Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The purpose of this study was to identify the optimal freezing conditions for human blood monocytes to allow their recovery and use for in vitro screening of activation stimuli. Human monocytes separated from buffy coats of healthy blood donors were suspended at a density of 1 x 10(7) cells/ml in freezing medium consisting of 70% medium: 20% fetal bovine serum: 10% DMSO frozen in a stepdown freezer, and stored at -180 degrees C. Monocytes were thawed at different times up to 4 months later. Viability was > 90%. Fresh monocytes from different donors and frozen monocytes thawed at different times were incubated with different concentrations of lipopolysaccharide, muramyl tripeptide, muramyl dipeptide, or lipopeptide. Tumoricidal activity and IL-1 production of fresh monocytes varied greatly among the 5 different preparations. In contrast, the frozen monocytes (thawed at different times) produced uniform levels of antitumor activity and IL-1 production. These results show that monocytes recovered from frozen storage maintain their ability to respond to activation stimuli in a uniform and reproducible manner. Thus, the use of frozen-thawed monocytes is recommended for screening of macrophage-activating agents.
 ...
PMID:Frozen-thawed human blood monocytes respond reproducibly to activation stimuli: implications for screening of BRMs. 129 Jul 26

Carbohydrate binding proteins, known as lectins, bind to specific sugar groups on most membranes. We used fluorescent and light microscopy to study the interaction of various lectins with the membranes of microglia cultured from neonatal rat or fetal mouse cerebral cortices. Microglia stained intensely with GS-1, RCA, WGA, and ConA and slightly with DBA, UEA, BPA, and SBA. No staining was seen with GS-2, MPA, or PNA. Staining was specific for microglia in the mixed glial cultures and was dose dependent. In addition, microglial lectin binding could be reduced or blocked by competitive inhibition using specific sugars. Treatment of the microglia with agents such as dimethylsulfoxide (DMSO), interleukin-1 (IL-1), interferon (IFN), or lipopolysaccharide (LPS) did not eliminate lectin staining, although the degree of staining was altered. Positive staining of the microglia was also associated with a functional change for at least one lectin, i.e., ConA. Superoxide anion production by microglia was increased in the presence of ConA. Overall, binding of the lectins GS-1, RCA, WGA, and ConA can be used as an identifying tool for microglia in glial cultures, but intensity of staining varies depending on their functional state.
 ...
PMID:Lectin staining of cultured CNS microglia. 137 34

1. Induction of tumor cell differentiation could reverse transformed cells into normal, mature cells. Important question is whether these malignant-to-normal reversed cells are really normal ones. 2. We have developed an experimental model based on the examination of three different levels of human acute myeloid leukemia cell properties before and after induction of differentiation: morphological (percentage of undifferentiated blast cells), functional (DNA ploidy, Fc receptors, phagocytic activity, clonogenic assay in soft agar, oxidative metabolism which accompanies phagocytosis in mature granulocytes) and genetical (expression of oncogene p53). 3. Several inducers have been employed: dimethylsulfoxide (DMSO) granulocyte-macrophage colony stimulating factor (GM-CSF); tunicamycin, interferon gamma, tumor necrosis factor and lipopolysaccharide. 4. Our results indicate that the reversion of leukemic cells into mature normal ones with some inducers (DMSO, GM-CSF) could be a complete process.
 ...
PMID:Artificial reversion of acute myeloid leukemia cells into normal phenotype. 218 58

Macrocyclic trichothecenes are a class of mycotoxins, some of which exhibit substantial antileukemic properties. These compounds vary in their toxicity by approximately 100 fold and are suspected immunotoxins. We studied 11 of these mycotoxins: roritoxin B, myrotoxin B, roridin A, verrucarin A, 16-hydroxyverrucarin A, verrucarin J, baccharinoid B12, roridin D, roridin E, baccharinoid B4 and baccharinoid B5 for their immunotoxicity in CD-1 mice. An equitoxic dose was prepared in 1% DMSO in saline and administered i.p. at half the LD50. Organ weights, WBC, RBC, differentials of blood cell counts, blastogenesis of splenic lymphocytes in response to concanavalin A (Con A), lipopolysaccharide (LPS), phytohemagglutinin (PHA) and pokeweed mitogen (PWM), and mixed lymphocyte reaction (MLR) were studied on day 4 after administration of each mycotoxin. Organ weights showed significant differences between the controls and the baccharinoids with a decrease in spleen weight in baccharinoid B12 and an increased liver weight in B4 and B5 treated animals. Administration of myrotoxin B, roridin A, verrucarin J and roridin E had total WBC counts statistically different from controls, while mice administered myrotoxin B shoed a decrease in numbers of RBC. Differentials of WBC were unremarkable regardless of the mycotoxin. Roritoxin B and baccharinoid B5 increased Con A stimulation of splenic lymphocytes. Roridin A and baccharinoid B12 increased LPS stimulation of splenic lymphocytes while baccharinoid B5 decreased the LPS response. Stimulation of splenic lymphocytes with PHA was significantly increased by roridin A and baccharinoid B5. Stimulation of splenic lymphocytes with PWM was not altered significantly by any mycotoxin.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Effects of macrocyclic trichothecene mycotoxins on the murine immune system. 278 85

