Publications by authors named "David L Williams"

314 Publications

FACTORS AFFECTING TEAR PRODUCTION AND INTRAOCULAR PRESSURE IN ANESTHETIZED CHIMPANZEES ().

J Zoo Wildl Med 2020 Nov;51(3):687-690

The Queen's Veterinary School Hospital, University of Cambridge, Cambridge CB3 0ES, United Kingdom.

Measurements of intraocular pressure (IOP) and tear production are key components of ophthalmic examination. Chimpanzees () were anesthetized using either tiletamine-zolazepam (TZ; 2 mg/kg) combined with medetomidine (TZM; 0.02 mg/kg), or, TZ alone (6mg/kg). Tear production was lower ( = 0.03) with TZM (5.63 ± 6.22 mm/min; = 16) than with TZ (11.13 ± 4.63 mm/min; = 8). Mean IOP, measured using rebound tonometry in an upright body position ( = 8) was 18.74 ± 3.01 mm Hg, with no differences between right and left eyes. However, positioning chimpanzees in left lateral recumbency ( = 27) resulted in higher IOP in the dependent (left) eye (24.77 ± 4.49 mm Hg) compared to the nondependent (right) eye (22.27 ± 4.65 mm Hg) of the same animal ( < 0.0001). These data indicate medetomidine anesthesia markedly lowers tear production in chimpanzees, and that body position should be taken into consideration when performing rebound tonometry.
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http://dx.doi.org/10.1638/2020-0014DOI Listing
November 2020

The expression of integrin α β (CD11d/CD18) on neutrophils orchestrates the defense mechanism against endotoxemia and sepsis.

J Leukoc Biol 2021 Jan 13. Epub 2021 Jan 13.

Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee, USA.

Neutrophil-macrophage interplay is a fine-tuning mechanism that regulates the innate immune response during infection and inflammation. Cell surface receptors play an essential role in neutrophil and macrophage functions. The same receptor can provide different outcomes within diverse leukocyte subsets in different inflammatory conditions. Understanding the variety of responses mediated by one receptor is critical for the development of anti-inflammatory treatments. In this study, we evaluated the role of a leukocyte adhesive receptor, integrin α β , in the development of acute inflammation. α β is mostly expressed on macrophages and contributes to the development of chronic inflammation. In contrast, we found that α -knockout dramatically increases mortality in the cecal ligation and puncture sepsis model and LPS-induced endotoxemia. This pathologic outcome of α -deficient mice is associated with a reduced number of monocyte-derived macrophages and an increased number of neutrophils in their lungs. However, the tracking of adoptively transferred fluorescently labeled wild-type (WT) and α monocytes in WT mice during endotoxemia demonstrated only a moderate difference between the recruitment of these two subsets. Moreover, the rescue experiment, using i.v. injection of WT monocytes to α -deficient mice followed by LPS challenge, showed only slightly reduced mortality. Surprisingly, the injection of WT neutrophils to the bloodstream of α mice markedly increased migration of monocyte-derived macrophage to lungs and dramatically improves survival. α -deficient neutrophils demonstrate increased necrosis/pyroptosis. α β -mediated macrophage accumulation in the lungs promotes efferocytosis that reduced mortality. Hence, integrin α β implements a complex defense mechanism during endotoxemia, which is mediated by macrophages via a neutrophil-dependent pathway.
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http://dx.doi.org/10.1002/JLB.3HI0820-529RRDOI Listing
January 2021

Taking Advantage of the Morpheein Behavior of Peroxiredoxin in Bionanotechnology.

Bioconjug Chem 2021 Jan 7;32(1):43-62. Epub 2021 Jan 7.

Department of Life, Health, and Environmental Sciences, University of L'Aquila, Piazzale Salvatore Tommasi 1, 67100 L'Aquila, Italy.

Morpheeins are proteins that reversibly assemble into different oligomers, whose architectures are governed by conformational changes of the subunits. This property could be utilized in bionanotechnology where the building of nanometric and new high-ordered structures is required. By capitalizing on the adaptability of morpheeins to create patterned structures and exploiting their inborn affinity toward inorganic and living matter, "bottom-up" creation of nanostructures could be achieved using a single protein building block, which may be useful as such or as scaffolds for more complex materials. Peroxiredoxins represent the paradigm of a morpheein that can be applied to bionanotechnology. This review describes the structural and functional transitions that peroxiredoxins undergo to form high-order oligomers, e.g., rings, tubes, particles, and catenanes, and reports on the chemical and genetic engineering approaches to employ them in the generation of responsive nanostructures and nanodevices. The usefulness of the morpheeins' behavior is emphasized, supporting their use in future applications.
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http://dx.doi.org/10.1021/acs.bioconjchem.0c00621DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8023583PMC
January 2021

Time to stop mink farming in the EU.

Authors:
David L Williams

Vet Rec 2020 12;187(12):498

Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES.

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http://dx.doi.org/10.1136/vr.m4804DOI Listing
December 2020

Repurposing Auranofin and Evaluation of a New Gold(I) Compound for the Search of Treatment of Human and Cattle Parasitic Diseases: From Protozoa to Helminth Infections.

Molecules 2020 Nov 1;25(21). Epub 2020 Nov 1.

UMR 7042 CNRS-Université de Strasbourg-Université Haute-Alsace, Laboratoire d'Innovation Moléculaire et Applications (LIMA), Bioorganic and Medicinal Chemistry Team, European School of Chemistry, Polymers and Materials (ECPM), 25, rue Becquerel, F-67087 Strasbourg, France.

