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1.
Chembiochem ; 23(3): e202100552, 2022 02 04.
Article in English | MEDLINE | ID: mdl-34851004

ABSTRACT

Cytokines such as interleukin-8 activate the immune system during infection and interact with sulfated glycosaminoglycans with specific sulfation patterns. In some cases, these interactions are mediated by metal ion binding which can be used to tune surface-based glycan-protein interactions. We evaluated the effect of both hyaluronan sulfation degree and Fe3+ on interleukin-8 binding by electrochemical impedance spectroscopy and surface characterizations. Our results show that sulfation degree and metal ion interactions have a synergistic effect in tuning the electrochemical response of the glycated surfaces to the cytokine.


Subject(s)
Ferric Compounds/chemistry , Hyaluronic Acid/metabolism , Interleukin-8/chemistry , Polysaccharides/chemistry , Electrochemical Techniques , Ferric Compounds/immunology , Humans , Hyaluronic Acid/chemistry , Interleukin-8/immunology , Models, Molecular , Molecular Structure , Polysaccharides/immunology
2.
Anal Biochem ; 632: 114384, 2021 11 01.
Article in English | MEDLINE | ID: mdl-34543643

ABSTRACT

Invasive pulmonary aspergillosis (IPA) is a severe life-threatening condition. Diagnosis of fungal disease in general, and especially that caused by Aspergillus fumigatus is problematic. A. fumigatus secretes siderophores to acquire iron during infection, which are also essential for virulence. We describe the chemoacetylation of ferrated fusarinine C to diacetylated fusarinine C (DAFC), followed by protein conjugation, which facilitated triacetylfusarinine C (TAFC)-specific monoclonal antibody production with specific recognition of the ferrated form of TAFC. A single monoclonal antibody sequence was ultimately elucidated by a combinatorial strategy involving protein LC-MS/MS, cDNA sequencing and RNAseq. The resultant murine IgG2a monoclonal antibody was secreted in, and purified from, mammalian cell culture (5 mg) and demonstrated to be highly specific for TAFC detection by competitive ELISA (detection limit: 15 nM) and in a lateral flow test system (detection limit: 3 ng), using gold nanoparticle conjugated- DAFC-bovine serum albumin for competition. Overall, this work reveals for the first time a recombinant TAFC-specific monoclonal antibody with diagnostic potential for IPA diagnosis in traditional and emerging patient groups (e.g., COVID-19) and presents a useful strategy for murine Ig sequence determination, and expression in HEK293 cells, to overcome unexpected limitations associated with aberrant or deficient murine monoclonal antibody production.


Subject(s)
Antibodies, Monoclonal/immunology , Aspergillosis/diagnosis , Ferric Compounds/immunology , Hydroxamic Acids/immunology , Immunoconjugates/chemistry , Siderophores/chemistry , Animals , Aspergillosis/microbiology , Aspergillus fumigatus/chemistry , Aspergillus fumigatus/pathogenicity , Enzyme-Linked Immunosorbent Assay , Ferric Compounds/analysis , HEK293 Cells , Humans , Hydroxamic Acids/analysis , Mice , Recombinant Proteins/immunology
3.
Colloids Surf B Biointerfaces ; 177: 105-111, 2019 May 01.
Article in English | MEDLINE | ID: mdl-30711758

ABSTRACT

This work reports immunomagnetic separation technology-assisted surface plasmon resonance (SPR) biosensing for human cardiac troponin-I (cTnI), a well-known diagnostic marker for myocardial damage. Au film modified by Au nanoparticles (AuNPs) and polydopamine (PDA) was employed as the platforms for immobilizing capture antibody (cAb) and SPR sensing. Magnetic immune probe was prepared by attaching detection antibody (dAb) on the surface of Fe3O4 nanoparticles (Fe3O4 NPs) coated by PDA for precise capture, magnetic separation and enrichment of target analyte (cTnI) from samples. This extraction process greatly improves the sensitivity and effectively reduces the nonspecific interference from complex matrixes. The analyte cTnI collected via Fe3O4@PDA-dAb immune probe can be specially recognized by cAb immobilized on the sensing platform. By introducing secondary antibody (Ab2) conjugated with multi-walled carbon nanotube-PDA-AgNPs (MWCNTs-PDA-AgNPs/Ab2) to the sensing system, the residual binding sites of cTnI were occupied, and the SPR response signals were further amplified. The obtained detection limit for cTnI is 3.75 ng mL-1, which is 320-folds lower than that achieved by PDA-based sensing strategy. The present method was applied to the examination of serum samples spiked with cTnI, and the good recoveries demonstrate its future applicability in clinical diagnosis.


