scholarly journals Effects of the Bacterial Extract OM-85 on Phagocyte Functions and the Stress Response

1994 ◽  
Vol 3 (2) ◽  
pp. 143-148 ◽  
Author(s):  
S. Baladi ◽  
S. Kantengwa ◽  
Y. R. A. Donati ◽  
B. S. Polla
Keyword(s):  
Stress Response ◽  
Respiratory Burst ◽  
Stress Proteins ◽  
Human Peripheral Blood ◽  
Stress Protein ◽  
Blood Monocytes ◽  
Bacterial Extract ◽  
Heat Shock Stress ◽  
Intracellular Expression ◽  
Glucose Regulated Protein

The effects of the bacterial extract OM-85 on the respiratory burst, intracellular calcium and the stress response have been investigated in human peripheral blood monocytes from normal donors. Activation of the respiratory burst during bacterial phagocytosis has been previously associated with heat shock/stress proteins synthesis. Whereas OM-85 stimulated superoxide production and increased Ca2+mobilization, it fared to induce synthesis of classical HSPs. The lack of stress protein induction was observed even in the presence of iron which potentiates both oxidative injury and stress protein induction during bacterial phagocytosis. However OM-85 induced a 75–78 kDa protein, which is likely to be a glucose regulated protein (GRP78), and enhanced intracellular expression of interleukin-lβ precursor.

scholarly journals Time Course and Cellular Distribution of Hsp27 and Hsp72 Stress Protein Expression in a Quantitative Gerbil Model of Ischemic Injury and Tolerance: Thresholds for Hsp72 Induction and Hilar Lesioning in the Context of Ischemic Preconditioning

2004 ◽  
Vol 24 (2) ◽  
pp. 167-178 ◽  
Author(s):  
Kazuhiko Nishino ◽  
Thaddeus S. Nowak
Keyword(s):  
Time Course ◽  
Stress Proteins ◽  
Stress Protein ◽  
Tolerance Induction ◽  
Ischemic Injury ◽  
Antigen Retrieval ◽  
Heat Shock Stress ◽  
Ischemic Depolarization ◽  
Map2 Immunoreactivity ◽  
Neuron Injury

The distribution and time course of expression of the heat shock/stress proteins, hsp27 and hsp72, were evaluated in a highly controlled gerbil model of ischemic injury and tolerance induction, in which the duration of ischemic depolarization in each hippocampus provides a precise quantitative index of insult severity. Gerbils were subjected to brief priming insults (2- to 3.5-minute depolarization) that produce optimal preconditioning, to severe test insults (6- to 8.5-minute depolarization) that produce complete CA1 neuron loss in naive animals, or to combined insults administered 1 week apart, after which almost complete tolerance to CA1 neuron injury is observed. Immunoreactivities of hsp27, hsp72, glial fibrillary acidic protein and microtubule-associated protein 2 (MAP2) were evaluated in animals perfused at defined intervals after the final insult in each treatment group, using a variation of established antigen-retrieval procedures that significantly improves detection of many proteins in vibratome brain sections. Hsp72 was detected in CA1 neurons of some hippocampi 2 to 4 days after preconditioning, but this was only seen after the longest priming depolarizations, whereas shorter insults that still induced optimal tolerance failed to induce hsp72. Hsp72 was induced after test insults in preconditioned hippocampi, but at a higher depolarization threshold than observed for naive animals. An astrocytic localization of hsp27 was observed in regions of neuron injury, as indicated by reduced MAP2 immunoreactivity, and was primarily restricted to dentate hilus after preconditioning insults. These results establish that limited hilar lesions are characteristic of optimal preconditioning, whereas prior neuronal expression of either hsp72 or hsp27 is not required for ischemic tolerance.

The stress response and the lung

1997 ◽  
Vol 273 (1) ◽  
pp. L1-L9 ◽  
Author(s):  
H. R. Wong ◽  
J. R. Wispe
Keyword(s):  
Gene Expression ◽  
Acute Lung Injury ◽  
Stress Response ◽  
Heat Shock ◽  
Lung Injury ◽  
Heat Shock Protein ◽  
Heat Shock Protein 70 ◽  
Stress Proteins ◽  
Stress Protein ◽  
Lung Cells

