calcimycin and Syndrome

Production of oxygen radicals is required for both microbicidal and tissue-toxic effector functions of granulocytes. Inasmuch as an ambivalent role of polymorphonuclear leukocytes (PMNs) may become apparent during sepsis, we studied levels of hydrogen peroxide (H2O2) production by PMNs depending upon the nature of different particulate and soluble stimuli in patients with increasing sepsis severity. Patients with sepsis (n = 15), severe sepsis (n = 12), or septic shock (n = 33) were prospectively enrolled in the study. Healthy volunteers of comparable age and sex served as controls (n = 50). Unopsonized and opsonized zymosan particles were used to assess adhesion, phagocytosis, and the associated H2O2 production. Zymosan particles are rich in beta-glucans and lectin structures that are known to trigger H2O2 production via two major non-toll-like receptor pathogen recognition receptors, comprising the lectin-binding site in the alpha-chain (CD11b) of the complement receptor type 3 and the more recently identified nonclassical C-type lectin, dectin-1. To determine H2O2 production upon cell activation by soluble stimuli, PMNs were activated by the chemotactic tripeptide (N-formyl-methionyl-leucyl-phenylalanine [fMLP]) alone or after priming of cells by preincubation with tumor necrosis factor alpha. To get insight into the changes of fMLP receptor classical intracellular signaling pathways, PMNs were also incubated with the calcium ionophore A23187 and the phorbol ester phorbol myristate acetate, bypassing receptor-dependent signal transduction to directly activate calcium/calmodulin kinase- and protein kinase C-dependent pathways, respectively. As compared with healthy volunteers, levels of H2O2 production by PMNs from septic patients varied depending upon the nature of the activating signal: reduced (zymosan), unchanged (phorbol myristate acetate, opsonized zymosan), and enhanced (spontaneous, fMLP, fMLP + tumor necrosis factor alpha, A23187), with the changes most pronounced in patients with septic shock. Specifically, phagocytosis of zymosan and the associated H2O2 production were significantly decreased whereas spontaneous and stimulated H2O2 production elicited by soluble stimuli strongly increased. Thus, these findings suggest the development of a PMN dysfunction syndrome in patients with increasing sepsis severity. Moreover, as binding of zymosan particles to the PMNs' surface remained unchanged despite increasingly suppressed phagocytosis and associ

Topics: C-Reactive Protein; Calcimycin; Calcitonin; CD18 Antigens; Humans; Hydrogen Peroxide; Interleukin-6; Leukocyte Count; Middle Aged; Multiple Organ Failure; N-Formylmethionine Leucyl-Phenylalanine; Neutrophil Activation; Neutrophils; Opsonin Proteins; Phagocytosis; Protein Precursors; Sepsis; Severity of Illness Index; Shock, Septic; Syndrome; Tetradecanoylphorbol Acetate; Tumor Necrosis Factor-alpha; Zymosan

In contrast to other agents able to induce apoptosis of cultured cells, Ca2+ ionophore A23187 was shown to elicit direct activation of intracellular signal(s). The phenotype of the cells derived from patients having the hemorrhagic disease Scott syndrome, is associated with an abnormally high proportion of apoptotic cells, both in basal culture medium and upon addition of low ionophore concentrations in long-term cultures. These features are presumably related to the mutation also responsible for the defective procoagulant plasma membrane remodeling. We analyzed the specific transcriptional re-programming induced by A23187 to get insights into the effect of this agent on gene expression and a defective gene regulation in Scott cells.. The changes in gene expression upon 48 hours treatment with 200 nM A23187 were measured in Scott B lymphoblasts compared to B lymphoblasts derived from the patient's daughter or unrelated individuals using Affymetrix microarrays. In a similar manner in all of the B cell lines, results showed up-regulation of 55 genes, out of 12,000 represented sequences, involved in various pathways of the cell metabolism. In contrast, a group of 54 down-regulated genes, coding for histones and proteins involved in the cell cycle progression, was more significantly repressed in Scott B lymphoblasts than in the other cell lines. These data correlated with the alterations of the cell cycle phases in treated cells and suggested that the potent effect of A23187 in Scott B lymphoblasts may be the consequence of the underlying molecular defect.. The data illustrate that the ionophore A23187 exerts its pro-apoptotic effect by promoting a complex pattern of genetic changes. These results also suggest that a subset of genes participating in various steps of the cell cycle progress can be transcriptionally regulated in a coordinated fashion. Furthermore, this research brings a new insight into the defect in cultured Scott B lymphoblasts, leading to hypothesize that a mutated gene plays a role not only in membrane remodeling but also in signal transduction pathway(s) leading to altered transcriptional regulation of cell cycle genes.

