scholarly journals Immunization against poly-N-acetylglucosamine reduces neutrophil activation and GVHD while sparing microbial diversity

2019 ◽  
Vol 116 (41) ◽  
pp. 20700-20706 ◽  
Author(s):  
Jan Hülsdünker ◽  
Oliver S. Thomas ◽  
Eileen Haring ◽  
Susanne Unger ◽  
Nicolás Gonzalo Núñez ◽  
...  
Keyword(s):  
Microbial Diversity ◽  
Hematopoietic Cell Transplantation ◽  
Polyclonal Antibodies ◽  
Passive Immunization ◽  
Neutrophil Activation ◽  
Neutrophil Granulocytes ◽  
Microbial Invasion ◽  
Novel Approach ◽  
Surface Polysaccharide

Microbial invasion into the intestinal mucosa after allogeneic hematopoietic cell transplantation (allo-HCT) triggers neutrophil activation and requires antibiotic interventions to prevent sepsis. However, antibiotics lead to a loss of microbiota diversity, which is connected to a higher incidence of acute graft-versus-host disease (aGVHD). Antimicrobial therapies that eliminate invading bacteria and reduce neutrophil-mediated damage without reducing the diversity of the microbiota are therefore highly desirable. A potential solution would be the use of antimicrobial antibodies that target invading pathogens, ultimately leading to their elimination by innate immune cells. In a mouse model of aGVHD, we investigated the potency of active and passive immunization against the conserved microbial surface polysaccharide poly-N-acetylglucosamine (PNAG) that is expressed on numerous pathogens. Treatment with monoclonal or polyclonal antibodies to PNAG (anti-PNAG) or vaccination against PNAG reduced aGVHD-related mortality. Anti-PNAG treatment did not change the intestinal microbial diversity as determined by 16S ribosomal DNA sequencing. Anti-PNAG treatment reduced myeloperoxidase activation and proliferation of neutrophil granulocytes (neutrophils) in the ileum of mice developing GVHD. In vitro, anti-PNAG treatment showed high antimicrobial activity. The functional role of neutrophils was confirmed by using neutrophil-deficient LysMcreMcl1fl/fl mice that had no survival advantage under anti-PNAG treatment. In summary, the control of invading bacteria by anti-PNAG treatment could be a novel approach to reduce the uncontrolled neutrophil activation that promotes early GVHD and opens a new avenue to interfere with aGVHD without affecting commensal intestinal microbial diversity.

scholarly journals Vaccination Against Poly-N-Acetylglucosamine Decreases Neutrophil Activation and Gvhd While Maintaining Microbial Diversity

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3209-3209
Author(s):  
Eileen Haring ◽  
Jan Hülsdünker ◽  
Oliver Thomas ◽  
Susanne Unger ◽  
Nicolás Núñez ◽  
...  
Keyword(s):  
Microbial Diversity ◽  
Intestinal Inflammation ◽  
Passive Immunization ◽  
Neutrophil Activation ◽  
Neutrophil Granulocytes ◽  
Myeloperoxidase Activity ◽  
Sequencing Analysis ◽  
Antibody Treatment ◽  
Microbial Invasion ◽  
Equity Ownership