Subject(s)
Ferric Compounds/chemistry , Indoles/chemistry , Molecular Probes/chemistry , Molecular Probes/immunology , Polymers/chemistry , Surface Plasmon Resonance/methods , Troponin I/analysis , Antibodies/chemistry , Antibodies/immunology , Ferric Compounds/immunology , Gold/chemistry , Gold/immunology , Humans , Indoles/immunology , Metal Nanoparticles/chemistry , Troponin I/immunology
4.
Brain Res ; 1707: 141-153, 2019 03 15.
Article in English | MEDLINE | ID: mdl-30481502

ABSTRACT

It is widely accepted that amyloid oligomers are the most toxic species to initiate the pathologic processes of Parkinson's disease (PD) and Huntingdon's disease (HD). But there is no definitive diagnosis for PD and HD at their early stages. Here, we conjugated an amyloid oligomer-specific scFv antibody (W20) to PEGylated superparamagnetic iron oxide nanoparticles (SPIONs) and detected the properties of the SPIONs conjugated with W20. The results showed that W20-SPIONs, with the size of around 11.8 nm in diameter, were stable and nontoxic, and had enough relaxation capacity to be used as an MRI contrast agent. When applied to the transgenic mouse models of PD and HD, W20-SPIONs crossed the blood-brain barrier and specifically bound to the oligomer area to give MRI signal, distinguishing PD and HD from healthy controls. These results indicated that W20-SPIONs had potential in early-stage diagnosis for PD and HD and also opened up a new strategy for evaluating the efficacy of new drugs.


Subject(s)
Ferric Compounds/immunology , Huntington Disease/diagnostic imaging , Parkinson Disease/diagnostic imaging , Amyloid/immunology , Animals , Contrast Media , Disease Models, Animal , Ferric Compounds/chemistry , Magnetic Resonance Imaging/methods , Magnetite Nanoparticles/chemistry , Male , Mice , Mice, Transgenic , Nanoparticles/chemistry , Single-Chain Antibodies/immunology
5.
Nanomedicine ; 14(3): 977-990, 2018 04.
Article in English | MEDLINE | ID: mdl-29409836

ABSTRACT

Nanotechnology offers several advantages for drug delivery. However, there is the need for addressing potential safety concerns regarding the adverse health effects of these unique materials. Some such effects may occur due to undesirable interactions between nanoparticles and the immune system, and they may include hypersensitivity reactions, immunosuppression, and immunostimulation. While strategies, models, and approaches for studying the immunological safety of various engineered nanoparticles, including metal oxides, have been covered in the current literature, little attention has been given to the interactions between iron oxide-based nanomaterials and various components of the immune system. Here we provide a comprehensive review of studies investigating the effects of iron oxides and iron-based nanoparticles on various types of immune cells, highlight current gaps in the understanding of the structure-activity relationships of these materials, and propose a framework for capturing their immunotoxicity to streamline comparative studies between various types of iron-based formulations.