Topics: Apoptosis; B-Lymphocytes; Calcimycin; Calcium; Cell Cycle; Cell Line; Cell Membrane; Cluster Analysis; Coagulants; Down-Regulation; Gene Expression Regulation; Hemorrhagic Disorders; Histones; Humans; Ionophores; Microarray Analysis; Mutation; Oligonucleotide Array Sequence Analysis; Phenotype; RNA, Complementary; Signal Transduction; Syndrome; Transcription, Genetic; Up-Regulation

The aim of this study was to investigate the effect of absent CD40-CD40 ligand interactions in patients with X-linked hyper-IgM syndrome (XHIGM) on the generation of Th1 and Th2 immunity. Whole blood from patients and sex- and age-matched controls was stimulated with phorbol myristate acetate (PMA) and calcium ionophore A23187 in the presence of Brefeldin A. After 5 h, cellular production of interferon-gamma, IL-4, tumour necrosis factor-alpha and IL-2 was measured by intracellular cytokine staining and flow cytometry. This method has been shown previously to preferentially activate memory T cells and in preliminary experiments cells making these cytokines were found to be predominantly CD45RO+. No differences in the proportion of T cells (CD3+) or T cell subsets (CD4+/CD8+) secreting these cytokines between XHIGM patients and age- and sex-matched controls were observed. In addition, production of IL-12 and IL-6 by monocytes in response to lipopolysaccharide and CD40 stimulation was equivalent in patients and controls. These results suggest that development of Th1 or Th2 memory cells in patients with XHIGM is unaffected by the absence of functional CD40 ligand. Rather, the susceptibility of these patients to intracellular pathogens, such as Pneumocystis carinii and Cryptosporidium parvum, is more likely to be due to an inability to activate the effector arm of the cellular immune response.

Topics: Adolescent; Adult; Calcimycin; Calcium; CD3 Complex; CD40 Antigens; CD40 Ligand; CD8-Positive T-Lymphocytes; Cell Differentiation; Child; Child, Preschool; Female; Humans; Hypergammaglobulinemia; Immunoglobulin M; Immunologic Memory; Infant; Ionophores; Lipopolysaccharide Receptors; Lipopolysaccharides; Lymphocyte Activation; Lymphokines; Male; Membrane Glycoproteins; Monocytes; Monokines; Syndrome; Tetradecanoylphorbol Acetate; Th1 Cells; Th2 Cells; X Chromosome

A significant increase in intracellular Ca(2+) is required to trigger the remodeling of the cell plasma membrane. Scott syndrome is an extremely rare inherited disorder of the transmembrane migration of phosphatidylserine toward the exoplasmic leaflet in blood cells. We have recently reported a reduced capacitative Ca(2+) entry in Scott cells [Martínez et al. (1999) Biochemistry 38, 10092-10098]. We have investigated here the links between defective phosphatidylserine exposure and Ca(2+) signaling in Scott cells by focusing on the Ca(2+) entry following the emptying of intracellular stores. After depletion of caffeine- or thapsigargin-sensitive stores, Ca(2+) entry was lower in Scott compared to control lymphoblasts. However, the simultaneous depletion of both types of stores restored a normal Ca(2+) influx across the plasma membrane in Scott cells and phosphatidylserine externalization ability was improved concomitantly with capacitative Ca(2+) entry. These observations point to the essential role of capacitative Ca(2+) entry in the control of phosphatidylserine exposure of stimulated cells.