Allogeneic hematopoietic cell transplantation (allo-HCT) is a curative therapy for different malignant and non-malignant hematologic diseases. Major life-threatening complications after allo-HCT are acute graft-versus-host disease (aGVHD) and severe infections. The incidence of GVHD after allo-HCT remains high, despite prophylactic immunosuppressive medication. According to the CIBMTR database, 60% of patients undergoing allo-HCT develop at least grade II-IV aGVHD. Microbial invasion into the intestinal mucosa after allo-HCT triggers the activation of neutrophil granulocytes (neutrophils) and requires antibiotic treatment to prevent sepsis. However, antibiotics lead to a loss of microbial diversity, which is connected to a higher incidence of aGVHD. Anti-microbial therapies which eliminate invading bacteria and diminish neutrophil-mediated damage without reducing the diversity of the microbiota are therefore highly desirable. A potential solution for this could be the use of anti-microbial antibodies that target and mark invading pathogens resulting in their elimination by innate immune cells. Therefore we investigated the potency of both active and passive immunization against the conserved microbial surface polysaccharide Poly-N-acetylglucosamine (PNAG) which is expressed on various pathogens in a murine aGVHD model. We could detect reduced aGVHD related mortality in mice which underwent treatment with an antibody against PNAG (anti-PNAG) or were actively immunized against PNAG. Sequencing analysis of the microbiota before and after allo-HCT showed that anti-PNAG treatment did not have any effect luminal microbial diversity. Mechanistically, we could show that anti-PNAG antibody treatment caused more abundant neutrophil recruitment to the intestinal submucosa. This supports the concept that neutrophils are able to effectively eliminate any opsonized bacteria in this tissue, leading to reduced local inflammation. In agreement with this we observed lower intestinal inflammation and reduced myeloperoxidase activity as well as proliferation of neutrophils in the small intestine of mice treated with anti-PNAG antibody. We demonstrate the potency of targeting PNAG as a novel antimicrobial treatment option in aGVHD by reducing uncontrolled neutrophil activation and thereby interfering with aGVHD without affecting commensal intestinal microbial diversity. Anti-PNAG-antibodies enhance anti-microbial immunity, while reducing the activation of neutrophil-mediated downstream immunopathology which is a novel approach to reduce the severity of GVHD. This could be translated into a clinical application given the modest toxicity profile of vaccination and the availability of fully human anti-PNAG antibodies, both of which have been tested in phase 1 trials in humans (ClinicalTrials.gov Identifier: NCT02853617). Disclosures Cywes-Bentley: OneBiopharma, Inc.: Honoraria. Koenecke:Novartis: Other: none. Pier:OneBiopharma, Inc.: Equity Ownership, Honoraria; Alopexx Vaccine, LLC: Equity Ownership, Honoraria.

scholarly journals Interleukin 8 Elicits Rapid Physiological Changes in Neutrophils That Are Altered by Inflammatory Conditions

2021 ◽  
pp. 1-17
Author(s):  
Stefan Bernhard ◽  
Stefan Hug ◽  
Alexander Elias Paul Stratmann ◽  
Maike Erber ◽  
Laura Vidoni ◽  
...  
Keyword(s):  
Systemic Inflammation ◽  
Severe Trauma ◽  
Induced Response ◽  
Neutrophil Granulocytes ◽  
Inflammatory Conditions ◽  
Flow Cytometric ◽  
Time Flow ◽  
Flow Cytometric Measurement ◽  
Detailed Kinetics

A sufficient response of neutrophil granulocytes stimulated by interleukin (IL)-8 is vital during systemic inflammation, for example, in sepsis or severe trauma. Moreover, IL-8 is clinically used as biomarker of inflammatory processes. However, the effects of IL-8 on cellular key regulators of neutrophil properties such as the intracellular pH (pH<sub>i</sub>) in dependence of ion transport proteins and during inflammation remain to be elucidated. Therefore, we investigated in detail the fundamental changes in pH<sub>i</sub>, cellular shape, and chemotactic activity elicited by IL-8. Using flow cytometric methods, we determined that the IL-8-induced cellular activity was largely dependent on specific ion channels and transporters, such as the sodium-proton exchanger 1 (NHE1) and non-NHE1-dependent sodium flux. Exposing neutrophils in vitro to a proinflammatory micromilieu with N-formyl-Met-Leu-Phe, LPS, or IL-8 resulted in a diminished response regarding the increase in cellular size and pH. The detailed kinetics of the reduced reactivity of the neutrophil granulocytes could be illustrated in a near-real-time flow cytometric measurement. Last, the LPS-mediated impairment of the IL-8-induced response in neutrophils was confirmed in a translational, animal-free human whole blood model. Overall, we provide novel mechanistic insights for the interaction of IL-8 with neutrophil granulocytes and report in detail about its alteration during systemic inflammation.