Native tumoricidal activity of human peripheral blood mononuclear cells was examined before and after their separation by counterflow centrifugation elutriation (CCE). Tumoricidal activity was found in the subpopulation of small mononuclear cells but not within the relatively pure subpopulation of large monocytes. Addition of lymphokine and/or lipopolysaccharide demonstrated that large monocytes were resistant to activation for tumor killing, in contrast to small mononuclear cells. However, cryopreservation or simply exposure to dimethyl sulfoxide (DMSO) rendered the large monocytes sensitive to activating agents without altering their unstimulated tumoricidal activity. Cryopreservation was not detrimental to small or large monocytes either in number or tumoricidal function but did decrease the number of large granular lymphocytes (LGL). The small mononuclear cell fraction was enriched for small monocytes to 80% by combining CCE with Percoll gradient separation. HNK-1 mouse monoclonal antibody against human LGL was used with complement to remove virtually all LGL from cryopreserved cells as judged by morphology and tumoricidal activity against K-562 human lymphoblastoid cells. Such treatment actually augmented rather than suppressed tumoricidal activity against P-815 mastocytoma cells. Therefore, we conclude that small monocytes but not large monocytes possess native tumoricidal activity distinct from that attributed to LGL or natural killer lymphocytes. Further, small monocytes are readily activated for tumor killing and can be cryopreserved without loss of tumoricidal activity.
 ...
PMID:Cytotoxicity of human peripheral blood monocytes. 664 Jun 73

In this study we have examined the expression and modulation of the human granulocyte colony-stimulating factor (G-CSF) receptor (R) in immature and differentiated myeloid cells using a 125I labelled human G-CSF analogue (TG50). Equilibrium binding data revealed a single affinity class of receptor on all cell types expressing G-CSFR (KD 235-606 pM) with neutrophils expressing 2883 +/- 672 Rs/cell. Rapid internalization of surface receptor-bound ligand at 37 degrees C was detected in both immature cells (U937) and neutrophils with > 70% of specifically bound ligand internalized within 5 min. Concentration-response data showed that the level of occupancy of neutrophil G-CSFRs by ligand at 37 degrees C was approximately 5-fold greater than predicted by equilibrium binding data and correlated closely with concentration-response data for biological activity. Re-expression of G-CSFRs following down-regulation by internalization was not detected. Down-regulation of the neutrophil G-CSFR by several agents including granulocyte-macrophage colony-stimulating factor (GM-CSF), tumour necrosis factor (TNF), lipopolysaccharide (LPS), f-met-leu-phe (fMLP), phorbol ester (TPA) and C5a was observed at 37 degrees C but not at 4 degrees C. In contrast, G-CSFRs on immature myeloid cells were significantly down-regulated by TPA only. Differentiation of myeloid leukaemic cell line HL-60 with DMSO, a frequently used model of granulocytic differentiation, was associated with a significant reduction in G-CSFR expression (11 +/- 5% of control) whereas treatment with retinoic acid led to increased G-CSFR expression (161 +/- 3%).
 ...
PMID:Expression and dynamic modulation of the human granulocyte colony-stimulating factor receptor in immature and differentiated myeloid cells. 750 64

All trans-retinoic acid (ATRA) can induce granulocytic differentiation both in vitro and in vivo, and its activity is mediated by the retinoic acid receptor-alpha (RAR-alpha). In the present study, we evaluated the ability of this inducer in HL-60 cells, to stimulate simultaneously granulocytic differentiation and the expression of the cytokines interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-3, IL-6, tumor necrosis factor-alpha (TNF-alpha), and stem cell factor (SCF). The level of expression of these cytokines in ATRA-treated HL-60 cells was compared with that observed in normal and lipopolysaccharide (LPS)-treated peripheral granulocytes. The results indicate that the expression of these cytokines is enhanced during differentiation so that the pattern observed in ATRA-treated HL-60 cells is close to that of LPS-stimulated normal granulocytes. In addition, tetra phorbol acetate (TPA)-treated HL-60 cells express several of the above listed cytokines. It is concluded that ATRA not only induces granulocytic differentiation of HL-60 cells, but also activation of these terminally differentiated cells. The activating cytokine expression in these cells appears related to the progress of the differentiation program induced by ATRA since normal granulocytes do not respond to this inducer by activation of the expression of these genes. Furthermore, the cytokine activation is a specific effect of ATRA, since DMSO does not have any stimulatory effect.
 ...
PMID:All-trans-retinoic acid induces simultaneously granulocytic differentiation and expression of inflammatory cytokines in HL-60 cells. 753 Feb 11

