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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mononuclear phagocytes play an important role in the regulation of hematopoiesis, not only by producing regulatory monokines such as prostaglandins, tumor necrosis factor and interleukin-1 (IL-1), but also by the production of colony-stimulating activity (CSA). Previously, we have demonstrated that granulocyte-macrophage CSA (GM-CSA) production by mononuclear phagocytes can be induced by IL-1. In the present study, the influence of culture conditions on the production of GM-CSA was studied. It was found that both human sera and fetal bovine sera contain constituents - at present undefined - that induce GM-CSA production. These factors are distinct from IL-1 and lipopolysaccharide. In selected experiments, no GM-CSA-inducing effect of serum was found, suggesting that the effect may be donor-related. GM-CSA release in the presence of serum could be reduced by 40% after incubation of mononuclear phagocytes at low cell concentrations in methylcellulose, indicating that intimate cell-cell contact is an additional factor that enhances GM-CSA release.
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PMID:Factors influencing release of granulocyte-macrophage colony-stimulating activity from human mononuclear phagocytes. 255 15

Female B6C3F1 mice were exposed to graded doses of nickel sulfate to determine a threshold response for myelotoxicity and immunotoxicity, and to identify which of the populations of lymphoreticular cells were most sensitive to the toxic effects of nickel. Animals were given free access to the chemical in the drinking water at 0, 1, 5, or 10 g/l for 180 d. Water consumption, blood and tissue nickel concentrations, body and organ weights, histopathology, immune responses, bone marrow cellularity and proliferation, and cellular enzyme activities were evaluated. There was no mortality. Mice in the 5-g/l and 10-g/l dose groups drank less water than controls; the responses measured in the 10-g/l group may have been due to a combination of dehydration and chemical toxicity. Decreases in body and organ weights were confined to mice in the 10-g/l dose group, except for the dose-related reductions in thymus weights. Blood nickel was measured at 4, 8, 16, and 23 wk of exposure. The mean blood nickel values showed increases between 4 and 8 wk that were proportional to time and dose; thereafter there was no substantial increase in blood nickel in any of the dose groups, except for an increase in the mean blood concentration in the 10-g/l group at 23 wk. The kidney was the major organ of nickel accumulation. The primary toxic effects of nickel sulfate were expressed in the myeloid system. There were dose-related decreases in bone marrow cellularity, and in granulocyte-macrophage and pluripotent stem-cell proliferative responses. In unfractionated bone marrow cells glucose-6-phosphate dehydrogenase enzyme activity from the hexose monophosphate shunt was more sensitive to nickel sulfate than were representative glycolytic or Krebs cycle enzymes, with 25-35% maximum inhibition at 5 g/l and 10 g/l. Aliquots of bone marrow cells were separated into enriched bands of lymphocytes, granulocyte-macrophages, and erythrocytes; enzyme inhibition that occurred in unfractionated bone marrow cell aliquots was only expressed after cell separation in the enriched granulocyte-macrophage cell population, suggesting that these committed stem cells were a primary target of nickel sulfate toxicity. There was one example of systemic immunotoxicity, reduction in the lymphoproliferative response to lipopolysaccharide, and it was regarded as secondary to the primary effect of nickel sulfate on the myeloid system, since this was the only significant change among a panel of seven immune parameters that were evaluated.
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PMID:Evaluation of tissue disposition, myelopoietic, and immunologic responses in mice after long-term exposure to nickel sulfate in the drinking water. 339 77

