scholarly journals Electrospun Polydioxanone Loaded With Chloroquine Modulates Template-Induced NET Release and Inflammatory Responses From Human Neutrophils

Author(s):  
Allison E. Fetz ◽  
Shannon E. Wallace ◽  
Gary L. Bowlin

The implantation of a biomaterial quickly initiates a tissue repair program initially characterized by a neutrophil influx. During the acute inflammatory response, neutrophils release neutrophil extracellular traps (NETs) and secrete soluble signals to modulate the tissue environment. In this work, we evaluated chloroquine diphosphate, an antimalarial with immunomodulatory and antithrombotic effects, as an electrospun biomaterial additive to regulate neutrophil-mediated inflammation. Electrospinning of polydioxanone was optimized for rapid chloroquine elution within 1 h, and acute neutrophil-biomaterial interactions were evaluated in vitro with fresh human peripheral blood neutrophils at 3 and 6 h before quantifying the release of NETs and secretion of inflammatory and regenerative factors. Our results indicate that chloroquine suppresses NET release in a biomaterial surface area–dependent manner at the early time point, whereas it modulates signal secretion at both early and late time points. More specifically, chloroquine elution down-regulates interleukin 8 (IL-8) and matrix metalloproteinase nine secretion while up-regulating hepatocyte growth factor, vascular endothelial growth factor A, and IL-22 secretion, suggesting a potential shift toward a resolving neutrophil phenotype. Our novel repurposing of chloroquine as a biomaterial additive may therefore have synergistic, immunomodulatory effects that are advantageous for biomaterial-guided in situ tissue regeneration applications.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anderson B. Guimaraes-Costa ◽  
John P. Shannon ◽  
Ingrid Waclawiak ◽  
Jullyanna Oliveira ◽  
Claudio Meneses ◽  
...  

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.


2001 ◽  
Vol 69 (1) ◽  
pp. 456-462 ◽  
Author(s):  
Joseph A. Gebbia ◽  
James L. Coleman ◽  
Jorge L Benach

ABSTRACT Borrelia burgdorferi, the spirochetal agent of Lyme disease, stimulated human peripheral blood monocytes to release pro-matrix metalloproteinase-9 (gelatinase B; pro-MMP-9) and active matrix metalloproteinase-1 (collagenase-1; MMP-1). Human neutrophils also released pro-MMP-9 and a 130-kDa protein with gelatinolytic activity in response to live B. burgdorferi. In addition, U937 cells and human keratinocyte cells were also stimulated to release pro-MMP-9 under the same conditions. However, human umbilical vein endothelial cells (HUVECs) released pro-MMP-9 and pro-MMP-2 in a constitutive manner and were not influenced by live spirochetes. MMPs produced by human monocytes also enhanced the penetration of B. burgdorferi through extracellular matrix component barriers in vitro. Plasmin stabilized on the surface of the Lyme disease spirochete was shown to activate pro-MMP-9 to its active form. This active form was also observed in the plasma of mice infected with a relapsing fever borrelia. These results suggest that borreliae can upregulate MMPs and possibly mediate an activation cascade initiated by plasmin bound to the microbial surface. MMPs may play a role in dissemination of the Lyme disease spirochete and in the pathogenesis ofBorrelia infection.


2002 ◽  
Vol 70 (3) ◽  
pp. 1591-1598 ◽  
Author(s):  
Céline Cougoule ◽  
Patricia Constant ◽  
Gilles Etienne ◽  
Mamadou Daffé ◽  
Isabelle Maridonneau-Parini

ABSTRACT Biogenesis of phagolysosomes is a very rapid event in neutrophils which takes place with nascent unclosed phagosomes, leading to the release of lysosomal enzymes such as β-glucuronidase in the extracellular medium. We have previously shown that, under nonopsonic conditions, both pathogenic and nonpathogenic mycobacteria uncouple phagocytosis from fusion of azurophil granules (specialized secretory lysosomes) with phagosomes. In the present study we questioned whether they actively act on neutrophils to block this process or use phagocytic receptors that negatively control the biogenesis of phagolysosomes. As for live unicellular Mycobacterium smegmatis, we observed that nonopsonic phagocytosis of heat-killed mycobacteria did not induce the release of β-glucuronidase, indicating that M. smegmatis does not actively act on the fusion process in neutrophils. In contrast, phagocytosis of unicellular M. smegmatis opsonized in immune serum or that of small nonopsonized mycobacterial aggregates restored the biogenesis of phagolysosomes. Aggregates were internalized in a CR3- and cholesterol-dependent manner as unicellular mycobacteria. However, aggregates but not unicellular bacteria triggered F-actin and Hck recruitment at the phagosomes, events that have been associated with lysosome fusion. Thus, we propose that M. smegmatis does not actively control the fusion of azurophil granules at early time points postinfection and that mycobacterial aggregates recruit large clusters of receptors at the neutrophil surface which could trap proteins implicated in the biogenesis of phagolysosomes.