Neglected parasitic diseases remain a major public health issue worldwide, especially in tropical and subtropical areas. Human parasite diversity is very large, ranging from protozoa to worms. In most cases, more effective and new drugs are urgently needed. Previous studies indicated that the gold(I) drug auranofin (Ridaura) is effective against several parasites. Among new gold(I) complexes, the phosphole-containing gold(I) complex {1-phenyl-2,5-di(2-pyridyl)phosphole}AuCl (abbreviated as GoPI) is an irreversible inhibitor of both purified human glutathione and thioredoxin reductases. GoPI-sugar is a novel 1-thio-β-d-glucopyranose 2,3,4,6-tetraacetato--derivative that is a chimera of the structures of GoPI and auranofin, designed to improve stability and bioavailability of GoPI. These metal-ligand complexes are of particular interest because of their combined abilities to irreversibly target the essential dithiol/selenol catalytic pair of selenium-dependent thioredoxin reductase activity, and to kill cells from breast and brain tumors. In this work, screening of various parasites-protozoans, trematodes, and nematodes-was undertaken to determine the in vitro killing activity of GoPI-sugar compared to auranofin. GoPI-sugar was found to efficiently kill intramacrophagic amastigotes and adult filarial and trematode worms.
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http://dx.doi.org/10.3390/molecules25215075DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7663263PMC
November 2020

Lactate Suppresses Macrophage Pro-Inflammatory Response to LPS Stimulation by Inhibition of YAP and NF-κB Activation GPR81-Mediated Signaling.

Front Immunol 2020 6;11:587913. Epub 2020 Oct 6.

Department of Surgery, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States.

Recent evidence from cancer research indicates that lactate exerts a suppressive effect on innate immune responses in cancer. This study investigated the mechanisms by which lactate suppresses macrophage pro-inflammatory responses. Macrophages [Raw 264.7 and bone marrow derived macrophages (BMDMs)] were treated with LPS in the presence or absence of lactate. Pro-inflammatory cytokines, NF-κB and YAP activation and nuclear translocation were examined. Our results show that lactate significantly attenuates LPS stimulated macrophage TNF-α and IL-6 production. Lactate also suppresses LPS stimulated macrophage NF-κB and YAP activation and nuclear translocation in macrophages. Interestingly, YAP activation and nuclear translocation are required for LPS stimulated macrophage NF-κB activation and TNFα production. Importantly, lactate suppressed YAP activation and nuclear translocation is mediated by GPR81 dependent AMKP and LATS activation which phosphorylates YAP, resulting in YAP inactivation. Finally, we demonstrated that LPS stimulation induces an interaction between YAP and NF-κB subunit p65, while lactate decreases the interaction of YAP and NF-κB, thus suppressing LPS induced pro-inflammatory cytokine production. Our study demonstrates that lactate exerts a previously unknown role in the suppression of macrophage pro-inflammatory cytokine production GPR81 mediated YAP inactivation, resulting in disruption of YAP and NF-κB interaction and nuclear translocation in macrophages.
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http://dx.doi.org/10.3389/fimmu.2020.587913DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7573489PMC
October 2020

Memory-Like Responses of Brain Microglia Are Controlled by Developmental State and Pathogen Dose.

Front Immunol 2020 25;11:546415. Epub 2020 Sep 25.

Hans-Berger Department of Neurology, Jena University Hospital, Jena, Germany.

Microglia, the innate immune cells of the central nervous system, feature adaptive immune memory with implications for brain homeostasis and pathologies. However, factors involved in the emergence and regulation of these opposing responses in microglia have not been fully addressed. Recently, we showed that microglia from the newborn brain display features of trained immunity and immune tolerance after repeated contact with pathogens in a dose-dependent manner. Here, we evaluate the impact of developmental stage on adaptive immune responses of brain microglia after repeated challenge with ultra-low (1 fg/ml) and high (100 ng/ml) doses of the endotoxin LPS . We find that priming of naïve microglia derived from newborn but not mature and aged murine brain with ultra-low LPS significantly increased levels of pro-inflammatory mediators TNF-α, IL-6, IL-1β, MMP-9, and iNOS as well as neurotrophic factors indicating induction of trained immunity ( < 0.05). In contrast, stimulation with high doses of LPS led to a robust downregulation of pro-inflammatory cytokines and iNOS independent of the developmental state, indicating induced immune tolerance. Furthermore, high-dose priming with LPS upregulated anti-inflammatory mediators IL-10, Arg-1, TGF- β, MSR1, and IL-4 in newborn microglia ( < 0.05). Our data indicate pronounced plasticity of the immune response of neonate microglia compared with microglia derived from mature and aged mouse brain. Induced trained immunity after priming with ultra-low LPS doses may be responsible for enhanced neuro-inflammatory susceptibility of immature brain. In contrast, the immunosuppressed phenotype following high-dose LPS priming might be prone to attenuate excessive damage after recurrent systemic inflammation.
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http://dx.doi.org/10.3389/fimmu.2020.546415DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7546897PMC
September 2020

Using Expanded Natural Killer Cells as Therapy for Invasive Aspergillosis.

J Fungi (Basel) 2020 Oct 17;6(4). Epub 2020 Oct 17.

Division of Infectious Diseases, University Medicine Cluster, National University Health System, Singapore 119228, Singapore.

