Effects of lipopolysaccharide on macrophages analyzed with anti‐lipid A monoclonal antibodies and polymyxin B

Lasfargues, A.; Tahri-Jouti, Mohamed-Ali; Pédron, Thierry; Girard, Robert; Chaby, Richard

doi:10.1002/eji.1830191207

Cited by 24 publications

(7 citation statements)

References 35 publications

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“…Therefore, to determine whether LPS was involved in TNF-α production, we conducted inhibition studies using PMB. PMB binds to the lipid A component of the LPS molecule, thereby preventing its interaction with its receptor and thus inhibiting TNF-α production (Lasfargues et al, 1989). Treatment with PMB at concentrations of 5, 50 and 100 µg ml −" prior to infection of macrophages reduced TNF-α production by 50, 75 and 85 %, respectively.…”

Section: Bacterial Infection Causes Activation Of Macrophagesmentioning

confidence: 99%

Intracellular survival of Burkholderia cepacia complex isolates in the presence of macrophage cell activation

et al. 1999

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Strains of the Burkholderia cepacia complex have emerged as a serious threat to patients with cystic fibrosis due to their ability to infect the lung and cause, in some patients, a necrotizing pneumonia that is often lethal. It has recently been shown that several strains of the B. cepacia complex can escape intracellular killing by free-living amoebae following phagocytosis. In this work, the ability of two B. cepacia complex strains to resist killing by macrophages was explored. Using fluorescence microscopy, electron microscopy and a modified version of the gentamicin-protection assay, we demonstrate that B. cepacia CEP021 (genomovar VI), and Burkholderia vietnamiensis (previously B. cepacia genomovar V) CEP040 can survive in PU5-1.8 murine macrophages for a period of at least 5 d without significant bacterial replication. Furthermore, bacterial entry into macrophages stimulated production of tumour necrosis factor and primed them to release toxic oxygen radicals following treatment with phorbol myristoyl acetate. These effects were probably caused by bacterial LPS, as they were blocked by polymyxin B. Infected macrophages primed with interferon gamma produced less nitric oxide than interferon-gamma-primed uninfected cells. We propose that the ability of B. cepacia to resist intracellular killing by phagocytic cells may play a role in the pathogenesis of cystic fibrosis lung infection. Our data are consistent with a model where repeated cycles of phagocytosis and cellular activation without bacterial killing may promote a deleterious inflammatory response causing tissue destruction and decay of lung function.

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Section: Bacterial Infection Causes Activation Of Macrophagesmentioning

confidence: 99%

Intracellular survival of Burkholderia cepacia complex isolates in the presence of macrophage cell activation

et al. 1999

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“…However, inhibition of in vitro LPS reactions does not necessarily establish the potential of an LPS-binding reagent to neutralize in vivo biological activity (18,44); furthermore, there is not a compulsory relationship between binding to lipid A and neutralization of the in vitro or the in vivo activity of the molecule (44,74). Differences in the neutralization characteristics of the various anti-LPS reagents may be due to affinity specificity for discrete and separate lipid A epitopes or substructures (28,66) which provide distinct binding sites associated with specific lipid A-evoked responses (15,45). The data from our study demonstrate that the LPS-binding characteristics of CAP37 P 20-44 meet the criteria required to provide effective neutralization of the in vivo responses evoked by endotoxin.…”

Section: Discussionmentioning

confidence: 99%

A synthetic lipopolysaccharide-binding peptide based on the neutrophil-derived protein CAP37 prevents endotoxin-induced responses in conscious rats

et al. 1997

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The lipid A component of lipopolysaccharide (LPS) derived from Escherichia coli has been implicated as a significant mediator in the development of circulatory and metabolic dysfunction and lethality associated with sepsis. A synthetic peptide corresponding to amino acid residues 20 through 44 of the neutrophil-derived 37-kDa cationic antimicrobial protein (CAP37 P 20-44) possesses lipid A binding characteristics which may be useful in attenuating in vivo responses induced during circumstances of endotoxemia, including sepsis. The E. coli LPS to be used in the in vivo study was shown to be attenuated by CAP37 P 20-44 in a dose-dependent manner in the in vitro reaction with Limulus amoebocyte lysate. Intravenous infusion of CAP37 P 20-44 (1.5 or 3.0 mg/kg of body weight) with E. coli LPS (250 g/kg over 30 min) into conscious, unrestrained rats prevented LPS-induced hyperdynamic and hypodynamic circulatory shock, hyperlactacidemia, and leukopenia in a dose-related fashion. CAP37 P 20-44 (0.2, 1.0, and 5.0 mg/kg) administered intravenously to conscious, actinomycin D-sensitized rats following a lethal dose of LPS neutralized LPS toxicity, resulting in dose-dependent 7-day survival rates of 30, 50, and 80%, respectively. CAP37 P 20-44 (5.0 mg/kg) significantly inhibited the endotoxin-induced increase in circulating tumor necrosis factor alpha in sensitized rats. These data demonstrate that CAP37 P 20-44 has the capacity to abolish in vivo biological responses to LPS that are relevant to human sepsis and to significantly neutralize the toxicity of circulating E. coli LPS.

