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Johnstone B, Gu D, Sinn A, Pollok K, Woods E. Hematopoietic Stem/Progenitor Cells and Engineering: HUMAN HEMATOPOIETIC STEM CELLS MAINTAIN POTENCY FOLLOWING REPETITIVE CRYOPRESERVATION. Cytotherapy 2022. [DOI: 10.1016/s1465-3249(22)00287-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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2
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Martignier A, Pacton M, Filella M, Jaquet JM, Barja F, Pollok K, Langenhorst F, Lavigne S, Guagliardo P, Kilburn MR, Thomas C, Martini R, Ariztegui D. Intracellular amorphous carbonates uncover a new biomineralization process in eukaryotes. Geobiology 2017; 15:240-253. [PMID: 27696636 DOI: 10.1111/gbi.12213] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 08/25/2016] [Indexed: 06/06/2023]
Abstract
Until now, descriptions of intracellular biomineralization of amorphous inclusions involving alkaline-earth metal (AEM) carbonates other than calcium have been confined exclusively to cyanobacteria (Couradeau et al., 2012). Here, we report the first evidence of the presence of intracellular amorphous granules of AEM carbonates (calcium, strontium, and barium) in unicellular eukaryotes. These inclusions, which we have named micropearls, show concentric and oscillatory zoning on a nanometric scale. They are widespread in certain eukaryote phytoplankters of Lake Geneva (Switzerland) and represent a previously unknown type of non-skeletal biomineralization, revealing an unexpected pathway in the geochemical cycle of AEMs. We have identified Tetraselmis cf. cordiformis (Chlorophyta, Prasinophyceae) as being responsible for the formation of one micropearl type containing strontium ([Ca,Sr]CO3 ), which we also found in a cultured strain of Tetraselmis cordiformis. A different flagellated eukaryotic cell forms barium-rich micropearls [(Ca,Ba)CO3 ]. The strontium and barium concentrations of both micropearl types are extremely high compared with the undersaturated water of Lake Geneva (the Ba/Ca ratio of the micropearls is up to 800,000 times higher than in the water). This can only be explained by a high biological pre-concentration of these elements. The particular characteristics of the micropearls, along with the presence of organic sulfur-containing compounds-associated with and surrounding the micropearls-strongly suggest the existence of a yet-unreported intracellular biomineralization pathway in eukaryotic micro-organisms.
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Affiliation(s)
- A Martignier
- Department of Earth Sciences, University of Geneva, Geneva, Switzerland
| | - M Pacton
- Laboratoire de Géologie de Lyon, Lyon 1 University, Villeurbanne, France
| | - M Filella
- Institute F.-A. Forel, University of Geneva, Geneva, Switzerland
| | - J-M Jaquet
- Department of Earth Sciences, University of Geneva, Geneva, Switzerland
| | - F Barja
- Microbiology unit, University of Geneva, Geneva, Switzerland
| | - K Pollok
- Institute of Geosciences, Friedrich Schiller University Jena, Jena, Germany
| | - F Langenhorst
- Institute of Geosciences, Friedrich Schiller University Jena, Jena, Germany
| | - S Lavigne
- Service de l'Ecologie de l'Eau (SECOE), Geneva, Switzerland
| | - P Guagliardo
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, WA, Australia
| | - M R Kilburn
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, WA, Australia
| | - C Thomas
- CARRTEL of Thonon-les-Bains, INRA, Thonon-les-Bains, France
| | - R Martini
- Department of Earth Sciences, University of Geneva, Geneva, Switzerland
| | - D Ariztegui
- Department of Earth Sciences, University of Geneva, Geneva, Switzerland
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Carter J, Cheng L, Zucker J, Marshall M, Pollok K, Murray M, Li L, Renbarger J. Use of Precision Medicine Molecular Profiling of Baseline Tumor Specimen May Not Benefit Outcomes in Children With Relapsed or Refractory Pediatric Sarcomas. Clin Pharmacol Ther 2016; 101:328-330. [PMID: 28001289 DOI: 10.1002/cpt.599] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 12/13/2016] [Accepted: 12/13/2016] [Indexed: 11/10/2022]
Affiliation(s)
- J Carter
- Section of Hematology/Oncology, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - L Cheng
- Section of Medical and Molecular Genetics, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - J Zucker
- Section of Hematology/Oncology, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - M Marshall
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - K Pollok
- Section of Hematology/Oncology, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - M Murray
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - L Li
- Section of Medical and Molecular Genetics, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - J Renbarger
- Section of Hematology/Oncology, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA
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Schäffner F, Merten D, Pollok K, Wagner S, Knoblauch S, Langenhorst F, Büchel G. Fast formation of supergene Mn oxides/hydroxides under acidic conditions in the oxic/anoxic transition zone of a shallow aquifer. Environ Sci Pollut Res Int 2015; 22:19362-19375. [PMID: 25822842 DOI: 10.1007/s11356-015-4404-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 03/18/2015] [Indexed: 06/04/2023]
Abstract
Extensive uranium mining in the former German Democratic Republic (GDR) in eastern Thuringia and Saxony took place during the period of 1946-1990. During mining activities, pelitic sediments rich in organic carbon and uranium were processed and exposed to oxygen. Subsequent pyrite oxidation and acidic leaching lead to partial contamination of the area with heavy metals and acid mine drainage (AMD) even few years after completion of remediation. One of those areas is the former heap Gessen (Ronneburg, Germany) were the residual contamination can be found 10 m under the base of the former heap containing partly permeable drainage channels. Actually, in such a system, a rapid but locally restricted mineralization of Mn oxides takes place under acidic conditions. This formation can be classified as a natural attenuation process as certain heavy metals, e.g., Cd (up to 6 μg/g), Ni (up to 311 μg/g), Co (up to 133 μg/g), and Zn (up to 104 μg/g) are bound to this phases. The secondary minerals occur as colored layers close to the shallow aquifer in glacial sediments and could be identified as birnessite and todorokite as Mn phase. The thermodynamic model shows that even small changes in the system are sufficient to shift either the pH or the Eh in the direction of stable Mn oxide phases in this acidic system. As a consequence of 9-15-year-long formation process (or even less), the supergene mineralization provides a cost-efficient contribution for remediation (natural attenuation) strategies of residual with heavy metals (e.g., Cd, Co, Ni, Zn) contaminated substrates.
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Affiliation(s)
- F Schäffner
- Applied Geology, Institute of Geosciences, Friedrich Schiller University, Burgweg 11, 07749, Jena, Germany.
| | - D Merten
- Applied Geology, Institute of Geosciences, Friedrich Schiller University, Burgweg 11, 07749, Jena, Germany
| | - K Pollok
- Analytical Mineralogy, Institute of Geosciences, Friedrich Schiller University, Burgweg 11, 07749, Jena, Germany
| | - S Wagner
- Applied Geology, Institute of Geosciences, Friedrich Schiller University, Burgweg 11, 07749, Jena, Germany
| | - S Knoblauch
- Thuringian Central Authority for Agriculture, Naumburgerstr. 98, 07743, Jena, Germany
| | - F Langenhorst
- Analytical Mineralogy, Institute of Geosciences, Friedrich Schiller University, Burgweg 11, 07749, Jena, Germany
| | - G Büchel
- Applied Geology, Institute of Geosciences, Friedrich Schiller University, Burgweg 11, 07749, Jena, Germany
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5
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Huang W, Dong Z, Chen Y, Wang F, Wang CJ, Peng H, He Y, Hangoc G, Pollok K, Sandusky G, Fu XY, Broxmeyer HE, Zhang ZY, Liu JY, Zhang JT. Small-molecule inhibitors targeting the DNA-binding domain of STAT3 suppress tumor growth, metastasis and STAT3 target gene expression in vivo. Oncogene 2015; 35:783-92. [PMID: 26073084 DOI: 10.1038/onc.2015.215] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 04/26/2015] [Accepted: 05/10/2015] [Indexed: 12/30/2022]
Abstract
Signal transducer and activator of transcription 3 (STAT3) is constitutively activated in malignant tumors and has important roles in multiple aspects of cancer aggressiveness. Thus targeting STAT3 promises to be an attractive strategy for treatment of advanced metastatic tumors. Although many STAT3 inhibitors targeting the SH2 domain have been reported, few have moved into clinical trials. Targeting the DNA-binding domain (DBD) of STAT3, however, has been avoided due to its 'undruggable' nature and potentially limited selectivity. In a previous study, we reported an improved in silico approach targeting the DBD of STAT3 that resulted in a small-molecule STAT3 inhibitor (inS3-54). Further studies, however, showed that inS3-54 has off-target effect although it is selective to STAT3 over STAT1. In this study, we describe an extensive structure and activity-guided hit optimization and mechanistic characterization effort, which led to identification of an improved lead compound (inS3-54A18) with increased specificity and pharmacological properties. InS3-54A18 not only binds directly to the DBD and inhibits the DNA-binding activity of STAT3 both in vitro and in situ but also effectively inhibits the constitutive and interleukin-6-stimulated expression of STAT3 downstream target genes. InS3-54A18 is completely soluble in an oral formulation and effectively inhibits lung xenograft tumor growth and metastasis with little adverse effect on animals. Thus inS3-54A18 may serve as a potential candidate for further development as anticancer therapeutics targeting the DBD of human STAT3 and DBD of transcription factors may not be 'undruggable' as previously thought.