Invasive aspergillosis (IA) is a major opportunistic fungal infection in patients with haematological malignancies. Morbidity and mortality rates are high despite anti-fungal treatment, as the compromised status of immune system prevents the host from responding optimally to conventional therapy. This raises the consideration for immunotherapy as an adjunctive treatment. In this study, we evaluated the utility of expanded human NK cells as treatment against infection in vitro and in vivo. The NK cells were expanded and activated by K562 cells genetically modified to express 4-1BB ligand and membrane-bound interleukin-15 (K562-41BBL-mbIL-15) as feeders. The efficacy of these cells was investigated in killing assays in vitro and as adoptive cellular therapy in vivo. The expanded NK cells possessed potent killing activity at low effector-to-target ratio of 2:1. Fungicidal activity was morphotypal-dependent and most efficacious against conidia. Fungicidal activity was mediated by dectin-1 receptors on the expanded NK cells leading to augmented release of perforin, resulting in enhanced direct cytolysis. In an immunocompromised mice pulmonary aspergillosis model, we showed that NK cell treatment significantly reduced fungal burden, hence demonstrating the translational potential of expanded NK cells as adjunctive therapy against IA in immunocompromised patients.
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http://dx.doi.org/10.3390/jof6040231DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7712362PMC
October 2020

Reversal of sepsis-induced T cell dysfunction: OX-40 to the rescue?

J Leukoc Biol 2021 Apr 29;109(4):689-691. Epub 2020 Sep 29.

Center of Excellence in Inflammation, Infectious Disease and Immunity, East Tennessee State University, Johnson City, Tennessee, USA.

The study of Unsinger and colleagues provide important insights into OX40 mediated immunotherapy as a potential approach for the treatment of sepsis induced immune suppression.
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http://dx.doi.org/10.1002/JLB.3CE0720-468DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7987777PMC
April 2021

Transcriptional and functional insights into the host immune response against the emerging fungal pathogen Candida auris.

Nat Microbiol 2020 12 24;5(12):1516-1531. Epub 2020 Aug 24.

Department of Internal Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands.

Candida auris is among the most important emerging fungal pathogens, yet mechanistic insights into its immune recognition and control are lacking. Here, we integrate transcriptional and functional immune-cell profiling to uncover innate defence mechanisms against C. auris. C. auris induces a specific transcriptome in human mononuclear cells, a stronger cytokine response compared with Candida albicans, but a lower macrophage lysis capacity. C. auris-induced innate immune activation is mediated through the recognition of C-type lectin receptors, mainly elicited by structurally unique C. auris mannoproteins. In in vivo experimental models of disseminated candidiasis, C. auris was less virulent than C. albicans. Collectively, these results demonstrate that C. auris is a strong inducer of innate host defence, and identify possible targets for adjuvant immunotherapy.
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http://dx.doi.org/10.1038/s41564-020-0780-3DOI Listing
December 2020

Endothelial cell HSPA12B and yes-associated protein cooperatively regulate angiogenesis following myocardial infarction.

JCI Insight 2020 09 17;5(18). Epub 2020 Sep 17.

Department of Surgery and.

Angiogenesis is essential for cardiac functional recovery after myocardial infarction (MI). HSPA12B is predominately expressed in endothelial cells and required for angiogenesis. Yes-associated protein (YAP) plays an important role in tumor angiogenesis. This study investigated the cooperative role of HSPA12B and YAP in angiogenesis after MI. Silencing of either HSPA12B or YAP impaired hypoxia-promoted endothelial cell proliferation and angiogenesis. Deficiency of HSPA12B suppressed YAP expression and nuclear translocation after hypoxia. Knockdown of YAP attenuated hypoxia-stimulated HSPA12B nuclear translocation and abrogated HSPA12B-promoted endothelial cell angiogenesis. Mechanistically, hypoxia induced an interaction between endothelial HSPA12B and YAP. ChIP assay showed that HSPA12B is a target gene of YAP/transcriptional enhanced associated domain 4 (TEAD4) and a coactivator in YAP-associated angiogenesis. In vivo studies using the MI model showed that endothelial cell-specific deficiency of HSPA12B (eHspa12b-/-) or YAP (eYap-/-) impaired angiogenesis and exacerbated cardiac dysfunction compared with WT mice. MI increased YAP expression and nuclear translocation in WT hearts but not eHspa12b-/- hearts. HSPA12B expression and nuclear translocation were upregulated in WT MI hearts but not eYap-/- MI myocardium. Our data demonstrate that endothelial HSPA12B is a target and coactivator for YAP/TEAD4 and cooperates with YAP to regulate endothelial angiogenesis after MI.
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http://dx.doi.org/10.1172/jci.insight.139640DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7526558PMC
September 2020

β-Glucan-induced reprogramming of human macrophages inhibits NLRP3 inflammasome activation in cryopyrinopathies.

J Clin Invest 2020 09;130(9):4561-4573

Immunology of Fungal Infections, Department of Mycology, Institut Pasteur, Paris, France.