Topics: Aged; B-Lymphocytes; Blood Coagulation Disorders; Caffeine; Calcimycin; Calcium; Calcium Signaling; Cell Membrane; Cells, Cultured; Egtazic Acid; Female; Hemorrhage; Herpesvirus 4, Human; Humans; Phosphatidylserines; Reference Values; Syndrome; Thapsigargin

The transverse redistribution of plasma membrane phosphatidylserine is one of the hallmarks of cells undergoing apoptosis and also occurs in cells fulfilling a more specialized function, such as platelets after appropriate activation. Although an increase in intracellular Ca2+ is required to trigger the remodeling of the plasma membrane, little information regarding intracellular signals leading to phosphatidylserine externalization has been provided. Scott syndrome is an extremely rare inherited disorder of the migration of phosphatidylserine toward the exoplasmic leaflet of the plasma membrane of stimulated blood cells. We have studied here the intracellular Ca2+ mobilization and Ca2+ entry involved in tyrosine phosphorylation in Epstein Barr virus (EBV)-infected B cells derived from a patient with Scott syndrome, her daughter, and control subjects. An alteration of Ca2+ entry through the plasma membrane and subsequent tyrosine phosphorylation induced by Ca2+ were observed in Scott EBV-B cells, but the release of Ca2+ from intracellular stores was normal. Furthermore, phosphatidylserine externalization at the surface of stimulated cells does not depend on tyrosine kinases. These results suggest that the defect of phosphatidylserine exposure in Scott syndrome cells is related to the alteration of a particular way of Ca2+ entry, referred to as capacitative Ca2+ entry, although some differences may be related to the cell type. Hence, this genetic mutant testifies to the prime significance of Ca2+ signaling in the regulation of phosphatidylserine expression at the surface of stimulated cells.

Topics: Aged; B-Lymphocytes; Blood Coagulation Disorders; Calcimycin; Calcium Channels; Cell Membrane; Cell Transformation, Viral; Cells, Cultured; Enzyme Inhibitors; Female; Genistein; Humans; Lymphocyte Activation; Phosphatidylserines; Phospholipids; Phosphorylation; Protein-Tyrosine Kinases; Syndrome; Thapsigargin; Tyrosine

We have investigated phospholipid redistribution, membrane vesicle shedding, shape change, and granule release following A23187 activation of platelets from a patient with Scott syndrome, characterized by impaired transmembrane migration of phosphatidylserine (PS) accompanied by haemorrhagic complications, and two of her children. Electron spin resonance spectroscopy measurement of phospholipids redistribution showed that the internalization of PS was unaffected by the disorder but, after activation, PS exposure was significantly reduced in platelets from the homozygous-type patient. Vesicle shedding was also reduced in these platelets. However, the slow redistribution of phosphatidylcholine was similar to that observed in normal platelets. When treated with calpeptin, platelets from the homozygous-type patient, unlike normal or heterozygous Scott syndrome platelets, showed a smoothly rounded shape without filopods after activation. Following A23187 activation of normal platelets, filopod formation was consecutive to the re-exposition of aminophospholipids on the outer leaflet of the plasma membrane, and the existence of a floppase (outward aminoPLs translocase) has been suggested. In homozygous Scott syndrome platelets the deficiency in PS re-exposition, the absence of filopod formation, and low vesicle shedding are correlated with each other, and argue in favour of a disruption of the proposed floppase activity.