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Affiliation(s)
- W Huang
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Z Dong
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Y Chen
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - F Wang
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - C J Wang
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - H Peng
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Y He
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - G Hangoc
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - K Pollok
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA.,IU Simon Cancer Center, Indiana University School of Medicine, Indianapolis, IN, USA
| | - G Sandusky
- IU Simon Cancer Center, Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Pathology and Molecular Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - X-Y Fu
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, USA.,IU Simon Cancer Center, Indiana University School of Medicine, Indianapolis, IN, USA
| | - H E Broxmeyer
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, USA.,IU Simon Cancer Center, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Z-Y Zhang
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA.,IU Simon Cancer Center, Indiana University School of Medicine, Indianapolis, IN, USA
| | - J-Y Liu
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Computer and Information Science, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - J-T Zhang
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA.,IU Simon Cancer Center, Indiana University School of Medicine, Indianapolis, IN, USA
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Kania K, Pollok K, Gelbert L, Shannon H, Bailey B, Batuello C. ET-25 * THERAPEUTIC MODULATION OF MDM2 IN NEUROBLASTOMA. Neuro Oncol 2014. [DOI: 10.1093/neuonc/nou255.25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Qui NV, Scholz P, Keller TF, Pollok K, Ondruschka B. Ozonated Multiwalled Carbon Nanotubes as Highly Active and Selective Catalyst in the Oxidative Dehydrogenation of Ethyl Benzene to Styrene. Chem Eng Technol 2013. [DOI: 10.1002/ceat.201200354] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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8
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Khawaja MR, Younger A, Funke JM, Waddell MJ, Jones DR, Pollok K, Prasad NK, Berry W, Sandusky G, Chiorean EG. Phase I study of everolimus (RAD001) and AMG 479 in patients (pts) with advanced solid tumors and colorectal cancer (CRC). J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.tps157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Nigrovski B, Scholz P, Krech T, Qui N, Pollok K, Keller T, Ondruschka B. The influence of microwave heating on the texture and catalytic properties of oxidized multi-walled carbon nanotubes. CATAL COMMUN 2009. [DOI: 10.1016/j.catcom.2009.03.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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10
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Zavyalova U, Pollok K, Langenhorst F, Scholz P, Ondruschka B. Combustion Synthesized Nanocrystalline Mixed Oxide Catalysts for Elimination of Volatile Organic Compounds. CHEM-ING-TECH 2007. [DOI: 10.1002/cite.200750337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Dardalhon V, Noraz N, Pollok K, Rebouissou C, Boyer M, Bakker AQ, Spits H, Taylor N. Green fluorescent protein as a selectable marker of fibronectin-facilitated retroviral gene transfer in primary human T lymphocytes. Hum Gene Ther 1999; 10:5-14. [PMID: 10022526 DOI: 10.1089/10430349950019147] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The success of gene therapy strategies for congenital and acquired blood disorders requires high levels of gene transfer into hematopoietic cells. Retroviral vectors have been extensively used to deliver foreign genes to mammalian cells and improvement of transduction protocols remains dependent on markers that can be rapidly monitored and used for efficient selection of transduced cells. The enhanced green fluorescent protein (EGFP) is a suitable reporter molecule for gene expression because of its lack of cytotoxicity and stable fluorescence signal that can be readily detected by flow cytometry. However, attempts to adapt the GFP system to stable transduction of human lymphocytes have not been satisfactory. In this article, transductions of primary human T lymphocytes were performed using cell-free supernatants from a PG13 packaging cell line in which a retroviral vector expressing EGFP was pseudotyped with the gibbon ape leukemia virus (GALV) envelope. Using this system combined with a fibronectin-facilitated protocol, primary lymphocytes were transduced with a mean gene transfer efficiency of 27.5% following a 2-day stimulation with either PHA or anti-CD3/CD28 antibodies. Conditions that increased the entry of lymphocytes into cell cycle did not consistently correlate with enhanced gene transfer, indicating that factors other than proliferation are important for optimal retroviral gene transfer. These results demonstrate the utility of EGFP as a marker for human T cell transduction and will enable further optimization of T cell gene therapy protocols.
