Upregulation of interleukin‐8 receptor in human polymorphonuclear neutrophils by formyl peptide and lipopolysaccharide

Manna, Sunil K.; Samanta, Abhishek

doi:10.1016/0014-5793(95)00525-e

Cited by 14 publications

(13 citation statements)

References 20 publications

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“…Neutrophils express the IL-8/GCP-2 receptor CXCR1 and the more promiscuous IL-8/GCP-2/Gro␣/NAP-2/ ENA-78 receptor CXCR2 (47). Previous studies of neutrophils using cLPS as the stimulus have found contrasting evidence of either cLPS-mediated up-regulation of IL-8 binding (27) or cLPSdriven protease-dependent shedding of these receptors (28,29). We observed little regulation of CXCR1 expression by TLR ligands, although this may have become evident over a longer time course, or in the presence of small numbers of monocytes.…”

Section: Discussionmentioning

confidence: 99%

“…Contradictory reports have shown that neutrophils respond to cLPS preparations with either an increase in 125 I-labeled IL-8 binding (27) or a protease-dependent shedding of the two major neutrophil chemokine receptors CXCR1 and CXCR2 (28,29). Using flow cytometry, we investigated the roles of TLR2 and TLR4 in mediating down-regulation of these receptors.…”

Section: Tlr-mediated Modulation Of Neutrophil Chemokine Receptor Expmentioning

confidence: 99%

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Selective Roles for Toll-Like Receptor (TLR)2 and TLR4 in the Regulation of Neutrophil Activation and Life Span

Sabroe

Prince

Jones

et al. 2003

The Journal of Immunology

305

290

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Neutrophil responses to commercial LPS, a dual Toll-like receptor (TLR)2 and TLR4 activator, are regulated by TLR expression, but are amplified by contaminating monocytes in routine cell preparations. Therefore, we investigated the individual roles of TLR2 and TLR4 in highly purified, monocyte-depleted neutrophil preparations, using selective ligands (TLR2, Pam3CysSerLys4 and Staphylococcus aureus peptidoglycan; TLR4, purified LPS). Activation of either TLR2 or TLR4 caused changes in adhesion molecule expression, respiratory burst (alone, and synergistically with fMLP), and IL-8 generation, which was, in part, dependent upon p38 mitogen-activated protein kinase signaling. Neutrophils also responded to Pam3CysSerLys4 and purified LPS with down-regulation of the chemokine receptor CXCR2 and, to a lesser extent, down-regulation of CXCR1. TLR4 was the principal regulator of neutrophil survival, and TLR2 signals showed relatively less efficacy in preventing constitutive apoptosis over short time courses. TLR4-mediated neutrophil survival depended upon signaling via NF-κB and mitogen-activated protein kinase cascades. Prolonged neutrophil survival required both TLR4 activation and the presence of monocytes. TLR4 activation of monocytes was associated with the release of neutrophil survival factors, which was not evident with TLR2 activation, and TLR2 activation in monocyte/neutrophil cocultures did not prevent late neutrophil apoptosis. Thus, TLRs are important regulators of neutrophil activation and survival, with distinct and separate roles for TLR2 and TLR4 in neutrophil responses. TLR4 signaling presents itself as a pharmacological target that may allow therapeutic modulation of neutrophil survival by direct and indirect mechanisms at sites of inflammation.

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Section: Discussionmentioning

confidence: 99%

Section: Tlr-mediated Modulation Of Neutrophil Chemokine Receptor Expmentioning

confidence: 99%

Selective Roles for Toll-Like Receptor (TLR)2 and TLR4 in the Regulation of Neutrophil Activation and Life Span

Sabroe

Prince

Jones

et al. 2003

The Journal of Immunology

305

290

View full text Add to dashboard Cite

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“…There have been several attempts to determine the molecular characteristics of IL-8R by cross-linking studies using radiolabeled ligands. These resulted in the detection of either a single surfaceexpressed molecule (27,28) or multiple variants diverging in molecular size (29,30). The only report providing some evidence for glycosylation of IL-8R (27) did not, however, discriminate between the different receptor types CXCR-1 and CXCR-2, which were only later shown to be coexpressed on neutrophils (31).…”