Subject(s)
Drug Delivery Systems , Ferric Compounds/immunology , Ferric Compounds/toxicity , Metal Nanoparticles/toxicity , Pharmaceutical Preparations/chemistry , Drug Compounding , Humans , Immune System/drug effects , Immune System/immunology , Pharmaceutical Preparations/administration & dosage
6.
Mini Rev Med Chem ; 17(17): 1677-1683, 2017.
Article in English | MEDLINE | ID: mdl-28440190

ABSTRACT

OBJECTIVE: Dioscorea opposita Thunb is the famous food and traditional medicine in China and it was rich in polysaccharides. Polysaccharides of Dioscorea Opposita Thunb possess immunoregulatory activity, free radical scavenging activity and anti-diabetic activity. A novel polysaccharide- iron(III) complex (CYPIC) was synthesized by using crude polysaccharide extracted from Dioscorea opposita Thunb. The component, structure, morphology and molecular weights of CYPIC were analysed, and the anti-anemia, acute toxicity and nonspecific immune regulating activities of CYPIC were assayed. The results showed that CYPIC could increase red blood cell count (RBC), hemoglobin (Hb), hematocrit (HCT), thymus and spleen index of mice with iron deficiency anemia (IDA). Although the structure and deeper mechanisms of CYPIC should be further studied, CYPIC has the potential to be used as an iron supplement for the treatment of iron deficiency anemia. CONCLUSION: The large scale industrial production was suggested due to the simple preparation processing of CYPIC.


Subject(s)
Anemia, Iron-Deficiency/drug therapy , Dioscorea/chemistry , Ferric Compounds/pharmacology , Polysaccharides/pharmacology , Anemia, Iron-Deficiency/immunology , Animals , Female , Ferric Compounds/chemistry , Ferric Compounds/immunology , Male , Mice , Mice, Inbred Strains , Polysaccharides/chemistry , Polysaccharides/immunology , Rats
9.
ACS Nano ; 8(12): 12437-49, 2014 Dec 23.
Article in English | MEDLINE | ID: mdl-25419856

ABSTRACT

One of the core issues of nanotechnology involves masking the foreignness of nanomaterials to enable in vivo longevity and long-term immune evasion. Dextran-coated superparamagnetic iron oxide nanoparticles are very effective magnetic resonance imaging (MRI) contrast agents, and strategies to prevent immune recognition are critical for their clinical translation. Here we prepared 20 kDa dextran-coated SPIO nanoworms (NWs) of 250 nm diameter and a high molar transverse relaxivity rate R2 (∼400 mM(-1) s(-1)) to study the effect of cross-linking-hydrogelation with 1-chloro-2,3-epoxypropane (epichlorohydrin) on the immune evasion both in vitro and in vivo. Cross-linking was performed in the presence of different concentrations of NaOH (0.5 to 10 N) and different temperatures (23 and 37 °C). Increasing NaOH concentration and temperature significantly decrease the binding of anti-dextran antibody and dextran-binding lectin conconavalin A to the NWs. The decrease in dextran immunoreactivity correlated with the decrease in opsonization by complement component 3 (C3) and with the decrease in the binding of the lectin pathway factor MASP-2 in mouse serum, suggesting that cross-linking blocks the lectin pathway of complement. The decrease in C3 opsonization correlated with the decrease in NW uptake by murine peritoneal macrophages. Optimized NWs demonstrated up to 10 h circulation half-life in mice and minimal uptake by the liver, while maintaining the large 250 nm size in the blood. We demonstrate that immune recognition of large iron oxide nanoparticles can be efficiently blocked by chemical cross-linking-hydrogelation, which is a promising strategy to improve safety and bioinertness of MRI contrast agents.


Subject(s)
Ferric Compounds/blood , Ferric Compounds/chemistry , Nanoparticles , Animals , Biological Transport , Dextrans/chemistry , Ferric Compounds/immunology , Ferric Compounds/toxicity , Half-Life , Macrophages/metabolism , Male , Mice , Particle Size , Sodium Hydroxide/chemistry , Temperature
10.
Small ; 8(18): 2841-8, 2012 Sep 24.
Article in English | MEDLINE | ID: mdl-22674628