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Affiliation(s)
- V Dardalhon
- Institut de Génétique Moléculaire de Montpellier, Université Montpellier II, France
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12
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Lucas KG, Burton R, Heilman DK, Pollok K, Emanuel D. Cord blood mononuclear cell transformation assay for screening for the presence of Epstein-Barr virus. J Hematother 1997; 6:587-90. [PMID: 9483194 DOI: 10.1089/scd.1.1997.6.587] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
EBV-induced lymphoproliferative disease (EBV-LPD) is a serious and potentially fatal complication following stem cell transplantation. Strategies have been developed for the cultivation of donor-derived, EBV-specific cytotoxic T lymphocytes (CTL) for stem cell transplant (SCT) patients affected with these disorders, using donor-derived, EBV-transformed B lymphoblastoid cell lines (BLCL) as stimulators. Although cultivation of EBV-transformed BLCL is possible without using an exogenous source of EBV, transformation of autologous B cells with endogenous virus may be slow and inconsistent. Therefore, if exogenous strains of EBV are used to generate BLCL, it may be beneficial to patients to ensure that these cell lines are not producing virus that potentially could be conveyed at the time of CTL infusion. A reliable method of screening for EBV using a cord blood transformation assay has been developed and is described.
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Affiliation(s)
- K G Lucas
- Bone Marrow Transplantation Program, University of Alabama, Birmingham, USA
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Zhou Z, Kim YJ, Pollok K, Hurtado J, Lee JK, Broxmeyer HE, Kwon BS. Macrophage inflammatory protein-1 alpha rapidly modulates its receptors and inhibits the anti-CD3 mAb-mediated proliferation of T lymphocytes. J Immunol 1993; 151:4333-41. [PMID: 8409405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Macrophage inflammatory protein-1 alpha (MIP-1 alpha) is a member of the intercrine/chemokine family which consists of basic, heparin-binding, small molecular weight proteins. We have previously shown that a T cell line, CTLL-R8, carried high-affinity receptors for MIP-1 alpha and the proliferation of CTLL-R8 cells was inhibited by murine recombinant (mr) MIP-1 alpha. We extended our previous studies to murine resting splenic T lymphocytes to determine whether the inhibition of T cell proliferation is a general property of MIP-1 alpha. The resting splenic T cells carried approximately 680 high-affinity binding sites for mrMIP-1 alpha; more than 90% of the primary T cells carried MIP-1 alpha receptors. When the T cells were stimulated with immobilized anti-CD3 mAb in the presence of accessory cells, the MIP-1 alpha binding was reduced. The lowest binding was obtained 2 h after anti-CD3 mAb stimulation due to the internalization of MIP-1 alpha receptors. mrMIP-1 alpha inhibited the anti-CD3 mAb-mediated proliferation of murine splenic T lymphocytes. The maximum inhibition was obtained when mrMIP-1 alpha was added 30 min before anti-CD3 mAb stimulation. Slight inhibition of T cell proliferation was observed when mrMIP-1 alpha was added at the same time as anti-CD3 mAb stimulation. These results indicate that T lymphocytes are regulated negatively by MIP-1 alpha, which occurs when the T cells are exposed to MIP-1 alpha before activation. The negative effect of MIP-1 alpha seems to be mediated in part by the inhibition of IL-2 production, for there was a reduction in both the IL-2 mRNA levels and the IL-2 activity in supernatants from T cells preincubated with MIP-1 alpha before anti-CD3 mAb stimulation.