scholarly journals Examination of the Efficacy and Cross-Reactivity of a Novel Polyclonal Antibody Targeting the Disintegrin Domain in SVMPs to Neutralize Snake Venom

Toxins ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 254
Author(s):  
Shelby S. Szteiter ◽  
Ilse N. Diego ◽  
Jonathan Ortegon ◽  
Eliana Salinas ◽  
Abcde Cirilo ◽  
...  
Keyword(s):  
Snake Venom ◽  
Polyclonal Antibody ◽  
Polyclonal Antibodies ◽  
Cross Reactivity ◽  
Snake Envenomation ◽  
Disintegrin Domain ◽  
The Common ◽  
Neutralization Ability ◽  
New Strategies

Snake envenomation can result in hemorrhage, local necrosis, swelling, and if not treated properly can lead to adverse systemic effects such as coagulopathy, nephrotoxicity, neurotoxicity, and cardiotoxicity, which can result in death. As such, snake venom metalloproteinases (SVMPs) and disintegrins are two toxic components that contribute to hemorrhage and interfere with the hemostatic system. Administration of a commercial antivenom is the common antidote to treat snake envenomation, but the high-cost, lack of efficacy, side effects, and limited availability, necessitates the development of new strategies and approaches for therapeutic treatments. Herein, we describe the neutralization ability of anti-disintegrin polyclonal antibody on the activities of isolated disintegrins, P-II/P-III SVMPs, and crude venoms. Our results show disintegrin activity on platelet aggregation in whole blood and the migration of the SK-Mel-28 cells that can be neutralized with anti-disintegrin polyclonal antibody. We characterized a SVMP and found that anti-disintegrin was also able to inhibit its activity in an in vitro proteolytic assay. Moreover, we found that anti-disintegrin could neutralize the proteolytic and hemorrhagic activities from crude Crotalus atrox venom. Our results suggest that anti-disintegrin polyclonal antibodies have the potential for a targeted approach to neutralize SVMPs in the treatment of snakebite envenomations.

scholarly journals Influences of advanced glycosylation end products on the inner blood–retinal barrier in a co-culture cell model in vitro

2020 ◽  
Vol 15 (1) ◽  
pp. 619-628
Author(s):  
Chen Yuan ◽  
Ya Mo ◽  
Jie Yang ◽  
Mei Zhang ◽  
Xuejun Xie
Keyword(s):  
Electrical Resistance ◽  
Cell Model ◽  
Polyclonal Antibodies ◽  
Time Dependent ◽  
Dependent Manner ◽  
Blood Retinal Barrier ◽  
Advanced Glycosylation End Products ◽  
End Products ◽  
Advanced Glycosylation

AbstractAdvanced glycosylation end products (AGEs) are harmful factors that can damage the inner blood–retinal barrier (iBRB). Rat retinal microvascular endothelial cells (RMECs) were isolated and cultured, and identified by anti-CD31 and von Willebrand factor polyclonal antibodies. Similarly, rat retinal Müller glial cells (RMGCs) were identified by H&E staining and with antibodies of glial fibrillary acidic protein and glutamine synthetase. The transepithelial electrical resistance (TEER) value was measured with a Millicell electrical resistance system to observe the leakage of the barrier. Transwell cell plates for co-culturing RMECs with RMGCs were used to construct an iBRB model, which was then tested with the addition of AGEs at final concentrations of 50 and 100 mg/L for 24, 48, and 72 h. AGEs in the in vitro iBRB model constructed by RMEC and RMGC co-culture led to the imbalance of the vascular endothelial growth factor (VEGF) and pigment epithelial derivative factor (PEDF), and the permeability of the RMEC layer increased because the TEER decreased in a dose- and time-dependent manner. AGEs increased VEGF but lowered PEDF in a dose- and time-dependent manner. The intervention with AGEs led to the change of the transendothelial resistance of the RMEC layer likely caused by the increased ratio of VEGF/PEDF.