ABSTRACT

The mechanisms associated with the induction of systemic immune responses by nanoparticles are not fully understood, but their elucidation is critical to address safety issues associated with the broader medical application of nanotechnology. In this study, a key role of nanoparticle-induced exosomes (extracellularly secreted membrane vesicles) as signaling mediators in the induction of T helper cell type 1 (Th1) immune activation is demonstrated. In vivo exposure to magnetic iron oxide nanoparticles (MIONs) results in significant exosome generation in the alveolar region of Balb/c mice. These act as a source of nanoparticle-induced, membrane-bound antigen/signaling cargo, which transfer their components to antigen-presenting cells (APCs) in the reticuloendothelial system. Through exosome-initiated signals, immature dendritic cells (iDCs) undergo maturation and differentiation to the DC1 subtype, while macrophages go through classical activation and differentiation to the M1 subtype. Simultaneously, iDCs and macrophages release various Th1 cytokines (including interleukin-12 and tumor necrosis factor α) driving T-cell activation and differentiation. Activated APCs (especially DC1 and M1 subtypes) consequently prime T-cell differentiation towards a Th1 subtype, thereby resulting in an orchestrated Th1-type immune response. Th1-polarized immune activation is associated with delayed-type hypersensitivity, which might underlie the long-term inflammatory effects frequently associated with nanoparticle exposure. These studies suggest that nanoparticle-induced exosomes provoke the immune activation and inflammatory responses that can accompany nanoparticle exposure.


Subject(s)
Antigen-Presenting Cells/immunology , Exosomes/metabolism , Ferric Compounds/immunology , Magnetite Nanoparticles/administration & dosage , Th1 Cells/immunology , Animals , Cell Differentiation , Cytokines/metabolism , Dendritic Cells/cytology , Dendritic Cells/drug effects , Dendritic Cells/immunology , Ferric Compounds/chemistry , Lymphocyte Activation , Macrophages/cytology , Macrophages/drug effects , Macrophages/immunology , Magnetite Nanoparticles/chemistry , Male , Mice , Mice, Inbred BALB C , Th1 Cells/cytology
11.
Biomaterials ; 32(36): 9758-65, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21920599

ABSTRACT

A highly efficient process using iron oxide magnetic nanoparticles (IO)-based immunomagnetic separation of tumor cells from fresh whole blood has been developed. The process involved polymer coated 30 nm IO that was modified with antibodies (Ab) against human epithelial growth factor receptor 2 (anti-HER2 or anti-HER2/neu) forming IO-Ab. HER2 is a cell membrane protein that is overexpressed in several types of human cancer cells. Using a HER2/neu overexpressing human breast cancer cell line, SK-BR3, as a model cell, the IO-Ab was used to separate 73.6% (with a maximum capture of 84%) of SK-BR3 cells that were spiked in 1 mL of fresh human whole blood. The IO-Ab preferentially bound to SK-BR3 cells over normal cells found in blood due to the high level of HER2/neu receptor on the cancer cells unlike the normal cell surfaces. The results showed that the nanosized magnetic nanoparticles exhibited an enrichment factor (cancer cells over normal cells) of 1:10,000,000 in a magnetic field (with gradient of 100 T/m) through the binding of IO-Ab on the cell surface that resulted in the preferential capture of the cancer cells. This research holds promise for efficient separation of circulating cancer cells in fresh whole blood.


Subject(s)
Antibodies/immunology , Ferric Compounds/immunology , Immunomagnetic Separation/methods , Magnetic Phenomena , Metal Nanoparticles/chemistry , Neoplasms/pathology , Blood , Body Fluids/metabolism , Buffers , Cell Line, Tumor , Electrophoresis, Polyacrylamide Gel , Female , Humans , Metal Nanoparticles/ultrastructure , Nanoparticles , Particle Size , Receptor, ErbB-2/immunology
12.
J Am Coll Cardiol ; 57(3): 337-47, 2011 Jan 18.
Article in English | MEDLINE | ID: mdl-21106318