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Affiliation(s)
- Z Zhou
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis 46202
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Zhou Z, Kim YJ, Pollok K, Hurtado J, Lee JK, Broxmeyer HE, Kwon BS. Macrophage inflammatory protein-1 alpha rapidly modulates its receptors and inhibits the anti-CD3 mAb-mediated proliferation of T lymphocytes. The Journal of Immunology 1993. [DOI: 10.4049/jimmunol.151.8.4333] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Macrophage inflammatory protein-1 alpha (MIP-1 alpha) is a member of the intercrine/chemokine family which consists of basic, heparin-binding, small molecular weight proteins. We have previously shown that a T cell line, CTLL-R8, carried high-affinity receptors for MIP-1 alpha and the proliferation of CTLL-R8 cells was inhibited by murine recombinant (mr) MIP-1 alpha. We extended our previous studies to murine resting splenic T lymphocytes to determine whether the inhibition of T cell proliferation is a general property of MIP-1 alpha. The resting splenic T cells carried approximately 680 high-affinity binding sites for mrMIP-1 alpha; more than 90% of the primary T cells carried MIP-1 alpha receptors. When the T cells were stimulated with immobilized anti-CD3 mAb in the presence of accessory cells, the MIP-1 alpha binding was reduced. The lowest binding was obtained 2 h after anti-CD3 mAb stimulation due to the internalization of MIP-1 alpha receptors. mrMIP-1 alpha inhibited the anti-CD3 mAb-mediated proliferation of murine splenic T lymphocytes. The maximum inhibition was obtained when mrMIP-1 alpha was added 30 min before anti-CD3 mAb stimulation. Slight inhibition of T cell proliferation was observed when mrMIP-1 alpha was added at the same time as anti-CD3 mAb stimulation. These results indicate that T lymphocytes are regulated negatively by MIP-1 alpha, which occurs when the T cells are exposed to MIP-1 alpha before activation. The negative effect of MIP-1 alpha seems to be mediated in part by the inhibition of IL-2 production, for there was a reduction in both the IL-2 mRNA levels and the IL-2 activity in supernatants from T cells preincubated with MIP-1 alpha before anti-CD3 mAb stimulation.
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Affiliation(s)
- Z Zhou
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis 46202
| | - Y J Kim
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis 46202
| | - K Pollok
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis 46202
| | - J Hurtado
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis 46202
| | - J K Lee
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis 46202
| | - H E Broxmeyer
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis 46202
| | - B S Kwon
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis 46202
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Abstract
Membranes were isolated from B cells stimulated with phorbol 12-myristate 13-acetate (PMA) for a time sufficient to allow maximal redistribution and activation of protein kinase C (PKC). Exposure of such membranes to a short incubation with [gamma-32P]ATP resulted in the detection of at least nine unique or hyperphosphorylated membrane proteins by SDS-PAGE and autoradiography. The appearance of these phosphoproteins was blocked by pretreatment of the membranes with H-7 or sangivamycin, two selective inhibitors of PKC. In addition, membranes purified from B cells treated with an inactive phorbol ester or stimulated with dibutyryl cAMP failed to exhibit a pattern of new phosphoproteins. These results are consistent with the involvement of PKC in the phosphorylation of the proteins. These phosphoproteins are also candidates for proteins whose functions are modified as a consequence of early signal delivery to resting B cells following membrane immunoglobulin occupancy. This system was utilized to identify the heavy chain of MHC class I molecules as one of the membrane proteins phosphorylated by PKC. The MHC class II molecules were not phosphorylated in membranes isolated from PMA-treated normal B cells or from PMA-treated B cells which had previously been exposed to IL-4. These results indicate that class I, but not class II, MHC molecules are phosphorylated by PKC. It is possible that such a modification of cell surface class I molecules may be involved during the process of signal transduction leading to B cell activation.
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Affiliation(s)
- T Burke
- Department of Microbiology and Immunology, University of Kentucky Medical Center, Lexington 40536-0081
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