Exposure of mononuclear phagocytes to β-glucan, a naturally occurring polysaccharide, contributes to the induction of innate immune memory, which is associated with long-term epigenetic, metabolic, and functional reprogramming. Although previous studies have shown that innate immune memory induced by β-glucan confers protection against secondary infections, its impact on autoinflammatory diseases, associated with inflammasome activation and IL-1β secretion, remains poorly understood. In particular, whether β-glucan-induced long-term reprogramming affects inflammasome activation in human macrophages in the context of these diseases has not been explored. We found that NLRP3 inflammasome-mediated caspase-1 activation and subsequent IL-1β production were reduced in β-glucan-reprogrammed macrophages. β-Glucan acted upstream of the NLRP3 inflammasome by preventing potassium (K+) efflux, mitochondrial ROS (mtROS) generation, and, ultimately, apoptosis-associated speck-like protein containing a CARD (ASC) oligomerization and speck formation. Importantly, β-glucan-induced memory in macrophages resulted in a remarkable attenuation of IL-1β secretion and caspase-1 activation in patients with an NLRP3-associated autoinflammatory disease, cryopyrin-associated periodic syndromes (CAPS). Our findings demonstrate that β-glucan-induced innate immune memory represses IL-1β-mediated inflammation and support its potential clinical use in NLRP3-driven diseases.
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http://dx.doi.org/10.1172/JCI134778DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7456248PMC
September 2020

Engineering Nanogels for Drug Delivery to Pathogenic Fungi by Tuning Polymer Amphiphilicity.

Biomacromolecules 2020 08 27;21(8):3112-3121. Epub 2020 Jul 27.

Department for Functional Materials in Medicine and Dentistry and Bavarian Polymer Institute, University of Würzburg, Pleicherwall 2, 97070 Würzburg, Germany.

Invasive aspergillosis is a serious threat to immunodeficient and critically ill patients caused mainly by the fungus . Here, poly(glycidol)-based nanogels (NGs) are proposed as delivery vehicles for antifungal agents for sustained drug release. NGs are formed by simple self-assembly of random copolymers, followed by oxidative cross-linking of thiol functionalities. We investigate the impact of copolymer amphiphilicity on NG interaction with mature fungal hyphae in order to select the optimal drug delivery system for model antifungal drug amphotericin B. The results show that drug-loaded NGs decrease minimal inhibitory concentration (MIC) for around four times and slow down the fungal biofilm synthesis at concentrations lower than MIC. Our results suggest that amphiphilicity of nanoparticle's polymer matrix is an important factor in understanding the action of nanocarriers toward fungal cells and should be considered in the development of nanoparticle-based antifungal therapy.
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http://dx.doi.org/10.1021/acs.biomac.0c00489DOI Listing
August 2020

Novel Role of Endothelial Derived Exosomal HSPA12B in Regulating Macrophage Inflammatory Responses in Polymicrobial Sepsis.

Front Immunol 2020 7;11:825. Epub 2020 May 7.

Department of Surgery, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States.

Endothelial cell dysfunction contributes to sepsis induced initiate immune response and the infiltration of immune cells into organs, resulting in organ injury. Heat shock protein A12B (HSPA12B) is predominantly expressed in endothelial cells. The present study investigated whether endothelial HSPA12B could regulate macrophage pro-inflammatory response during sepsis. Wild type (WT) and endothelial cell-specific HSPA12B deficient (HSPA12B) mice were subjected to CLP sepsis. Mortality and cardiac function were monitored. Higher mortality, worsened cardiac dysfunction, and greater infiltrated macrophages in the myocardium and spleen were observed in HSPA12B septic mice compared with the WT septic mice. The serum levels of TNF-α and IL-1β were higher and the levels of IL-10 were lower in HSPA12B septic mice than in WT septic mice. Importantly, endothelial exosomes contain HSPA12B which can be uptaken by macrophages. Interestingly, endothelial exosomal HSPA12B significantly increases IL-10 levels and decreases TNF-α and IL-1β production in LPS-stimulated macrophages. Mechanistic studies show that endothelial exosomal HSPA12B downregulates NF-κB activation and nuclear translocation in LPS stimulated macrophages. These data suggest that endothelial HSPA12B plays a novel role in the regulation of macrophage pro-inflammatory response via exosomes during sepsis and that sepsis induced cardiomyopathy and mortality are associated with endothelial cell deficiency of HSPA12B.
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http://dx.doi.org/10.3389/fimmu.2020.00825DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7221167PMC
March 2021

Inflammatory Type 2 cDCs Acquire Features of cDC1s and Macrophages to Orchestrate Immunity to Respiratory Virus Infection.

Immunity 2020 06 8;52(6):1039-1056.e9. Epub 2020 May 8.

Laboratory of Immunoregulation and Mucosal Immunology, VIB-UGent Center for Inflammation Research, Ghent 9052, Belgium; Department of Internal Medicine and Pediatrics, Ghent University, Ghent 9000, Belgium; Department of Pulmonary Medicine, Erasmus University Medical Center Rotterdam, Rotterdam 3015 GJ, the Netherlands. Electronic address:

The phenotypic and functional dichotomy between IRF8 type 1 and IRF4 type 2 conventional dendritic cells (cDC1s and cDC2s, respectively) is well accepted; it is unknown how robust this dichotomy is under inflammatory conditions, when additionally monocyte-derived cells (MCs) become competent antigen-presenting cells (APCs). Using single-cell technologies in models of respiratory viral infection, we found that lung cDC2s acquired expression of the Fc receptor CD64 shared with MCs and of IRF8 shared with cDC1s. These inflammatory cDC2s (inf-cDC2s) were superior in inducing CD4 T helper (Th) cell polarization while simultaneously presenting antigen to CD8 T cells. When carefully separated from inf-cDC2s, MCs lacked APC function. Inf-cDC2s matured in response to cell-intrinsic Toll-like receptor and type 1 interferon receptor signaling, upregulated an IRF8-dependent maturation module, and acquired antigens via convalescent serum and Fc receptors. Because hybrid inf-cDC2s are easily confused with monocyte-derived cells, their existence could explain why APC functions have been attributed to MCs.
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http://dx.doi.org/10.1016/j.immuni.2020.04.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7207120PMC
June 2020

Beta-glucan's varying structure characteristics modulate survival and immune-related genes expression from Vibrio harveyi-infected Artemia franciscana in gnotobiotic conditions.

