Determination of the monomer-dimer equilibrium of interleukin-8 reveals it is a monomer at physiological concentrations

Burrows, Stephen D.; Doyle, Michael L.; Murphy, Kenneth P.; Franklin, Samuel G.; White, John R.; Brooks, Ian; McNulty, Dean E.; Scott, Miller; Knutson, Jay R.; Porter, Denise; Young, Peter R.; Hensley, Preston

doi:10.1021/bi00209a002

Cited by 155 publications

(128 citation statements)

References 33 publications

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“…This IL-8 is biologically active and is present in the dimeric and monomeric forms in culture medium. It has been demonstrated that an equilibrium between the dimeric and monomeric forms of IL-8 exists [41,42]. We assume that dimerization has occurred in the culture medium, presumably after the production of monomeric IL-8 by PTEC, as shown by gel filtration.…”

Section: Discussionmentioning

confidence: 93%

Regulation and production of IL-8 by human proximal tubular epithelial cells in vitro

Gerritsma¹,

Hiemstra

Gerritsen³

et al. 1996

Clinical and Experimental Immunology

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SUMMARYA number of inflammatory kidney diseases are associated with interstitial nephritis and influx of leucocytes in the renal interstitium. Potentially the influx of neutrophils in the interstitium may be induced by the chemotactic cytokine IL-8. In the present study we have analysed the production of IL-8 by cultured human proximal tubular epithelial cells (PTEC) in response to a number of proinflammatory cytokines. Primary cell lines of proximal tubular epithelium obtained from ten different kidneys, and cultured under serum-free conditions, were found to produce IL-8 to different degrees from not detectable levels up to 10

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Section: Discussionmentioning

confidence: 93%

Regulation and production of IL-8 by human proximal tubular epithelial cells in vitro

Gerritsma¹,

Hiemstra

Gerritsen³

et al. 1996

Clinical and Experimental Immunology

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“…7,9 As CXCL8 is secreted at high concentrations from injured or cancerous tissues, its local concentration can vary significantly, leading to the existence of both the monomeric and dimeric forms at different locations and over time. 10,11 This differential distribution of the CXCL8 dimeric and monomeric forms may suggest an important role for each of them in the functional activity of this chemokine. For example, one may hypothesise that the formation of CXCL8 dimers at high concentrations may diminish the binding affinity of CXCL8 to its receptors, and thereby serve as a control mechanism to downregulate signaling.…”

Section: Introductionmentioning

confidence: 97%

“…1,2 CXC chemokines are small proteins (8)(9)(10)(11)(12) kDa) that contain a conserved CXC residue motif (C-cysteine, X-any other residue) proximal to the N-terminal region of the protein. 3 Solution and solid-state structures of several human CXC chemokines have been solved, revealing a common tertiary fold for all members of the family consisting of an unstructured N-terminal loop, antiparellel b-strands and a C-terminal a-helix.…”

Section: Introductionmentioning

confidence: 99%

The dynamics of interleukin‐8 and its interaction with human CXC receptor I peptide

et al. 2014

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Interleukin-8 (CXCL8, IL-8) is a proinflammatory chemokine important for the regulation of inflammatory and immune responses via its interaction with G-protein coupled receptors, including CXC receptor 1 (CXCR1). CXCL8 exists as both a monomer and as a dimer at physiological concentrations, yet the molecular basis of CXCL8 interaction with its receptor as well as the importance of CXCL8 dimer formation remain poorly characterized. Although several biological studies have indicated that both the CXCL8 monomer and dimer are active, biophysical studies have reported conflicting results regarding the binding of CXCL8 to CXCR1. To clarify this problem, we expressed and purified a peptide (hCXCR1pep) corresponding to the N-terminal region of human CXCR1 (hCXCR1) and utilized nuclear magnetic resonance (NMR) spectroscopy to interrogate the binding of wild-type CXCL8 and a previously reported mutant (CXCL8M) that stabilizes the monomeric form. Our data reveal that the CXCL8 monomer engages hCXCR1pep with a slightly higher affinity than the CXCL8 dimer, but that the CXCL8 dimer does not dissociate upon binding hCXCR1pep. These investigations also showed that CXCL8 is dynamic on multiple timescales, which may help explain the versatility in this interleukin for engaging its target receptors.

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“…IL-8 has been shown to exist and function both as a monomer and dimer (10)(11)(12). The monomer binds to the N-terminal domain of CXCR1 with higher affinity than the dimer (13)(14)(15), and is believed to be the biologically active form of the protein.…”

Section: Introductionmentioning

confidence: 99%

Interaction of Monomeric Interleukin-8 with CXCR1 Mapped by Proton-Detected Fast MAS Solid-State NMR

Park

Berkamp

Radoicic

et al. 2017

Biophysical Journal

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The human chemokine interleukin-8 (IL-8; CXCL8) is a key mediator of innate immune and inflammatory responses. This small, soluble protein triggers a host of biological effects upon binding and activating CXCR1, a G proteincoupled receptor, located in the cell membrane of neutrophils. Here, we describe 1 H-detected magic angle spinning solid-state NMR studies of monomeric IL-8 (1-66) bound to full-length and truncated constructs of CXCR1 in phospholipid bilayers under physiological conditions. Cross-polarization experiments demonstrate that most backbone amide sites of IL-8 (1-66) are immobilized and that their chemical shifts are perturbed upon binding to CXCR1, demonstrating that the dynamics and environments of chemokine residues are affected by interactions with the chemokine receptor. Comparisons of spectra of IL-8 (1-66) bound to full-length CXCR1 (1-350) and to N-terminal truncated construct NT-CXCR1 (39-350) identify specific chemokine residues involved in interactions with binding sites associated with N-terminal residues (binding site-I) and extracellular loop and helical residues (binding site-II) of the receptor. Intermolecular paramagnetic relaxation enhancement broadening of IL-8 (1-66) signals results from interactions of the chemokine with CXCR1 (1-350) containing Mn 2þ chelated to an unnatural amino acid assists in the characterization of the receptor-bound form of the chemokine.

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Determination of the monomer-dimer equilibrium of interleukin-8 reveals it is a monomer at physiological concentrations

Cited by 155 publications

References 33 publications

Regulation and production of IL-8 by human proximal tubular epithelial cells in vitro

Regulation and production of IL-8 by human proximal tubular epithelial cells in vitro

The dynamics of interleukin‐8 and its interaction with human CXC receptor I peptide

Interaction of Monomeric Interleukin-8 with CXCR1 Mapped by Proton-Detected Fast MAS Solid-State NMR

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