ABSTRACT

OBJECTIVES: The aim of this study was to determine whether iron oxide particles targeted to oxidation-specific epitopes image atherosclerotic lesions. BACKGROUND: Oxidized low-density lipoprotein plays a major role in atherosclerotic plaque progression and destabilization. Prior studies indicate that gadolinium micelles labeled with oxidation-specific antibodies allow for in vivo detection of vulnerable plaques with magnetic resonance imaging (MRI). However, issues related to biotransformation/retention of gadolinium might limit clinical translation. Iron oxides are recognized as safe and effective contrast agents for MRI. Because the efficacy of passively targeted iron particles remains variable, it was hypothesized that iron particles targeted to oxidation-specific epitopes might increase the utility of this platform. METHODS: Lipid-coated ultra-small superparamagnetic iron particles (LUSPIOs) (<20 nm) and superparamagnetic iron particles (<40 nm) were conjugated with antibodies targeted to either malondialdehyde-lysine or oxidized phospholipid epitopes. All formulations were characterized, and their in vivo efficacy evaluated in apolipoprotein E deficient mice 24 h after bolus administration of a 3.9-mg Fe/kg dose with MRI. In vivo imaging data were correlated with the presence of oxidation-specific epitopes with immunohistochemistry. RESULTS: MRI of atherosclerotic lesions, as manifested by signal loss, was observed after administration of targeted LUSPIOs. Immunohistochemistry confirmed the presence of malondialdehyde-epitopes and iron particles. Limited signal attenuation was observed for untargeted LUSPIOs. Additionally, no significant arterial wall uptake was observed for targeted or untargeted lipid-coated superparamagnetic iron oxide particles, due to their limited ability to penetrate the vessel wall. CONCLUSIONS: This study demonstrates that LUSPIOs targeted to oxidation-specific epitopes image atherosclerotic lesions and suggests a clinically translatable platform for the detection of atherosclerotic plaque.


Subject(s)
Antibodies , Atherosclerosis/diagnosis , Drug Delivery Systems/methods , Epitopes/immunology , Ferric Compounds/immunology , Magnetic Resonance Imaging/methods , Animals , Antibodies/administration & dosage , Atherosclerosis/metabolism , Contrast Media/administration & dosage , Epitopes/administration & dosage , Ferric Compounds/administration & dosage , Mice , Mice, Inbred C57BL , Mice, Knockout , Oxidation-Reduction , Particle Size
13.
J Nanosci Nanotechnol ; 10(1): 514-9, 2010 Jan.
Article in English | MEDLINE | ID: mdl-20352885

ABSTRACT

The aim of this paper is to prepare Fe3O4 nanoparticles and study its immunotherapeutic effect as adjuvants on mice H22 live cancer. The Fe3O4 nanoparticles were prepared by chemical coprecipitation route. Transmission electron microscopy (TEM), X-ray diffraction (XRD), Energy Dispersive Analysis (EDS) were used to characterize Fe3O4 nanoparticles. The Fe3O4 nanoparticles were compared with the common alum adjuvants for its ability to induce immunity to inhibit tumor growth rate by prophylactic and therapeutic studies. Results indicated that Fe3O4 nanopaticles adsorbed autovaccine took great advantages over the common alum adjuvants after subcutaneous injection, raised the mass inhibitory rate of tumor, boosted the activity of cytotoxicity and enhanced the level of IFN-gamma cytokine. Thus, we concluded that Fe3O4 nanoparticles as adjuvants had great potential for enhancing anti-tumor immune response.


Subject(s)
Adjuvants, Immunologic/pharmacology , Cancer Vaccines/pharmacology , Drug Delivery Systems/methods , Ferric Compounds/pharmacology , Metal Nanoparticles/chemistry , Metal Nanoparticles/therapeutic use , Neoplasms, Experimental/therapy , Adjuvants, Immunologic/chemistry , Animals , Cancer Vaccines/chemistry , Cancer Vaccines/immunology , Cell Line, Tumor , Enzyme-Linked Immunosorbent Assay , Ferric Compounds/chemistry , Ferric Compounds/immunology , Interferon-gamma/blood , Interleukin-4/blood , Metal Nanoparticles/ultrastructure , Mice , Neoplasm Transplantation , Neoplasms, Experimental/immunology , T-Lymphocytes, Cytotoxic/drug effects , T-Lymphocytes, Cytotoxic/immunology , X-Ray Diffraction
14.
Immunobiology ; 213(9-10): 767-78, 2008.
Article in English | MEDLINE | ID: mdl-18926292