Fish Shellfish Immunol 2020 Jul 3;102:307-315. Epub 2020 May 3.

Laboratory of Aquaculture & Artemia Reference Center, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Gent, Belgium.

β-Glucans have long been used as an immunostimulant in aquaculture. However, the relationship of its structure to its immunomodulatory properties are poorly understood. In this study, the particle size and chemical structure of β-glucans extracted from wild-type strain of baker's yeast (Saccharomyces cerevisiae) and its null-mutant yeasts Gas1 were characterised. Using Sigma β-glucan as a reference, the immunomodulatory properties of these polysaccharides in the germ-free Artemia franciscana model system in the presence of Vibrio harveyi bacterial challenge were investigated. The survival of the A. franciscana nauplii, upon challenge with V. harveyi, was significantly higher in all three glucan-treated groups compared to the control. The glucan Gas1 with a lower degree of branching and shorter side chain length had the most prominent V. harveyi-protective effects. The particle size did not affect the nauplii survival when challenged with V. harveyi. Results also showed that the salutary effect of the tested glucans was associated with the upregulation of innate immune genes such as lipopolysaccharide and β-1,3-glucan-binding protein (lgbp), high mobility group box protein (hmgb), and prophenoloxidase (proPO). Interestingly, the up-regulation of superoxidase dismutase (sod) and glutathione-s-transferase (gst) was only observed in Gas1 treated group, indicating that Gas1 could function to induce higher reactive oxygen species and stronger immunomodulatory function in A. franciscana, and therefore higher survival rate. The expression of heat shock protein 70 (hsp70), peroxinectin (pxn), and down syndrome cell adhesion molecule (dscam) remain unaltered in response to glucan treatment. Taken together, this study provides insights into the structure-function relationship of β-glucan and the results confirmed that β-glucan can be an effective immunostimulant in aquaculture, especially the Gas1 glucan.
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http://dx.doi.org/10.1016/j.fsi.2020.04.062DOI Listing
July 2020

Cholinergic leukocytes in sepsis and at the neuroimmune junction in the spleen.

Int Immunopharmacol 2020 Apr 3;81:106359. Epub 2020 Mar 3.

Department of Surgery, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA; Center of Excellence in Inflammation, Infectious Disease and Immunity, East Tennessee State University, Johnson City, TN 37614, USA.

The spleen is a key participant in the pathophysiology of sepsis and inflammatory disease. Many splenocytes exhibit a cholinergic phenotype, but our knowledge regarding their cholinergic biology and how they are affected by sepsis is incomplete. We evaluated effects of acute sepsis on the spleen using the cecal ligation and puncture (CLP) model in C57BL/6 and ChAT-eGFP mice. Quantification of cholinergic gene expression showed that choline acetyltransferase and vesicular acetylcholine transporter (VAChT) are present and that VAChT is upregulated in sepsis, suggesting increased capacity for release of acetylcholine (ACh). High affinity choline transporter is not expressed but organic acid transporters are, providing additional mechanisms for release. Flow cytometry studies identified subpopulations of cholinergic T and B cells as well as monocytes/macrophages. Neither abundance nor GFP intensity of cholinergic T cells changed in sepsis, suggesting that ACh synthetic capacity was not altered. Spleens have low acetylcholinesterase activity, and the enzyme is localized primarily in red pulp, characteristics expected to favor cholinergic signaling. For cellular studies, ACh was quantified by mass spectroscopy using d-ACh internal standard. Isolated splenocytes from male mice contain more ACh than females, suggesting the potential for gender-dependent differences in cholinergic immune function. Isolated splenocytes exhibit basal ACh release, which can be increased by isoproterenol (4 and 24 h) or by T cell activation with antibodies to CD3 and CD28 (24 h). Collectively, these data support the concept that sepsis enhances cholinergic function in the spleen and that release of ACh can be triggered by stimuli via different mechanisms.
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http://dx.doi.org/10.1016/j.intimp.2020.106359DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7315439PMC
April 2020

Characterization of Lead Compounds Targeting the Selenoprotein Thioredoxin Glutathione Reductase for Treatment of Schistosomiasis.

ACS Infect Dis 2020 03 24;6(3):393-405. Epub 2020 Jan 24.

Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, Illinois 60612, United States.