A stromal cell line, GY30, was cloned from mouse bone marrow adherent cell layers. In culture, GY30 cells sustain the production of granulocyte-macrophage progenitor cells (GM-CFU) but fail to support the survival of pluripotential stem cells (CFU-S). GY30 cells secrete two growth factor activities distinct from interleukin-3 (IL-3), IL-2, and macrophage colony-stimulating factor (M-CSF) but functionally similar to GM-CSF and G-CSF. The production of both CSFs is increased 70- to 200-fold by treating GY30 cells with lipopolysaccharide or IL-1. RNA blot analysis reveals the presence of GM-CSF and G-CSF transcripts and demonstrates that IL-1 regulates the production of both factors at the mRNA level. Further, these studies show that the GM-CSF secreted by GY30 cells is structurally similar to the GM-CSF produced by activated T cells.
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PMID:Control of hemopoiesis by a bone marrow stromal cell clone: lipopolysaccharide- and interleukin-1-inducible production of colony-stimulating factors. 349 27

An attempt was made to establish long-term cultures of marrow cells from genetically anaemic W/Wv mice. Two batches of horse sera were used. One batch of horse serum (HS-lot A) supported long-term maintenance (up to 20 weeks) of granulopoiesis in vitro. The number of suspension cells in W/Wv marrow culture was maintained at the same level as that in the control +/+ culture, but the number of granulocyte-macrophage progenitor cells (GM-CFC) and the ratio of immature to mature granulocytes were at a lower level than those in +/+ culture. These data suggest that haemopoietic progenitors in W/Wv cultures maintain a higher level of differentiation, and hence an increased self-renewal than those in +/+ cultures. Another batch of horse serum (HS-lot B) was less effective in the maintenance of the cultures, and the cultures deteriorated within 10 weeks. Addition of bacterial lipopolysaccharide (LPS) induced increased granulopoiesis in +/+ cultures, whereas such treatment resulted in the depletion of suspension cells in W/Wv cultures. The results suggest that haemopoietic cells of W/Wv mouse cannot cope with the strong stimulus for differentiation that occurs after the administration of LPS, although the cells can continue a moderately increased self-renewal and differentiation, as indicated by the results in the culture with HS-lot A.
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PMID:Maintenance of granulopoiesis in long-term bone marrow cultures from W/Wv mice and effects of lipopolysaccharide on granulopoiesis in culture. 349 16

Intravenous (i.v.) injection of mice with lipopolysaccharide (LPS), and the proteolytic enzymes trypsin and proteinase, mobilizes pluripotent haemopoietic stem cells (CFU-s) as well as granulocyte-macrophage progenitor cells (GM-CFU) and the early progenitors of the erythroid lineage (E-BFU) from the haemopoietic tissues into the peripheral blood. We investigated the involvement of the complement (C) system in this process. It appeared that the early mobilization induced by LPS and other activators of the alternative complement pathway, such as Listeria monocytogenes (Lm) and zymosan, but not that induced by the proteolytic enzymes, was absent in C5-deficient mice. The mobilization by C activators in these mice could be restored by injection of C5-sufficient serum, suggesting a critical role for C5. The manner in which C5 was involved in the C activation-mediated stem cell mobilization was studied using a serum transfer system. C5-sufficient serum, activated in vitro by incubation with Lm and subsequently liberated from the bacteria, caused mobilization in both C5-sufficient and C5-deficient mice. C5-deficient serum was not able to do so. The resistance of the mobilizing principle to heat treatment (56 degrees C, 30 min) strongly suggests that it is identical with the C5 split product C5a, or an in vivo derivative of C5a. This conclusion was reinforced by the observation that a single injection of purified rat C5a into C5-deficient mice also induced mobilization of CFU-s.
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PMID:Complement split product C5a mediates the lipopolysaccharide-induced mobilization of CFU-s and haemopoietic progenitor cells, but not the mobilization induced by proteolytic enzymes. 353 67

