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- Persson Skare, Tor, et al.
(författare)
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Quartz Crystal Microbalance Measurement of Histidine-Rich Glycoprotein and Stanniocalcin-2 Binding to Each Other and to Inflammatory Cells
- 2022
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Ingår i: Cells. - : MDPI. - 2073-4409. ; 11:17
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Tidskriftsartikel (refereegranskat)abstract
- The plasma protein histidine-rich glycoprotein (HRG) is implicated in the polarization of macrophages to an M1 antitumoral phenotype. The broadly expressed secreted protein stanniocalcin 2 (STC2), also implicated in tumor inflammation, is an HRG interaction partner. With the aim to biochemically characterize the HRG and STC2 complex, binding of recombinant HRG and STC2 preparations to each other and to cells was explored using the quartz crystal microbalance (QCM) methodology. The functionality of recombinant proteins was tested in a phagocytosis assay, where HRG increased phagocytosis by monocytic U937 cells while STC2 suppressed HRG-induced phagocytosis. The binding of HRG to STC2, measured using QCM, showed an affinity between the proteins in the nanomolar range, and both HRG and STC2 bound individually and in combination to vitamin D3-treated, differentiated U937 monocytes. HRG, but not STC2, also bound to formaldehyde-fixed U937 cells irrespective of their differentiation stage in part through the interaction with heparan sulfate. These data show that HRG and STC2 bind to each other as well as to U937 monocytes with high affinity, supporting the relevance of these interactions in monocyte/macrophage polarity.
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| 3. |
- Roche, Francis P., et al.
(författare)
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Leukocyte differentiation by histidine-rich glycoprotein/stanniocalcin-2 complex regulates murine glioma growth through modulation of anti-tumor immunity
- 2018
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Ingår i: Molecular Cancer Therapeutics. - 1535-7163 .- 1538-8514. ; 17:9, s. 1961-1972
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Tidskriftsartikel (refereegranskat)abstract
- The plasma-protein histidine-rich glycoprotein (HRG) is implicated in phenotypic switching of tumor-associated macrophages, regulating cytokine production and phagocytotic activity, thereby promoting vessel normalization and anti-tumor immune responses. To assess the therapeutic effect of HRG gene delivery on CNS tumors, we used adenovirus-encoded HRG to treat mouse intracranial GL261 glioma. Delivery of Ad5-HRG to the tumor site resulted in a significant reduction in glioma growth, associated with increased vessel perfusion and increased CD45+ leukocyte and CD8+ T cell accumulation in the tumor. Antibody-mediated neutralization of colony-stimulating factor-1 suppressed the effects of HRG on CD45+ and CD8+ infiltration. Using a novel protein interaction-decoding technology, TRICEPS-based ligand receptor capture (LRC), we identified Stanniocalcin-2 (STC2) as an interacting partner of HRG on the surface of inflammatory cells in vitro and co-localization of HRG and STC2 in gliomas. HRG reduced the suppressive effects of STC2 on monocyte CD14+ differentiation and STC2-regulated immune response pathways. In consequence, Ad5-HRG treated gliomas displayed decreased numbers of Interleukin-35+ Treg cells, providing a mechanistic rationale for the reduction in GL261 growth in response to Ad5-HRG delivery. We conclude that HRG suppresses glioma growth by modulating tumor inflammation through monocyte infiltration and differentiation. Moreover, HRG acts to balance the regulatory effects of its partner, STC2, on inflammation and innate and/or acquired immunity. HRG gene delivery therefore offers a potential therapeutic strategy to control anti-tumor immunity.
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| 4. |
- Tor, Persson Skare, et al.
(författare)
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Histidine-rich glycoprotein and stanniocalcin-2 high affinity interactions with inflammatory cells
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- AbstractThe plasma protein Histidine-rich protein (HRG), is implicated in macrophage polarization to an M1 antitumoral phenotype. The broadly expressed, secreted protein Stanniocalcin 2 (STC2), also implicated in tumor inflammation, is an HRG interaction partner. To assess the effects of HRG and STC2 on inflammation in a biologically relevant model, binding of recombinant HRG and STC2 preparations to each other and to cells was explored using quartz crystal microbalance (QCM) methodology. Protein functionality was tested in a phagocytosis assay. Stimulation with HRG increased phagocytosis in U937 cells while STC2 suppressed HRG-induced phagocytosis. Binding of HRG to STC2 measured using QCM showed an affinity in the nanomolar range and occurred in a conformation-dependent manner. Both HRG and STC2 bound individually and in combination to monocytic U937 cells with higher efficiency after vitamin D3-induced differentiation. HRG, but not STC2, also bound to formaldehyde-fixed U937 cells irrespective of differentiation stage, potentially through heparan sulphate. These data show that binding of HRG to STC2 is specific and conformation-dependent, and HRG and STC2 bind to separate sites on U937 cells, suggesting that they exert their effects through distinct cell surface entities.
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