Topics: Biological Transport; Blood Coagulation Disorders; Blood Platelets; Calcimycin; Cell Membrane; Cell Size; Female; Humans; Male; Microscopy, Electron, Scanning; Phosphatidylserines; Phospholipids; Platelet Activation; Syndrome

Nonactivated, fixed peripheral blood T cells (PBT) from healthy donors or patients with X-linked-hyper-IgM (HIGM) syndrome, or cloned T cells provided effective help for tonsillar B lymphocytes for induction of IgE or other immunoglobulin (Ig) isotypes. Helper activity was mediated by staphylococcal superantigens adsorbed to the T cells prior to fixation and required presence of IL-4 in the cultures. We demonstrated that the T cells neither expressed detectable CD40 ligand at the beginning of the superantigen treatment nor 24 h later. Phorbol ester (PMA) plus Ca-ionophore treatment efficiently induced CD40L. Such T cells did not, however, provide any help for B-cell activation in some experiments or stimulated only low responses in others. Antibodies against CD2, CD3 and ICAM-1 adsorbed to fixed T cells prior to coculturing inhibited helper activity. A soluble CTLA4 construct was also inhibitory. Our results suggest a pathway of B-cell activation independent of CD40L expressed on T cells.

Topics: Adult; B-Lymphocytes; Calcimycin; CD40 Antigens; Child; Genetic Linkage; Humans; Hypergammaglobulinemia; Immunoglobulin E; Immunoglobulin M; Ligands; Lymphocyte Activation; Palatine Tonsil; Staphylococcus; Superantigens; Syndrome; T-Lymphocytes, Helper-Inducer; Tetradecanoylphorbol Acetate; X Chromosome

We have identified a patient with a number of neutrophil dysfunctions. The patient was a female baby who lived for 8 months. During her life, she developed severe bacterial infections and showed omphalitis, impaired wound healing, and a pronounced leukocytosis. She was not a patient with leukocyte adhesion deficiency, because all leukocyte CD18 complex proteins were expressed at normal levels. Yet, neutrophil polarization and chemotaxis to platelet-activating factor, leukotriene B4, or formyl-methionyl-leucyl-phenylalanine (FMLP) were completely absent. We found a strong defect in actin polymerization in response to chemotactic stimuli, but only a retarded or even normal reaction with other stimuli. This indicates that the cellular dysfunctions were not due to an intrinsic defect in actin metabolism. Instead, the regulation of actin polymerization with chemotactic stimuli seemed to be defective. We concentrated on FMLP-induced responses in the patient's neutrophils. Functions dependent on activation of complement receptor type 3, such as aggregation or adherence to endothelial cells, were normally induced. Binding to serum-coated coverslips was normal in cell number; however, spreading was not observed. Exocytosis from the specific granules was readily induced. In contrast, FMLP failed to induce a respiratory burst activity or degranulation of the azurophil granules. FMLP induced a normal increase in free intracellular Ca2+, but a decreased formation of diglycerides (especially the 1-O-alkyl,2-acyl compounds). Thus, we have described a patient whose neutrophils show a severe defect in functional activation via chemotaxin receptors, resulting in a selective absence of NADPH oxidase activity, exocytosis from the azurophil granules, and actin polymerization. Our findings show that actin polymerization for neutrophil spreading and locomotion is regulated differently from that for phagocytosis. Also, the release of azurophil and specific granule contents is clearly shown to be regulated in a different way.

Topics: Actins; Antigens, CD; Calcimycin; Calcium; CD18 Antigens; CD4 Antigens; CD8 Antigens; Cell Adhesion; Cell Aggregation; Chemotaxis, Leukocyte; Cytochalasin B; Endothelium, Vascular; Female; Humans; Immunologic Deficiency Syndromes; In Vitro Techniques; Infant, Newborn; Kinetics; Leukocyte Count; Leukotriene B4; N-Formylmethionine Leucyl-Phenylalanine; Neutrophils; Oxygen Consumption; Platelet Activating Factor; Reference Values; Sepsis; Syndrome; T-Lymphocyte Subsets