Blood ◽  
1987 ◽  
Vol 70 (5) ◽  
pp. 1624-1629
Author(s):  
RT McCormack ◽  
RD Nelson ◽  
DE Chenoweth ◽  
TW LeBien

We have previously demonstrated that human neutrophils synthesize the common acute lymphoblastic leukemia antigen (CALLA/CD10). To determine whether CALLA/CD10-positive and -negative neutrophils have similar or distinct functional attributes, we sorted normal peripheral blood neutrophils for CALLA/CD10 expression and compared their chemotactic ability. Surprisingly, the low-frequency (approximately 5%), CALLA/CD10- negative neutrophils displayed a dramatically heightened chemotactic response to activated complement (C') that was (a) specific for C', (b) not observed with other minor subpopulations of neutrophils, (c) not due to previous activation in vivo or in vitro, and (d) apparently not due to an increase in C5a receptors. These results underscore the concept of neutrophil heterogeneity and prompt the hypothesis that CALLA/CD10-negative neutrophils may participate in an inflammatory response to trauma involving complement activation.


1993 ◽  
Vol 264 (1) ◽  
pp. L36-L42 ◽  
Author(s):  
E. M. Denholm ◽  
S. M. Rollins

Bleomycin-induced fibrosis in rodents has been used extensively as a model of human pulmonary fibrosis. The influx of monocytes observed during the early stages of fibrosis is at least partially regulated by the elaboration of chemotactic factors in the lung. Exposure of alveolar macrophages (AM phi) to bleomycin either in vivo or in vitro stimulated secretion of monocyte chemotactic activity (MCA). This MCA has been previously characterized as being primarily due to fibronectin fragments. The present experiments revealed that bleomycin also induced AM phi to secrete a second chemotactic factor, transforming growth factor-beta (TGF-beta). However, the TGF-beta secreted by macrophages was in latent form, since no TGF-beta activity was detected unless AM phi conditioned medium (CM) was acid-activated. After acidification, chemotactic activity in CM from AM phi stimulated with bleomycin in vitro was increased by 3.6, whereas activity in AM phi CM from fibrotic rats increased by 2 and that of a bleomycin-stimulated AM phi cell line increased by 1.6. This acid-activatable chemotactic activity was inhibited by antibody to TGF-beta. Bleomycin-stimulated AM phi s secreted significantly more TGF-beta than did unstimulated controls. Further, in vitro exposure of AM phi to bleomycin induced TGF-beta mRNA expression in a time- and concentration-dependent manner, with maximal mRNA being detected following a 16-h incubation with 1 microgram/ml bleomycin.


Cytokine ◽  
2016 ◽  
Vol 88 ◽  
pp. 184-192 ◽  
Author(s):  
Hélio Galdino ◽  
Rodrigo Saar Gomes ◽  
Jessica Cristina dos Santos ◽  
Lívia Lara Pessoni ◽  
Anetícia Eduarda Maldaner ◽  
...  

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Susmita Sahoo ◽  
Sol Misener ◽  
Tina Thorne ◽  
Meredith Millay ◽  
Kathryn M Schultz ◽  
...  

Local transplantation of human CD34+ hematopoietic stem cells has been shown to promote neovascularization in pre-clinical studies in models of myocardial and limb ischemia. In early phase clinical trials, transplantation of CD34+ cells has been associated with reduced angina, improved exercise time and reduced amputation rates. Several studies have suggested that paracrine effects by these pro-angiogenic cells mediate the effects induced by cell transplantation. We hypothesized that CD34+ cells secrete exosomes (Exo), which mediate at least a part of the therapeutic function of the cells. Methods and Results: We isolated Exo from the conditioned media of adult human peripheral blood (PB) CD34+ cells. The angiogenic and therapeutic potency of CD34+ Exo was compared with the intact CD34+ cells and also with PB mononuclear cell (MNC) Exo. Exo from both CD34+ cells and MNC are 50–90nm in size, have cup shaped morphology, and carry known Exo-marker proteins such as CD63, TSG101 and Annexin V as shown by electron microscopy, Western blot and flow cytometry. Compared to CD34+ cells or MNC Exo, CD34+ Exo significantly induces in vitro angiogenic activities such as viability, proliferation and tube formation of HUVECs on matrigel- in a dose dependent manner. In vivo, CD34+ Exo stimulated significant neovascularization in mouse corneal angiogenesis assay (14±4 mm v MNC Exo, 4±1 mm, p<0.01) and incorporation of endothelial (CD31+) cells in mouse matrigel-plug assay (6±1.7% v CD34+ cells, 2±0.8%, p<0.01). Finally, in a mouse model of hind limb ischemia (HLI), CD34+ Exo significantly improved perfusion (ratio: 1.01±0.04 v 0.57±0.1, P<0.05), increased capillary density (1.8±0.3/HPF v 0.9±0.1/HPF, p<0.001) and prevented ischemic leg amputation (16% v 100%), as compared with MNC Exo. Conclusions: These data demonstrate that CD34+ Exo induce angiogenic activity and ischemic tissue repair in the absence of CD34+ cells, and suggest that Exo represent important mediators of the therapeutic effects associated with CD34+ cell therapy. We speculate that Exo derived from CD34+ cells may represent a significant component of the paracrine effect of progenitor-cell transplantation for therapeutic angiogenesis.