Pure murine colony-stimulating factor-1 (CSF-1) was assessed for its effects in vivo in mice pretreated seven days earlier with a sublethal dosage of cyclophosphamide. The multipotential (CFU-GEMM), erythroid (BFU-E), and granulocyte-macrophage (CFU-GM) progenitor cells in these mice were in a slowly cycling or noncycling state. Intravenous administration of 20,000 units of CSF-1 to these mice stimulated the hematopoietic progenitors into a rapidly cycling state in the marrow and spleen within three hours. Significant increases in absolute numbers of marrow and spleen CFU-GM and spleen BFU-E and CFU-GEMM were also detected. No endotoxin was detected in the CSF-1 preparation by Limulus lysate assay, and treatment of CSF-1 at 100 degrees C for 20 to 30 minutes completely inactivated the in vitro and in vivo stimulating effects. The effects of CSF-1 were not mimicked by the in vivo administration of 0.1 to 10 ng Escherichia coli lipopolysaccharide. These results suggest that the effects of CSF-1 in vivo were not due to contaminating endotoxin or to a nonspecific protein effect. CSF-1 did not enhance colony formation by BFU-E or stimulate colony formation by CFU-GEMM in vitro, thus suggesting that at least some of the effects of CSF-1 noted in vivo are probably indirect and mediated by accessory cells.
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PMID:The influence in vivo of murine colony-stimulating factor-1 on myeloid progenitor cells in mice recovering from sublethal dosages of cyclophosphamide. 354 24

Purified murine colony-stimulating factors (CSF) recombinant interleukin 3 (IL-3), natural CSF-1, and recombinant granulocyte-macrophage (GM) CSF were assessed in vivo for their effects on BDF1 mouse bone marrow and spleen granulocyte-macrophage (CFU-GM), erythroid (BFU-E), and multipotential (CFU-GEMM) progenitor cells in untreated mice and in mice pretreated with purified iron-saturated human lactoferrin (LF). The CSF and LF preparations did not contain detectable endotoxin (less than 0.1 ng). Mice pretreated with LF were more sensitive to the effects of CSF. In mice pretreated with LF, 2,000 U IL-3 or 20,000 U CSF-1 significantly enhanced the cycling status and absolute numbers of all progenitors, whereas 20,000 U GM-CSF significantly increased the cycling status of CFU-GM and CFU-GEMM, but had no effect on cycling of BFU-E or on numbers of any of the progenitors. The effects of CSF in mice pretreated with LF were not mimicked by 0.1-100 ng E. coli lipopolysaccharide.
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PMID:Comparative effects in vivo of recombinant murine interleukin 3, natural murine colony-stimulating factor-1, and recombinant murine granulocyte-macrophage colony-stimulating factor on myelopoiesis in mice. 354 76

Cultured monocytes release a factor, monocyte-derived recruiting activity (MRA), which stimulates fibroblasts, endothelial cells, and T lymphocytes to produce colony-stimulating activity (CSA). We studied the kinetics of MRA production using a technique in which MRA levels were measured in a two stage bioassay. We used umbilical vein endothelial cells as the MRA-responsive (CSA-producing) cells, and normal colony-forming unit granulocyte-macrophage (CFU-GM)-enriched bone marrow cells (T lymphocyte- and monocyte-depleted, low density bone marrow cells) as the CSA-responsive cells. MRA stimulated a 30-fold increase in CSA production by endothelial cells. MRA production was detected in supernatants from as few as 10(3) monocytes per milliliter, required the presence of fetal calf serum, and was inhibited by cycloheximide (10 to 100 micrograms/mL) and puromycin (10 to 50 micrograms/mL). Production was detectable after 24 hours of monocyte incubation, was maintained for three days, and fell to undetectable levels by seven days. With the addition of bacterial endotoxin (lipopolysaccharide [LPS]) (50 micrograms per 10(6) cells), MRA was detectable after only three hours of incubation, and levels peaked at 24 hours. Further, maximum MRA levels in the supernatants of LPS-stimulated monocytes were up to ten times greater than peak levels in the supernatants of unstimulated monocytes. Endotoxin augmented monocyte production of MRA to a greater extent than it did CSA production, indicating that the stimulation of CSA production by endotoxin may be at least partly indirect. The responsiveness of MRA production to endotoxin in vitro is consistent with the notion that MRA may be a biologically relevant regulator of CSA production by cells of the hematopoietic microenvironment.
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PMID:Monocyte-derived recruiting activity: kinetics of production and effects of endotoxin. 387 45