Schistosomiasis is a widespread human parasitic disease currently affecting over 200 million people. Chemotherapy for schistosomiasis relies exclusively on praziquantel. Although significant advances have been made in recent years to reduce the incidence and intensity of schistosome infections, these gains will be at risk should drug-resistant parasites evolve. Thioredoxin glutathione reductase (TGR) is a selenoprotein of the parasite essential for the survival of schistosomes in the mammalian host. Several high-throughput screening campaigns have identified inhibitors of TGR. Follow up analyses of select active compounds form the basis of the present study. We identified eight compounds effective against worms. Compounds - are active against all major species and development stages. The ability of these compounds to target immature worms is especially critical because praziquantel is poorly active against this stage. Compounds -, , and displayed schistosomicidal activity even after only 1 h incubation with the worms. Compounds - meet or exceed standards set by the World Health Organization for leads for schistosomiasis therapy activity. The mechanism of TGR inhibition was studied further with wild-type and mutant TGR proteins. Compounds - were found to induce an nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity in TGR, leading to the production of superoxide and hydrogen peroxide. Collectively, this effort has identified several active compound series that may serve as the basis for the development of new schistosomicidal compounds.
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http://dx.doi.org/10.1021/acsinfecdis.9b00354DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7072008PMC
March 2020

Characterization of Lead Compounds Targeting the Selenoprotein Thioredoxin Glutathione Reductase for Treatment of Schistosomiasis.

ACS Infect Dis 2020 03 24;6(3):393-405. Epub 2020 Jan 24.

Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, Illinois 60612, United States.

Schistosomiasis is a widespread human parasitic disease currently affecting over 200 million people. Chemotherapy for schistosomiasis relies exclusively on praziquantel. Although significant advances have been made in recent years to reduce the incidence and intensity of schistosome infections, these gains will be at risk should drug-resistant parasites evolve. Thioredoxin glutathione reductase (TGR) is a selenoprotein of the parasite essential for the survival of schistosomes in the mammalian host. Several high-throughput screening campaigns have identified inhibitors of TGR. Follow up analyses of select active compounds form the basis of the present study. We identified eight compounds effective against worms. Compounds - are active against all major species and development stages. The ability of these compounds to target immature worms is especially critical because praziquantel is poorly active against this stage. Compounds -, , and displayed schistosomicidal activity even after only 1 h incubation with the worms. Compounds - meet or exceed standards set by the World Health Organization for leads for schistosomiasis therapy activity. The mechanism of TGR inhibition was studied further with wild-type and mutant TGR proteins. Compounds - were found to induce an nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity in TGR, leading to the production of superoxide and hydrogen peroxide. Collectively, this effort has identified several active compound series that may serve as the basis for the development of new schistosomicidal compounds.
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http://dx.doi.org/10.1021/acsinfecdis.9b00354DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7072008PMC
March 2020

Animal models of scarring control.

Authors:
David L Williams

Eye (Lond) 2020 02 10;34(2):263-270. Epub 2019 Dec 10.

Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK.

Filtration surgery has, for the past 50 years been key in the treatment of glaucoma yet a significant issue in the long-term success of such surgery is fibrosis limiting aqueous drainage. Numerous methods have been used to reduce such scarring after filtration surgery and animal models have been important in the development of such techniques. First animal models have been central in understanding molecular and cellular changes occurring in fibrosis and thus which pathways might be valuable therapeutic. Secondly animal models have been critical in determining which of these therapies is likely to be most worthwhile. Having said that animals differ substantially from humans in the anatomy of their aqueous drainage pathways and in the mechanisms of fibrotic change. Rodents and lagomorphs vary more markedly from humans than do primates at an anatomic, biochemical and physiological level, and thus the latter might seem more appropriate as models for antifibrotic techniques. However the welfare implications, and thus ethical issues, in using primates are more concerning than with rodents or rabbits and efforts to refine, reduce and replace living animals in such model systems are crucially important. One problem is that the animal models normally involve healthy eyes, not ones with glaucoma. In veterinary ophthalmology we see large numbers of dogs with glaucoma, many of which have filtration implants placed. Potentially these could be a valuable animal model where benefits of antifibrotic treatment could benefit the animals involved and the research seeking to optimise such treatments.
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http://dx.doi.org/10.1038/s41433-019-0727-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7002449PMC
February 2020

Memory-Like Inflammatory Responses of Microglia to Rising Doses of LPS: Key Role of PI3Kγ.

Front Immunol 2019 8;10:2492. Epub 2019 Nov 8.

Institute of Molecular Cell Biology, Jena University Hospital, Jena, Germany.

Trained immunity and immune tolerance have been identified as long-term response patterns of the innate immune system. The causes of these opposing reactions remain elusive. Here, we report about differential inflammatory responses of microglial cells derived from neonatal mouse brain to increasing doses of the endotoxin LPS. Prolonged priming with ultra-low LPS doses provokes trained immunity, i.e., increased production of pro-inflammatory mediators in comparison to the unprimed control. In contrast, priming with high doses of LPS induces immune tolerance, implying decreased production of inflammatory mediators and pronounced release of anti-inflammatory cytokines. Investigation of the signaling processes and cell functions involved in these memory-like immune responses reveals the essential role of phosphoinositide 3-kinase γ (PI3Kγ), one of the phosphoinositide 3-kinase species highly expressed in innate immune cells. Together, our data suggest profound influence of preceding contacts with pathogens on the immune response of microglia. The impact of these interactions-trained immunity or immune tolerance-appears to be shaped by pathogen dose.
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http://dx.doi.org/10.3389/fimmu.2019.02492DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6856213PMC
October 2020

Tissue-Specific Macrophage Responses to Remote Injury Impact the Outcome of Subsequent Local Immune Challenge.

Immunity 2019 11 12;51(5):899-914.e7. Epub 2019 Nov 12.