scholarly journals HSP90-dependent PUS7 overexpression facilitates the metastasis of colorectal cancer cells by regulating LASP1 abundance

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Dan Song ◽  
Ming Guo ◽  
Shuai Xu ◽  
Xiaotian Song ◽  
Bin Bai ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Intellectual Development ◽  
Molecular Mechanisms ◽  
Hsp90 Inhibitor ◽  
Pseudouridine Synthase ◽  
Novel Approach ◽  
Cell Metastasis ◽  
Underlying Mechanisms

Abstract Background Pseudouridine synthase (PUS) 7 is a member of the PUS family that catalyses pseudouridine formation. It has been shown to be involved in intellectual development and haematological malignancies. Nevertheless, the role and the underlying molecular mechanisms of PUS7 in solid tumours, such as colorectal cancer (CRC), remain unexplored. This study elucidated, for the first time, the role of PUS7 in CRC cell metastasis and the underlying mechanisms. Methods We conducted immunohistochemistry, qPCR, and western blotting to quantify the expression of PUS7 in CRC tissues as well as cell lines. Besides, diverse in vivo and in vitro functional tests were employed to establish the function of PUS7 in CRC. RNA-seq and proteome profiling analysis were also applied to identify the targets of PUS7. PUS7-interacting proteins were further uncovered using immunoprecipitation and mass spectrometry. Results Overexpression of PUS7 was observed in CRC tissues and was linked to advanced clinical stages and shorter overall survival. PUS7 silencing effectively repressed CRC cell metastasis, while its upregulation promoted metastasis, independently of the PUS7 catalytic activity. LASP1 was identified as a downstream effector of PUS7. Forced LASP1 expression abolished the metastasis suppression triggered by PUS7 silencing. Furthermore, HSP90 was identified as a client protein of PUS7, associated with the increased PUS7 abundance in CRC. NMS-E973, a specific HSP90 inhibitor, also showed higher anti-metastatic activity when combined with PUS7 repression. Importantly, in line with these results, in human CRC tissues, the expression of PUS7 was positively linked to the expression of HSP90 and LASP1, and patients co-expressing HSP90/PUS7/LASP1 showed a worse prognosis. Conclusions The HSP90-dependent PUS7 upregulation promotes CRC cell metastasis via the regulation of LASP1. Thus, targeting the HSP90/PUS7/LASP1 axis may be a novel approach for the treatment of CRC.

scholarly journals Plasma cells shape the mesenchymal identity of ovarian cancers through transfer of exosome-derived microRNAs

2021 ◽  
Vol 7 (9) ◽  
pp. eabb0737
Author(s):  
Zhengnan Yang ◽  
Wei Wang ◽  
Linjie Zhao ◽  
Xin Wang ◽  
Ryan C. Gimple ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
Plasma Cell ◽  
Plasma Cells ◽  
Ovarian Cancer Cells ◽  
Mesenchymal Phenotype ◽  
Ovarian Cancers ◽  
Novel Approach

Ovarian cancer represents a highly lethal disease that poses a substantial burden for females, with four main molecular subtypes carrying distinct clinical outcomes. Here, we demonstrated that plasma cells, a subset of antibody-producing B cells, were enriched in the mesenchymal subtype of high-grade serous ovarian cancers (HGSCs). Plasma cell abundance correlated with the density of mesenchymal cells in clinical specimens of HGSCs. Coculture of nonmesenchymal ovarian cancer cells and plasma cells induced a mesenchymal phenotype of tumor cells in vitro and in vivo. Phenotypic switch was mediated by the transfer of plasma cell–derived exosomes containing miR-330-3p into nonmesenchymal ovarian cancer cells. Exosome-derived miR-330-3p increased expression of junctional adhesion molecule B in a noncanonical fashion. Depletion of plasma cells by bortezomib reversed the mesenchymal characteristics of ovarian cancer and inhibited in vivo tumor growth. Collectively, our work suggests targeting plasma cells may be a novel approach for ovarian cancer therapy.

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