We describe the biologic characteristics of an activity produced by human monocyte-derived lipid-containing cells (MDLCCs) that enhances the colony-forming capacity of granulocyte-macrophage progenitors (CFU-GM). Medium conditioned by well-developed MDLCCs (at day 21 to day 28 of cultivation) was added to bone marrow cultures containing GCT cell line-conditioned medium (GCT-CM) or other material as a source of granulocyte-macrophage colony-stimulating factors (GM-CSFs). MDLCC-conditioned medium (CM) had no detectable granulocyte-macrophage colony-stimulating activity (GM-CSA), but it contained an activity that enhanced the colony number in both day 7 and day 14 CFU-GM cultures. Dose-response curves for GCT-CM in the presence of MDLCC-CM demonstrated that this enhancing effect occurred at concentrations of GM-CSFs that stimulate maximal CFU-GM growth. This enhancing effect was seen with both granulocytic and monocytic progenitor cells. It was titratible and required the continuous presence of MDLCC-CM from initiation of culture. No enhancement was noted when MDLCC-CM was added 48 hours after plating. The enhancement still occurred when marrow cells were first incubated with MDLCC-CM and GCT-CM was added at later times. Neither the enhancing activity nor its production was dependent on horse serum contained in MDLCC culture medium. The enhancing effect was also seen when other sources of GM-CSA were used: medium conditioned by 5637 cell line, phytohemagglutinin-stimulated lymphocytes (PHAL), or placenta tissue. Furthermore, this enhancing activity appeared to be specific for CFU-GM. Addition of MDLCC-CM to mixed and erythroid cultures, stimulated by suboptimal and optimal concentrations of PHAL-CM did not modify the number of mixed colonies or erythroid bursts. This granulomonopoietic enhancing activity contained in MDLCC-CM was heat stable (56 degrees C and 75 degrees C for 30 minutes) and nondialyzable (3,500 and 14,000 molecular weight cut off tubing). Its production was increased by treating MDLCC with lipopolysaccharide (5 micrograms/mL) or zymosan (60 micrograms/mL) and inhibited by lactoferrin (10(-7) mol/L). The production of a granulomonopoietic enhancing activity by MDLCCs represents the demonstration of another positive feedback regulator of myelopoiesis involving the monocyte-macrophage system.
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PMID:Biological characterization of a granulomonopoietic enhancing activity derived from cultured human lipid-containing macrophages. 387 61

The restoration of immune functions was followed in dogs for 101 days after fractionated total body irradiation and autologous transfusion of peripheral blood leukocytes (PBL) or bone marrow (BM) cells. Median numbers of 0.9 X 10(5) granulocyte-macrophage progenitor cells per kilogram of body weight were transferred in either group of recipients. The following parameters recovered more rapidly in PBL recipients as opposed to BM recipients: total blood lymphocyte, T- and B-cell counts, serum levels of immunoglobulins IgM and IgA, in vitro blastogenic responses after stimulation with concanavalin A and pokeweed mitogen, and in vitro plasma cell formation after polyclonal B-cell activation with pokeweed mitogen with or without lipopolysaccharide. No major differences were noted for the restoration of serum IgG levels. Circulating lymphocyte and T-cell numbers remained subnormal for more than three months in both groups, whereas B-cell numbers and serum levels of IgA continued to be depressed in BM recipients only. Thus, autologous PBL restored immune functions more rapidly than did BM. Transplantation of PBL, alone or in addition to autologous BM, might also shorten the period of immunodeficiency after cytoreduction in a variety of malignancies in man.
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PMID:Recovery of immune functions in dogs after total body irradiation and transplantation of autologous blood or bone marrow cells. 389 1


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