Center for Systems Biology, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Simches Research Building, 185 Cambridge Street, Boston, MA 02114, USA; Cardiovascular Research Center, Massachusetts General Hospital and Harvard Medical School, 185 Cambridge Street, Boston, MA 02114, USA; Department of Internal Medicine I, University Hospital Wuerzburg, Wuerzburg, Germany. Electronic address:

Myocardial infarction, stroke, and sepsis trigger systemic inflammation and organism-wide complications that are difficult to manage. Here, we examined the contribution of macrophages residing in vital organs to the systemic response after these injuries. We generated a comprehensive catalog of changes in macrophage number, origin, and gene expression in the heart, brain, liver, kidney, and lung of mice with myocardial infarction, stroke, or sepsis. Predominantly fueled by heightened local proliferation, tissue macrophage numbers increased systemically. Macrophages in the same organ responded similarly to different injuries by altering expression of tissue-specific gene sets. Preceding myocardial infarction improved survival of subsequent pneumonia due to enhanced bacterial clearance, which was caused by IFNɣ priming of alveolar macrophages. Conversely, EGF receptor signaling in macrophages exacerbated inflammatory lung injury. Our data suggest that local injury activates macrophages in remote organs and that targeting macrophages could improve resilience against systemic complications following myocardial infarction, stroke, and sepsis.
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http://dx.doi.org/10.1016/j.immuni.2019.10.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6892583PMC
November 2019

Immunobiology and application of toll-like receptor 4 agonists to augment host resistance to infection.

Pharmacol Res 2019 12 2;150:104502. Epub 2019 Nov 2.

Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.

Infectious diseases remain a threat to critically ill patients, particularly with the rise of antibiotic-resistant bacteria. Septic shock carries a mortality of up to ∼40% with no compelling evidence of promising therapy to reduce morbidity or mortality. Septic shock survivors are also prone to nosocomial infections. Treatment with toll-like receptor 4 (TLR4) agonists have demonstrated significant protection against common nosocomial pathogens in various clinically relevant models of infection and septic shock. TLR4 agonists are derived from a bacteria cell wall or synthesized de novo, and more recently novel small molecule TLR4 agonists have also been developed. TLR4 agonists augment innate immune functions including expansion and recruitment of innate leukocytes to the site of infection. Recent studies demonstrate TLR4-induced leukocyte metabolic reprogramming of cellular metabolism to improve antimicrobial function. Metabolic changes include sustained augmentation of macrophage glycolysis, mitochondrial function, and tricarboxylic acid cycle flux. These findings set the stage for the use of TLR4 agonists as standalone therapeutic agents or antimicrobial adjuncts in patient populations vulnerable to nosocomial infections.
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http://dx.doi.org/10.1016/j.phrs.2019.104502DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6884699PMC
December 2019

Development and optimization of a high-throughput screening method utilizing Ancylostoma ceylanicum egg hatching to identify novel anthelmintics.

PLoS One 2019 3;14(6):e0217019. Epub 2019 Jun 3.

Department of Pathology, University of California, San Francisco, California, United States of America.

Hookworms remain a major health burden in the developing world, with hundreds of millions currently afflicted by these blood-feeding parasites. There exists a vital need for the discovery of novel drugs and identification of parasite drug targets for the development of chemotherapies. New drug development requires the identification of compounds that target molecules essential to parasite survival and preclinical testing in robust, standardized animal models of human disease. This process can prove costly and time consuming using conventional, low-throughput methods. We have developed a novel high-throughput screen (HTS) to identify anthelmintics for the treatment of soil-transmitted helminths. Our high-throughput, plate reader-based assay was used to rapidly assess compound toxicity to Ancylostoma ceylanicum L1 larva. Using this method, we screened 39,568 compounds from several small molecule screening libraries at 10 μM and identified 830 bioactive compounds that inhibit egg hatching of the human hookworm A. ceylanicum by >50%. Of these, 132 compounds inhibited hookworm egg hatching by >90% compared to controls. The nematicidal activities of 268 compounds were verified by retesting in the egg hatching assay and were also tested for toxicity against the human HeLa cell line at 10 μM. Fifty-nine compounds were verified to inhibit A. ceylanicum egg hatching by >80% and were <20% toxic to HeLa cells. Half-maximal inhibitory concentration (IC50) values were determined for the 59 hit compounds and ranged from 0.05-8.94 μM. This stringent advancement of compounds was designed to 1) systematically assess the nematicidal activity of novel compounds against the egg stage of A. ceylanicum hookworms in culture and 2) define their chemotherapeutic potential in vivo by evaluating their toxicity to human cells. Information gained from these experiments may directly contribute to the development of new drugs for the treatment of human hookworm disease.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0217019PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6546214PMC
February 2020

Dendritic Cell-Derived TSLP Negatively Regulates HIF-1α and IL-1β During Dectin-1 Signaling.

Front Immunol 2019 8;10:921. Epub 2019 May 8.

Department of Medicine, School of Clinical Medicine, Addenbrookes Hospital, University of Cambridge, Cambridge, United Kingdom.