The erythrocytes from a patient with Scott syndrome, a bleeding disorder characterized by an isolated defect in expression of platelet procoagulant activity, have been studied. When incubated with the calcium ionophore A23187, Scott syndrome red blood cells (RBCs) expressed less than 10% of the prothrombinase (enzyme complex of coagulation factors Va and Xa) activity of A23187-treated RBCs obtained from normal controls. Consistent with the results from enzyme assay, the ionophore-treated Scott syndrome erythrocytes exhibited diminished membrane vesiculation and decreased exposure of membrane binding sites for factor Va compared with identically treated controls. When examined by scanning electron microscopy, untreated Scott syndrome RBCs were indistinguishable from normal cells. After incubation with A23187, however, the morphology of Scott syndrome RBCs contrasted markedly from normal erythrocytes. Whereas the Ca2+ ionophore induced marked echinocytosis and spiculation of normal RBCs, Scott syndrome RBCs remained mostly discoid under these conditions, with only an occasional echinocyte-like cell observed. These aberrant responses to intracellular Ca2+ were also observed for resealed ghosts prepared from Scott syndrome erythrocytes, indicating that they are related to a defect in the membrane or membrane-associated cytoskeleton. The finding that the erythrocytes of this patient share many of the membrane abnormalities reported previously for Scott syndrome platelets suggests that this defect is common to both cell lines and involves a membrane component required for vesicle formation and for expression of prothrombinase sites.

Topics: Adult; Blood Coagulation Disorders; Blood Platelets; Calcimycin; Calcium; Erythrocyte Membrane; Erythrocytes; Factor Va; Flow Cytometry; Fluorescent Antibody Technique; Humans; Kinetics; Magnesium; Membrane Proteins; Microscopy, Electron, Scanning; Syndrome; Thromboplastin

We measured the in vitro production of interferon-gamma (IFN-gamma) in five cases of hyper-IgE syndrome (HIgE), induced by mitogens, calcium ionophores and phorbol ester. The biosynthesis of IFN-gamma was severely reduced or undetectable in HIgE, while it was near normal in most atopic patients. The in vitro spontaneous production of IgE was increased overall in HIgE patients, although no correlation was found with serum IgE levels. Recombinant interleukin-4 (IL-4) induced a further increase in IgE synthesis, and its effect was totally antagonized by recombinant IFN-gamma; the same pattern of response was also observed in atopic subjects with high production of IgE. IFN-alpha synergized with IL-4 on IgE synthesis, whereas recombinant IL-6 gave opposite changes in individual cases tested. We propose that IFN-gamma deficiency may be responsible for some of the features of HIgE patients, including IgE levels and infections.

Topics: Adolescent; Adult; Calcimycin; Child; Child, Preschool; Enzyme-Linked Immunosorbent Assay; Female; Humans; Hypergammaglobulinemia; Hypersensitivity, Immediate; Immunoglobulin E; Interferon-gamma; Interleukin-4; Lymphocyte Activation; Male; Middle Aged; Mitogens; Recombinant Proteins; Syndrome; Tetradecanoylphorbol Acetate

Eosinophil degranulation induced by the calcium ionophore A23187 and opsonized zymosan particles was examined ultrastructurally in peripheral blood cells obtained from patients with the hypereosinophilic syndrome. Unstimulated hypereosinophilic syndrome eosinophils contained altered, vacuolated cytoplasmic granules and large cytoplasmic crystalloid structures not seen in normal cells. By morphometric analysis of transmission electron micrographs, the hypereosinophilic syndrome eosinophils contained a larger percentage of smaller sized cytoplasmic granules than normal cells. The hypereosinophilic syndrome eosinophils, however, were capable of undergoing noncytotoxic degranulation after stimulation with either A23187 or opsonized zymosan. Hypereosinophilic syndrome eosinophil degranulation was characterized by fusion of the perigranular membranes of adjacent cytoplasmic granules and vesiculation of the fused granules. Granule contents were released intracellularly into vacuoles after ionophore stimulation and into phagosomes containing the ingested zymosan particles. Noncytotoxic extracellular release of eosinophil peroxidase (EPO) was also observed after cell stimulation by either A23187 or zymosan. The capacity of hypereosinophilic syndrome eosinophils to degranulate after appropriate stimulation with release of toxic granule constituents such as EPO and other basic proteins may be important in the tissue injury observed in this syndrome.