ABSTRACT

The saprophytic fungus Aspergillus fumigatus is the most prevalent airborne fungal pathogen, which is responsible for invasive aspergillosis in immunocompromised patients. Iron plays an essential role for the growth and proliferation of A. fumigatus. This fungus synthesizes three major siderophores. It excretes triacetylfusarinine C to capture iron, while it accumulates ferricrocin and hydroxyferricrocin for hyphal and conidial iron storage, respectively. Herein, we investigated the role of the siderophore system of A. fumigatus in the modulation of immune effector pathways and iron homeostasis in macrophages. We set up a co-culture system consisting of the murine macrophage cell line RAW264.7 and either A. fumigatus wild type or a siderophore-deficient mutant (DeltasidA). We used real-time quantitative RT-PCR and Western blot analyses to study the expression of macrophage iron metabolism and innate immune response genes in response to pathogen challenge. Infection of macrophages with A. fumigatus wild type, but not with the DeltasidA mutant, induced expression of TNF and phagocyte oxidase subunit 47 at the transcriptional level. Moreover, infection with A. fumigatus wild type, but not with the DeltasidA mutant, compromised macrophage iron homeostasis. Infection with wild-type A. fumigatus decreased expression of the two cellular iron importers, the divalent metal transporter-1 and the transferrin receptor, and the only known iron exporter ferroportin. At the same time, it increased macrophage iron retention and ferritin synthesis. These data indicate that A. fumigatus affects the regulation of macrophage iron homeostasis and innate immune effector pathways via its siderophore system. The changes in immune response may be a consequence of macrophage iron restriction.


Subject(s)
Aspergillosis/immunology , Aspergillus fumigatus/pathogenicity , Iron/immunology , Macrophages/immunology , Siderophores/metabolism , Animals , Aspergillus fumigatus/genetics , Aspergillus fumigatus/immunology , Aspergillus fumigatus/metabolism , Cell Line , Coculture Techniques , Ferric Compounds/immunology , Ferric Compounds/metabolism , Ferrichrome/analogs & derivatives , Ferrichrome/immunology , Ferrichrome/metabolism , Hydroxamic Acids/immunology , Hydroxamic Acids/metabolism , Immunity, Innate , Iron/metabolism , Macrophages/metabolism , Macrophages/microbiology , Mice , Phagocytosis/immunology , Receptors, Transferrin/biosynthesis , Siderophores/genetics
15.
J Immunol Methods ; 332(1-2): 103-11, 2008 Mar 20.
Article in English | MEDLINE | ID: mdl-18242636

ABSTRACT

This paper reports a simple, sensitive, and reusable piezoelectric immunosensor using magnetic hydroxyapatite (HAP)/gamma-Fe(2)O(3)/Au nanocomposite. Use of porous HAP nanocrystals embedded with gamma-Fe(2)O(3) and colloidal gold nanoparticles resulted in a multifunctional HAP/gamma-Fe(2)O(3)/Au nanocomposite. Under optimized conditions, the biocompatible nanocomposites were exploited for direct adsorption of large quantities of rabbit anti-human immunoglobulin G antibodies (anti-hIgG) with well-preserved immunoactivity. In a homogeneous bulk solution, the hIgG analytes were captured by the anti-hIgG-derivatized immunocomposites followed by magnetic separation/enrichment onto a bovine serum albumin (BSA)-sealed QCM probe before measuring. This QCM immunosensor can quantitatively determine concentrations of hIgG ranging from approximately 20 to 800 ng/ml, with a detection limit of approximately 15 ng/ml. Moreover, regeneration of the immunosensor can be simply realized by canceling the controllable magnetic field. With the possibility of performing the analysis automatically and considering its ease of use, high sensitivity, and good reusability, this magnetic separation-assisted QCM immunosensor may have great potential to be further tailored as a general and promising alternative for a broad range of practical applications.