1995 ◽  
Vol 269 (1) ◽  
pp. H239-H245
Author(s):  
K. Nakagawa ◽  
F. N. Miller ◽  
A. W. Knott ◽  
M. J. Edwards

The acute inflammatory responses to the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (FMLP) and the effects of pentoxifylline (PTXF) on the responses in vivo were studied. We used intravital microscopy with rat cremaster muscle preparation to determine inflammatory responses of microcirculation. Macromolecular leakage from postcapillary venules was evaluated by quantifying the extravasation of fluorescein isothiocyanate conjugated to bovine serum albumin. FMLP induced a rapid increase in macromolecular leakage, an increase in leukocyte-endothelium adhesion, and a decrease in blood flow in the microcirculation. PTXF inhibited FMLP-induced responses in a dose-dependent manner but failed to block the histamine-dependent leakage induced by compound 48/80. In addition, diphenhydramine, a histamine-receptor blocker, did not affect the macromolecular leakage induced by FMLP. The cell-permeable adenosine 3',5'-cyclic monophosphate (cAMP) analogue N6,2'-O-dibutyryladenosine 3',5'-cyclic monophosphate mimicked PTXF's effects on the microcirculation and also inhibited FMLP-induced macromolecular leakage. PTXF is known to inhibit phosphodiesterase and increase intracellular cAMP, which modulates functions of endothelial cells, smooth muscle cells, and neutrophils in vitro. Our findings suggest that FMLP induces acute inflammatory responses through activation of neutrophils, independent of endogenous histamine release, and that PTXF inhibits these responses through elevated intracellular cAMP.


Blood ◽  
1985 ◽  
Vol 65 (2) ◽  
pp. 423-432 ◽  
Author(s):  
E Cramer ◽  
KB Pryzwansky ◽  
JL Villeval ◽  
U Testa ◽  
J Breton-Gorius

Abstract Colloidal gold was used as a marker for immunoelectron microscopy to localize lactoferrin (LF) and myeloperoxidase (MPO) in human peripheral blood neutrophils. Cells were reacted with monospecific antibodies against LF or MPO and then with gold-labeled antiglobulin. MPO cytochemistry was also associated with immunologic detection of LF. Immunologic labeling of thin sections after embedding in glycol methacrylate gave good ultrastructural morphology and specific localization of both proteins. MPO was detected in the large azurophil granules, whereas LF was consistently localized in the matrix of another population of morphologically distinct granules, smaller and more numerous than azurophil granules. When cytochemical detection of MPO was coupled with immunologic detection of LF, LF was observed in the population of MPO-negative granules, which were identified as specific. This was confirmed on cells that were permeabilized with saponin and stained for LF and MPO before embedding. No other neutrophil organelles displayed labeling for LF; other blood cells also were unreactive for LF. In the bone marrow, myeloblast and promyelocyte granulations were not stained and LF-containing granules appeared at the myelocyte stage. In conclusion, we confirm previous biochemical and light microscopic studies by ultrastructural demonstration of LF and MPO in two categories of granules, the specific and azurophil granules, respectively. The method described in this article avoids disruption caused by cell fractionation procedures. In the future, other intragranular proteins can be localized by a similar approach.


Blood ◽  
2000 ◽  
Vol 95 (7) ◽  
pp. 2275-2283 ◽  
Author(s):  
Naoki Nakayama ◽  
Jae Lee ◽  
Laura Chiu

Abstract The totipotent mouse embryonic stem (ES) cell is known to differentiate into cells expressing the β-globin gene when stimulated with bone morphogenetic protein (BMP)-4. Here, we demonstrate that BMP-4 is essential for generating both erythro-myeloid colony-forming cells (CFCs) and lymphoid (B and NK) progenitor cells from ES cells and that vascular endothelial growth factor (VEGF) synergizes with BMP-4. The CD45+ myelomonocytic progenitors and Ter119+ erythroid cells began to be detected with 0.5 ng/mL BMP-4, and their levels plateaued at approximately 2 ng/mL. VEGF alone weakly elevated the CD34+ cell population though no lymphohematopoietic progenitors were induced. However, when combined with BMP-4, 2 to 20 ng/mL VEGF synergistically augmented the BMP-4-dependent generation of erythro-myeloid CFCs and lymphoid progenitors from ES cells, which were enriched in CD34+ CD31lo and CD34+CD45− cell populations, respectively, in a dose-dependent manner. Furthermore, during the 7 days of in vitro differentiation, BMP-4 was required within the first 4 days, whereas VEGF was functional after the action of BMP-4 (in the last 3 days). Thus, VEGF is a synergistic enhancer for the BMP-4-dependent differentiation processes, and it seems to be achieved by the ordered action of the 2 factors.


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