Topics: Calcimycin; Cytoplasmic Granules; Eosinophilia; Eosinophils; Humans; Microscopy, Electron; Phagocytosis; Syndrome; Zymosan

Platelets from a patient with the Hermansky-Pudlak syndrome were studied. These platelets had decreased amounts of serotonin and adenine nucleotides, and a decreased number of mepacrine-labeled dense bodies. beta-Thromboglobulin and acid hydrolases contained in alpha-granules and lysosomes respectively were present in normal amount. Platelets in platelet-rich plasma did not respond to collagen, but arachidonic acid and ionophore A 23187 induced normal aggregation and normal thromboxane (TX) synthesis. Alpha-granule release was found impaired and remained subnormal even with high doses of inducers. In response to thrombin aggregation, release and TX synthesis of isolated metrizamide gradient platelets were found at lower than normal levels. Phosphorylation of P20 and P43 proteins was normal. Only a combination of ADP plus thrombin could restore a normal aggregation, with normal alpha-granule and lysosome release and normal TX synthesis. These results indicated that in the absence of dense bodies: the release of other granules is impaired; the TX synthesis is delayed except when induced by arachidonic acid and A 23187 ionophore; the absence of dense bodies could be compensated for by the addition of ADP which restores the impaired release reaction and TX formation; and P20 and P43 polypeptides were phosphorylated as rapidly as those in normal platelets.

Topics: Adenine Nucleotides; Adenosine Diphosphate; Adolescent; Albinism; Blood Platelet Disorders; Blood Platelets; Calcimycin; Drug Synergism; Humans; Male; Phosphorylation; Platelet Aggregation; Platelet Storage Pool Deficiency; Serotonin; Syndrome; Thrombin; Thromboxanes

The formation of 5- and 15-lipoxygenase products of arachidonic acid metabolism was examined in human peripheral blood eosinophils obtained from five normal individuals and five patients with the hypereosinophilic syndrome (HES). Normal and HES eosinophils after stimulation with the calcium ionophore A23187 produced in comparable amounts leukotriene (LT)C4, LTD4, LTB4 and two of its isomers (5-(S),12-(R)-6-trans-LTB4 and 5-(S), 12-(S)-6-trans-LTB4), 15-hydroxy-eicosatetraenoic acid (HETE), 5,15-di-HETE and 8,15-di-HETE. No single lipoxygenase product predominated in the absence of added arachidonic acid whereas 15-HETE was the major product formed when either normal or HES eosinophils were stimulated with A23187 in the presence of added arachidonic acid (10(-4) M).

Topics: Arachidonate Lipoxygenases; Arachidonic Acids; Calcimycin; Chromatography, High Pressure Liquid; Eosinophilia; Eosinophils; Humans; Leukotriene B4; Lipoxygenase; SRS-A; Syndrome

This report describes a 3-year-old male patient with dwarfism, generalized muscular hypertrophy, stiffness, myotonia, multiple skeletal deformities and normal intelligence. Serum creatine kinase was twice elevated. EMG showed 'dive bomber' discharges and muscle biopsy revealed mild to moderate myopathic changes with variability in fiber size and 'moth-eaten' fibers. Multiple muscle cell cultures showed significantly lower values of total protein synthesis as determined by (3H)-leucine incorporation. The addition of calcium and/or A23187 calcium ionophore to cultures significantly stimulated total protein synthesis in contrast to the lack of effect of these drugs in control cultures. These findings suggest a dysfunction of muscle sarcolemma in Schwartz-Jampel syndrome.

Topics: Abnormalities, Multiple; Anti-Bacterial Agents; Calcimycin; Calcium; Child, Preschool; Dwarfism; Hip Dislocation, Congenital; Humans; Male; Muscle Proteins; Myotonia Congenita; Syndrome