Subject(s)
Antibodies/analysis , Biosensing Techniques/instrumentation , Biosensing Techniques/methods , Immunoglobulin G/analysis , Magnetics , Nanoparticles/chemistry , Adsorption , Animals , Antibodies/immunology , Cattle , Colloids/chemistry , Durapatite/chemistry , Durapatite/immunology , Ferric Compounds/chemistry , Ferric Compounds/immunology , Gold/chemistry , Gold/immunology , Humans , Hydrogen-Ion Concentration , Immunoglobulin G/immunology , Particle Size , Sensitivity and Specificity , Serum Albumin, Bovine/chemistry , Serum Albumin, Bovine/immunology , Surface Properties , Swine , Time Factors
16.
J Immunol ; 179(11): 7840-51, 2007 Dec 01.
Article in English | MEDLINE | ID: mdl-18025230

ABSTRACT

Heme oxygenase-1 (HO-1; encoded by the Hmox1 gene) catalyzes the degradation of free heme into biliverdin, via a reaction that releases iron (Fe) and carbon monoxide. We report that HO-1 down-regulates the proinflammatory phenotype associated with endothelial cell (EC) activation by reducing intracellular nonprotein-bound Fe (labile Fe). EC isolated from Hmox1(-/-) mice have higher levels of intracellular labile Fe and reactive oxygen species (ROS) as compared with EC isolated from Hmox1(+/+) mice. Basal and TNF-induced expression of VCAM-1, ICAM-1, and E-selectin were increased in Hmox1(-/-) vs Hmox1(+/+) EC, an effect reversed by Fe chelation using deferoxamine mesylate (DFO). Fe chelation inhibits TNF-driven transcription of Vcam-1, Icam-1, and E-selectin, as assessed using luciferase reporter assays. This effect is associated with inhibition of the transcription factor NF-kappaB via a mechanism that is not associated with the inhibition of IkappaBalpha phosphorylation/degradation or NF-kappaB (i.e., RelA) nuclear translocation, although it affects very modestly NF-kappaB binding to DNA kappaB consensus sequences in the Vcam-1 and E-selectin promoters. HO-1 inhibits NF-kappaB (i.e., RelA) phosphorylation at Ser(276), a phosphoacceptor that is critical to sustain TNF-driven NF-kappaB activity in EC. This effect was mimicked by Fe chelation as well as by antioxidants (N-acetylcysteine). In conclusion, we demonstrate a novel mechanism via which HO-1 down-modulates the proinflammatory phenotype of activated EC, i.e., the inhibition of RelA phosphorylation at Ser(276).


Subject(s)
Cell Adhesion Molecules/immunology , Endothelial Cells/immunology , Gene Expression Regulation/immunology , Heme Oxygenase-1/immunology , Serine/immunology , Transcription Factor RelA/metabolism , Animals , Cell Adhesion Molecules/drug effects , Cell Adhesion Molecules/genetics , Cells, Cultured , Down-Regulation/immunology , Endothelial Cells/cytology , Endothelial Cells/drug effects , Ferric Compounds/immunology , Gene Expression Regulation/drug effects , Heme Oxygenase-1/deficiency , Heme Oxygenase-1/pharmacology , Inflammation , Mice , Mice, Inbred BALB C , Mice, Knockout , NF-kappa B/antagonists & inhibitors , NF-kappa B/immunology , Phosphorylation/drug effects , Serine/drug effects , Transcription Factor RelA/drug effects , Transcription, Genetic/drug effects , Vascular Cell Adhesion Molecule-1/biosynthesis , Vascular Cell Adhesion Molecule-1/drug effects
17.
Kidney Int ; 63(1): 217-24, 2003 Jan.
Article in English | MEDLINE | ID: mdl-12472786

