemotaxis, cytokines, PGE2 production, and NF-κB activation in PBMCs. Results: The extract showed a decreased ROS production in stimulated cells. It increased PBMC chemokine secretion and up-regulated the differentiation of THP-1 monocytes into macrophage-like cells, indicating a potential interest of the extract in the resolution of acute inflammation. In addition, the analysis of cytokine production suggests that Bupleurum rotundifolium has immunomodulatory properties. Conclusions: Cytokines secretion, especially IL-1β and IL-12p70, provided us with a set of indicators suggesting that the extract might be able to drive the polarization of macrophages and lymphocytes toward a Th2 anti-inflammatory profile in excessive inflammation.

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