The stress response is a highly conserved cellular defense mechanism defined by the rapid and specific expression of stress proteins, with concomitant transient inhibition of nonstress protein gene expression. The stress proteins mediate cellular and tissue protection against diverse cytotoxic stimuli. Among the many classes of stress proteins, heat shock protein 70 and heme oxygenase-1 are the best characterized with respect to lung biology. A potential role for stress proteins in human lung disease is inferred from studies demonstrating stress protein expression in the lungs of patients with cancer, asthma, and acute lung injury. Several examples of stress protein-mediated cytoprotection exist in cell and animal models of acute lung injury. Stress protein induction protects rats against acute lung injury caused by either systemic administration of endotoxin or intratracheal administration of phospholipase A1. In vitro, increased expression of stress proteins protects lung cells against endotoxin-mediated apoptosis and oxidant injury. The mechanisms of stress response-mediated cytoprotection may involve the enzymatic and molecular chaperone properties of stress proteins. Alternatively, the stress response may protect by modulating lung proinflammatory responses. Data from extrapulmonary systems suggest that stress response-associated factors (heat shock protein 70 and heat shock factor) are directly involved in modulation of proinflammatory gene expression. Recent evidence also demonstrates interactions between the stress response and the I-kappa B/nuclear factor-kappa B pathway in cultured lung cells. Increased understanding about the role of stress proteins in lung biology may support efforts to selectively increase expression of one or more stress proteins to provide protection against human acute lung injury.

scholarly journals Alterations of transcription and translation in HeLa cells exposed to amino acid analogs.

1984 ◽  
Vol 4 (6) ◽  
pp. 1063-1072 ◽  
Author(s):  
G P Thomas ◽  
M B Mathews
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Stress Response ◽  
Mammalian Cells ◽  
Stress Proteins ◽  
Prolonged Exposure ◽  
Stress Protein ◽  
Electrophoretic Patterns ◽  
Amino Acid Analogs ◽  
Polypeptide Chains

Amino acid analogs, like other effectors of the stress response, induce in mammalian cells the same gene products that are induced upon heat shock; incorporation of the analog into protein is required for induction. We show here that induction by analogs involves controls operating at the levels of both transcription and translation. The electrophoretic patterns of newly made mRNAs simplify with time such that the putative stress protein mRNAs are the only species transported from the nucleus. Concomitantly, the patterns of protein synthesis simplify such that the stress proteins become nearly exclusive polypeptide products. Although the normal mRNAs are either not used or used with greatly reduced efficiency, they are not degraded and retain translatability when transferred to cell-free systems. Soon after the stress response has been induced, there follows a defect in the initiation of polypeptide chains, as evidenced by examination of polysome profiles. Upon prolonged exposure, polysomes are recovered, and although they give rise to stress proteins almost exclusively, the normal mRNAs are still present in these structures. Thus, in addition to the initiation defect, a lesion in elongation may also be involved. The extreme sensitivity of protein synthesis to the inhibition of RNA synthesis, together with the parallel simplifications in the patterns of newly made mRNAs and polypeptides, may imply that only newly made mRNAs are efficiently translated in analog-treated cells.

scholarly journals The CD11c antigen couples concanavalin A binding to generation of superoxide anion in human phagocytes

1990 ◽  
Vol 268 (3) ◽  
pp. 707-712 ◽  
Author(s):  
P M Lacal ◽  
J Balsinde ◽  
C Cabañas ◽  
C Bernabeu ◽  
F Sánchez-Madrid ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Concanavalin A ◽  
Respiratory Burst ◽  
Superoxide Anion ◽  
Human Peripheral Blood ◽  
Significant Inhibition ◽  
U937 Cells ◽  
Blood Monocytes ◽  
Peripheral Blood Monocytes ◽  
Molecular Masses

We have found that an anti-CD11c monoclonal antibody (MAb) inhibits the respiratory burst induced in phorbol 12-myristate 13-acetate (PMA)-differentiated U937 cells as well as in human peripheral blood monocytes and neutrophils upon cell stimulation with concanavalin A. The MAb had no effect, however, when the added stimulus was fMet-Leu-Phe or PMA. Flow cytometry analyses indicated that concanavalin A was able to interact with CD11c. The anti-CD11c MAb inhibited significantly concanavalin A binding to differentiated U937 cells, and concanavalin A blocked binding of anti-CD11c MAb to the cells. Binding of labelled concanavalin A to membrane proteins which were separated by PAGE and transferred to nitrocellulose paper indicated that proteins with apparent molecular masses similar to those of CD11c (150 kDa) and CD18 (95 kDa) molecules were the main concanavalin A-binding proteins in differentiated U937 cells as well as in mature neutrophils. Similar experiments carried out in the presence of the anti-CD11c MAb showed a specific and significant inhibition of concanavalin A binding to the CD11c molecule. These results indicate that concanavalin A binds to the CD11c molecule and this binding is responsible for the concanavalin A-induced respiratory burst in PMA-differentiated U937 cells as well as in human mature monocytes and neutrophils.