Homeobox genes encode transcription factors known to be important morphogenic regulators during embryogenesis. An increasing body of work implies a role for homeobox genes in both hematopoiesis and oncogenesis. We have analyzed the role of the homeobox gene, HOX B7, in the program of differentiation of the biphenotypic myeloid cell line, HL60. Induction of monocytic differentiation in HL-60 cells by vitamin D3 resulted in rapid expression of HOX B7 mRNA, but stimulation with phorbol ester or dimethyl sulfoxide (DMSO) did not. Constitutive overexpression of HOX B7 in the HL60 cell line inhibited the granulocytic differentiation associated with stimulation with DMSO or retinoic acid, but had no effect on the monocytic differentiation induced by vitamin D3. Normal human monocytes do not constitutively express HOX B7, nor are they able to be induced to do so by stimulation with colony-stimulating factor 1 (CSF-1) and gamma interferon (IFN gamma), or with vitamin D3 and lipopolysaccharide. Human bone marrow (BM) cells were found to express HOX B7 in response to granulocyte-macrophage CSF (GM-CSF) and antisense oligonucleotides directed against HOX B7 inhibited the formation of colonies derived from GM-CSF-stimulated BM. These data suggest a critical role for HOX B7 in myelomonocytic differentiation.
 ...
PMID:The role of the homeobox gene, HOX B7, in human myelomonocytic differentiation. 753 May 3

Tissue injury that occurs as a result of ischemia and subsequent reperfusion is characterized by endothelial cell injury, edema formation, and the influx of inflammatory leukocytes. Two macrophage-derived proinflammatory cytokines which may play a critical role in cellular injury and leukocyte recruitment/activation that occurs in the setting of ischemia-reperfusion injury are tumor necrosis factor alpha (TNF) and macrophage inflammatory protein-1 alpha (MIP-1 alpha). To determine if modulation of ambient oxygen tensions in vitro alters the expression of proinflammatory cytokines from activated macrophages, murine alveolar macrophages (AMO) were cultured in various combinations of ambient oxygen concentrations, then the supernatant fluid and cell pellet assayed for the presence of TNF and MIP-1 alpha messenger RNA (mRNA) and protein. We demonstrated that conditions of anoxia (95% nitrogen/5% CO2) or hyperoxia (95% oxygen/5% CO2) independently resulted in the increased expression of both TNF and MIP-1 alpha mRNA and protein from lipopolysaccharide (LPS)-stimulated AMO, as compared with cells cultured in room air. The specific culture condition of anoxia (x 6 h) followed by hyperoxia (x 18 h) produced the greatest increases in both TNF and MIP-1 alpha, suggesting that when following a period of anoxic priming, oxygen stress results in exaggerated cytokine production. A period of at least 4.5 to 6 h of anoxia prior to hyperoxic exposure was found to be the minimal time required for anoxic priming. Furthermore, the coincubation of LPS-treated AMO with dimethyl sulfoxide (DMSO) attenuated the anoxia-hyperoxia-induced increases in TNF and MIP-1 alpha mRNA by 23% and 34%, respectively. These findings suggested that alterations in ambient oxygen tension can regulate the expression of TNF and MIP-1 alpha from activated AMO, and that oxidant-related cytokine production may represent an important mechanism by which inflammation occurs in the clinical settings of ischemia-reperfusion injury and hyperoxia.
 ...
PMID:Alterations of ambient oxygen tension modulate the expression of tumor necrosis factor and macrophage inflammatory protein-1 alpha from murine alveolar macrophages. 754 69

Natural killer cell-stimulatory factor or interleukin-12 (NKSF/IL-12) was originally identified and purified from the conditioned medium of Epstein-Barr virus (EBV)-transformed B-cell lines. Phorbol diesters were observed to be potent stimulators of NKSF/IL-12 production from the B-cell lines. Although monocytes were found to be the major producers of NKSF/IL-12 in peripheral blood (PB) in response to lipopolysaccharide (LPS) or to Staphylococcus aureus, several myeloid leukemia cell lines tested did not produce detectable NKSF/IL-12 either constitutively or upon stimulation with phorbol diesters. However, three lines, ML-3, HL-60, and THP-1, responded to LPS with significant levels of NKSF/IL-12 production, whereas S aureus was effective only on THP-1 cells. When the cell lines were preincubated with compounds known to induce them to differentiate, production of tumor necrosis factor alpha (TNF alpha) and IL-1 beta was in most cases maximal in cells with differentiated characteristics, whereas NKSF/IL-12 production in response to LPS in all three producing cell lines was significantly enhanced only by pretreatment with dimethylsulfoxide (DMSO) for 24 hours, or by costimulation with interferon gamma (IFN gamma). The efficiency of DMSO enhancement of NKSF/IL-12 production decreased after 2 to 5 days of incubation, when the cells acquired differentiated characteristics. Unlike DMSO, IFN gamma enhanced NKSF/IL-12 production, and IL-10 and dexamethasone inhibited it in cell lines and PB mononuclear cells stimulated by either LPS or S aureus. The ability of the cell lines to respond to these mediators of possibly physiologically relevant function provides a tissue-culture model for studying their mechanism of action.
 ...
PMID:Differential regulation of interleukin-12 (IL-12), tumor necrosis factor alpha, and IL-1 beta production in human myeloid leukemia cell lines and peripheral blood mononuclear cells. 790 32


1 2 3 4 5 6 7 8 9 Next >>