ABSTRACT

BACKGROUND: Iron dextran administration is associated with a high incidence of adverse reactions including anaphylaxis and death. Although dextran, rather than iron, is believed to be the cause of these reactions, it is not known whether iron dextran-sensitive patients can be safely administered another form of parenteral iron, sodium ferric gluconate in sucrose (SFGC). METHODS: In a 69 center, prospective, double-blind, controlled trial of safety and tolerability of SFGC, the rate of reactions to SFGC and placebo in 144 iron dextran-sensitive patients was compared with 2194 patients who were previously tolerant to iron dextran preparations. Serum tryptase levels, a marker of mast cell degranulation, also were measured. RESULTS: Among 143 iron dextran-sensitive patients exposed to SFGC, three (2.1%) were intolerant. All three had suspected allergic events to SFGC, including one patient with a serious reaction (0.7%). One dextran-sensitive patient (0.7%) had a suspected allergic reaction after placebo. In contrast, among 2194 iron dextran-tolerant patients, reactions to SFGC were significantly less common, with SFGC intolerance seen in seven patients (0.3%; P = 0.020), including five (0.2%) who had suspected allergic events (P = 0.010), but none who had serious events (0.0%; P = 0.061). Two iron dextran-tolerant patients (0.09%) had allergic-like reactions following placebo injections. Two of the three suspected allergic events in the iron dextran-sensitive group were confirmed as mast cell dependent by a 100% increase in serum tryptase, while there were no confirmed allergic events in the iron dextran-tolerant group. Long-term exposure to SFGC in iron dextran-sensitive patients resulted in intolerance in only one additional patient and no serious adverse events. CONCLUSIONS: Patients with a history of iron dextran sensitivity had approximately sevenfold higher rates of reaction to both placebo and SFGC compared to iron dextran tolerant patients. However, logistic regression analysis, performed to account for the higher reaction rate to placebo, suggests that this increased reactivity was not drug-specific nor immunologically mediated, but represented host idiosyncrasy. These results support the conclusions that reactions to SFGC can be attributed to pseudoallergy, and that SFGC is not a true allergen.


Subject(s)
Ferric Compounds/adverse effects , Iron-Dextran Complex/adverse effects , Kidney Failure, Chronic/drug therapy , Renal Dialysis , Drug Hypersensitivity/immunology , Female , Ferric Compounds/administration & dosage , Ferric Compounds/immunology , Humans , Iron-Dextran Complex/administration & dosage , Iron-Dextran Complex/immunology , Kidney Failure, Chronic/immunology , Male , Mast Cells/immunology , Middle Aged , Prospective Studies , Serine Endopeptidases/blood , Sucrose , Tryptases
19.
Infect Immun ; 31(2): 631-5, 1981 Feb.
Article in English | MEDLINE | ID: mdl-6452414

ABSTRACT

Normal human serum contains an enterochelin-specific antibody which presumably acts with transferrin to hinder iron assimilation by enterochelin-producing pathogens. This antibody can be isolated from serum by sodium sulfate fractionation or affinity chromatography by employing an enterochelin-derived ligand (2,3-dihydroxy-N-benzoyl-L-serine) attached to aminohexyl Sepharose 4B. In assays of iron uptake by whole cells, the antibody inhibited enterochelin-directed uptake but not that mediated by citrate or ferrichrome. Also, the growth stimulatory effect of enterochelin on an Ent- strain of Escherichia coli was blocked by the immunoglobulin. This antibody has a high affinity for enterochelin; various elution procedures employing high salt concentrations and low pH failed to remove it from affinity columns. Elution with 3 M sodium thiocyanate or 13 mM 2,3-dihydroxybenzoic acid proved successful. Two pieces of evidence indicate the enterochelin-specific antibody is primarily of the immunoglobulin A (IgA) isotype. It could be removed from serum with goat antihuman IgA and was present only in sodium sulfate fractions of serum known to contain IgA.


Subject(s)
Antibodies, Bacterial , Enterobactin/immunology , Escherichia coli/immunology , Serine/analogs & derivatives , Biological Transport , Escherichia coli/metabolism , Ferric Compounds/immunology , Ferric Compounds/metabolism , Ferrichrome/metabolism , Humans , Immunoglobulin A , Iron/metabolism
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