The Effect of C-Reactive Protein (CRP) on Respiratory Burst of Human Peripheral Blood Phagocytes

1995 ◽  
Vol 8 (2) ◽  
pp. 95-102
Author(s):  
J. Cofta ◽  
J.K. Lacki ◽  
S.H. Mackiewicz ◽  
K.E. Wiktorowicz
Keyword(s):  
Respiratory Burst ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Low Doses ◽  
Blood Monocytes ◽  
C Reactive Protein ◽  
Free Oxygen ◽  
Peripheral Blood Monocytes ◽  
Reactive Protein ◽  
Enhanced Chemiluminescence

The effect of C-reactive protein (CRP) on the oxidative response of human peripheral blood monocytes and granulocytes was investigated. The respiratory burst of phagocytes induced by phorbol-myristate-13-acetate (PMA), phytohaemagglutinin (PHA) or opsonized zymosan (OZ) was measured in luminol-enhanced chemiluminescence. The effect of CRP on PMA-induced monocyte chemiluminescence (CL) depended both on CRP concentration and incubation time. A short incubation of cells with CRP (15–30 min.) enhanced the oxidative burst. Preincubation of cells for 1h (or longer) with low doses of CRP (about 2 μg/ml) increased, while with higher (>10 μg/ml) inhibited PMA-stimulated chemiluminescence. CRP reduced also PHA or OZ-induced monocyte respiratory response. CRP diminished PMA, PHA, and OZ-induced granulocyte chemiluminescence, except the response to PHA in the presence of low doses CRP (about 5 μg/ml). The action of CRP on phagocytes probably involves activation of some intracellular mechanisms. During immune response, CRP could protect tissues against damage by excess of free oxygen and its biological active derivatives.

Alterations of transcription and translation in HeLa cells exposed to amino acid analogs

1984 ◽  
Vol 4 (6) ◽  
pp. 1063-1072
Author(s):  
G P Thomas ◽  
M B Mathews
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Stress Response ◽  
Mammalian Cells ◽  
Stress Proteins ◽  
Prolonged Exposure ◽  
Stress Protein ◽  
Electrophoretic Patterns ◽  
Amino Acid Analogs ◽  
Polypeptide Chains

Amino acid analogs, like other effectors of the stress response, induce in mammalian cells the same gene products that are induced upon heat shock; incorporation of the analog into protein is required for induction. We show here that induction by analogs involves controls operating at the levels of both transcription and translation. The electrophoretic patterns of newly made mRNAs simplify with time such that the putative stress protein mRNAs are the only species transported from the nucleus. Concomitantly, the patterns of protein synthesis simplify such that the stress proteins become nearly exclusive polypeptide products. Although the normal mRNAs are either not used or used with greatly reduced efficiency, they are not degraded and retain translatability when transferred to cell-free systems. Soon after the stress response has been induced, there follows a defect in the initiation of polypeptide chains, as evidenced by examination of polysome profiles. Upon prolonged exposure, polysomes are recovered, and although they give rise to stress proteins almost exclusively, the normal mRNAs are still present in these structures. Thus, in addition to the initiation defect, a lesion in elongation may also be involved. The extreme sensitivity of protein synthesis to the inhibition of RNA synthesis, together with the parallel simplifications in the patterns of newly made mRNAs and polypeptides, may imply that only newly made mRNAs are efficiently translated in analog-treated cells.

scholarly journals Surfactant phospholipid DPPC downregulates monocyte respiratory burst via modulation of PKC

2005 ◽  
Vol 288 (6) ◽  
pp. L1070-L1080 ◽  
Author(s):  
Alex Tonks ◽  
Joan Parton ◽  
Amanda J. Tonks ◽  
Roger H. K. Morris ◽  
Alison Finall ◽  
...  
Keyword(s):  
Respiratory Burst ◽  
Pulmonary Surfactant ◽  
Inflammatory Responses ◽  
Human Peripheral Blood ◽  
Cell System ◽  
Blood Monocytes ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Human Monocytic Cell Line ◽  
Oxidative Response