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“…The addition of PmB to culture media in in vitro studies to block the effects of possible LPS contamination has been questioned for a long time [13,16]. Of particular con cern has been its reported capacity to induce cells to pro duce interleukin 1 [17].…”

Section: Discussionmentioning

confidence: 99%

“…the hemodynamic effects [8] or lethality [9]. Because LPS is a potent activator of B cells and macrophages, PmB is also commonly used in immu nological studies to block untoward effects resulting from possible LPS contamination of media or cultures [10][11][12], However, this use has now become questionable since conflicting results have been reported on the capacity of PmB to neutralize LPS contamination [13][14][15][16] and because it was recently shown that PmB has the ability to activate certain lytic effector cells [16,17]. Finally, other properties of PmB include inhibition of the complement system 118], inhibition of phosphorylase kinase activity [19], and inhibi tion of cell 'activators' such as phorbol ester [20], The lat ter effect has been related to its ability to block protein ki nase C [21], We have also used PmB in in vitro immunolog ical studies to verify that effects seen after the addition of certain agents to cell culture were not due to LPS contam ination of media and/or reagents [12,22], In some cases the agents were removed prior to the addition of the target tu mor cells; in other cases, however, the agents (including PmB) and tumor target cells were present in the cultures at the same time.…”

Section: Introductionmentioning

confidence: 99%

Polymyxin B-Mediated Lysis of Tumor Cells

Verstovšek

Maccubbin

Ehrke

et al. 1993

Int Arch Allergy Immunol

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Polymyxin B (PmB) in the concentration range of 10–50 μg/ml is used routinely in immunological studies to neutralize low levels of contaminating lipopolysaccharide (LPS) in media or reagents. While using PmB for such a purpose unexpected results were obtained, which led to the finding that low levels of PmB are cytotoxic to certain tumor cells. Further examination of a panel of 10 tumor cell lines revealed that in an 18-hour ⁵¹Cr release assay, EL4 cells and EL4/ADM cells were very sensitive (lysed by ≥ 10 μg PmB/ml), C1498 cells and REH cells were moderately sensitive (lysed by ≥ 20 μg PmB/ml) and cells of the remaining 6 lines were resistant (lysed only by 100 μg/ml) to PmB. A similar pattern of sensitivity was observed when ³H-thymidine incorporation was used as a measure of PmB effects in cell proliferation. The PmB concentration needed to kill 50% of the tumor cells in a suspension differed greatly among lines; thus for cells of a resistant line 8-fold more PmB was required for 50% killing than for those of a sensitive line. PmB toxicity toward EL4 cells was shown to increase to a plateau level with increasing time of exposure; however, the higher the concentration the earlier the plateau was reached. LPS may prevent PmB toxic effects since PmB binds to the lipid A portion of the LPS molecule, but 100 μg LPS/ml was only able to reduce the toxicity of 10 and 20 μg PmB/ml, and not that of 50 or 100 μg PmB/ml. Based on these findings, it is clear that PmB should be used cautiously in in vitro systems.

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Effects of lipopolysaccharide on macrophages analyzed with anti‐lipid A monoclonal antibodies and polymyxin B

Cited by 24 publications

References 35 publications

Intracellular survival of Burkholderia cepacia complex isolates in the presence of macrophage cell activation

Intracellular survival of Burkholderia cepacia complex isolates in the presence of macrophage cell activation

A synthetic lipopolysaccharide-binding peptide based on the neutrophil-derived protein CAP37 prevents endotoxin-induced responses in conscious rats

Polymyxin B-Mediated Lysis of Tumor Cells

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