Section: Discussionmentioning

confidence: 99%

Identification of Distinct Surface-Expressed and Intracellular CXC-Chemokine Receptor 2 Glycoforms in Neutrophils:N-Glycosylation Is Essential for Maintenance of Receptor Surface Expression

Ludwig

Ehlert

Flad

et al. 2000

The Journal of Immunology

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The G protein-coupled CXC-chemokine receptor CXCR-2 mediates activation of neutrophil effector functions in response to multiple ligands, including IL-8 and neutrophil-activating peptide 2 (NAP-2). Although CXCR-2 has been successfully cloned and expressed in several cell lines, the molecular properties of the native neutrophil-expressed receptor have remained largely undefined. Here we report on the identification and characterization of distinct CXCR-2 glycoforms and their subcellular distribution in neutrophils. Immunoprecipitation and Western blot analyses of surface-expressed receptors covalently linked to IL-8 or NAP-2 as well as in their unloaded state revealed the occurrence of a single CXCR-2 variant with an apparent size of 56 kDa. According to deglycosylation experiments surface-expressed CXCR-2 carries two N-linked 9-kDa carbohydrate moieties that are both of complex structure. In addition, two other CXCR-2 variants of 38 and 40 kDa were found to occur exclusively intracellular and to carry N-glycosylations of high mannose or hybrid type. These receptors did not participate in ligand-induced receptor trafficking, while surface-expressed CXCR-2 was internalized and re-expressed following stimulation with NAP-2. By enzymatic removal of one 9-kDa carbohydrate moiety in surface-expressed CXCR-2 we can show that neither NAP-2-induced trafficking nor signaling of the receptor is dependent on its full glycosylation. Instead, glycosylation was found to protect CXCR-2 from proteolytic attack, as even partial deglycosylation is associated with serine protease-mediated disappearance of the receptor from the neutrophil surface. Thus, although not directly involved in signaling, glycosylation appears to be required to maintain neutrophil responsiveness to CXC-chemokines during inflammation.

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“…Polyclonal human anti-IL-8R antibody was raised in rabbits against 58 kDa receptor protein of human neutrophils, and the anti-IL-8R antibody was characterized by 60-70% binding inhibition of [125I]IL-8 to neutrophils and also by Western blotting analysis [15].…”

Section: Methodsmentioning

confidence: 99%

Dansyl cadaverine regulates ligand induced endocytosis of interleukin‐8 receptor in human polymorphonuclear neutrophils

Ray

Samanta

1996

FEBS Letters

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Interleukin-8 (IL-8), a neutrophil chemotactic agent, acts as a key mediator in a large number of acute and chronic inflammatory diseases. At 37°C, the receptor for IL-8 is rapidly internalized with its ligand. But no specific inhibitor of this ligand induced internalization of the receptor has been reported so far. We have found that monodansyl cadaverine (MDC) inhibited about 70% of IL-8 induced endocytosis and caused 70% and 66% inhibition of IL-8 mediated chemotaxis and respiratory burst response, respectively, in neutrophils. The uninternalized receptor was detected by anti IL-8R antibody in MDC treated cells. The endocytosis of IL-8R was strongly inhibited under Ca 2÷ depleted conditions which was restored on addition of 1 mM CaCI 2 indicating the critical involvement of a Ca 2+ ion in the process. Absence of receptor internalisation makes the MDC treated neutrophils suitable for studying the interaction of IL-8R with potential therapeutic agents e.g. for in vitro screening of anti-inflammatory agents.

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Upregulation of interleukin‐8 receptor in human polymorphonuclear neutrophils by formyl peptide and lipopolysaccharide

Cited by 14 publications

References 20 publications

Selective Roles for Toll-Like Receptor (TLR)2 and TLR4 in the Regulation of Neutrophil Activation and Life Span

Selective Roles for Toll-Like Receptor (TLR)2 and TLR4 in the Regulation of Neutrophil Activation and Life Span

Identification of Distinct Surface-Expressed and Intracellular CXC-Chemokine Receptor 2 Glycoforms in Neutrophils:N-Glycosylation Is Essential for Maintenance of Receptor Surface Expression

Dansyl cadaverine regulates ligand induced endocytosis of interleukin‐8 receptor in human polymorphonuclear neutrophils

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