Thymic stromal lymphopoietin (TSLP) is a functionally pleotropic cytokine important in immune regulation, and TSLP dysregulation is associated with numerous diseases. TSLP is produced by many cell types, but has predominantly been characterized as a secreted factor from epithelial cells which activates dendritic cells (DC) that subsequently prime T helper (T) 2 immunity. However, DC themselves make significant amounts of TSLP in response to microbial products, but the functional role of DC-derived TSLP remains unclear. We show that TSLPR signaling negatively regulates IL-1β production during dectin-1 stimulation of human DC. This regulatory mechanism functions by dampening Syk phosphorylation and is mediated via NADPH oxidase-derived ROS, HIF-1α and pro-IL-1β expression. Considering the profound effect TSLPR signaling has on the metabolic status and the secretome of dectin-1 stimulated DC, these data suggest that autocrine TSLPR signaling could have a fundamental role in modulating immunological effector responses at sites removed from epithelial cell production of TSLP.
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http://dx.doi.org/10.3389/fimmu.2019.00921DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6519317PMC
September 2020

Loss of monocyte metabolic plasticity in endotoxin tolerance: A model for understanding sepsis-induced immune paralysis?

J Leukoc Biol 2019 07 14;106(1):7-9. Epub 2019 May 14.

Center of Excellence in Inflammation, Infectious Disease and Immunity, East Tennessee State University, Johnson City, Tennessee, 37614, USA.

Discussion on implications of the immune paralysis that occurs in many sepsis patients.
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http://dx.doi.org/10.1002/JLB.4CE0319-100RDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6597287PMC
July 2019

Pilot evaluation of the circadian rhythm of tear production in a population of healthy adult cats.

Vet Ophthalmol 2019 Nov 17;22(6):916-920. Epub 2019 Apr 17.

Department of Veterinary Medicine, University of Cambridge, Cambridge, UK.

Objectives: The purpose of this study was to determine if a circadian rhythm exists in Schirmer's tear test (STT-1) values in a group of healthy adult cats.

Animals Studied: Twenty adult neutered Domestic Short-haired cats (DSH) were used in the study.

Procedures: Tear production was measured with the Schirmer tear test (STT-1) at 12 different time points over a 48-hour period.

Results: A significant difference (approximately 4.3 mm/min) was noted between STT-1 values measured between 4 pm (lowest) and 12 am (highest) on both day 1 (P = 0.02) and day 2 (P = 0.01), and substantial variation in STT-1 values was observed at different times during the 48-hour period.

Conclusions: Significant variation in mean STT-1 values demonstrates that there is a circadian rhythm in tear production in cats and thus shows the importance of taking the time of day into account when measuring STT-1 in cats.
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http://dx.doi.org/10.1111/vop.12673DOI Listing
November 2019

Multimodality characteristics of multifocal choroid plexus carcinoma with bilateral calvarial defects in a dog.

Vet Radiol Ultrasound 2019 Mar 20. Epub 2019 Mar 20.

Queen's Veterinary School Hospital, Madingley Rd, Cambridge, UK.

An 8-year-old male intact miniature poodle presented for blindness, obtundation, tetraparesis, and vestibular signs. Magnetic resonance imaging, radiography, and ultrasound revealed a left piriform lobe lesion, right cerebellar and left brainstem lesions, and hydrocephalus and bilateral calvarial defects. Histopathology confirmed a choroid plexus carcinoma with meningeal and intraventricular metastases. The calvarial defect did not show evidence of necrosis, osteoclastic resorption, inflammation or neoplastic infiltration, reflecting a quiescent calvarial atrophy or dysplasia. These novel findings supported inclusion of bone atrophy secondary to chronic increased intracranial pressure as a differential diagnosis for large calvarial defects in dogs with choroid plexus carcinoma.
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http://dx.doi.org/10.1111/vru.12732DOI Listing
March 2019

Comparative efficacy of topical oclacitinib 0.1% and tacrolimus 0.01% in canine keratoconjunctivitis sicca.

Vet Ophthalmol 2019 Sep 6;22(5):633-643. Epub 2019 Feb 6.

Departamento de Medicina Veterinária, Universidade Federal do Paraná (UFPR), Curitiba, Brazil.

Objective: To assess the efficacy of 0.1% oclacitinib as a single agent, and in combination with tacrolimus 0.01%, for the control of ophthalmic signs of keratoconjunctivitis sicca (KCS) in dogs.

Animals Studied: Thirty-two dogs (57 eyes) diagnosed with idiopathic KCS were included. Inclusion criteria were Schirmer Tear Test 1 (STT-1) values <15 mm/min and concurrent clinical signs such as ocular hyperemia and discharge.

Procedures: The animals were submitted to a randomized, open-label, 5-week study and divided into 3 treatment groups treated with the following ophthalmic solutions: (a) 0.1% oclacitinib, (b) 0.1% oclacitinib +0.01% tacrolimus, and (c) 0.01% tacrolimus. Eye drops were instilled twice daily (12-hour intervals). At each follow-up examination, STT-1, clinical signs, and potential drug side effects were assessed.

Results: Oclacitinib did not significantly improve STT-1 values or clinical scores. Tacrolimus alone and in combination with oclacitinib increased mean STT-1 values by 11.84 ± 5.2 and 12.46 ± 5.3 mm/min, respectively (P = 0.0001). Clinical scores of ocular discharge and hyperemia also improved significantly in both groups receiving treatment with tacrolimus (P < 0.05). However, addition of oclacitinib to tacrolimus provided no additional improvement over tacrolimus alone.

Conclusions: Topical 0.1% oclacitinib twice daily is not effective in controlling the ocular signs of KCS in dogs. 0.01% tacrolimus increased STT-1 values significantly and could potentially be used as a treatment for mild-to-moderate cases of KCS. Synergism between drugs did not occur, and therefore the use of oclacitinib is not justified in cases of canine KCS.
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http://dx.doi.org/10.1111/vop.12634DOI Listing
September 2019