Pulmonary surfactant phospholipids have been shown previously to regulate inflammatory functions of human monocytes. This study was undertaken to delineate the mechanisms by which pulmonary surfactant modulates the respiratory burst in a human monocytic cell line, MonoMac-6 (MM6). Preincubation of MM6 cells with the surfactant preparations Survanta, Curosurf, or Exosurf Neonatal inhibited the oxidative response to either lipopolysaccharide (LPS) and zymosan or phorbol 12-myristate 13-acetate (PMA) by up to 50% ( P < 0.01). Preincubation of MM6 cells and human peripheral blood monocytes with dipalmitoyl phosphatidylcholine (DPPC), the major phospholipid component of surfactant, inhibited the oxidative response to zymosan. DPPC did not directly affect the activity of the NADPH oxidase in a MM6 reconstituted cell system, suggesting that DPPC does not affect the assembly of the individual components of this enzyme into a functional unit. The effects of DPPC were evaluated on both LPS/zymosan and PMA activation of protein kinase C (PKC), a ubiquitous intracellular kinase, in MM6 cells. We found that DPPC significantly inhibited the activity of PKC in stimulated cells by 70% ( P < 0.01). Western blotting experiments demonstrated that DPPC was able to attenuate the activation of the PKCδ isoform but not PKCα. These results suggest that DPPC, the major component of pulmonary surfactant, plays a role in modulating leukocyte inflammatory responses in the lung via downregulation of PKC, a mechanism that may involve the PKCδ isoform.

Ultrastructural Changes in Tumor Cells During Human Peripheral Blood Monocyte-Mediated Cytotoxicity

1981 ◽  
Vol 39 ◽  
pp. 452-453
Author(s):  
K. E. Muse ◽  
D. G. Fischer ◽  
H. S. Koren
Keyword(s):  
Target Cell ◽  
Human Peripheral Blood ◽  
Mononuclear Phagocytes ◽  
Ultrastructural Changes ◽  
Target Cells ◽  
Limited Information ◽  
Blood Monocytes ◽  
Tumoricidal Activity ◽  
Activated State

Mononuclear phagocytes, a pluripotential cell line, manifest an array of basic extracellular functions. Among these physiological regulatory functions is the expression of spontaneous cytolytic potential against tumor cell targets.The limited observations on human cells, almost exclusively blood monocytes, initially reported limited or a lack of tumoricidal activity in the absence of antibody. More recently, freshly obtained monocytes have been reported to spontaneously impair the biability of tumor target cells in vitro (Harowitz et al., 1979; Montavani et al., 1979; Hammerstrom, 1979). Although the mechanism by which effector cells express cytotoxicity is poorly understood, discrete steps can be distinguished in the process of cell mediated cytotoxicity: recognition and binding of effector to target cells,a lethal-hit stage, and subsequent lysis of the target cell. Other important parameters in monocyte-mediated cytotoxicity include, activated state of the monocyte, effector cell concentrations, and target cell suseptibility. However, limited information is available with regard to the ultrastructural changes accompanying monocyte-mediated cytotoxicity.

Detection of both Type 1 and Type 2 Plasminogen Activator Inhibitors in Human Monocytes

1990 ◽  
Vol 63 (01) ◽  
pp. 067-071 ◽  
Author(s):  
Joan C Castellote ◽  
Enric Grau ◽  
Maria A Linde ◽  
Nuria Pujol-Moix ◽  
Miquel LI Rutllant
Keyword(s):  
Molecular Mass ◽  
Plasminogen Activator ◽  
Human Peripheral Blood ◽  
Direct Interaction ◽  
Apparent Molecular Weight ◽  
Fibrinolytic System ◽  
Human Monocytes ◽  
Blood Monocytes ◽  
Single Chain ◽  
Sds Page

SummaryIncreasing evidence suggests the involvement of leukocytes in the fibrinolytic system. Monocytes secrete pro-urokinase (Grau, Thromb Res 1989; 53: 145) and it has been shown that these cells have specific receptors for urokinase and plasminogen (Miles, Thromb Haemostas 1987; 58: 936). The aim of this study was to analyse the presence of plasminogen activator inhibitor(s) in platelet-free suspensions of human peripheral blood monocytes and polymorphonuclear leukocytes (PMN). SDS-PAGE and reverse fibrin autography showed an inhibitory band of 50 kDa in the monocyte extracts (Triton X-100) but not in the PMN extracts. Urokinase (u-PA) was mixed with increasing amounts of monocyte extract for 10 min and the mixtures were added to 125Ifibrin coated wells containing plasminogen. A dose-dependent decrease in the u-PA fibrinolytic activity was observed. The amount of inhibition increased when the monocyte releasates were preincubated with u-PA (40% inhibition after 5 min preincubation and 80% after 15 min), indicating a direct interaction between this activator and an inhibitor(s). After SDS-PAGE of monocyte extracts, immunoblotting and peroxidase staining identified both PAI1 and PAI2, with an apparent molecular weight of 47-50 kDa. Monocyte-associated PAI1 formed complexes with single chain t-PA with a molecular mass 50 kDa higher than the molecular mass of the free PAI1. However, a significant amount of PAI remained unbound to t-PA. This inactive PAI1 could have come from a rapid inactivation of the primary active PAI1. These PAI1 and PAI2 detected in human monocytes may be transcendent in the regulation of the fibrinolytic system.

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